Getting Started
+2. Getting Started
hunk ./docs/tutorial/Tutorial_Port/chap2.xhtml 45 -
GtkChap3a.hs is the filename. Alternatively you can use
+assuming GtkChap2.hs is the filename. Alternatively you can use
hunk ./docs/tutorial/Tutorial_Port/chap2.xhtml 129
-
Packing Widgets
+3.1 Packing Widgets
hunk ./docs/tutorial/Tutorial_Port/chap3-1.xhtml 67 -
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- Gtk2HsTutorial - |
- ||
|---|---|---|
| - - | - -
- Packing Demonstration - |
+
hunk ./docs/tutorial/Tutorial_Port/chap3-2.xhtml 12
- - - | -
+
Gtk2Hs Tutorial
+ + + +Packing Demonstration - Program
+3.2 Packing Demonstration Program
hunk ./docs/tutorial/Tutorial_Port/chap3-2.xhtml 21 -The base of all widgets here is a vertical box, which itself - is a child of the window. The child widgets are not displayed - homogeneously and there is no additional spacing (other than the - standard spacing). There are 6 horizontal boxes in the vertical - box, as defined by the function makeBox, which has the type as - shown. Furthermore, there are 2 labels in the vertical box as - well as 2 horizontal separators. The last widget is the quit - button, whose onClicked signal is attached to the - mainQuit function.
+
+The base of all widgets here is a vertical box, which itself is a child of the
+window. The child widgets are not displayed homogeneously and there is no
+additional spacing (other than the standard spacing). There are six horizontal
+boxes in the vertical box, as defined by the function makeBox,
+which has the type as shown. Furthermore, there are two labels in the vertical
+box as well as two horizontal separators. The last widget is the Quit
+button, whose onClicked signal is attached to the
+mainQuit function.
+
The separators are created with hSeparatorNew and they - are spaced by boxPackStart with a padding of 10 pixels. - The labels are created by labelNew which takes a Maybe - String and their positioning is set by - miscSetAlignment to be left and top justified.
+
+The separators are created with hSeparatorNew and they are spaced
+by boxPackStart with a padding of ten pixels. The labels are
+created by labelNew which takes a Maybe String and
+their positioning is set by miscSetAlignment to be left and top
+justified.
+
+The function makeBox :: Bool -> Int -> Packing -> Int -> IO
+HBox demonstrates how Gtk2Hs widgets fit into the Haskell type system.
+Packing is just a type like Int and Bool
+and IO HBox is just like IO String in the usual
+IO. The function creates five buttons, labels them with the
+appropriate text and packs them into a horizontal box. The function is then
+used in the main program to create the desired ways of packing.
+
The function makeBox :: Bool -> Int -> Packing -> - Int -> IO HBox demonstrates how Gtk2Hs widgets fit into - the Haskell type system. Packing is just a type like - Int and Bool and IO HBox is just like IO - String in the usual IO. The function creates 5 buttons, - labels them with the appropriate text and packs them into a - horizontal box. The function is then used in the main program to - create the desired ways of packing.
- -
- +hunk ./docs/tutorial/Tutorial_Port/chap3-2.xhtml 57 - initGUI - window <- windowNew - vbox <- vBoxNew False 0 - set window [containerBorderWidth := 10, - windowTitle := "Packing Demonstration", - containerChild := vbox ] - label1 <- labelNew (Just "hBoxNew False 0") - miscSetAlignment label1 0 0 - boxPackStart vbox label1 PackNatural 0 - box1 <- makeBox False 0 PackNatural 0 - boxPackStart vbox box1 PackNatural 0 - box2 <- makeBox False 0 PackRepel 0 - boxPackStart vbox box2 PackNatural 0 - box3 <- makeBox False 0 PackGrow 0 - boxPackStart vbox box3 PackNatural 0 - sep1 <- hSeparatorNew - boxPackStart vbox sep1 PackNatural 10 - label2 <- labelNew (Just "hBoxNew True 0") - miscSetAlignment label2 0 0 - boxPackStart vbox label2 PackNatural 0 - box4 <- makeBox True 0 PackNatural 0 - boxPackStart vbox box4 PackNatural 0 - box5 <- makeBox True 0 PackRepel 0 - boxPackStart vbox box5 PackNatural 0 - box6 <- makeBox False 0 PackGrow 0 - boxPackStart vbox box6 PackNatural 0 - sep <- hSeparatorNew - boxPackStart vbox sep PackNatural 10 - quitbox <- hBoxNew False 0 - boxPackStart vbox quitbox PackNatural 0 - quitbutton <- buttonNewWithLabel "Quit" - boxPackStart quitbox quitbutton PackRepel 0 - onClicked quitbutton mainQuit - onDestroy window mainQuit - widgetShowAll window - mainGUI + initGUI + window <- windowNew + vbox <- vBoxNew False 0 + set window [containerBorderWidth := 10, + windowTitle := "Packing Demonstration", + containerChild := vbox] + label1 <- labelNew (Just "hBoxNew False 0") + miscSetAlignment label1 0 0 + boxPackStart vbox label1 PackNatural 0 + box1 <- makeBox False 0 PackNatural 0 + boxPackStart vbox box1 PackNatural 0 + box2 <- makeBox False 0 PackRepel 0 + boxPackStart vbox box2 PackNatural 0 + box3 <- makeBox False 0 PackGrow 0 + boxPackStart vbox box3 PackNatural 0 + sep1 <- hSeparatorNew + boxPackStart vbox sep1 PackNatural 10 + label2 <- labelNew (Just "hBoxNew True 0") + miscSetAlignment label2 0 0 + boxPackStart vbox label2 PackNatural 0 + box4 <- makeBox True 0 PackNatural 0 + boxPackStart vbox box4 PackNatural 0 + box5 <- makeBox True 0 PackRepel 0 + boxPackStart vbox box5 PackNatural 0 + box6 <- makeBox False 0 PackGrow 0 + boxPackStart vbox box6 PackNatural 0 + sep <- hSeparatorNew + boxPackStart vbox sep PackNatural 10 + quitbox <- hBoxNew False 0 + boxPackStart vbox quitbox PackNatural 0 + quitbutton <- buttonNewWithLabel "Quit" + boxPackStart quitbox quitbutton PackRepel 0 + onClicked quitbutton mainQuit + onDestroy window mainQuit + widgetShowAll window + mainGUI hunk ./docs/tutorial/Tutorial_Port/chap3-2.xhtml 97 - box <- hBoxNew homogeneous spacing - button1 <- buttonNewWithLabel "boxPackStart" - boxPackStart box button1 packing padding - button2 <- buttonNewWithLabel "box" - boxPackStart box button2 packing padding - button3 <- buttonNewWithLabel "button" - boxPackStart box button3 packing padding - button4 <- case packing of - PackNatural -> buttonNewWithLabel "PackNatural" - PackRepel -> buttonNewWithLabel "PackRepel" - PackGrow -> buttonNewWithLabel "PackGrow" - boxPackStart box button4 packing padding - button5 <- buttonNewWithLabel (show padding) - boxPackStart box button5 packing padding - return box + box <- hBoxNew homogeneous spacing + button1 <- buttonNewWithLabel "boxPackStart" + boxPackStart box button1 packing padding + button2 <- buttonNewWithLabel "box" + boxPackStart box button2 packing padding + button3 <- buttonNewWithLabel "button" + boxPackStart box button3 packing padding + button4 <- case packing of + PackNatural -> buttonNewWithLabel "PackNatural" + PackRepel -> buttonNewWithLabel "PackRepel" + PackGrow -> buttonNewWithLabel "PackGrow" + boxPackStart box button4 packing padding + button5 <- buttonNewWithLabel (show padding) + boxPackStart box button5 packing padding + return box hunk ./docs/tutorial/Tutorial_Port/chap3-2.xhtml 113 - |
-
The image below shows the effects of resizing the window - horizontally. In the first group, with homogeneous False - horizontal resizing leaves the first row of buttons as it is, - spaces the second row evenly, and enlarges the buttons in the - third row. In the second group the buttons are set to be packed - homogeneously, and the first 2 rows will look the same. Resizing - the window vertically just add extra space at the end, because - the vertical box was initialized with False.
-
- -
| - - | - -- - | hunk ./docs/tutorial/Tutorial_Port/chap3-2.xhtml 114 -- - | -
|
- Packing Widgets - |
+
- Packing Using Tables - |
-
-
|
- Gtk2Hs Tutorial - |
- ||
|---|---|---|
| - - | - -
- Tables - |
+
hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 12
- - - | -
+
Gtk2Hs Tutorial
+ + + +Packing Using Tables
+3.3 Packing Using Tables
hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 21 -Let's take a look at another way of packing - Tables. These - can be extremely useful in certain situations.
++Let's take a look at another way of packing: tables. These can be +extremely useful in certain situations. Using tables, we create a grid that we +can place widgets in. The widgets may take up as many spaces as we specify. +
hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 27 -Using tables, we create a grid that we can place widgets in. - The widgets may take up as many spaces as we specify.
+
+The first thing to look at, of course, is the tableNew function:
+
The first thing to look at, of course, is the tableNew - function:
- -
- +hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 34 - |
-
The first argument is the number of rows to make in the table, - while the second, obviously, is the number of columns.
++The first argument is the number of rows to make in the table, while the +second, obviously, is the number of columns. +
hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 40 -The boolean argument (homogeneous) has to do with how the - table's boxes are sized. If homogeneous is TRUE, the table boxes - are resized to the size of the largest widget in the table. If - homogeneous is FALSE, the size of a table boxes is dictated by - the tallest widget in its same row, and the widest widget in its - column.
++The boolean argument (homogeneous) has to do with how the table's +boxes are sized. If homogeneous is set to True, the table +boxes are resized to the size of the largest widget in the table. If +homogeneous is False, the size of a table boxes is +dictated by the tallest widget in its same row, and the widest widget in its +column. +
hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 49 -The rows and columns are laid out from 0 to n, where n was the - number specified in the call to tableNew. So, if you - specify rows = 2 and columns = 2, the layout would look something - like this:
+
+The rows and columns are laid out from 0 to n, where
+n was the number specified in the call to tableNew. So
+if you specify rows = 2 and columns =
+2, the layout would look something like this:
+
- +hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 64 - |
-
Note that the coordinate system starts in the upper left hand - corner. To place a widget into a box, use the following - function:
++Note that the coordinate system starts in the upper left hand corner. To place +a widget into a box, use the following function: +
hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 70 -
- -tableAttach :: (TableClass self, WidgetClass child) => - self -- self - the table - -> child -- child - The widget to add. - -> Int --- leftAttach - the column number to attach the left side of a child widget to. - -> Int --- rightAttach - the column number to attach the right side of a child widget to. - -> Int -- topAttach - the row number to attach the top of a child widget to. - -> Int -- bottomAttach - the row number to attach the bottom of a child widget to. - -> [AttachOptions] --- xoptions - Used to specify the properties of the child widget when the table is resized. - -> [AttachOptions] --- yoptions - The same as xoptions, except this field determines behaviour of vertical resizing. - -> Int --- xpadding - An integer value specifying the padding on the left and right of the widget being added to the table. - -> Int -- ypadding - The amount of padding above and below the child widget. ++tableAttach :: (TableClass self, WidgetClass child) + => self -- self - The table. + -> child -- child - The widget to add. + -> Int -- leftAttach - The column number to attach the left + -- side of a child widget to. + -> Int -- rightAttach - The column number to attach the right + -- side of a child widget to. + -> Int -- topAttach - The row number to attach the top of a + -- child widget to. + -> Int -- bottomAttach - The row number to attach the bottom + -- of a child widget to. + -> [AttachOptions] -- xoptions - Used to specify the properties of the + -- child widget when the table is + -- resized. + -> [AttachOptions] -- yoptions - The same as xoptions, except this + -- field determines behaviour of + -- vertical resizing. + -> Int -- xpadding - An integer value specifying the + -- padding on the left and right of the + -- widget being added to the table. + -> Int -- ypadding - The amount of padding above and below + -- the child widget. hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 95 - |
-
The first argument (self) is the table you've created and the - second (child) the widget you wish to place in the table.
- -The left and right attach arguments specify where to place the - widget, and how many boxes to use. If you want a button in the - lower right table entry of our 2x2 table, and want it to fill - that entry only, left_attach would be = 1, right_attach = - 2, top_attach = 1, bottom_attach = 2.
- -Now, if you wanted a widget to take up the whole top row of - our 2x2 table, you'd use left_attach = 0, right_attach = 2, - top_attach = 0, bottom_attach = 1.
hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 96 -The xoptions and yoptions are used to specify packing options - and the list may contain more than one to allow multiple - options.
++The first argument (self) is the table you've created and the second +(child) is the widget you wish to place in the table. +
hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 101 -These options are:
++The left and right attach arguments specify where to place the widget, and how +many boxes to use. If you want a button in the lower right table entry of our +2x2 table, and want it to fill that entry only, +leftAttach would be = 1, rightAttach = +2, topAttach = 1, and bottomAttach += 2. +
hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 110 --
-
- Fill +
- If the table box is larger than the widget, and - Fill is specified, the widget will expand to use all - the room available. +
- Shrink +
- If the table widget was allocated less space then was - requested (usually by the user resizing the window), then the - widgets would normally just be pushed off the bottom of the - window and disappear. If Shrink is specified, the - widgets will shrink with the table. +
Fill
+ -
+ If the table box is larger than the widget, and
Fillis + specified, the widget will expand to use all the room available. +
hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 131
- - Expand +
Shrink
+ -
+ If the table widget was allocated less space then was requested (usually by
+ the user resizing the window), then the widgets would normally just be pushed
+ off the bottom of the window and disappear. If
Shrinkis + specified, the widgets will shrink with the table. +
hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 139
- - This will cause the table to expand to use up any remaining - space in the window. -
Expand
+ - + This will cause the table to expand to use up any remaining space in the + window. + +
+Now, if you wanted a widget to take up the whole top row of our 2x2 table, +you'd use leftAttach = 0, rightAttach = +2, topAttach = 0, and bottomAttach = +1. +
hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 117 -+The xoptions and yoptions are used to specify packing +options and the list may contain more than one to allow multiple options. +
hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 122 -These options are:
hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 124 --
+
Padding is just like in boxes, creating a clear area around - the widget specified in pixels.
++Padding is just like in boxes, creating a clear area around the widget +specified in pixels. +
hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 151 -tableAttach has many options. So, there's a - shortcut:
+
+tableAttach has many options, so there's a shortcut:
+
- -tableAttachDefaults :: (TableClass self, WidgetClass widget) => self - -> widget -- widget - The child widget to add. - -> Int --- leftAttach - The column number to attach the left side of the child widget to. - -> Int --- rightAttach - The column number to attach the right side of the child widget to. - -> Int --- topAttach - The row number to attach the top of the child widget to. - -> Int --- bottomAttach - The row number to attach the bottom of the child widget to. ++tableAttachDefaults :: (TableClass self, WidgetClass widget) + => self -- self - The table. + -> widget -- widget - The child widget to add. + -> Int -- leftAttach - The column number to attach the left side of + -- the child widget to. + -> Int -- rightAttach - The column number to attach the right side of + -- the child widget to. + -> Int -- topAttach - The row number to attach the top of the child + -- widget to. + -> Int -- bottomAttach - The row number to attach the bottom of the + -- child widget to. hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 169 - |
-
The values used for the AttachOptions are [Expand, - Fill], and the padding is set to 0. The rest of the - arguments are identical to the previous function.
+
+The values used for the [AttachOptions] parameters are
+[Expand, Fill], and the padding is set to 0. The rest of
+the arguments are identical to the previous function.
+
We also have tableSetRowSpacing and tableSetColSpacing. These - place spacing at the specified row or column.
+
+We also have tableSetRowSpacing and
+tableSetColSpacing. These place spacing at the specified row or
+column.
+
- +hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 185 - |
-
and,
- -
- +hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 189 - |
-
The first Int argument is the row/column and the second - the spacing in pixels. Note that for columns, the space goes to - the right of the column, and for rows, the space goes below the - row.
+
+The first Int argument is the row/column and the second is the
+spacing in pixels. Note that for columns, the space goes to the right of the
+column, and for rows, the space goes below the row.
+
You can also set a consistent spacing of all rows and/or - columns with:
++You can also set a consistent spacing of all rows and/or columns with: +
hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 200 -
- +hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 203 - |
-
and,
+and:
hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 206 -
- +hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 209 - |
-
Note that with these calls, the last row and last column do - not get any spacing.
hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 210 -
-
+Note that with these calls, the last row and last column do not get any +spacing. +
hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 215 -Table Packing Example
+Table Packing Example
hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 217 -Here we make a window with three buttons in a 2x2 table. The - first two buttons will be placed in the upper row. A third, quit - button, is placed in the lower row, spanning both columns. Which - means it should look something like this:
++Here we make a window with three buttons in a 2x2 table. The first two buttons +will be placed in the upper row. A third button (Quit) is placed in +the lower row, spanning both columns, which means it should look something like +this: +
hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 224 -
Here's the source code:
+Here's the source code:
hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 228 -
- +hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 233 - initGUI - window <- windowNew - set window [windowTitle := "Table", containerBorderWidth := 20, - windowDefaultWidth := 150, windowDefaultHeight := 100 ] - table <- tableNew 2 2 True - containerAdd window table - button1 <- buttonNewWithLabel "On" - onClicked button1 (buttonSwitch button1) - tableAttachDefaults table button1 0 1 0 1 - button2 <- buttonNewWithLabel "Off" - onClicked button2 (buttonSwitch button2) - tableAttachDefaults table button2 1 2 0 1 - button3 <- buttonNewWithLabel "Quit" - onClicked button3 mainQuit - tableAttachDefaults table button3 0 2 1 2 - onDestroy window mainQuit - widgetShowAll window - mainGUI + initGUI + window <- windowNew + set window [windowTitle := "Table", containerBorderWidth := 20, + windowDefaultWidth := 150, windowDefaultHeight := 100] + table <- tableNew 2 2 True + containerAdd window table + button1 <- buttonNewWithLabel "On" + onClicked button1 (buttonSwitch button1) + tableAttachDefaults table button1 0 1 0 1 + button2 <- buttonNewWithLabel "Off" + onClicked button2 (buttonSwitch button2) + tableAttachDefaults table button2 1 2 0 1 + button3 <- buttonNewWithLabel "Quit" + onClicked button3 mainQuit + tableAttachDefaults table button3 0 2 1 2 + onDestroy window mainQuit + widgetShowAll window + mainGUI hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 254 - txt <- buttonGetLabel b - let newtxt = case txt of - "Off" -> "On" - "On" -> "Off" - buttonSetLabel b newtxt + txt <- buttonGetLabel b + let newtxt = case txt of + "Off" -> "On" + "On" -> "Off" + buttonSetLabel b newtxt hunk ./docs/tutorial/Tutorial_Port/chap3-3.xhtml 260 - |
-
- -
The buttonSwitch function is attached to both buttons - in the top row. The buttonGetLabel function is an example - of how to get an attribute from a widget using a standard method. - There is also a more general alternative get (analogous to - set) which takes a widget and an attribute. In the above - example this should be:
- -|
- txt <- get b buttonLabel - |
-
+The buttonSwitch function is attached to both buttons in the top
+row. The buttonGetLabel function is an example of how to get an
+attribute from a widget using a standard method. There is also a more general
+alternative get (analogous to set) which takes a
+widget and an attribute. In the above example this should be:
+
with the same result.
- -| - - | - -- - | - -- - | -
|
- Packing Demonstration - |
+
- Button Widget - |
-
-
|
- GTK2Hs Tutorial - |
- ||
|---|---|---|
| - - | + hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 12 -+ | - - | -
+
4.1 The Button Widget
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 21 -The Button - Widget
+Normal Buttons
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 23 -Normal - Buttons
+
+We've almost seen all there is to see of the button widget. It's pretty simple.
+There is however more than one way to create a button. You can use the
+buttonNewWithLabel or buttonNewWithMnemonic to create
+a button with a label, use buttonNewFromStock to create a button
+containing the image and text from a stock item or use buttonNew
+to create a blank button. It's then up to you to pack a label or pixmap into
+this new button. To do this, create a new box, and then pack your objects into
+this box using the usual boxPackStart (or boxPackEnd
+to pack from the end), and then use containerAdd to pack the box
+into the button.
+
We've almost seen all there is to see of the button widget. - It's pretty simple. There is however more than one way to create - a button. You can use the buttonNewWithLabel or - buttonNewWithMnemonic to create a button with a label, use - buttonNewFromStock to create a button containing the image - and text from a stock item or use buttonNew to create a - blank button. It's then up to you to pack a label or pixmap into - this new button. To do this, create a new box, and then pack your - objects into this box using the usual boxPackStart (or - boxPackEnd to pack from the end), and then use - containerAdd to pack the box into the button.
+
+buttonNewWithMnemonic and buttonNewFromStock both
+take a string as first argument. Use an underline to mark a character as a
+mnemonic, which is a keyboard accelerator. Pressing Alt and
+that key activates the button. In the second function the string is a
+stockId, an identifier to a list of predefined images with labels.
+
buttonNewWithMnemonic and - buttonNewFromStock both take a string as first argument. - Use an underline to mark a character as a mnemonic, which is a - keyboard accelarator. Pressing Alt and that key activates the - button. In the second function the string is a stockId, an - identifier to a list of predefined images with labels.
+
+Here's an example of using buttonNew to create a button with an
+image and a label in it.
+
Here's an example of using buttonNew to create a button - with a image and a label in it.
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 59 - containerBorderWidth := 10 ] + containerBorderWidth := 10] hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 62 - box <- labelBox "info.xpm" "cool button" + box <- labelBox "info.xpm" "cool button" hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 71 - box <- hBoxNew False 0 - set box [containerBorderWidth := 2 ] + box <- hBoxNew False 0 + set box [containerBorderWidth := 2] hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 75 - boxPackStart box image PackNatural 3 + boxPackStart box image PackNatural 3 hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 77 - return box + return box hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 79 - |
-
The labelBox function could be used to pack images and - labels into any widget that can be a container. The image comes - from a file using imageNewFromFile and the label comes - from labelNew , which takes a Maybe String as its - argument. Nothing means no label.
+
+The labelBox function could be used to pack images and labels into
+any widget that can be a container. The image comes from a file using
+imageNewFromFile and the label comes from labelNew,
+which takes a Maybe String as its argument. Nothing
+means no label.
+
The Button widget has the following basic signals, - which are almost self explaining:
+
+The Button widget has the following basic signals, which are
+almost self-explanatory:
+
-
-
-
-
onPressed - emitted when pointer button is - pressed within Button widget
-
+ -
+
onPressed- emitted when pointer button is pressed within +Buttonwidget +
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 99
- -
-
onReleased - emitted when pointer button is - released within Button widget
-
+ -
+
onReleased- emitted when pointer button is released within +Buttonwidget +
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 104
- -
-
onClicked - emitted when pointer button is - pressed and then released within Button widget
-
+ -
+
onClicked- emitted when pointer button is pressed and then + released withinButtonwidget +
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 109
- -
-
onEnter - emitted when pointer enters Button - widget
-
+ -
+
onEnter- emitted when pointer entersButtonwidget +
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 113
- -
-
onLeave - emitted when pointer leaves Button - widget
-
- -
+
onLeave- emitted when pointer leavesButtonwidget +
+
-
+
+
Toggle - Buttons
+Toggle Buttons
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 120 -Toggle buttons are derived from normal buttons and are very - similar, except they will always be in one of two states, - alternated by a click. They may be depressed, and when you click - again, they will pop back up. Click again, and they will pop back - down.
++Toggle buttons are derived from normal buttons and are very similar, except +they will always be in one of two states, alternated by a click. They may be +depressed, and when you click again, they will pop back up. Click again, and +they will pop back down. +
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 127 -Toggle buttons are the basis for check buttons and radio - buttons, as such, many of the calls used for toggle buttons are - inherited by radio and check buttons. I will point these out when - we come to them.
++Toggle buttons are the basis for check buttons and radio buttons, as such, many +of the calls used for toggle buttons are inherited by radio and check buttons. +I will point these out when we come to them. +
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 133 -Creating a new toggle button:
++Creating a new toggle button: +
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 137 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 144 - |
-
As you can imagine, these work identically to the normal - button widget calls. The first creates a blank toggle button, and - the last two, a button with a label widget already packed into - it. The mnemonic variant additionally parses the label for - '_'-prefixed mnemonic characters.
++As you can imagine, these work identically to the normal button widget calls. +The first creates a blank toggle button, and the last two, a button with a +label widget already packed into it. The mnemonic variant additionally parses +the label for "_"-prefixed mnemonic characters. +
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 152 -To retrieve the state of the toggle widget, including radio - and check buttons, we use:
++To retrieve the state of the toggle widget, including radio and check buttons, +we use: +
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 157 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 160 - |
-
Returns True if the toggle button is pressed in and - False if it is raised.
++This returns True if the toggle button is pressed in and +False if it is raised. +
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 166 -To force the state of a toggle button, and its children, the - radio and check buttons, use this function:
++To force the state of a toggle button, and its children, the radio and check +buttons, use this function: +
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 171 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 174 - |
-
The above call can be used to set the state of the toggle - button, and its children the radio and check buttons. Passing in - your created button as the first argument, and True of - False for the second state argument to specify whether it - should be down (depressed) or up (released). Default is up, or - False.
++The above call can be used to set the state of the toggle button, and its +children the radio and check buttons. Passing in your created button as the +first argument, and True or False for the second state +argument to specify whether it should be down (depressed) or up (released). +Default is up, or False. +
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 183 -Note that when you use the toggleButtonSetActive function, and - the state is actually changed, it causes the onClicked and - onToggled signals to be emitted from the button.
-+
+Note that when you use the toggleButtonSetActive function, and the
+state is actually changed, it causes the onClicked and
+onToggled signals to be emitted from the button.
+
Check Buttons
+Check Buttons
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 191 -Check buttons inherit many properties and functions from the - the toggle buttons above, but look a little different. Rather - than being buttons with text inside them, they are small squares - with the text to the right of them. These are often used for - toggling options on and off in applications.
++Check buttons inherit many properties and functions from the the toggle buttons +above, but look a little different. Rather than being buttons with text inside +them, they are small squares with the text to the right of them. These are +often used for toggling options on and off in applications. +
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 198 -The creation functions are similar to those of the normal - button.
++The creation functions are similar to those of the normal button. +
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 202 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 209 - |
-
The checkButtonNewWithLabel function creates a check button - with a label beside it.
+
+The checkButtonNewWithLabel function creates a check button with a
+label beside it.
+
CheckButton is an instance of ToggleButtonClass - and the onToggled signal is used when a CheckButton - is checked or unchecked, just as with the toggle button.
-+
+CheckButton is an instance of ToggleButtonClass and
+the onToggled signal is used when a CheckButton is
+checked or unchecked, just as with the toggle button.
+
Radio Buttons
+Radio Buttons
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 223 -Radio buttons are similar to check buttons except they are - grouped so that only one may be selected/depressed at a time. - This is good for places in your application where you need to - select from a short list of options. Creating a new radio button - is done with one of these calls:
++Radio buttons are similar to check buttons except they are grouped so that only +one may be selected/depressed at a time. This is good for places in your +application where you need to select from a short list of options. Creating a +new radio button is done with one of these calls: +
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 230 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 237 -radioButtonNewFromWidget :: RadioButton -> IO RadioButton +radioButtonNewFromWidget :: RadioButton -> IO RadioButton hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 243 - |
-
You'll notice the extra argument to tthe last three functions. - They are used to link the new buttons to the ones constructed - earlier in a group.
++You'll notice the extra argument to the last three functions. They are used to +link the new buttons to the ones constructed earlier in a group. +
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 249 -It is also a good idea to explicitly set which button should - be the default depressed button with:
++It is also a good idea to explicitly set which button should be the default +depressed button with: +
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 254 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 257 - |
-
This is described in the section on toggle buttons, and works - in exactly the same way. Once the radio buttons are grouped - together, only one of the group may be active at a time. If the - user clicks on one radio button, and then on another, the first - radio button will first emit a onToggled signal (to report - becoming inactive), and then the second will emit its - onToggled signal (to report becoming active).
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 258 -The following example creates a radio button group with three - buttons, and when the user presses one of the radiobuttons, the - toggled ones will report this to stdout , using putStrLn - in the setRadioState function defined below.
+
+This is described in the section on toggle buttons, and works in exactly the
+same way. Once the radio buttons are grouped together, only one of the group
+may be active at a time. If the user clicks on one radio button, and then on
+another, the first radio button will first emit a onToggled signal
+(to report becoming inactive), and then the second will emit its
+onToggled signal (to report becoming active).
+
- 
+The following example creates a radio button group with three buttons, and when
+the user presses one of the radio buttons, the toggled ones will report this to
+stdout, using putStrLn in the
+setRadioState function defined below.
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 282 - window <- windowNew - set window [windowTitle := "Radio Button", containerBorderWidth := 5 , - windowDefaultWidth := 200, windowDefaultHeight := 150 ] - box1 <- vBoxNew False 0 + window <- windowNew + set window [windowTitle := "Radio Button", containerBorderWidth := 5, + windowDefaultWidth := 200, windowDefaultHeight := 150] + box1 <- vBoxNew False 0 hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 287 - box2 <- vBoxNew False 10 + box2 <- vBoxNew False 10 hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 300 - sep <- hSeparatorNew + sep <- hSeparatorNew hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 302 - box3 <- vBoxNew False 10 + box3 <- vBoxNew False 10 hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 305 - closeb <- buttonNewWithLabel "close" + closeb <- buttonNewWithLabel "close" hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 318 - |
-
- -
| - - | - -- - | - -- - | -
|
- Tables - |
-
-
- - |
hunk ./docs/tutorial/Tutorial_Port/chap4-1.xhtml 319
-
- Adjustments - |
-
-
|
- GTK2Hs Tutorial - |
- ||
|---|---|---|
| - - | - -+ hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 12 - | - - | -
+
Gtk2Hs Tutorial
+ + + +Adjustments, - Scale and Range
+4.2 Adjustments, Scale and Range
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 21 -GTK has various widgets that can be visually adjusted by the - user using the mouse or the keyboard, such as the range widgets, - described in the range widget section. There are also a few - widgets that display some adjustable portion of a larger area of - data, such as the text widget and the viewport widget.
++Gtk2Hs has various widgets that can be visually adjusted by the user using the +mouse or the keyboard, such as the range widgets, described in the range widget +section. There are also a few widgets that display some adjustable portion of a +larger area of data, such as the text widget and the viewport widget. +
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 28 -Obviously, an application needs to be able to react to changes - the user makes in range widgets. One way to do this would be to - have each widget emit its own type of signal when its adjustment - changes. But you may also want to connect the adjustments of - several widgets together, so that adjusting one adjusts the - others. The most obvious example of this is connecting a - scrollbar to a panning viewport or a scrolling text area.
++Obviously, an application needs to be able to react to changes the user makes +in range widgets. One way to do this would be to have each widget emit its own +type of signal when its adjustment changes. But you may also want to connect +the adjustments of several widgets together, so that adjusting one adjusts the +others. The most obvious example of this is connecting a scrollbar to a panning +viewport or a scrolling text area. +
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 37 -The adjustment object can be used to store the configuration - parameters and values of range widgets, such as scrollbars and - scale controls. Because Adjustment is derived from - GObject and Object, adjustments can emit signals, - which can be used not only to allow your program to react to user - input on adjustable widgets, but also to propagate adjustment - values transparently between adjustable widgets.
+
+The adjustment object can be used to store the configuration parameters and
+values of range widgets, such as scrollbars and scale controls. Because
+Adjustment is derived from GObject and
+Object, adjustments can emit signals, which can be used not only
+to allow your program to react to user input on adjustable widgets, but also to
+propagate adjustment values transparently between adjustable widgets.
+
Many of the widgets which use adjustment objects, like - ScrolledWindow, can create their own adjustments, but you - create one yourself with:
+
+Many of the widgets which use adjustment objects, like
+ScrolledWindow, can create their own adjustments, but you create
+one yourself with:
+
- -adjustmentNew -:: Double -- value, the initial value of the range --> Double -- lower, the minimum value of the range --> Double -- upper, the maximum value of the range --> Double -- stepIncrement, the smaller of two possible increments --> Double -- pageIncrement, the larger of two possible increments --> Double -- pageSize, the size of the visible area --> IO Adjustment ++adjustmentNew :: Double -- value - The initial value of the range + -> Double -- lower - The minimum value of the range + -> Double -- upper - The maximum value of the range + -> Double -- stepIncrement - The smaller of two possible increments + -> Double -- pageIncrement - The larger of two possible increments + -> Double -- pageSize - The size of the visible area + -> IO Adjustment hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 61 - |
-
The creation function takes every value that is contained in - the object: value is the initial value and should be - between the upper and lower bounds of the - slider. Clicking on the arrows increases this value by - stepIncrement. Clicking in the slider advances by - pageIncrement. The pageSize is needed to - determine if the end of the slider is still in the range. You can - get and set all the parameters of an adjustment by methods or - using the general set and get functions on the - adjustment attributes.
+
+The creation function takes every value that is contained in the object:
+value is the initial value and should be between the
+upper and lower bounds of the slider. Clicking on the
+arrows increases this value by stepIncrement. Clicking in the
+slider advances by pageIncrement. The pageSize is
+needed to determine if the end of the slider is still in the range. You can get
+and set all the parameters of an adjustment by methods or using the general
+set and get functions on the adjustment attributes.
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 76 - |
-
is the signal emitted when the value of the adjustment - changes, and
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 77 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 84 - |
-
is the signal emitted when one or more of the other than the - value fields have changed.
++is the signal emitted when one or more of the other than the value fields have +changed. +
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 90 -Scale and Range Widgets
+Scale and Range Widgets
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 92 -Scale widgets are used to allow the user to visually select - and manipulate a value within a specific range using a slider. - You might want to use a scale widget, for example, to adjust the - magnification level on a zoomed preview of a picture, or to - control the brightness of a color, or to specify the number of - minutes of inactivity before a screensaver takes over the - screen.
++Scale widgets are used to allow the user to visually select and manipulate a +value within a specific range using a slider. You might want to use a scale +widget, for example, to adjust the magnification level on a zoomed preview of a +picture, or to control the brightness of a color, or to specify the number of +minutes of inactivity before a screensaver takes over the screen. +
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 100 -The following functions create vertical and horizontal scale - widgets, respectively:
++The following functions create vertical and horizontal scale widgets, +respectively: +
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 105 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 110 - |
-
There are also two constructors which do not take an - adjustment:
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 111 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 120 - |
-
The Double parameters refer to the minimum and maximum - values and the step. The step increment (preferably a power of - 10) is the value the scale moves when the arrow keys are - used.
+
+The Double parameters refer to the minimum and maximum values and
+the step. The step increment (preferably a power of 10) is the value the scale
+moves when the arrow keys are used.
+
Horizontal and vertical scales are instances of - ScaleClass and their common behaviors are defined in the - module: Graphics.UI.Gtk.Abstract.Scale.
+
+Horizontal and vertical scales are instances of ScaleClass and
+their common behaviors are defined in the module
+Graphics.UI.Gtk.Abstract.Scale.
+
Scale widgets can display their current value as a number - beside the trough. The default behaviour is to show the value, - but you can change this with this function:
++Scale widgets can display their current value as a number beside the trough. +The default behaviour is to show the value, but you can change this with this +function: +
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 139 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 142 - |
-
The value displayed by a scale widget is rounded to one - decimal point by default, as is the value field in its - Adjustment. You can change this with:
+
+The value displayed by a scale widget is rounded to one decimal point by
+default, as is the value field in its Adjustment. You
+can change this with:
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 152 - |
-
Finally, the value can be drawn in different positions - relative to the trough:
++Finally, the value can be drawn in different positions relative to the trough: +
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 157 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 160 - |
-
The PositionType is defined as:
+
+The PositionType is defined as:
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 168 - |
-
Scale itself inherits many methods form its base class, - which is Range.
+
+Scale itself inherits many methods form its base class, which is
+Range.
+
Setting the Update - Policy
+Setting the Update Policy
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 176 -The "update policy" of a range widget defines at what points - during user interaction it will change the value field - of its Adjustment and emit the onRangeValueChanged signal - on this Adjustment. The update policies, are defined by the - UpdateType, which has three constructors:
+
+The update policy of a range widget defines at what points during user
+interaction it will change the value field of its
+Adjustment and emit the onRangeValueChanged signal
+on this Adjustment. The update policies are defined by the
+UpdateType, which has three constructors:
+
-
-
- UpdateContinuous +
UpdateContinuous
+ -
+ This is the default. The
onRangeValueChangedsignal is emitted + continuously, i.e., whenever the slider is moved by even the tiniest + amount. +
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 192
- - This is the default. The onRangeValueChanged signal - is emitted continuously, i.e., whenever the slider is moved by - even the tiniest amount. +
UpdateDiscontinuous
+ -
+ The
onRangeValueChangedsignal is only emitted once the slider + has stopped moving and the user has released the mouse button. +
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 198
- - UpdateDiscontinuous +
UpdateDelayed
+ -
+ The
onRangeValueChangedsignal is emitted when the user releases + the mouse button, or if the slider stops moving for a short period of time. +
+ - The onRangeValueChanged signal is only emitted once - the slider has stopped moving and the user has released the - mouse button. +
- UpdateDelayed - -
- The onRangeValueChanged signal is emitted when the - user releases the mouse button, or if the slider stops moving - for a short period of time. -
-
+
+The update policy of a range widget can be set by: +
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 209 -The update policy of a range widget can be set by:
- -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 212 - |
-
Getting and Setting - Adjustments
+Getting and Setting Adjustments
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 215 -Getting and setting the adjustment for a range widget "on the - fly" is done, predictably, with:
++Getting and setting the adjustment for a range widget on the fly is done, +predictably, with: +
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 220 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 225 - |
-
rangeSetAdjustment does absolutely nothing if - you pass it the adjustment that it is already using, - regardless of whether you changed any of its fields or not. If - you pass it a new Adjustment, it will unreference the old one if - it exists (possibly destroying it), connect the appropriate - signals to the new one, and call the private function - gtk_range_adjustment_changed(), which will (or at least, - is supposed to...) recalculate the size and/or position of the - slider and redraw if necessary. As mentioned in the section on - adjustments, if you wish to reuse the same Adjustment, when you - modify its values directly, you should emit the "changed" signal - on it.
+
+rangeSetAdjustment does absolutely nothing if you pass it the
+adjustment that it is already using, regardless of whether you changed
+any of its fields or not. If you pass it a new Adjustment, it will
+unreference the old one if it exists (possibly destroying it), connect the
+appropriate signals to the new one, and call the private function
+gtk_range_adjustment_changed(), which will (or at least, is
+supposed to...) recalculate the size and/or position of the slider and redraw
+if necessary. As mentioned in the section on adjustments, if you wish to reuse
+the same Adjustment, when you modify its values directly, you
+should emit the changed signal on it.
+
Key and Mouse bindings
+Key and Mouse Bindings
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 241 -All of the GTK range widgets react to mouse clicks in more or - less the same way. Clicking button-1 in the trough will cause its - adjustment's stepIncrement to be added or - subtracted from its value, and the slider to be - moved accordingly. Clicking mouse button-2 in the trough will - jump the slider to the point at which the button was clicked. - Clicking button-3 in the trough of a range or any button on a - scrollbar's arrows will cause its adjustment's value to change by - stepIncrement at a time.
+
+All of the Gtk2Hs range widgets react to mouse clicks in more or less the same
+way. Clicking mouse button 1 in the trough will cause its adjustment's
+stepIncrement to be added or subtracted from its value,
+and the slider to be moved accordingly. Clicking mouse button 2 in the trough
+will jump the slider to the point at which the button was clicked. Clicking
+mouse button 3 in the trough of a range or any button on a scrollbar's arrows
+will cause its adjustment's value to change by stepIncrement at a
+time.
+
Note: this did not work on Linux Fedora 6 with the standard - mouse bindings.
++Note: This did not work on Linux Fedora 6 with the standard mouse bindings. +
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 256 -Scrollbars are not focusable, thus have no key bindings. The - key bindings for the other range widgets (which are, of course, - only active when the widget has focus) do not - differentiate between horizontal and vertical range widgets.
++Scrollbars are not focusable, thus have no key bindings. The key bindings for +the other range widgets (which are, of course, only active when the widget has +focus) do not differentiate between horizontal and vertical range +widgets. +
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 263 -All range widgets can be operated with the left, right, up and - down arrow keys, as well as with the Page Up and - Page Down keys. The arrows move the slider up and down - by stepIncrement, while Page Up and - Page Down move it by pageIncrement. - Homeand Endmove to the beginning and end of the - slide.
+
+All range widgets can be operated with the left, right, up and down arrow keys,
+as well as with the Page Up and Page Down
+keys. The arrows move the slider up and down by stepIncrement,
+while Page Up and Page Down move it by
+pageIncrement. Home and End move
+to the beginning and end of the slider.
+
The user can also move the slider all the way to one end or - the other of the trough using the keyboard. This is done with the - Home and End keys.
-+
+The user can also move the slider all the way to one end or the other of the +trough using the keyboard. This is done with the Home and +End keys. +
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 278 -Example
+Example
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 280 -This example puts up a window with three range widgets all - connected to the same adjustment, and a couple of controls for - adjusting some of the parameters mentioned above, so you can see - how they affect the way these widgets work for the user.
++This example puts up a window with three range widgets all connected to the +same adjustment, and a couple of controls for adjusting some of the parameters +mentioned above so you can see how they affect the way these widgets work for +the user. +
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 287 -
The three scales are placed so the vertical is next to the two - horizontal ones, one above the other. So we need a horizontal box - for the vertical scale and a vertical box next to it for the - horizontal scales. The scales and the boxes must be packed with - PackGrow so the scales will resize with the main box, - which is a vertical box in the window.
+
+The three scales are placed so the vertical is next to the two horizontal ones,
+one above the other. So we need a horizontal box for the vertical scale and a
+vertical box next to it for the horizontal scales. The scales and the boxes
+must be packed with PackGrow so the scales will resize with the
+main box, which is a vertical box in the window.
+
All three scales ar constructed with the same adjustment, - setting the initial value at 0.0, the minimum value at 0.0, the - maximu value at 101.0, the step increment at 0.1 , the page - increment at 1.0 and the page size at 1.0 .
++All three scales ar constructed with the same adjustment, setting the initial +value at 0.0, the minimum value at 0.0, the maximum value at 101.0, the step +increment at 0.1, the page increment at 1.0 and the page size at 1.0. +
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 303 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 306 - |
-
-
The user can control whether the scale values are displayed - with a checkButton. This is packed into the main box and - set to be active initially. A check button is a toggle button and - when the user checks or uncehecks it th onToggled signal - is sent. this causes the toggleDisplay function to be evaluated, - which is defined as:
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 307 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 317 -toggleDisplay b scls = sequence_ (map change scls) where +toggleDisplay b scls = sequence_ (map change scls) where hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 321 - |
-
The function has a checkButton type as its parameter, - and a list of instances of ScaleClass . However, a list - can only contain values of the same type, and vScale and hScale - are different types. So, we can use the function on lists of - vertical scales or horizontal scales, but lists containing both - types result in a typing error.
+
+The function has a checkButton type as its parameter, and a list
+of instances of ScaleClass. However, a list can only contain
+values of the same type, and vScale and hScale are
+different types. So, we can use the function on lists of vertical scales or
+horizontal scales, but lists containing both types result in a typing error.
+
The user can select the positionType using a widget not - mentioned before, a ComboBox. This allows a selection of - choices as shown below. The one to be set active is determined by - an index, which is 0 here, the first one.
+
+The user can select the positionType using a widget not mentioned
+before, a ComboBox. This allows a selection of choices as shown
+below. The one to be set active is determined by an index, which is 0 here, the
+first one.
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 341 - comboBoxAppendText cb "TOP" + comboBoxAppendText cb "TOP" hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 343 - comboBoxAppendText cb "LEFT" - comboBoxAppendText cb "RIGHT" + comboBoxAppendText cb "LEFT" + comboBoxAppendText cb "RIGHT" hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 348 - |
-
A second comboBox lets the user select the update - policy, one of the three UpDateType constructors.
+
+A second comboBox lets the user select the update policy, one of
+the three UpdateType constructors.
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 358 - comboBoxAppendText cb "Continuous" + comboBoxAppendText cb "Continuous" hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 360 - comboBoxAppendText cb "Delayed" + comboBoxAppendText cb "Delayed" hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 364 - |
-
The combo boxes themselves just display text, of course. To - select the position, respectively the update policy, we - define:
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 365 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 375 - (Just "TOP") -> PosTop + (Just "TOP") -> PosTop hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 377 - (Just "LEFT") -> PosLeft - (Just "RIGHT") -> PosRight - Nothing -> error "GtkChap9.hs setScalePos: no position set" - scaleSetValuePos sc pos + (Just "LEFT") -> PosLeft + (Just "RIGHT") -> PosRight + Nothing -> error "setScalePos: no position set" + scaleSetValuePos sc pos hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 386 - (Just "Continuous") -> UpdateContinuous + (Just "Continuous") -> UpdateContinuous hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 388 - (Just "Delayed") -> UpdateDelayed - Nothing -> error "GtkChap9.hs setUpdatePol: no policy set" - rangeSetUpdatePolicy sc pol + (Just "Delayed") -> UpdateDelayed + Nothing -> error "setUpdatePol: no policy set" + rangeSetUpdatePolicy sc pol hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 392 - |
-
Here we have not used lists to manage the vertical and - horizontal scales, so each horizontal scale is addressed - separately.
++Here we have not used lists to manage the vertical and horizontal scales, so +each horizontal scale is addressed separately. +
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 398 -The number of precision shown on the three scles will be - managed with another scale, for which we use a new adjustment. - The maximum precision is 10 and each increment is 1. The - precision of this control scale itself is set to 1.
++The number of precision shown on the three scles will be managed with another +scale, for which we use a new adjustment. The maximum precision is 10 and each +increment is 1. The precision of this control scale itself is set to 1. +
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 404 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 407 - |
-
When the control adjustment changes the signal - onValueChanged will be emitted and then the defined - function setDigits is evaluated.
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 408 -
+When the control adjustment changes the signal onValueChanged will
+be emitted and then the defined function setDigits is evaluated.
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 416 - set sc [scaleDigits := (round val) ] + set sc [scaleDigits := (round val)] hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 418 - |
-
Here we use the general functions set and get on - the attributes; we might have used the appropriate methods as - well. Note that the Double of the adjustment value must be - rounded to an Integral type.
- -We use another horizontal scale to manage the page size of the - three example scales. When set at 0.0 the scales can reach their - initial maximum of 100.0 and when set at 100.0 the scales are - fixed at the lowest value. This involves the adjusting of the - adjustment by a the onValueChanged signal from a third - adjustment by this code snippet:
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 419 -
+Here we use the general functions set and get on the
+attributes; we might have used the appropriate methods as well. Note that the
+Double of the adjustment value must be rounded to an
+Integral type.
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 438 - |
-
+The main function is: +
hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 443 -The main function is:
- -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 449 - window <- windowNew + window <- windowNew hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 451 - windowDefaultWidth := 250 ] + windowDefaultWidth := 250] hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 459 - vsc <- vScaleNew adj1 + vsc <- vScaleNew adj1 hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 463 - boxPackStart box1 box2 PackGrow 0 + boxPackStart box1 box2 PackGrow 0 hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 474 - box3 <- hBoxNew False 10 + box3 <- hBoxNew False 10 hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 478 - opt1 <- makeOpt1 + opt1 <- makeOpt1 hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 481 - box4 <- hBoxNew False 10 + box4 <- hBoxNew False 10 hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 485 - opt2 <- makeOpt2 + opt2 <- makeOpt2 hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 490 - box5 <- hBoxNew False 0 + box5 <- hBoxNew False 0 hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 495 - dsc <- hScaleNew adj2 + dsc <- hScaleNew adj2 hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 501 - box6 <- hBoxNew False 0 + box6 <- hBoxNew False 0 hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 506 - psc <- hScaleNew adj3 + psc <- hScaleNew adj3 hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 513 - onChanged opt1 $ do setScalePos opt1 hsc1 + onChanged opt1 $ do setScalePos opt1 hsc1 hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 517 - onChanged opt2 $ do setUpdatePol opt2 hsc1 + onChanged opt2 $ do setUpdatePol opt2 hsc1 hunk ./docs/tutorial/Tutorial_Port/chap4-2.xhtml 532 - |
-
The non standard functions used in the listing have already - been listed above.
-- -
| - - | - -- - | - -- - | -
|
- Button - |
+
- to be continued... - |
-
-
|
- Gtk2Hs Tutorial - |
- ||
|---|---|---|
| - - | - -+ hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 12 - | - - | -
+
Gtk2Hs Tutorial
+ + + +Labels
+4.3 Labels
hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 21 -Labels are used a lot in Gtk2Hs, and are relatively simple. - Labels emit no signals as they do not have an associated X - window. If you need to catch signals, or do clipping, place it - inside an EventBox widget, which allows you to catch - signals for widgets which do not have their own window, or a - button.
+
+Labels are used a lot in Gtk2Hs, and are relatively simple. Labels emit no
+signals as they do not have an associated X window. If you need to catch
+signals, or do clipping, place it inside an EventBox widget,
+which allows you to catch signals for widgets which do not have their own
+window, or a button.
+
To create a new label, use:
++To create a new label, use: +
hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 33 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 38 - |
-
With the second function, if characters in the string are - preceded by an underscore, they are underlined. If you need a - literal underscore character in a label, use '__' (two - underscores). The first underlined character represents a - keyboard accelerator called a mnemonic. When that key is pressed - the activable widget which contains the label (e.g. a button) - will be activated. The widget which is to be affected can also be - set by labelSetMnemonicWidget.
+
+With the second function, if characters in the string are preceded by an
+underscore, they are underlined. If you need a literal underscore character in
+a label, use "__" (two underscores). The first underlined character represents
+a keyboard accelerator called a mnemonic. When that key is pressed the
+activable widget which contains the label (e.g. a button) will be activated.
+The widget which is to be affected can also be set by
+labelSetMnemonicWidget.
+
To change the label's text after creation, or to get the - label's text, use the functions:
++To change the label's text after creation, or to get the label's text, use the +functions: +
hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 54 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 59 - |
-
or, of course, the generic set or get functions. - The space needed for the new string will be automatically - adjusted if needed. You can produce multi-line labels by putting - line breaks in the label string. If you have multi-line labels - the lines can be justified relatively to each other using:
+
+or, of course, the generic set or get functions. The
+space needed for the new string will be automatically adjusted if needed. You
+can produce multi-line labels by putting line breaks in the label string. If
+you have multi-line labels the lines can be justified relatively to each other
+using:
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 71 - |
-
where the type Justification has one of four - constructors:
+
+where the type Justification has one of four constructors:
+
- -JustifyLeft -JustifyRight -JustifyCenter -JustifyFill -- |
-
-
+
JustifyLeft
+ JustifyRight
+ JustifyCenter
+ JustifyFill
+
The label widget is also capable of line wrapping the text - automatically. This can be activated using:
++The label widget is also capable of line wrapping the text automatically. This +can be activated using: +
hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 88 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 91 - |
-
If you want your label underlined, then you can set a pattern - on the label:
++If you want your label underlined, then you can set a pattern on the label: +
hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 96 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 99 - |
-
The list of Ints marks the underlined parts of the label text - alternated by the non-interlined parts. For example, [3,1,3] - means first 3 characters underlined, the next not, the next 3 - underlined.
+
+The list of Ints marks the underlined parts of the label text
+alternated by the non-interlined parts. For example, [3, 1, 3] means
+first three characters underlined, the next not, and the next three underlined.
+
You can also make text in a lable selectable, so the user can - copy and paste it, and use some formatting options.
++You can also make text in a lable selectable, so the user can copy and paste +it, and use some formatting options. +
hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 111 -Below is a short example to illustrate a few of - these functions. It makes use of the Frame widget to - better demonstrate the label styles. A Frame is just an - ornament like a HSeparator and a VSeparator but it - surrounds the widget and is an instance of Container. - Therefore the widget it frames must be added to it with - containerAdd. A frame itself can have a label to convey - information about its contents.
+
+Below is a short example to illustrate a few of these functions. It makes use
+of the Frame widget to better demonstrate the label styles. A
+Frame is just an ornament like a HSeparator and a
+VSeparator but it surrounds the widget and is an instance of
+Container. Therefore the widget it frames must be added to it with
+containerAdd. A frame itself can have a label to convey
+information about its contents.
+
Because all the labels are framed, a function - myLabelWithFrameNew is defined, which returns a - tuple.Gtk2Hs is truly Haskell, so you can use all the Haskell - data types and features. The justifications are pretty obvious, - but they only refer to the lines inside the label. So, to to - right justify label2 itself, you need miscSetAlignment as - shown below. The last two widgets in the left horizontal box are - packed with boxPackEnd instead of the usual - boxPackStart. The button label demonstrates the use of a - mnemonic as an accellarator key. Pressing Alt_C on the keyboard - has the same effect as clicking the button.
+
+Because all the labels are framed, a function myLabelWithFrameNew
+is defined, which returns a tuple. Gtk2Hs is truly Haskell, so you can use all
+the Haskell data types and features. The justifications are pretty obvious, but
+they only refer to the lines inside the label. So, to right justify
+label2 itself, you need miscSetAlignment as shown
+below. The last two widgets in the left horizontal box are packed with
+boxPackEnd instead of the usual boxPackStart. The
+button label demonstrates the use of a mnemonic as an accellerator key.
+Pressing Alt-C on the keyboard has the same effect as clicking
+the button.
+
Note: when tested on Fedora 6, pressing Enter or the space bar - also had this effect. Also note the effect of the y-character on - the placement of the underline.
++Note: When tested on Fedora 6, pressing Enter +or the space bar also had this effect. Also note the effect of the character +"y" on the placement of the underline. +
hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 142 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 147 - initGUI - window <- windowNew - set window [windowTitle := "Labels", containerBorderWidth := 10 ] - mainbox <- vBoxNew False 10 - containerAdd window mainbox - hbox <- hBoxNew True 5 - boxPackStart mainbox hbox PackNatural 0 - vbox1 <- vBoxNew False 10 - vbox2 <- vBoxNew False 0 - boxPackStart hbox vbox1 PackNatural 0 - boxPackStart hbox vbox2 PackNatural 0 + initGUI + window <- windowNew + set window [windowTitle := "Labels", containerBorderWidth := 10] + mainbox <- vBoxNew False 10 + containerAdd window mainbox + hbox <- hBoxNew True 5 + boxPackStart mainbox hbox PackNatural 0 + vbox1 <- vBoxNew False 10 + vbox2 <- vBoxNew False 0 + boxPackStart hbox vbox1 PackNatural 0 + boxPackStart hbox vbox2 PackNatural 0 + + (label1,frame1) <- myLabelWithFrameNew + boxPackStart vbox1 frame1 PackNatural 0 + labelSetText label1 "Penny Harter" hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 163 - (label1,frame1) <- myLabelWithFrameNew - boxPackStart vbox1 frame1 PackNatural 0 - labelSetText label1 "Penny Harter" + (label2,frame2) <- myLabelWithFrameNew + boxPackStart vbox1 frame2 PackNatural 0 + labelSetText label2 "broken bowl\nthe pieces\nstill rocking" + miscSetAlignment label2 0.0 0.0 + hsep1 <- hSeparatorNew + boxPackStart vbox1 hsep1 PackNatural 10 hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 170 - (label2,frame2) <- myLabelWithFrameNew - boxPackStart vbox1 frame2 PackNatural 0 - labelSetText label2 "broken bowl\nthe pieces\nstill rocking" - miscSetAlignment label2 0.0 0.0 - hsep1 <- hSeparatorNew - boxPackStart vbox1 hsep1 PackNatural 10 + (label3,frame3) <- myLabelWithFrameNew + boxPackStart vbox1 frame3 PackNatural 0 + labelSetText label3 "Gary Snyder" hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 174 - (label3,frame3) <- myLabelWithFrameNew - boxPackStart vbox1 frame3 PackNatural 0 - labelSetText label3 "Gary Snyder" + (label4,frame4) <- myLabelWithFrameNew + boxPackStart vbox1 frame4 PackNatural 0 + labelSetText label4 "After weeks of watching the roof leak\nI fixed it tonight\nby moving a single board" + labelSetJustify label4 JustifyCenter hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 179 - (label4,frame4) <- myLabelWithFrameNew - boxPackStart vbox1 frame4 PackNatural 0 - labelSetText label4 "After weeks of watching the roof leak\nI fixed it tonight\nby moving a single board" - labelSetJustify label4 JustifyCenter + (label5,frame5) <- myLabelWithFrameNew + boxPackStart vbox2 frame5 PackNatural 0 + labelSetText label5 "Kobayashi Issa" hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 183 - (label5,frame5) <- myLabelWithFrameNew - boxPackStart vbox2 frame5 PackNatural 0 - labelSetText label5 "Kobayashi Issa" - - (label7,frame7) <- myLabelWithFrameNew - boxPackEnd vbox2 frame7 PackNatural 0 - labelSetText label7 "only one guy and\nonly one fly trying to\nmake the guest room do" - labelSetJustify label7 JustifyRight + (label7,frame7) <- myLabelWithFrameNew + boxPackEnd vbox2 frame7 PackNatural 0 + labelSetText label7 "only one guy and\nonly one fly trying to\nmake the guest room do" + labelSetJustify label7 JustifyRight hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 188 - (label6,frame6) <- myLabelWithFrameNew - boxPackEnd vbox2 frame6 PackNatural 10 - labelSetText label6 "One Guy" - frameSetLabel frame6 "Title:" - labelSetPattern label6 [3,1,3] + (label6,frame6) <- myLabelWithFrameNew + boxPackEnd vbox2 frame6 PackNatural 10 + labelSetText label6 "One Guy" + frameSetLabel frame6 "Title:" + labelSetPattern label6 [3, 1, 3] hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 194 - button <- buttonNew - boxPackEnd mainbox button PackNatural 20 - buttonlabel <- labelNewWithMnemonic "Haiku _Clicked" - containerAdd button buttonlabel + button <- buttonNew + boxPackEnd mainbox button PackNatural 20 + buttonlabel <- labelNewWithMnemonic "Haiku _Clicked" + containerAdd button buttonlabel hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 199 - widgetShowAll window - onClicked button (putStrLn "button clicked...") - onDestroy window mainQuit - mainGUI + widgetShowAll window + onClicked button (putStrLn "button clicked...") + onDestroy window mainQuit + mainGUI hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 207 - label <- labelNew Nothing - frame <- frameNew - containerAdd frame label - frameSetShadowType frame ShadowOut - return (label, frame) --- Haikus quoted from X.J. Kennedy, Dana Gioia, Introduction to Poetry, Longman, 1997 -- |
-
- -
| - - | - -- - | + label <- labelNew Nothing + frame <- frameNew + containerAdd frame label + frameSetShadowType frame ShadowOut + return (label, frame) hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 213 -- - | -
|
- Adjustments, Scale and Range - |
-
-
- - |
+-- Haikus quoted from X.J. Kennedy, Dana Gioia, Introduction to Poetry, Longman, 1997
+
hunk ./docs/tutorial/Tutorial_Port/chap4-3.xhtml 217
-
- to be continued... - |
-
-
|
- Gtk2Hs Tutorial - |
- ||
|---|---|---|
| - - | - -
- |
+
hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 12
- - - | -
+
Gtk2Hs Tutorial
+ + + +Arrows and - Tooltips
+4.4 Arrows and Tooltips
hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 21 -The Arrow widget draws an arrowhead, facing in a number of - possible directions and having a number of possible styles. Like - the Label widget, it emits no signals.
+
+The Arrow widget draws an arrowhead, facing in a number of
+possible directions and having a number of possible styles. Like the
+Label widget, it emits no signals.
+
There are only two functions for manipulating an Arrow - widget:
+
+There are only two functions for manipulating an Arrow widget:
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 36 - |
-
The ArrowType has 5 constructors:
+
+The ArrowType has five constructors:
+
- -ArrowUp -ArrowDown -ArrowLeft -ArrowRight -ArrowNone -- |
-
-
+
ArrowUp
+ ArrowDown
+ ArrowLeft
+ ArrowRight
+ ArrowNone
+
The ShadowType also has 5 constructors:
+
+The ShadowType also has five constructors:
+
- -ShadowNone -ShadowIn -ShadowOut -ShadowEtchedIn -ShadowEtchedOut -- |
-
-
+
ShadowIn
+ ShadowOut
+ ShadowEtchedIn
+ ShadowEtchedOut
+ ShadowNone
+
Tooltips are the little text strings that pop up when you - leave your pointer over a button or other widget for a few - seconds.
++Tooltips are the little text strings that pop up when you leave your pointer +over a button or other widget for a few seconds. +
hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 66 -Widgets that do not receive events (widgets that do not have - their own window) will not work with tooltips.
++Widgets that do not receive events (widgets that do not have their own window) +will not work with tooltips. +
hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 71 -The first call you will use creates a new tooltip. You only - need to do this once for a set of tooltips.
++The first call you will use creates a new tooltip. You only need to do this +once for a set of tooltips. +
hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 76 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 79 - |
-
Then, for every widget, use:
++Then, for every widget, use: +
hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 84 -
- -tooltipsSetTip :: (TooltipsClass self, WidgetClass widget) -=> self -> widget -> String -> String -> IO () ++tooltipsSetTip :: (TooltipsClass self, WidgetClass widget) + => self -> widget -> String -> String -> IO () hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 88 - |
-
The first argument is the tooltip you've already created, - followed by the widget you wish to have this tooltip pop up for, - and the text you wish it to say. The last argument is a text - string that can be used as an identifier.
++The first argument is the tooltip you've already created, followed by the +widget you wish to have this tooltip pop up for, and the text you wish it to +say. The last argument is a text string that can be used as an identifier. +
hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 95 -You can turn the tips associated with a Tooltips value - on or off using:
+
+You can turn the tips associated with a Tooltips value on or off
+using:
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 104 - |
-
Here's an example to illustrate the use of arrows and - tooltips.
hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 105 -
- 
+Here's an example to illustrate the use of arrows and tooltips. +
hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 109 -The window above has been resized from its default size, to - show how the packing in a table preserves the spacing of the - buttons with their arrows.
+
Note: the tooltips don't work with GHCi (on my machine) but - they do when compiled. You cannot see them in the screenshot, of - course.
++The window above has been resized from its default size, to show how the +packing in a table preserves the spacing of the buttons with their arrows. +
hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 116 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 126 - initGUI - window <- windowNew - set window [windowTitle := "Arrow Tips", - windowDefaultWidth := 200, - windowDefaultHeight := 200, containerBorderWidth := 20 ] + initGUI + window <- windowNew + set window [windowTitle := "Arrow Tips", + windowDefaultWidth := 200, + windowDefaultHeight := 200, containerBorderWidth := 20] hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 132 - table <- tableNew 5 5 True - containerAdd window table - - button1 <- buttonNew - button2 <- buttonNew - button3 <- buttonNew - button4 <- buttonNew + table <- tableNew 5 5 True + containerAdd window table hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 135 - tableAttachDefaults table button1 0 1 2 3 - tableAttachDefaults table button2 2 3 0 1 - tableAttachDefaults table button3 4 5 2 3 - tableAttachDefaults table button4 2 3 4 5 + button1 <- buttonNew + button2 <- buttonNew + button3 <- buttonNew + button4 <- buttonNew hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 140 - tlt <- tooltipsNew + tableAttachDefaults table button1 0 1 2 3 + tableAttachDefaults table button2 2 3 0 1 + tableAttachDefaults table button3 4 5 2 3 + tableAttachDefaults table button4 2 3 4 5 hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 145 - arrow1 <- arrowNew ArrowLeft ShadowEtchedIn - containerAdd button1 arrow1 - tooltipsSetTip tlt button1 "West" "T1" + tlt <- tooltipsNew hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 147 - arrow2 <- arrowNew ArrowUp ShadowEtchedOut - containerAdd button2 arrow2 - tooltipsSetTip tlt button2 "North" "T2" + arrow1 <- arrowNew ArrowLeft ShadowEtchedIn + containerAdd button1 arrow1 + tooltipsSetTip tlt button1 "West" "T1" hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 151 - arrow3 <- arrowNew ArrowRight ShadowEtchedIn - containerAdd button3 arrow3 - tooltipsSetTip tlt button3 "East" "T3" + arrow2 <- arrowNew ArrowUp ShadowEtchedOut + containerAdd button2 arrow2 + tooltipsSetTip tlt button2 "North" "T2" hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 155 - arrow4 <- arrowNew ArrowDown ShadowEtchedOut - containerAdd button4 arrow4 - tooltipsSetTip tlt button4 "South" "T4" + arrow3 <- arrowNew ArrowRight ShadowEtchedIn + containerAdd button3 arrow3 + tooltipsSetTip tlt button3 "East" "T3" hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 159 - tooltipsEnable tlt - widgetShowAll window - onDestroy window mainQuit - mainGUI -- |
-
- -
| - - | - -- - | + arrow4 <- arrowNew ArrowDown ShadowEtchedOut + containerAdd button4 arrow4 + tooltipsSetTip tlt button4 "South" "T4" hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 163 -- - | -
|
- Labels - |
-
-
- |
+ tooltipsEnable tlt
+ widgetShowAll window
+ onDestroy window mainQuit
+ mainGUI
+
hunk ./docs/tutorial/Tutorial_Port/chap4-4.xhtml 169
-
- Dialogs, Stock Items Progress Bars - |
-
-
|
- Gtk2Hs Tutorial - |
- ||
|---|---|---|
| - - | - -
- |
+
hunk ./docs/tutorial/Tutorial_Port/chap4-5.xhtml 12
- - - | -
Gtk2Hs Tutorial
+ + + +Dialogs, Stock - Items and Progress Bars
+4.5 Dialogs, Stock Items and Progress Bars
hunk ./docs/tutorial/Tutorial_Port/chap4-5.xhtml 21 -A dialog is an example of a composite widget. It consists of a - window, an upper part which is a vertical box, and an action area - which is a horizontal box. By default, both parts are separated - by a horizontal separator.
++A dialog is an example of a composite widget. It consists of a window, an upper +part which is a vertical box, and an action area which is a horizontal box. By +default, both parts are separated by a horizontal separator. +
hunk ./docs/tutorial/Tutorial_Port/chap4-5.xhtml 27 -The Dialog widget can be used for pop-up messages to - the user, and other similar tasks. The basic functions needed - are:
+
+The Dialog widget can be used for pop-up messages to the user, and
+other similar tasks. The basic functions needed are:
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-5.xhtml 37 - |
-
You add buttons into the action area with:
++You add buttons into the action area with: +
hunk ./docs/tutorial/Tutorial_Port/chap4-5.xhtml 42 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-5.xhtml 45 - |
-
Any widget can be added in a similar way with - dialogAddActionWidget.
+
+Any widget can be added in a similar way with
+dialogAddActionWidget.
+
The String in dialogAddButton can be the text of - the button, but since dialogs are mostly used for standard - situations a StockItem will usually be more - appropriate.
+
+The String in dialogAddButton can be the text of the
+button, but since dialogs are mostly used for standard situations a
+StockItem will usually be more appropriate.
+
StockItems are resources which are known throughout - Gtk2Hs, such as standard IconSets. You can define your - own, but many useful ones are listed in the - Graphics.UI.Gtk.General.StockItems module. They have an - identifier StockId ,which is a type synonym for - String. From this identifier a widget (usually a button) - with the appropriate standard text and icon is automatically - selected.
+
+StockItems are resources which are known throughout Gtk2Hs, such
+as standard IconSets. You can define your own, but many useful
+ones are listed in the Graphics.UI.Gtk.General.StockItems module.
+They have an identifier StockId, which is a type synonym for
+String. From this identifier a widget (usually a button) with the
+appropriate standard text and icon is automatically selected.
+
If you use a StockId when adding a button to a dialog, - you can also use a pre-defined ResponseId constructor with - the buttons. (ResponseId is not a String.) - Customized responses may be constructed with ResponseUser - Int .
+
+If you use a StockId when adding a button to a dialog, you can
+also use a pre-defined ResponseId constructor with the buttons.
+(ResponseId is not a String.) Customized responses
+may be constructed with ResponseUser Int.
+
Whenever a dialog button is pressed, its response is passed to - the calling application through dialogRun. According to - the Gtk2Hs API documentation dialogRun blocks in a - recursive main loop until the dialog either emits the response - signal, or is destroyed. The default mode is modal, which means - the user cannot access any other window while dialogRun is - waiting for a response.
+
+Whenever a dialog button is pressed, its response is passed to the calling
+application through dialogRun. According to the Gtk2Hs API
+documentation dialogRun blocks in a recursive main loop until the
+dialog either emits the response signal, or is destroyed. The default mode is
+modal, which means the user cannot access any other window while
+dialogRun is waiting for a response.
+
Progress bars are used to show the status of an ongoing - operation.
++Progress bars are used to show the status of an ongoing operation. +
hunk ./docs/tutorial/Tutorial_Port/chap4-5.xhtml 86 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-5.xhtml 89 - |
-
Though there is only one type, there are two distinct ways to - use a progress bar. If it is known how much of the task has been - completed, the fraction (between 0.0 and 1.0 inclusive) can be - set with:
++Though there is only one type, there are two distinct ways to use a progress +bar. If it is known how much of the task has been completed, the fraction +(between 0.0 and 1.0 inclusive) can be set with: +
hunk ./docs/tutorial/Tutorial_Port/chap4-5.xhtml 96 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-5.xhtml 99 - |
-
This causes the progress bar to be filled in with the - specified amount (between 0.0 and 1.0). To trace the progress - this function should be called at regular times during the - operation.
hunk ./docs/tutorial/Tutorial_Port/chap4-5.xhtml 100 -When it is not known how much of the operation has been - completed, the bar can be moved back and forth with:
++This causes the progress bar to be filled in with the specified amount (between +0.0 and 1.0). To trace the progress this function should be called at regular +times during the operation. +
hunk ./docs/tutorial/Tutorial_Port/chap4-5.xhtml 106 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-5.xhtml 114 - |
-
This function must also be called repeatedly, to show that the - activity is going on. There are several other functions to - control the display of a progress bar, like orientation, - additional text etc.; they are fairly trivial.
++This function must also be called repeatedly, to show that the activity is +going on. There are several other functions to control the display of a +progress bar, like orientation, additional text etc.; they are fairly trivial. +
hunk ./docs/tutorial/Tutorial_Port/chap4-5.xhtml 121 -Application, however, is not trivial because progress bars are - usually applied with timeouts or other such functions to give the - illusion of multitasking. With concurrent Haskell you can also - use threads and communication between threads.
++Application, however, is not trivial because progress bars are usually applied +with timeouts or other such functions to give the illusion of multitasking. +With concurrent Haskell you can also use threads and communication between +threads. +
hunk ./docs/tutorial/Tutorial_Port/chap4-5.xhtml 128 -In the following example we'll simulate an activity using - timeoutAdd, which runs a function repeatedly at the - interval specified, in milliseconds. The function is passed to - timeoutAdd and must return a type of IO Bool. When - true the timeout is run again, when false it stops. The priority - of timeoutAdd is priorityDefault of type - Priority.
+
+In the following example we'll simulate an activity using
+timeoutAdd, which runs a function repeatedly at the interval
+specified, in milliseconds. The function is passed to timeoutAdd
+and must return a type of IO Bool. When true the timeout is run
+again, when false it stops. The priority of timeoutAdd is
+priorityDefault of type Priority.
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-5.xhtml 140 - |
-
In the example we define the function showPulse , which - causes the progress bar to pulse and always returns IO - True. The pulse step, the amount which the indicator moves - through the bar, is set to 1.0 with - progressBarSetPulseStep.
+
+In the example we define the function showPulse, which causes the
+progress bar to pulse and always returns IO True. The pulse step,
+the amount which the indicator moves through the bar, is set to 1.0 with
+progressBarSetPulseStep.
+
- 
The example is somewhat atypical of the use of a dialog, since - we keep it to show the progress after the user has pressed the - apply button. To close the application the dialog must be - destroyed by destroying the window. The close and cancel buttons - don't work after apply has been selected. If selected, instead of - Apply, the first time, the application will close. This is done - by testing the response from dialogRun.
+
+The example is somewhat atypical of the use of a dialog, since we keep it to
+show the progress after the user has pressed the apply button. To close the
+application the dialog must be destroyed by destroying the window. The close
+and cancel buttons don't work after apply has been selected. If selected,
+instead of Apply, the first time, the application will close. This is
+done by testing the response from dialogRun.
+
If the dialog widget is destroyed, mainQuit is called. - As mentioned above, a Dialog consists of a window and two - boxes. The boxes must be accessed through special functions, and - the progress bar is packed into the upper part using - dialogGetUpper. The buttons in a dialog are visible by - default, but the widgets in the upper part are not. A - Dialog is an instance of the WindowClass, and so we - can set the title and/or default length and height if we - want.
+
+If the dialog widget is destroyed, mainQuit is called. As
+mentioned above, a Dialog consists of a window and two boxes. The
+boxes must be accessed through special functions, and the progress bar is
+packed into the upper part using dialogGetUpper. The buttons in a
+dialog are visible by default, but the widgets in the upper part are not. A
+Dialog is an instance of the WindowClass, and so we
+can set the title and/or default length and height if we want.
+
A trivial feature to watch out for: - a widget can only be made visible if its parent is visible. So, - to show the progress bar, we use widgetShowAll on the - vertical box and not widgetShow on the progress bar.
+
+A trivial feature to watch out for: A widget can only be made visible if its
+parent is visible. So, to show the progress bar, we use
+widgetShowAll on the vertical box and not widgetShow
+on the progress bar.
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-5.xhtml 181 - initGUI - - dia <- dialogNew - set dia [windowTitle := "Time Flies"] - dialogAddButton dia stockApply ResponseApply - dialogAddButton dia stockCancel ResponseCancel - dialogAddButton dia stockClose ResponseClose + initGUI + + dia <- dialogNew + set dia [windowTitle := "Time Flies"] + dialogAddButton dia stockApply ResponseApply + dialogAddButton dia stockCancel ResponseCancel + dialogAddButton dia stockClose ResponseClose hunk ./docs/tutorial/Tutorial_Port/chap4-5.xhtml 189 - pr <- progressBarNew - progressBarSetPulseStep pr 1.0 + pr <- progressBarNew + progressBarSetPulseStep pr 1.0 hunk ./docs/tutorial/Tutorial_Port/chap4-5.xhtml 192 - upbox <- dialogGetUpper dia - boxPackStart upbox pr PackGrow 10 - widgetShowAll upbox - - answer <- dialogRun dia - if answer == ResponseApply - then do tmhandle <- timeoutAdd (showPulse pr) 500 - return () - else widgetDestroy dia - - onDestroy dia mainQuit - mainGUI + upbox <- dialogGetUpper dia + boxPackStart upbox pr PackGrow 10 + widgetShowAll upbox + + answer <- dialogRun dia + if answer == ResponseApply + then do tmhandle <- timeoutAdd (showPulse pr) 500 + return () + else widgetDestroy dia + + onDestroy dia mainQuit + mainGUI hunk ./docs/tutorial/Tutorial_Port/chap4-5.xhtml 209 - |
-
- -
| - - | - -- - | - -- - | -
|
- Arrows and Tooltips - |
-
-
- |
hunk ./docs/tutorial/Tutorial_Port/chap4-5.xhtml 210
-
- Text Entries and Satusbars - |
-
-
|
- Gtk2Hs Tutorial - |
- ||
|---|---|---|
| - - | + hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 12 -
- |
- |
+
Gtk2Hs Tutorial
+ + + +Text - Entries and Status Bars
+4.6 Text Entries and Status Bars
hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 21 -The Entry widget allows text to be typed and displayed - in a single line text box. A fairly large set of key bindings are - supported by default. The user can choose between insert and - overwite mode by toggling the Insert key.
+
+The Entry widget allows text to be typed and displayed in a single
+line text box. A fairly large set of key bindings are supported by default. The
+user can choose between insert and overwite mode by toggling the
+Insert key.
+
Create a new Entry widget with the following - function.
+
+Create a new Entry widget with the following function.
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 35 - |
-
To replace or get the text which is currently within the - Entry widget:
+
+To replace or get the text which is currently within the Entry
+widget:
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 46 - |
-
If we don't want the contents of the Entry to be - changed by someone typing into it, we can change its editable - state. We can also set visibility (e.g. for passwords), the - maximum number of characters (0 if no maximum), whether the entry - has a frame or not, the number of characters to leave space for, - and a few other attributes. Text completion is also possible (see - EntryCompletion in the API documentation for its use). The - Entry attributes, which, of course, can be accessed with - get and set are:
+
+If we don't want the contents of the Entry to be changed by
+someone typing into it, we can change its editable state. We can also set
+visibility (e.g. for passwords), the maximum number of characters (0
+if no maximum), whether the entry has a frame or not, the number of characters
+to leave space for, and a few other attributes. Text completion is also
+possible (see EntryCompletion in the API documentation for its
+use). The Entry attributes, which, of course, can be accessed with
+get and set are:
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 69 - |
-
The Entry type is an instance of EditableClass - and many attributes and methods are defined there. Some - particularly useful ones are:
+
+The Entry type is an instance of EditableClass and
+many attributes and methods are defined there. Some particularly useful ones
+are:
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 85 - |
-
where the parameters of type Int denote the appropriate - start or end positions. The user can also cut, copy and paste - to/from the clipboard.
hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 86 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 98 - |
-
These all take the current cursor position. You can get and - set that position with:
hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 99 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 109 - |
-
The cursor is displayed before the character with the given - (base 0) index in the widget. The value must be less than or - equal to the number of characters in the widget. A value of -1 - indicates that the position should be set after the last - character in the entry.
++The cursor is displayed before the character with the given (base 0) index in +the widget. The value must be less than or equal to the number of characters in +the widget. A value of -1 indicates that the position should be set after the +last character in the entry. +
hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 117 -The Editable class has a number of signals which use higher - order functions (not discussed here). The Entry widget - itself has a signal, which is sent after the user presses the - Enter key:
+
+The Editable class has a number of signals which use higher order
+functions (not discussed here). The Entry widget itself has a
+signal, which is sent after the user presses the Enter key:
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 126 - |
-
There are also signals sent when text is copied, cut or pasted - to the clipboard, and when the user toggles overwrite/insert - mode.
++There are also signals sent when text is copied, cut or pasted to the +clipboard, and when the user toggles overwrite/insert mode. +
hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 132 -Statusbars are simple widgets used to display a text message. - They keep a stack of the messages pushed onto them, so that - popping the current message will re-display the previous text - message. A statusbar has a resize grip by default, so the user - can resize it.
++Status bars are simple widgets used to display a text message. They keep a +stack of the messages pushed onto them, so that popping the current message +will re-display the previous text message. A status bar has a resize grip by +default, so the user can resize it. +
hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 139 -In order to allow different parts of an application to use the - same statusbar to display messages, the statusbar widget issues - Context Identifiers which are used to identify different "users". - The message on top of the stack is the one displayed, no matter - what context it is in. Messages are stacked in last-in-first-out - order, not context identifier order. A statusbar is created - with:
+
+In order to allow different parts of an application to use the same status bar
+to display messages, the status bar widget issues ContextIds which
+are used to identify different "users". The message on top of the stack is the
+one displayed, no matter what context it is in. Messages are stacked in
+last-in-first-out order, not context identifier order. A status bar is created
+with:
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 151 - |
-
A new Context Identifier is generated by the following - function, with a String used as textual description of the - context:
+
+A new ContextId is generated by the following function, with a
+String used as textual description of the context:
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 160 - |
-
There are three functions that can operate on statusbars:
++There are three functions that can operate on status bars: +
hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 165 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 172 - |
-
The first, statusbarPush , is used to add a new message - to the statusbar. It returns a MessageId, which can be - passed later to statusbarRemove to remove the message with - the given ContextId and MessageId from the - statusbar's stack. Function statusbarPop removes the - message highest in the stack with the given context - identifier.
hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 173 -Statusbars, like progress bars, are used to display messages - to the user about some ongoing operation. We'll simulate such an - operation in the example below, by testing whether the text the - user submits (by pressing Enter) is the same as its reverse, and - pushing the result on the stack. The user can then see the - results by pressing the information button, which pops the stack - of messages. The first time the stack is empty, so the button is - greyed out using:
+
+The first, statusbarPush, is used to add a new message to the
+status bar. It returns a MessageId, which can be passed later to
+statusbarRemove to remove the message with the given
+ContextId and MessageId from the status bar's stack.
+Function statusbarPop removes the message highest in the stack
+with the given context identifier.
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 195 - |
-
Note that status bars would not be the first choice here, - since there is no testing if the stack is empty, but the example - does show how they can be applied. The resize handle of the - status bar is not very clear, but it is there, at the bottom - right.
hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 196 -
+
+Note that status bars would not be the first choice here, since there is no +testing if the stack is empty, but the example does show how they can be +applied. The resize handle of the status bar is not very clear, but it is +there, at the bottom right. +
hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 203 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 210 - initGUI - window <- windowNew - set window [windowTitle := "Text Entry", containerBorderWidth := 10] + initGUI + window <- windowNew + set window [windowTitle := "Text Entry", containerBorderWidth := 10] hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 214 - vb <- vBoxNew False 0 - containerAdd window vb + vb <- vBoxNew False 0 + containerAdd window vb hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 217 - hb <- hBoxNew False 0 - boxPackStart vb hb PackNatural 0 + hb <- hBoxNew False 0 + boxPackStart vb hb PackNatural 0 hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 220 - txtfield <- entryNew - boxPackStart hb txtfield PackNatural 5 - button <- buttonNewFromStock stockInfo - boxPackStart hb button PackNatural 0 + txtfield <- entryNew + boxPackStart hb txtfield PackNatural 5 + button <- buttonNewFromStock stockInfo + boxPackStart hb button PackNatural 0 hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 225 - txtstack <- statusbarNew - boxPackStart vb txtstack PackNatural 0 - id <- statusbarGetContextId txtstack "Line" + txtstack <- statusbarNew + boxPackStart vb txtstack PackNatural 0 + id <- statusbarGetContextId txtstack "Line" hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 229 - widgetShowAll window - widgetSetSensitivity button False + widgetShowAll window + widgetSetSensitivity button False hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 232 - onEntryActivate txtfield (saveText txtfield button txtstack id) - onPressed button (statusbarPop txtstack id) - onDestroy window mainQuit - mainGUI + onEntryActivate txtfield (saveText txtfield button txtstack id) + onPressed button (statusbarPop txtstack id) + onDestroy window mainQuit + mainGUI hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 239 - txt <- entryGetText fld - let mesg | txt == reverse txt = "\"" ++ txt ++ "\"" ++ - " is equal to its reverse" - | otherwise = "\"" ++ txt ++ "\"" ++ - " is not equal to its reverse" - widgetSetSensitivity b True - msgid <- statusbarPush stk id mesg - return () + txt <- entryGetText fld + let mesg | txt == reverse txt = "\"" ++ txt ++ "\"" ++ + " is equal to its reverse" + | otherwise = "\"" ++ txt ++ "\"" ++ + " is not equal to its reverse" + widgetSetSensitivity b True + msgid <- statusbarPush stk id mesg + return () hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 248 - |
-
- -
| - - | - -- - | -|
|
- Dialogs, Progress Bars - |
hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 249
-
- |
+
hunk ./docs/tutorial/Tutorial_Port/chap4-6.xhtml 255
-
- To be continued - |
-
|
- Gtk2Hs Tutorial - |
- ||
|---|---|---|
| - - | + hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 12 -
- Next - |
- |
+
Gtk2Hs Tutorial
+ + + +Spin - Buttons
+4.7 Spin Buttons
hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 21 -The SpinButton widget is generally used to allow the - user to select a value from a range of numeric values. It - consists of a text entry box with up and down arrow buttons - attached to the side. Selecting one of the buttons causes the - value to "spin" up and down the range of possible values. The - entry box may also be edited directly to enter a specific value. - SpinButton is an instance of EditableClass, so the - attributes and functions defined there are also available.
+
+The SpinButton widget is generally used to allow the user to
+select a value from a range of numeric values. It consists of a text entry box
+with up and down arrow buttons attached to the side. Selecting one of the
+buttons causes the value to "spin" up and down the range of possible values.
+The entry box may also be edited directly to enter a specific value.
+SpinButton is an instance of EditableClass, so the
+attributes and functions defined there are also available.
+
The spin button allows the value to have zero or a number of - decimal places and to be incremented/decremented in configurable - steps. The action of holding down one of the buttons optionally - results in an acceleration of change in the value according to - how long it is depressed.
++The spin button allows the value to have zero or a number of decimal places and +to be incremented/decremented in configurable steps. The action of holding down +one of the buttons optionally results in an acceleration of change in the value +according to how long it is depressed. +
hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 38 -SpinButton uses an Adjustment object to hold - information about the range of values that the spin button can - take. Recall that an Adjustment widget is created with the - following function:
+
+SpinButton uses an Adjustment object to hold
+information about the range of values that the spin button can take. Recall
+that an Adjustment widget is created with the following function:
+
- -adjustmentNew - :: Double -- value - -> Double -- lower - -> Double -- upper - -> Double -- stepIncrement - -> Double -- pageIncrement - -> Double -- pageSize - -> IO Adjustment ++adjustmentNew :: Double -- value + -> Double -- lower + -> Double -- upper + -> Double -- stepIncrement + -> Double -- pageIncrement + -> Double -- pageSize + -> IO Adjustment hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 53 - |
-
These attributes of an Adjustment are used by the - SpinButton in the following way:
+
+These attributes of an Adjustment are used by the
+SpinButton in the following way:
+
-
-
- value: initial value for the Spin Button +
- value — Initial value for the
SpinButton
hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 62
- - lower: lower range value +
- lower — Lower range value hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 64 -
- upper: upper range value +
- upper — Upper range value hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 66 -
- stepIncrement: value to increment/decrement when pressing - mouse button 1 on a button +
- stepIncrement — Value to increment/decrement when pressing + mouse button 1 on a button hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 69 -
- pageIncrement: value to increment/decrement when pressing - mouse button 2 on a button +
- pageIncrement — Value to increment/decrement when pressing + mouse button 2 on a button hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 72 -
- pageSize: unused -
- pageSize — Unused +
-
+
Additionally, mouse button 3 can be used to jump directly to - the upper or lower values when used to select one of the buttons. - Note that this may depend on the way your mouse is configured on - your computer system.
++Additionally, mouse button 3 can be used to jump directly to the upper or lower +values when used to select one of the buttons. Note that this may depend on the +way your mouse is configured on your computer system. +
hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 81 -Lets look at how to create a spin button:
++Let's look at how to create a spin button: +
hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 85 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 88 - |
-
The second argument (climbRate) take a value between 0.0 and - 1.0 and indicates how fast the spin button changes when an arrow - is clicked on. The third argument specifies the number of decimal - places to which the value will be displayed.
++The second argument (climbRate) takes a value between 0.0 and 1.0 +and indicates how fast the spin button changes when an arrow is clicked on. The +third argument specifies the number of decimal places to which the value will +be displayed. +
hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 96 -There also is a convenience constructor that allows creation - of a spin button without manually creating an adjustment.
++There also is a convenience constructor that allows creation of a spin button +without manually creating an adjustment. +
hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 101 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 104 - |
-
The three arguments, all of type Double, specify the - minum allowable value, the maximum allowable value, and the - increment added or subtracted by spinning the widget.
+
+The three arguments, all of type Double, specify the minum
+allowable value, the maximum allowable value, and the increment added or
+subtracted by spinning the widget.
+
A Spin Button can be reconfigured after creation using the - following function:
+
+A SpinButton can be reconfigured after creation using the
+following function:
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 119 - |
-
The first argument specifies the SpinButton widget that - is to be reconfigured. The other arguments are the climbRate and - the number of decimal places (digits) to disply.
+
+The first argument specifies the SpinButton widget that is to be
+reconfigured. The other arguments are the climbRate and the number
+of decimal places (digits) to disply.
+
The SpinButton attributes, which can be retrieved and - changed with the generic get and set functions - are:
+
+The SpinButton attributes, which can be retrieved and changed with
+the generic get and set functions are:
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 142 - |
-
The first three are as discussed before. The attribute - spinButtonSnapToTicks determines whether erroneous values - are automatically changed to the spin button's nearest increment - (default is False). Attribute spinButtonNumeric determines - whether non-numeric characters should be ignored (default False), - and spinButtonWrap is used to set whether a spin button - should wraparound upon reaching its limits (default False).
hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 143 -Attribute spinButtonValue is used to read the current - value or set a new value (default is 0).
+
+The first three are as discussed before. The attribute
+spinButtonSnapToTicks determines whether erroneous values are
+automatically changed to the spin button's nearest increment (default is
+False). Attribute spinButtonNumeric determines whether
+non-numeric characters should be ignored (default False), and
+spinButtonWrap is used to set whether a spin button should
+wraparound upon reaching its limits (default False).
+
To change the value of a spin button you can also use:
+
+Attribute spinButtonValue is used to read the current value or set
+a new value (default is 0).
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 165 - |
-
where SpinType determines the kind of change and - Double (increment) determines the value.
+
+where SpinType determines the kind of change and
+Double (increment) determines the value.
+
SpinType has the following constructors:
+
+SpinType has the following constructors:
+
- -SpinStepForward -SpinStepBackward -SpinPageForward -SpinPageBackward -SpinHome -SpinEnd -SpinUserDefined -- |
-
-
+
SpinStepForward
+ SpinStepBackward
+ SpinPageForward
+ SpinPageBackward
+ SpinHome
+ SpinEnd
+ SpinUserDefined
+
Many of these settings use values from the Adjustment - object that is associated with a spin button. - SpinStepForward and SpinStepBackwardchange the - value of the spin button by the amount specified by the - increment, unless it is equal to 0, in which case the value is - changed by the value of the stepIncrement in the adjustment. - SpinPageForward and SpinPageBackward simply alter - the value of the Spin Button by the increment. - SpinPageHome and SpinPageEnd set the value to the - bottom repectively the top of the Adjustment range. - i>SpinUserDefined simply alters the value of the spin - button by the specified amount.
+
+Many of these settings use values from the Adjustment object that
+is associated with a spin button. SpinStepForward and
+SpinStepBackward change the value of the spin button by the amount
+specified by the increment, unless it is equal to 0, in which case the value is
+changed by the value of the stepIncrement in the adjustment.
+SpinPageForward and SpinPageBackward simply alter the
+value of the SpinButton by the increment.
+SpinPageHome and SpinPageEnd set the value to the
+bottom repectively the top of the Adjustment range.
+i>SpinUserDefined simply alters the value of the spin button by
+the specified amount.
A spin button has an update policy:
++A spin button has an update policy: +
hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 202 -
- +hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 205 - |
-
The constructors of SpinButtonUpdatePolicy are either - UdateAlways or UpdateIfValid. These policies affect - the behavior of a Spin Button when parsing inserted text and - synchronizing its value with the values of the Adjustment. In the - case of UpdateIfValid the spin button only value gets - changed if the text input is a numeric value within the range - specified by the Adjustment. Otherwise the text is reset to the - current value. In case of UpdateAlways we ignore errors - while converting text into a numeric value.
+
+The constructors of SpinButtonUpdatePolicy are either
+UdateAlways or UpdateIfValid. These policies affect
+the behavior of a SpinButton when parsing inserted text and
+synchronizing its value with the values of the Adjustment. In the
+case of UpdateIfValid the spin button only value gets changed if
+the text input is a numeric value within the range specified by the
+Adjustment. Otherwise the text is reset to the current value. In
+case of UpdateAlways we ignore errors while converting text into a
+numeric value.
+
Finally, you can explicitly request that a Spin Button update - itself:
+
+Finally, you can explicitly request that a SpinButton update
+itself:
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 226 - |
-
It's example time again; this is a screenshot after playing - around with some of the settings.
hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 227 -
+It's example time again. This is a screenshot after playing around with some of +the settings: +
hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 232 -The spin buttons have all been created with the following - function which uses spinButtonNewWithRange. Because the - stepIncrement will be 1.0 in all cases, this is not a parameter - in myAddSpinButton.
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 243 - vbox <- vBoxNew False 0 - boxPackStart box vbox PackRepel 0 - label <- labelNew (Just name) - miscSetAlignment label 0.0 0.5 - boxPackStart vbox label PackNatural 0 - spinb <- spinButtonNewWithRange min max 1.0 - boxPackStart vbox spinb PackNatural 0 - return spinb + vbox <- vBoxNew False 0 + boxPackStart box vbox PackRepel 0 + label <- labelNew (Just name) + miscSetAlignment label 0.0 0.5 + boxPackStart vbox label PackNatural 0 + spinb <- spinButtonNewWithRange min max 1.0 + boxPackStart vbox spinb PackNatural 0 + return spinb hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 252 - |
-
In the main function we use one of the spin buttons - which already exist, but give it a new adjustment with - spinButtonConfigure. The old limits of -1000.0 and 1000.0 - are now replaced with -100.0 and 100.0. Note the brackets around - the negative numbers. The initial value is set at 0.0 and the - step increment is 0.25. The page increment, which is what you get - when pressing mouse button 2 on the arrow in the spin button, is - set at 10.0. The page size, which is not used, is 0.0 here. - Pressing mouse button 3 on an arrow jumps to the appropriate - limit of -100.0 or 100.0.
hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 253 -The new signal here is onValueSpinned ,which is emitted - whenever the user changes the value of a spin button. Here it is - used to control the number of decimal digits which are to be - displayed in the spinLarge spin button. Note the rounding of the - value, which is needed to convert the Double to an - Integral type.
+
+In the main function we use one of the spin buttons which already
+exist, but give it a new adjustment with spinButtonConfigure. The
+old limits of -1000.0 and 1000.0 are now replaced with -100.0 and 100.0. Note
+the brackets around the negative numbers. The initial value is set at 0.0 and
+the step increment is 0.25. The page increment, which is what you get when
+pressing mouse button 2 on the arrow in the spin button, is set at 10.0. The
+page size, which is not used, is 0.0 here. Pressing mouse button 3 on an arrow
+jumps to the appropriate limit of -100.0 or 100.0.
+
In this example we've used the generic get and
- set functions on attributes rather than the corresponding
- functions, which are also available. This is actually the
- recommended style when programming Gtk2Hs, and in the future many
- specific functions will be deprecated.
+The new signal here is onValueSpinned, which is emitted whenever
+the user changes the value of a spin button. Here it is used to control the
+number of decimal digits which are to be displayed in the
+spinLarge spin button. Note the rounding of the value, which is
+needed to convert the Double to an Integral type.
+
- +hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 284 - initGUI - window <- windowNew - mainbox <- vBoxNew False 0 - set window [windowTitle := "Spin Buttons", containerBorderWidth := 10, - windowDefaultWidth := 250, - windowDefaultHeight := 200, - containerChild := mainbox ] - hbox1 <- hBoxNew False 0 - frame1 <- frameNew - set frame1 [frameLabel := "Simple SpinButtons", containerChild := hbox1, - frameLabelYAlign := 0.8, frameShadowType := ShadowOut] - boxPackStart mainbox frame1 PackNatural 5 - - spinD <- myAddSpinButton hbox1 "Day:" 1.0 31.0 - spinM <- myAddSpinButton hbox1 "Month:" 1.0 12.0 - spinY <- myAddSpinButton hbox1 "Year:" 2000.0 2100.0 - set spinY [spinButtonValue := 2007] + initGUI + window <- windowNew + mainbox <- vBoxNew False 0 + set window [windowTitle := "Spin Buttons", containerBorderWidth := 10, + windowDefaultWidth := 250, windowDefaultHeight := 200, + containerChild := mainbox] + hbox1 <- hBoxNew False 0 + frame1 <- frameNew + set frame1 [frameLabel := "Simple SpinButtons", containerChild := hbox1, + frameLabelYAlign := 0.8, frameShadowType := ShadowOut] + boxPackStart mainbox frame1 PackNatural 5 hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 296 - vbox1 <- vBoxNew False 5 - frame2 <- frameNew - set frame2 [frameLabel := "More Features", containerChild := vbox1, - frameLabelYAlign := 0.8, frameShadowType:= ShadowOut ] - boxPackStart mainbox frame2 PackNatural 5 - - hbox2 <- hBoxNew False 0 - boxPackStart vbox1 hbox2 PackNatural 0 + spinD <- myAddSpinButton hbox1 "Day:" 1.0 31.0 + spinM <- myAddSpinButton hbox1 "Month:" 1.0 12.0 + spinY <- myAddSpinButton hbox1 "Year:" 2000.0 2100.0 + set spinY [spinButtonValue := 2007] hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 301 - spinLarge <- myAddSpinButton hbox2 "Value:" (-1000.0) 1000.0 - adj <- adjustmentNew 0.0 (-100.0) 100.0 0.25 10.0 0.0 - spinButtonConfigure spinLarge adj 0.0 2 - spnctl <- myAddSpinButton hbox2 "Decimal:" 0.0 10.0 - set spnctl [spinButtonValue := 2.0] - - tsnap <- checkButtonNewWithLabel "Snap to 0.25-ticks" - boxPackStart vbox1 tsnap PackNatural 0 + vbox1 <- vBoxNew False 5 + frame2 <- frameNew + set frame2 [frameLabel := "More Features", containerChild := vbox1, + frameLabelYAlign := 0.8, frameShadowType:= ShadowOut] + boxPackStart mainbox frame2 PackNatural 5 hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 307 - tnumr <- checkButtonNewWithLabel "Numeric only input mode" - boxPackStart vbox1 tnumr PackNatural 0 + hbox2 <- hBoxNew False 0 + boxPackStart vbox1 hbox2 PackNatural 0 hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 310 - twrap <- checkButtonNewWithLabel "Wraparound at limits" - boxPackStart vbox1 twrap PackNatural 0 + spinLarge <- myAddSpinButton hbox2 "Value:" (-1000.0) 1000.0 + adj <- adjustmentNew 0.0 (-100.0) 100.0 0.25 10.0 0.0 + spinButtonConfigure spinLarge adj 0.0 2 + spnctl <- myAddSpinButton hbox2 "Decimal:" 0.0 10.0 + set spnctl [spinButtonValue := 2.0] hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 316 - widgetShowAll window + tsnap <- checkButtonNewWithLabel "Snap to 0.25-ticks" + boxPackStart vbox1 tsnap PackNatural 0 hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 319 - onValueSpinned spnctl $ do newdig <- get spnctl spinButtonValue - set spinLarge [spinButtonDigits := (round newdig)] + tnumr <- checkButtonNewWithLabel "Numeric only input mode" + boxPackStart vbox1 tnumr PackNatural 0 hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 322 - onToggled tsnap $ do st <- get tsnap toggleButtonActive - set spinLarge [spinButtonSnapToTicks := st] + twrap <- checkButtonNewWithLabel "Wraparound at limits" + boxPackStart vbox1 twrap PackNatural 0 hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 325 - onToggled tnumr $ do st <- get tnumr toggleButtonActive - set spinLarge [spinButtonNumeric := st] + widgetShowAll window hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 327 - onToggled twrap $ do st <- get twrap toggleButtonActive - set spinLarge [spinButtonWrap := st] + onValueSpinned spnctl $ do newdig <- get spnctl spinButtonValue + set spinLarge [spinButtonDigits := (round newdig)] hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 330 - onDestroy window mainQuit - mainGUI -- |
-
+ onToggled tsnap $ do st <- get tsnap toggleButtonActive + set spinLarge [spinButtonSnapToTicks := st] hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 333 -
| - - | + onToggled tnumr $ do st <- get tnumr toggleButtonActive + set spinLarge [spinButtonNumeric := st] hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 336 -- - | -|
|
- Text Entries and Status Bars - |
+ onDestroy window mainQuit
+ mainGUI
+
hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 343
-
- |
+
hunk ./docs/tutorial/Tutorial_Port/chap4-7.xhtml 349
-
- To be continued - |
-