Gtk2HsContentsIndex
Graphics.UI.Gtk.Gdk.DrawWindow
Portabilityportable (depends on GHC)
Stabilityprovisional
Maintainergtk2hs-users@lists.sourceforge.net
Contents
Class Hierarchy
Types
Methods
Description
A DrawWindow is a rectangular region on the screen.
Synopsis
data DrawWindow
class DrawableClass o => DrawWindowClass o
castToDrawWindow :: GObjectClass obj => obj -> DrawWindow
data WindowState
= WindowStateWithdrawn
| WindowStateIconified
| WindowStateMaximized
| WindowStateSticky
| WindowStateFullscreen
| WindowStateAbove
| WindowStateBelow
drawWindowGetState :: DrawWindowClass self => self -> IO [WindowState]
drawWindowClear :: DrawWindowClass self => self -> IO ()
drawWindowClearArea :: DrawWindowClass self => self -> Int -> Int -> Int -> Int -> IO ()
drawWindowClearAreaExpose :: DrawWindowClass self => self -> Int -> Int -> Int -> Int -> IO ()
drawWindowRaise :: DrawWindowClass self => self -> IO ()
drawWindowLower :: DrawWindowClass self => self -> IO ()
drawWindowBeginPaintRect :: DrawWindowClass self => self -> Rectangle -> IO ()
drawWindowBeginPaintRegion :: DrawWindowClass self => self -> Region -> IO ()
drawWindowEndPaint :: DrawWindowClass self => self -> IO ()
drawWindowInvalidateRect :: DrawWindowClass self => self -> Rectangle -> Bool -> IO ()
drawWindowInvalidateRegion :: DrawWindowClass self => self -> Region -> Bool -> IO ()
drawWindowGetUpdateArea :: DrawWindowClass self => self -> IO (Maybe Region)
drawWindowFreezeUpdates :: DrawWindowClass self => self -> IO ()
drawWindowThawUpdates :: DrawWindowClass self => self -> IO ()
drawWindowProcessUpdates :: DrawWindowClass self => self -> Bool -> IO ()
drawWindowSetAcceptFocus :: DrawWindowClass self => self -> Bool -> IO ()
drawWindowShapeCombineMask :: DrawWindowClass self => self -> Maybe Pixmap -> Int -> Int -> IO ()
drawWindowShapeCombineRegion :: DrawWindowClass self => self -> Maybe Region -> Int -> Int -> IO ()
drawWindowSetChildShapes :: DrawWindowClass self => self -> IO ()
drawWindowMergeChildShapes :: DrawWindowClass self => self -> IO ()
drawWindowGetPointer :: DrawWindowClass self => self -> IO (Maybe (Bool, Int, Int, [Modifier]))
drawWindowGetOrigin :: DrawWindow -> IO (Int, Int)
Class Hierarchy
 |  GObject
 |   +----Drawable
 |         +----DrawWindow
 
Types
data DrawWindow
show/hide Instances
class DrawableClass o => DrawWindowClass o
show/hide Instances
castToDrawWindow :: GObjectClass obj => obj -> DrawWindow
data WindowState
The state a DrawWindow is in.
Constructors
WindowStateWithdrawn
WindowStateIconified
WindowStateMaximized
WindowStateSticky
WindowStateFullscreen
WindowStateAbove
WindowStateBelow
show/hide Instances
Methods
drawWindowGetState
:: DrawWindowClass self
=> self
-> IO [WindowState]returns DrawWindow flags
Gets the bitwise OR of the currently active drawWindow state flags, from the WindowState enumeration.
drawWindowClear :: DrawWindowClass self => self -> IO ()
Clears an entire DrawWindow to the background color or background pixmap.
drawWindowClearArea
:: DrawWindowClass self
=> self
-> Intx - x coordinate of rectangle to clear
-> Inty - y coordinate of rectangle to clear
-> Intwidth - width of rectangle to clear
-> Intheight - height of rectangle to clear
-> IO ()
Clears an area of DrawWindow to the background color or background pixmap.
drawWindowClearAreaExpose
:: DrawWindowClass self
=> self
-> Intx - x coordinate of rectangle to clear
-> Inty - y coordinate of rectangle to clear
-> Intwidth - width of rectangle to clear
-> Intheight - height of rectangle to clear
-> IO ()
Like drawWindowClearArea, but also generates an expose event for the cleared area.
drawWindowRaise :: DrawWindowClass self => self -> IO ()

Raises DrawWindow to the top of the Z-order (stacking order), so that other drawWindows with the same parent drawWindow appear below DrawWindow. This is true whether or not the drawWindows are visible.

If DrawWindow is a toplevel, the drawWindow manager may choose to deny the request to move the drawWindow in the Z-order, drawWindowRaise only requests the restack, does not guarantee it.

drawWindowLower :: DrawWindowClass self => self -> IO ()

Lowers DrawWindow to the bottom of the Z-order (stacking order), so that other windows with the same parent window appear above DrawWindow. This is true whether or not the other windows are visible.

If DrawWindow is a toplevel, the window manager may choose to deny the request to move the drawWindow in the Z-order, drawWindowLower only requests the restack, does not guarantee it.

Note that a widget is raised automatically when it is mapped, thus you need to call drawWindowLower after widgetShow if the window should not appear above other windows.

drawWindowBeginPaintRect
:: DrawWindowClass self
=> self
-> Rectanglerectangle - rectangle you intend to draw to
-> IO ()

A convenience wrapper around drawWindowBeginPaintRegion which creates a rectangular region for you.

drawWindowBeginPaintRegion
:: DrawWindowClass self
=> self
-> Regionregion - region you intend to draw to
-> IO ()

Indicate that you are beginning the process of redrawing region.

  • A backing store (offscreen buffer) large enough to contain region will be created. The backing store will be initialized with the background color or background pixmap for DrawWindow. Then, all drawing operations performed on DrawWindow will be diverted to the backing store. When you call drawWindowEndPaint, the backing store will be copied to DrawWindow, making it visible onscreen. Only the part of DrawWindow contained in region will be modified; that is, drawing operations are clipped to region.

The net result of all this is to remove flicker, because the user sees the finished product appear all at once when you call drawWindowEndPaint. If you draw to DrawWindow directly without calling drawWindowBeginPaintRegion, the user may see flicker as individual drawing operations are performed in sequence. The clipping and background-initializing features of drawWindowBeginPaintRegion are conveniences for the programmer, so you can avoid doing that work yourself.

When using GTK+, the widget system automatically places calls to drawWindowBeginPaintRegion and drawWindowEndPaint around emissions of the expose_event signal. That is, if you're writing an expose event handler, you can assume that the exposed area in EventExpose has already been cleared to the window background, is already set as the clip region, and already has a backing store. Therefore in most cases, application code need not call drawWindowBeginPaintRegion. (You can disable the automatic calls around expose events on a widget-by-widget basis by calling widgetSetDoubleBuffered.)

If you call this function multiple times before calling the matching drawWindowEndPaint, the backing stores are pushed onto a stack. drawWindowEndPaint copies the topmost backing store onscreen, subtracts the topmost region from all other regions in the stack, and pops the stack. All drawing operations affect only the topmost backing store in the stack. One matching call to drawWindowEndPaint is required for each call to drawWindowBeginPaintRegion.

drawWindowEndPaint :: DrawWindowClass self => self -> IO ()

Signal that drawing has finished.

drawWindowInvalidateRect
:: DrawWindowClass self
=> self
-> Rectanglerect - rectangle to invalidate
-> BoolinvalidateChildren - whether to also invalidate child drawWindows
-> IO ()
A convenience wrapper around drawWindowInvalidateRegion which invalidates a rectangular region. See drawWindowInvalidateRegion for details.
drawWindowInvalidateRegion
:: DrawWindowClass self
=> self
-> Regionregion - a Region
-> BoolinvalidateChildren - True to also invalidate child drawWindows
-> IO ()

Adds region to the update area for DrawWindow. The update area is the region that needs to be redrawn, or "dirty region.". During the next idle period of the main look, an expose even for this region will be created. An application would normally redraw the contents of DrawWindow in response to those expose events.

The invalidateChildren parameter controls whether the region of each child drawWindow that intersects region will also be invalidated. If False, then the update area for child drawWindows will remain unaffected.

drawWindowGetUpdateArea
:: DrawWindowClass self
=> self
-> IO (Maybe Region)returns the update area for DrawWindow

Ask for the dirty region of this window.

  • Transfers ownership of the update area from DrawWindow to the caller of the function. That is, after calling this function, DrawWindow will no longer have an invalid/dirty region; the update area is removed from DrawWindow and handed to you. If a this window has no update area, drawWindowGetUpdateArea returns Nothing.
drawWindowFreezeUpdates :: DrawWindowClass self => self -> IO ()
Temporarily freezes a drawWindow such that it won't receive expose events. * The drawWindow will begin receiving expose events again when drawWindowThawUpdates is called. If drawWindowFreezeUpdates has been called more than once, drawWindowThawUpdates must be called an equal number of times to begin processing exposes.
drawWindowThawUpdates :: DrawWindowClass self => self -> IO ()
Thaws a drawWindow frozen with drawWindowFreezeUpdates.
drawWindowProcessUpdates
:: DrawWindowClass self
=> self
-> BoolupdateChildren - whether to also process updates for child drawWindows
-> IO ()

Sends one or more expose events to DrawWindow.

  • The areas in each expose event will cover the entire update area for the window (see drawWindowInvalidateRegion for details). Normally Gtk calls drawWindowProcessUpdates on your behalf, so there's no need to call this function unless you want to force expose events to be delivered immediately and synchronously (vs. the usual case, where Gtk delivers them in an idle handler). Occasionally this is useful to produce nicer scrolling behavior, for example.
drawWindowSetAcceptFocus
:: DrawWindowClass self
=> self
-> BoolacceptFocus - True if the drawWindow should receive input focus
-> IO ()

Setting acceptFocus to False hints the desktop environment that the window doesn't want to receive input focus.

On X, it is the responsibility of the drawWindow manager to interpret this hint. ICCCM-compliant drawWindow manager usually respect it.

  • Available since Gdk version 2.4
drawWindowShapeCombineMask
:: DrawWindowClass self
=> self
-> Maybe Pixmapmask - region of drawWindow to be non-transparent
-> IntoffsetX - X position of shapeRegion in DrawWindow coordinates
-> IntoffsetY - Y position of shapeRegion in DrawWindow coordinates
-> IO ()

Applies a shape mask to window. Pixels in window corresponding to set bits in the mask will be visible; pixels in window corresponding to unset bits in the mask will be transparent. This gives a non-rectangular window.

  • If mask is Nothing, the shape mask will be unset, and the x/y parameters are not used. The mask must be a bitmap, that is, a Pixmap of depth one.
  • On the X11 platform, this uses an X server extension which is widely available on most common platforms, but not available on very old X servers, and occasionally the implementation will be buggy. On servers without the shape extension, this function will do nothing. On the Win32 platform the functionality is always present.
  • This function works on both toplevel and child windows.
drawWindowShapeCombineRegion
:: DrawWindowClass self
=> self
-> Maybe RegionshapeRegion - region of drawWindow to be non-transparent
-> IntoffsetX - X position of shapeRegion in DrawWindow coordinates
-> IntoffsetY - Y position of shapeRegion in DrawWindow coordinates
-> IO ()

Makes pixels in DrawWindow outside shapeRegion transparent.

  • Makes pixels in DrawWindow outside shapeRegion transparent, so that the window may be nonrectangular.

If shapeRegion is Nothing, the shape will be unset, so the whole DrawWindow will be opaque again. The parameters offsetX and offsetY are ignored if shapeRegion is Nothing.

On the X11 platform, this uses an X server extension which is widely available on most common platforms, but not available on very old X servers, and occasionally the implementation will be buggy. On servers without the shape extension, this function will do nothing.

This function works on both toplevel and child drawWindows.

drawWindowSetChildShapes :: DrawWindowClass self => self -> IO ()
Sets the shape mask of DrawWindow to the union of shape masks for all children of DrawWindow, ignoring the shape mask of DrawWindow itself. Contrast with drawWindowMergeChildShapes which includes the shape mask of DrawWindow in the masks to be merged.
drawWindowMergeChildShapes :: DrawWindowClass self => self -> IO ()

Merges the shape masks for any child drawWindows into the shape mask for DrawWindow. i.e. the union of all masks for DrawWindow and its children will become the new mask for DrawWindow. See drawWindowShapeCombineMask.

This function is distinct from drawWindowSetChildShapes because it includes DrawWindow's shape mask in the set of shapes to be merged.

drawWindowGetPointer :: DrawWindowClass self => self -> IO (Maybe (Bool, Int, Int, [Modifier]))

Obtains the current pointer position and modifier state.

  • The position is given in coordinates relative to the given window.
  • The return value is Just (same, x, y, mod) where same is True if the passed in window is the window over which the mouse currently resides.
  • The return value is Nothing if the mouse cursor is over a different application.
drawWindowGetOrigin
:: DrawWindow
-> IO (Int, Int)
(x, y)

Obtains the position of a window in screen coordinates.

You can use this to help convert a position between screen coordinates and local DrawWindow relative coordinates.

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