Gtk2HsContentsIndex
Graphics.UI.Gtk.Pango.Rendering
Portabilityportable (depends on GHC)
Stabilityprovisional
Maintainergtk2hs-users@lists.sourceforge.net
Description

Functions to run the rendering pipeline.

  • The Pango rendering pipeline takes a string of Unicode characters and converts it into glyphs. The functions described in this module accomplish various steps of this process.
Synopsis
data PangoContext
contextListFamilies :: PangoContext -> IO [FontFamily]
contextGetMetrics :: PangoContext -> FontDescription -> Language -> IO FontMetrics
data FontMetrics = FontMetrics {
ascent :: Rational
descent :: Rational
approximateCharWidth :: Rational
approximateDigitWidth :: Rational
}
contextSetFontDescription :: PangoContext -> FontDescription -> IO ()
contextGetFontDescription :: PangoContext -> IO FontDescription
contextSetLanguage :: PangoContext -> Language -> IO ()
contextGetLanguage :: PangoContext -> IO Language
contextSetTextDir :: PangoContext -> TextDirection -> IO ()
contextGetTextDir :: PangoContext -> IO TextDirection
data TextDirection
= TextDirNone
| TextDirLtr
| TextDirRtl
Documentation
data PangoContext
show/hide Instances
contextListFamilies :: PangoContext -> IO [FontFamily]

Retrieve a list of all available font families.

  • A font family is the name of the font without further attributes like slant, variant or size.
contextGetMetrics :: PangoContext -> FontDescription -> Language -> IO FontMetrics

Load a font.

contextLoadFont :: PangoContext -> FontDescription -> Language -> IO (Maybe Font) contextLoadFont pc fd l = do fsPtr <- {} pc fd l if fsPtr==nullPtr then return Nothing else liftM Just $ makeNewGObject mkFont (return fsPtr)

Load a font set.

contextLoadFontSet :: PangoContext -> FontDescription -> Language -> IO (Maybe FontSet) contextLoadFontSet pc fd l = do fsPtr <- {} pc fd l if fsPtr==nullPtr then return Nothing else liftM Just $ makeNewGObject mkFontSet (return fsPtr)

Query the metrics of the given font implied by the font description.

data FontMetrics

The characteristic measurements of a font.

  • All values are measured in pixels.
Constructors
FontMetrics
ascent :: RationalThe ascent is the distance from the baseline to the logical top of a line of text. (The logical top may be above or below the top of the actual drawn ink. It is necessary to lay out the text to figure where the ink will be.)
descent :: RationalThe descent is the distance from the baseline to the logical bottom of a line of text. (The logical bottom may be above or below the bottom of the actual drawn ink. It is necessary to lay out the text to figure where the ink will be.)
approximateCharWidth :: RationalThe approximate character width. This is merely a representative value useful, for example, for determining the initial size for a window. Actual characters in text will be wider and narrower than this.
approximateDigitWidth :: RationalThe approximate digit widt. This is merely a representative value useful, for example, for determining the initial size for a window. Actual digits in text can be wider and narrower than this, though this value is generally somewhat more accurate than approximateCharWidth.
contextSetFontDescription :: PangoContext -> FontDescription -> IO ()
Set the default FontDescription of this context.
contextGetFontDescription :: PangoContext -> IO FontDescription
Get the current FontDescription of this context.
contextSetLanguage :: PangoContext -> Language -> IO ()
Set the default Language of this context.
contextGetLanguage :: PangoContext -> IO Language
Get the current Language of this context.
contextSetTextDir :: PangoContext -> TextDirection -> IO ()
Set the default text direction of this context.
contextGetTextDir :: PangoContext -> IO TextDirection
Get the current text direction of this context.
data TextDirection
Is the text written from left to right or the awkward way?
Constructors
TextDirNone
TextDirLtr
TextDirRtl
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