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Graphics.UI.Gtk.Pango.Context

Portability | portable (depends on GHC)
Stability | provisional
Maintainer | gtk2hs-users@lists.sourceforge.net

Contents

Types and Methods for `PangoContext`s

Description

This module defines `PangoContext`s, an environment that provides information on available fonts, internationalization and output capabilities of the medium. Given such a context, text can be rendered into strings of glyphs (see Graphics.UI.Gtk.Pango.Rendering) or, at a more abstract level, using layouts (see Graphics.UI.Gtk.Pango.Layout).

- A `PangoContext` is a prerequisite for all text rendering functions. A context can be created from scratch or, more conveniently, by using default settings that are already used in the application. When text is rendered through Gdk, use Graphics.UI.Gtk.Abstract.Widget.widgetCreatePangoContext, if you use the Cairo rendering engine, a new context can be acquired using Graphics.UI.Gtk.Cairo.cairoCreateContext.
- The properties of a `PangoContext` can be changed which, in turn, has an effect on how text is rendered. To reflect such a change in the rendered text, call Graphics.UI.Gtk.Pango.Layout.layoutContextChanged.

Synopsis

data PangoContext
contextListFamilies :: PangoContext -> IO [FontFamily]
contextGetMetrics :: PangoContext -> FontDescription -> Language -> IO FontMetrics
contextSetFontDescription :: PangoContext -> FontDescription -> IO ()
contextGetFontDescription :: PangoContext -> IO FontDescription
data Language
emptyLanguage
languageFromString :: String -> IO Language
contextSetLanguage :: PangoContext -> Language -> IO ()
contextGetLanguage :: PangoContext -> IO Language
contextSetTextDir :: PangoContext -> PangoDirection -> IO ()
contextGetTextDir :: PangoContext -> IO PangoDirection
contextSetTextGravity :: PangoContext -> PangoGravity -> IO ()
contextGetTextGravity :: PangoContext -> IO PangoGravity
contextSetTextGravityHint :: PangoContext -> PangoGravityHint -> IO ()
contextGetTextGravityHint :: PangoContext -> IO PangoGravityHint
contextGetMatrix :: PangoContext -> IO Matrix
contextSetMatrix :: PangoContext -> Matrix -> IO ()

Types and Methods for `PangoContext`s
data PangoContext

Instances

GObjectClass PangoContext
PangoContextClass PangoContext

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
Query the metrics of the given font implied by the font description.
contextSetFontDescription :: PangoContext -> FontDescription -> IO ()
Set the default `FontDescription` of this context.
contextGetFontDescription :: PangoContext -> IO FontDescription
Get the current `FontDescription` of this context.
data Language

An RFC-3066 language designator to choose scripts.
Instances

Eq Language
Show Language

emptyLanguage
languageFromString :: String -> IO Language

Specifying no particular language.

Take a RFC-3066 format language tag as a string and convert it to a `Language` type that can be efficiently passed around and compared with other language tags.

- This function first canonicalizes the string by converting it to lowercase, mapping '_' to '-', and stripping all characters other than letters and '-'.

contextSetLanguage :: PangoContext -> Language -> IO ()
Set the default `Language` of this context.
contextGetLanguage :: PangoContext -> IO Language
Get the current `Language` of this context.
contextSetTextDir :: PangoContext -> PangoDirection -> IO ()
Set the default text direction of this context.
contextGetTextDir :: PangoContext -> IO PangoDirection
Get the current text direction of this context.
contextSetTextGravity :: PangoContext -> PangoGravity -> IO ()
Set the text gravity of this context. If the given value is `PangoGravityAuto` then the gravity is derived from the current rotation matrix.
contextGetTextGravity :: PangoContext -> IO PangoGravity
Get the current text gravity of this context.
contextSetTextGravityHint :: PangoContext -> PangoGravityHint -> IO ()
Set the text gravity hint of this context.
contextGetTextGravityHint :: PangoContext -> IO PangoGravityHint
Get the current text gravity of this context.
contextGetMatrix :: PangoContext -> IO Matrix

Gets the transformation matrix that will be applied when rendering with this context.

- Since Pango 1.6

contextSetMatrix :: PangoContext -> Matrix -> IO ()

Sets the transformation matrix that will be applied when rendering with this context. Note that any metrics reported by other functions are in user space coordinates before the application of the matrix, not device-space coordinates after the application of the matrix. So, they don't scale with the matrix, though they may change slightly for different matrices, depending on how the text is fit to the pixel grid.

- Since Pango 1.6

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