Class Renderer

java.lang.Object

org.javagi.base.ProxyInstance

org.gnome.gobject.TypeInstance

org.gnome.gobject.GObject

org.gnome.pango.Renderer

All Implemented Interfaces:

Proxy

Direct Known Subclasses:

Renderer.Renderer$Impl

@Generated("org.javagi.JavaGI")
public abstract class Renderer
extends GObject

PangoRenderer is a base class for objects that can render text provided as PangoGlyphString or PangoLayout.

By subclassing PangoRenderer and overriding operations such as drawGlyphs and drawRectangle, renderers for particular font backends and destinations can be created.

Since:

1.8

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Renderer.Builder<B extends Renderer.Builder<B>>	Inner class implementing a builder pattern to construct a GObject with properties.
static class	Renderer.Renderer$Impl	The Renderer$Impl type represents a native instance of the abstract Renderer class.
static class	Renderer.RendererClass	Class structure for PangoRenderer.

Nested classes/interfaces inherited from class GObject

GObject.NotifyCallback, GObject.ObjectClass

Constructor Summary

Constructors

Constructor	Description
Renderer()	Create a new Renderer.
Renderer(MemorySegment address)	Create a Renderer instance for the provided memory address.

Method Summary

Modifier and Type	Method	Description
void	activate()	Does initial setup before rendering operations on renderer.
protected Renderer	asParent()	Return this instance as if it were its parent type.
protected void	begin()	Do renderer-specific initialization before drawing
void	deactivate()	Cleans up after rendering operations on renderer.
void	drawErrorUnderline(int x, int y, int width, int height)	Draw a squiggly line that approximately covers the given rectangle in the style of an underline used to indicate a spelling error.
void	drawGlyph(Font font, Glyph glyph, double x, double y)	Draws a single glyph with coordinates in device space.
void	drawGlyphItem(@Nullable String text, GlyphItem glyphItem, int x, int y)	Draws the glyphs in glyphItem with the specified PangoRenderer, embedding the text associated with the glyphs in the output if the output format supports it.
void	drawGlyphs(Font font, GlyphString glyphs, int x, int y)	Draws the glyphs in glyphs with the specified PangoRenderer.
void	drawLayout(Layout layout, int x, int y)	Draws layout with the specified PangoRenderer.
void	drawLayoutLine(LayoutLine line, int x, int y)	Draws line with the specified PangoRenderer.
void	drawRectangle(RenderPart part, int x, int y, int width, int height)	Draws an axis-aligned rectangle in user space coordinates with the specified PangoRenderer.
protected void	drawShape(AttrShape attr, int x, int y)	draw content for a glyph shaped with PangoAttrShape x, y are the coordinates of the left edge of the baseline, in user coordinates.
void	drawTrapezoid(RenderPart part, double y1, double x11, double x21, double y2, double x12, double x22)	Draws a trapezoid with the parallel sides aligned with the X axis using the given PangoRenderer; coordinates are in device space.
protected void	end()	Do renderer-specific cleanup after drawing
short	getAlpha(RenderPart part)	Gets the current alpha for the specified part.
@Nullable Color	getColor(RenderPart part)	Gets the current rendering color for the specified part.
@Nullable Layout	getLayout()	Gets the layout currently being rendered using renderer.
@Nullable LayoutLine	getLayoutLine()	Gets the layout line currently being rendered using renderer.
@Nullable Matrix	getMatrix()	Gets the transformation matrix that will be applied when rendering.
static MemoryLayout	getMemoryLayout()	The memory layout of the native struct.
static @Nullable Type	getType()	Get the GType of the Renderer class.
void	partChanged(RenderPart part)	Informs Pango that the way that the rendering is done for part has changed.
protected void	prepareRun(LayoutRun run)	updates the renderer for a new run
void	setAlpha(RenderPart part, short alpha)	Sets the alpha for part of the rendering.
void	setColor(RenderPart part, @Nullable Color color)	Sets the color for part of the rendering.
void	setMatrix(@Nullable Matrix matrix)	Sets the transformation matrix that will be applied when rendering.

Methods inherited from class GObject

addToggleRef, addWeakPointer, bindProperty, bindProperty, bindProperty, bindPropertyFull, bindPropertyFull, bindPropertyWithClosures, bindPropertyWithClosures, builder, compatControl, connect, connect, connect, constructed, disconnect, dispatchPropertiesChanged, dispose, dupData, dupQdata, emit, emitNotify, finalize_, forceFloating, freezeNotify, get, getData, getProperty, getProperty, getProperty, getQdata, getv, interfaceFindProperty, interfaceInstallProperty, interfaceListProperties, isFloating, newInstance, newInstance, newv, notify, notify, notifyByPspec, onNotify, ref, refSink, removeToggleRef, removeWeakPointer, replaceData, replaceQdata, runDispose, set, setData, setDataFull, setProperty, setProperty, setProperty, setQdata, setQdataFull, setv, stealData, stealQdata, takeRef, thawNotify, unref, watchClosure, weakRef, weakUnref, withProperties

Methods inherited from class TypeInstance

callParent, callParent, cast, getPrivate, readGClass, writeGClass

Methods inherited from class ProxyInstance

equals, handle, hashCode

Methods inherited from class Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Renderer

public Renderer(MemorySegment address)

Create a Renderer instance for the provided memory address.

Parameters:

address - the memory address of the native object

Renderer

public Renderer()

Create a new Renderer.

Method Details

getType

public static @Nullable Type getType()

Get the GType of the Renderer class.

Returns:

the GType

getMemoryLayout

public static MemoryLayout getMemoryLayout()

The memory layout of the native struct.

Returns:

the memory layout

asParent

protected Renderer asParent()

Return this instance as if it were its parent type. Comparable to the Java super keyword, but ensures the parent typeclass is also used in native code.

Overrides:

asParent in class GObject

Returns:

the instance as if it were its parent type

activate

public void activate()

Does initial setup before rendering operations on renderer.

deactivate() should be called when done drawing. Calls such as drawLayout(Layout, int, int) automatically activate the layout before drawing on it.

Calls to activate() and deactivate() can be nested and the renderer will only be initialized and deinitialized once.

Since:

1.8

deactivate

public void deactivate()

Cleans up after rendering operations on renderer.

See docs for activate().

Since:

1.8

drawErrorUnderline

public void drawErrorUnderline(int x,
 int y,
 int width,
 int height)

Draw a squiggly line that approximately covers the given rectangle in the style of an underline used to indicate a spelling error.

The width of the underline is rounded to an integer number of up/down segments and the resulting rectangle is centered in the original rectangle.

This should be called while this Renderer is already active. Use activate() to activate a renderer.

Parameters:

x - X coordinate of underline, in Pango units in user coordinate system

y - Y coordinate of underline, in Pango units in user coordinate system

width - width of underline, in Pango units in user coordinate system

height - height of underline, in Pango units in user coordinate system

Since:

1.8

drawGlyph

public void drawGlyph(Font font,
 Glyph glyph,
 double x,
 double y)

Draws a single glyph with coordinates in device space.

Parameters:

font - a PangoFont

glyph - the glyph index of a single glyph

x - X coordinate of left edge of baseline of glyph

y - Y coordinate of left edge of baseline of glyph

Since:

1.8

drawGlyphItem

public void drawGlyphItem(@Nullable String text,
 GlyphItem glyphItem,
 int x,
 int y)

Draws the glyphs in glyphItem with the specified PangoRenderer, embedding the text associated with the glyphs in the output if the output format supports it.

This is useful for rendering text in PDF.

Note that this method does not handle attributes in glyphItem. If you want colors, shapes and lines handled automatically according to those attributes, you need to use pango_renderer_draw_layout_line() or pango_renderer_draw_layout().

Note that text is the start of the text for layout, which is then indexed by glyph_item->item->offset.

If text is null, this simply calls drawGlyphs(Font, GlyphString, int, int).

The default implementation of this method simply falls back to drawGlyphs(Font, GlyphString, int, int).

Parameters:

text - the UTF-8 text that glyphItem refers to

glyphItem - a PangoGlyphItem

x - X position of left edge of baseline, in user space coordinates in Pango units

y - Y position of left edge of baseline, in user space coordinates in Pango units

Since:

1.22

drawGlyphs

public void drawGlyphs(Font font,
 GlyphString glyphs,
 int x,
 int y)

Draws the glyphs in glyphs with the specified PangoRenderer.

Parameters:

font - a PangoFont

glyphs - a PangoGlyphString

x - X position of left edge of baseline, in user space coordinates in Pango units.

y - Y position of left edge of baseline, in user space coordinates in Pango units.

Since:

1.8

drawLayout

public void drawLayout(Layout layout,
 int x,
 int y)

Draws layout with the specified PangoRenderer.

This is equivalent to drawing the lines of the layout, at their respective positions relative to x, y.

Parameters:

layout - a PangoLayout

x - X position of left edge of baseline, in user space coordinates in Pango units.

y - Y position of left edge of baseline, in user space coordinates in Pango units.

Since:

1.8

drawLayoutLine

public void drawLayoutLine(LayoutLine line,
 int x,
 int y)

Draws line with the specified PangoRenderer.

This draws the glyph items that make up the line, as well as shapes, backgrounds and lines that are specified by the attributes of those items.

Parameters:

line - a PangoLayoutLine

x - X position of left edge of baseline, in user space coordinates in Pango units.

y - Y position of left edge of baseline, in user space coordinates in Pango units.

Since:

1.8

drawRectangle

public void drawRectangle(RenderPart part,
 int x,
 int y,
 int width,
 int height)

Draws an axis-aligned rectangle in user space coordinates with the specified PangoRenderer.

This should be called while this Renderer is already active. Use activate() to activate a renderer.

Parameters:

part - type of object this rectangle is part of

x - X position at which to draw rectangle, in user space coordinates in Pango units

y - Y position at which to draw rectangle, in user space coordinates in Pango units

width - width of rectangle in Pango units

height - height of rectangle in Pango units

Since:

1.8

drawTrapezoid

public void drawTrapezoid(RenderPart part,
 double y1,
 double x11,
 double x21,
 double y2,
 double x12,
 double x22)

Draws a trapezoid with the parallel sides aligned with the X axis using the given PangoRenderer; coordinates are in device space.

Parameters:

part - type of object this trapezoid is part of

y1 - Y coordinate of top of trapezoid

x11 - X coordinate of left end of top of trapezoid

x21 - X coordinate of right end of top of trapezoid

y2 - Y coordinate of bottom of trapezoid

x12 - X coordinate of left end of bottom of trapezoid

x22 - X coordinate of right end of bottom of trapezoid

Since:

1.8

getAlpha

public short getAlpha(RenderPart part)

Gets the current alpha for the specified part.

Parameters:

part - the part to get the alpha for

Returns:

the alpha for the specified part, or 0 if it hasn't been set and should be inherited from the environment.

Since:

1.38

getColor

public @Nullable Color getColor(RenderPart part)

Gets the current rendering color for the specified part.

Parameters:

part - the part to get the color for

Returns:

the color for the specified part, or null if it hasn't been set and should be inherited from the environment.

Since:

1.8

getLayout

public @Nullable Layout getLayout()

Gets the layout currently being rendered using renderer.

Calling this function only makes sense from inside a subclass's methods, like in its draw_shape vfunc, for example.

The returned layout should not be modified while still being rendered.

Returns:

the layout, or null if no layout is being rendered using this Renderer at this time.

Since:

1.20

getLayoutLine

public @Nullable LayoutLine getLayoutLine()

Gets the layout line currently being rendered using renderer.

Calling this function only makes sense from inside a subclass's methods, like in its draw_shape vfunc, for example.

The returned layout line should not be modified while still being rendered.

Returns:

the layout line, or null if no layout line is being rendered using this Renderer at this time.

Since:

1.20

getMatrix

public @Nullable Matrix getMatrix()

Gets the transformation matrix that will be applied when rendering.

See setMatrix(Matrix).

Returns:

the matrix, or null if no matrix has been set (which is the same as the identity matrix). The returned matrix is owned by Pango and must not be modified or freed.

Since:

1.8

partChanged

public void partChanged(RenderPart part)

Informs Pango that the way that the rendering is done for part has changed.

This should be called if the rendering changes in a way that would prevent multiple pieces being joined together into one drawing call. For instance, if a subclass of PangoRenderer was to add a stipple option for drawing underlines, it needs to call

pango_renderer_part_changed (render, PANGO_RENDER_PART_UNDERLINE);

When the stipple changes or underlines with different stipples might be joined together. Pango automatically calls this for changes to colors. (See setColor(RenderPart, Color))

Parameters:

part - the part for which rendering has changed.

Since:

1.8

setAlpha

public void setAlpha(RenderPart part,
 short alpha)

Sets the alpha for part of the rendering.

Note that the alpha may only be used if a color is specified for part as well.

Parameters:

part - the part to set the alpha for

alpha - an alpha value between 1 and 65536, or 0 to unset the alpha

Since:

1.38

setColor

public void setColor(RenderPart part,
 @Nullable Color color)

Sets the color for part of the rendering.

Also see setAlpha(RenderPart, short).

Parameters:

part - the part to change the color of

color - the new color or null to unset the current color

Since:

1.8

setMatrix

public void setMatrix(@Nullable Matrix matrix)

Sets the transformation matrix that will be applied when rendering.

Parameters:

matrix - a PangoMatrix, or null to unset any existing matrix (No matrix set is the same as setting the identity matrix.)

Since:

1.8

begin

protected void begin()

Do renderer-specific initialization before drawing

drawShape

protected void drawShape(AttrShape attr,
 int x,
 int y)

draw content for a glyph shaped with PangoAttrShape x, y are the coordinates of the left edge of the baseline, in user coordinates.

end

protected void end()

Do renderer-specific cleanup after drawing

prepareRun

protected void prepareRun(LayoutRun run)

updates the renderer for a new run