PangoRenderer

typedef struct {
  PangoMatrix *matrix;		/* May be NULL */
} PangoRenderer;

PangoRenderer is a base class for objects that are used to render Pango objects such as PangoGlyphString and PangoLayout.

Since 1.8

enum PangoRenderPart

typedef enum
{
  PANGO_RENDER_PART_FOREGROUND,
  PANGO_RENDER_PART_BACKGROUND,
  PANGO_RENDER_PART_UNDERLINE,
  PANGO_RENDER_PART_STRIKETHROUGH
} PangoRenderPart;

PangoRenderPart defines different items to render for such purposes as setting colors.

Since 1.8

PANGO_TYPE_RENDER_PART

#define PANGO_TYPE_RENDER_PART (pango_render_part_get_type())

The GObject type for PangoRenderPart.

PangoRendererClass

typedef struct {
  /* All of the following have default implementations
   * and take as coordinates user coordinates in Pango units
   */
  void (*draw_glyphs) (PangoRenderer     *renderer,
		       PangoFont         *font,
		       PangoGlyphString  *glyphs,
		       int                x,
		       int                y);
  void (*draw_rectangle) (PangoRenderer     *renderer,
			  PangoRenderPart    part,
			  int                x,
			  int                y,
			  int                width,
			  int                height);
  void (*draw_error_underline) (PangoRenderer     *renderer,
				int                x,
				int                y,
				int                width,
				int                height);

  /* Nothing is drawn for shaped glyphs unless this is implemented */
  void (*draw_shape) (PangoRenderer  *renderer,
		      PangoAttrShape *attr,
		      int             x,
		      int             y);

  /* These two must be implemented and take coordinates in
   * device space as doubles.
   */
  void (*draw_trapezoid) (PangoRenderer  *renderer,
			  PangoRenderPart part,
			  double          y1_,
			  double          x11,
			  double          x21,
			  double          y2,
			  double          x12,
			  double          x22);
  void (*draw_glyph) (PangoRenderer *renderer,
		      PangoFont     *font,
		      PangoGlyph     glyph,
		      double         x,
		      double         y);

  /* Notification of change in rendering attributes
   */
  void (*part_changed) (PangoRenderer   *renderer,
			PangoRenderPart  part);

  /* Paired around drawing operations
   */
  void (*begin) (PangoRenderer *renderer);
  void (*end)   (PangoRenderer *renderer);

  /* Hooks into the details of layout rendering
   */
  void (*prepare_run) (PangoRenderer  *renderer,
		       PangoLayoutRun *run);

  /* All of the following have default implementations
   * and take as coordinates user coordinates in Pango units
   */
  void (*draw_glyph_item) (PangoRenderer     *renderer,
			   const char        *text,
			   PangoGlyphItem    *glyph_item,
			   int                x,
			   int                y);
} PangoRendererClass;

Class structure for PangoRenderer.

Since 1.8

pango_renderer_draw_layout ()

void                pango_renderer_draw_layout          (PangoRenderer *renderer,
                                                         PangoLayout *layout,
                                                         int x,
                                                         int y);

Draws layout with the specified PangoRenderer.

Since 1.8

pango_renderer_draw_layout_line ()

void                pango_renderer_draw_layout_line     (PangoRenderer *renderer,
                                                         PangoLayoutLine *line,
                                                         int x,
                                                         int y);

Draws line with the specified PangoRenderer.

Since 1.8

pango_renderer_draw_glyphs ()

void                pango_renderer_draw_glyphs          (PangoRenderer *renderer,
                                                         PangoFont *font,
                                                         PangoGlyphString *glyphs,
                                                         int x,
                                                         int y);

Draws the glyphs in glyphs with the specified PangoRenderer.

Since 1.8

pango_renderer_draw_glyph_item ()

void                pango_renderer_draw_glyph_item      (PangoRenderer *renderer,
                                                         const char *text,
                                                         PangoGlyphItem *glyph_item,
                                                         int x,
                                                         int y);

Draws the glyphs in glyph_item with the specified PangoRenderer, embedding the text associated with the glyphs in the output if the output format supports it (PDF for example).

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

The default implementation of this method simply falls back to pango_renderer_draw_glyphs().

Since 1.22

pango_renderer_draw_rectangle ()

void                pango_renderer_draw_rectangle       (PangoRenderer *renderer,
                                                         PangoRenderPart 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 renderer is already active. Use pango_renderer_activate() to activate a renderer.

Since 1.8

pango_renderer_draw_error_underline ()

void                pango_renderer_draw_error_underline (PangoRenderer *renderer,
                                                         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 renderer is already active. Use pango_renderer_activate() to activate a renderer.

Since 1.8

pango_renderer_draw_trapezoid ()

void                pango_renderer_draw_trapezoid       (PangoRenderer *renderer,
                                                         PangoRenderPart 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.

Since 1.8

pango_renderer_draw_glyph ()

void                pango_renderer_draw_glyph           (PangoRenderer *renderer,
                                                         PangoFont *font,
                                                         PangoGlyph glyph,
                                                         double x,
                                                         double y);

Draws a single glyph with coordinates in device space.

Since 1.8

pango_renderer_activate ()

void                pango_renderer_activate             (PangoRenderer *renderer);

Does initial setup before rendering operations on renderer. pango_renderer_deactivate() should be called when done drawing. Calls such as pango_renderer_draw_layout() automatically activate the layout before drawing on it. Calls to pango_renderer_activate() and pango_renderer_deactivate() can be nested and the renderer will only be initialized and deinitialized once.

Since 1.8

pango_renderer_deactivate ()

void                pango_renderer_deactivate           (PangoRenderer *renderer);

Cleans up after rendering operations on renderer. See docs for pango_renderer_activate().

Since 1.8

pango_renderer_part_changed ()

void                pango_renderer_part_changed         (PangoRenderer *renderer,
                                                         PangoRenderPart part);

Informs Pango that the way that the rendering is done for part has changed 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 pango_renderer_set_color())

Since 1.8

pango_renderer_set_color ()

void                pango_renderer_set_color            (PangoRenderer *renderer,
                                                         PangoRenderPart part,
                                                         const PangoColor *color);

Sets the color for part of the rendering.

Since 1.8

pango_renderer_get_color ()

PangoColor*         pango_renderer_get_color            (PangoRenderer *renderer,
                                                         PangoRenderPart part);

Gets the current rendering color for the specified part.

Since 1.8

pango_renderer_set_matrix ()

void                pango_renderer_set_matrix           (PangoRenderer *renderer,
                                                         const PangoMatrix *matrix);

Sets the transformation matrix that will be applied when rendering.

Since 1.8

pango_renderer_get_matrix ()

const PangoMatrix*  pango_renderer_get_matrix           (PangoRenderer *renderer);

Gets the transformation matrix that will be applied when rendering. See pango_renderer_set_matrix().

Since 1.8

pango_renderer_get_layout ()

PangoLayout*        pango_renderer_get_layout           (PangoRenderer *renderer);

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() for example.

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

Since 1.20

pango_renderer_get_layout_line ()

PangoLayoutLine*    pango_renderer_get_layout_line      (PangoRenderer *renderer);

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() for example.

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

Since 1.20