/* Pango
 * pango-renderer.h: Base class for rendering
 *
 * Copyright (C) 2004, Red Hat, Inc.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */
#ifndef __PANGO_RENDERER_H_
#define __PANGO_RENDERER_H_

#include <pango/pango-layout.h>

G_BEGIN_DECLS

#define PANGO_TYPE_RENDERER            (pango_renderer_get_type())
#define PANGO_RENDERER(object)         (G_TYPE_CHECK_INSTANCE_CAST ((object), PANGO_TYPE_RENDERER, PangoRenderer))
#define PANGO_IS_RENDERER(object)      (G_TYPE_CHECK_INSTANCE_TYPE ((object), PANGO_TYPE_RENDERER))
#define PANGO_RENDERER_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), PANGO_TYPE_RENDERER, PangoRendererClass))
#define PANGO_IS_RENDERER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), PANGO_TYPE_RENDERER))
#define PANGO_RENDERER_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), PANGO_TYPE_RENDERER, PangoRendererClass))

typedef struct _PangoRenderer        PangoRenderer;
typedef struct _PangoRendererClass   PangoRendererClass;
typedef struct _PangoRendererPrivate PangoRendererPrivate;

/**
 * PangoRenderPart:
 * @PANGO_RENDER_PART_FOREGROUND: the text itself
 * @PANGO_RENDER_PART_BACKGROUND: the area behind the text
 * @PANGO_RENDER_PART_UNDERLINE: underlines
 * @PANGO_RENDER_PART_STRIKETHROUGH: strikethrough lines
 *
 * #PangoRenderPart defines different items to render for such
 * purposes as setting colors.
 *
 * Since: 1.8
 **/
/* When extending, note N_RENDER_PARTS #define in pango-renderer.c */
typedef enum
{
  PANGO_RENDER_PART_FOREGROUND,
  PANGO_RENDER_PART_BACKGROUND,
  PANGO_RENDER_PART_UNDERLINE,
  PANGO_RENDER_PART_STRIKETHROUGH
} PangoRenderPart;

/**
 * PangoRenderer:
 * @matrix: the current transformation matrix for the Renderer; may
 *    be %NULL, which should be treated the same as the identity matrix.
 *
 * #PangoRenderer is a base class for objects that are used to
 * render Pango objects such as #PangoGlyphString and
 * #PangoLayout.
 *
 * Since: 1.8
 **/
struct _PangoRenderer
{
  /*< private >*/
  GObject parent_instance;

  PangoUnderline underline;
  gboolean strikethrough;
  int active_count;
  
  /*< public >*/
  PangoMatrix *matrix;		/* May be NULL */
  
  /*< private >*/
  PangoRendererPrivate *priv;
};

/**
 * PangoRendererClass:
 * @draw_glyphs: draws a #PangoGlyphString
 * @draw_rectangle: draws a rectangle
 * @draw_error_underline: draws a squiggly line that approximately
 * covers the given rectangle in the style of an underline used to
 * indicate a spelling error. 
 * @draw_shape: draw content for a glyph shaped with #PangoAttrShape.
 *   @x, @y are the coordinates of the left edge of the baseline,
 *   in user coordinates.
 * @draw_trapezoid: draws a trapezoidal filled area
 * @draw_glyph: draws a single glyph
 * @part_changed: do renderer specific processing when rendering
 *  attributes change
 * @begin: Do renderer-specific initialization before drawing
 * @end: Do renderer-specific cleanup after drawing
 * @prepare_run: updates the renderer for a new run
 *
 * Class structure for #PangoRenderer.
 *
 * Since: 1.8
 **/
struct _PangoRendererClass
{
  /*< private >*/
  GObjectClass parent_class;

  /* vtable - not signals */
  /*< public >*/

  /* 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);

  /*< private >*/
  
  /* Padding for future expansion */
  void (*_pango_reserved1) (void);
  void (*_pango_reserved2) (void);
  void (*_pango_reserved3) (void);
  void (*_pango_reserved4) (void);
};

GType pango_renderer_get_type    (void);

void pango_renderer_draw_layout          (PangoRenderer    *renderer,
					  PangoLayout      *layout,
					  int               x,
					  int               y);
void pango_renderer_draw_layout_line     (PangoRenderer    *renderer,
					  PangoLayoutLine  *line,
					  int               x,
					  int               y);
void pango_renderer_draw_glyphs          (PangoRenderer    *renderer,
					  PangoFont        *font,
					  PangoGlyphString *glyphs,
					  int               x,
					  int               y);
void pango_renderer_draw_rectangle       (PangoRenderer    *renderer,
					  PangoRenderPart   part,
					  int               x,
					  int               y,
					  int               width,
					  int               height);
void pango_renderer_draw_error_underline (PangoRenderer    *renderer,
					  int               x,
					  int               y,
					  int               width,
					  int               height);
void pango_renderer_draw_trapezoid       (PangoRenderer    *renderer,
					  PangoRenderPart   part,
					  double            y1_,
					  double            x11,
					  double            x21,
					  double            y2,
					  double            x12,
					  double            x22);
void pango_renderer_draw_glyph           (PangoRenderer    *renderer,
					  PangoFont        *font,
					  PangoGlyph        glyph,
					  double            x,
					  double            y);

void pango_renderer_activate             (PangoRenderer    *renderer);
void pango_renderer_deactivate           (PangoRenderer    *renderer);

void        pango_renderer_part_changed (PangoRenderer   *renderer,
					 PangoRenderPart  part);

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

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

G_END_DECLS

#endif /* __PANGO_RENDERER_H_ */

