gtk/gdk/gdkpango.c

/* GDK - The GIMP Drawing Kit
 * Copyright (C) 2000 Red Hat, Inc. 
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser 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.
 */

#include <config.h>
#include <math.h>
#include <pango/pangocairo.h>
#include "gdkcolor.h"
#include "gdkgc.h"
#include "gdkinternals.h"
#include "gdkpango.h"
#include "gdkrgb.h"
#include "gdkprivate.h"
#include "gdkscreen.h"
#include "gdkalias.h"

/* This is for P_() ... a bit non-kosher, but works fine */
#include "gtk/gtkintl.h"

#define GDK_INFO_KEY "gdk-info"

/* We have various arrays indexed by render part; if PangoRenderPart
 * is extended, we want to make sure not to overwrite the end of
 * those arrays.
 */
#define MAX_RENDER_PART  PANGO_RENDER_PART_STRIKETHROUGH

struct _GdkPangoRendererPrivate
{
  GdkScreen *screen;

  /* GdkPangoRenderer specific state */
  PangoColor override_color[MAX_RENDER_PART + 1];
  gboolean override_color_set[MAX_RENDER_PART + 1];
  
  GdkBitmap *stipple[MAX_RENDER_PART + 1];
  gboolean embossed;

  cairo_t *cr;
  PangoRenderPart last_part;

  /* Current target */
  GdkDrawable *drawable;
  GdkGC *base_gc;
};

static PangoAttrType gdk_pango_attr_stipple_type;
static PangoAttrType gdk_pango_attr_embossed_type;

enum {
  PROP_0,
  PROP_SCREEN
};

G_DEFINE_TYPE (GdkPangoRenderer, gdk_pango_renderer, PANGO_TYPE_RENDERER)

static void
gdk_pango_renderer_finalize (GObject *object)
{
  GdkPangoRenderer *gdk_renderer = GDK_PANGO_RENDERER (object);
  GdkPangoRendererPrivate *priv = gdk_renderer->priv;
  int i;

  if (priv->base_gc)
    g_object_unref (priv->base_gc);
  if (priv->drawable)
    g_object_unref (priv->drawable);

  for (i = 0; i <= MAX_RENDER_PART; i++)
    if (priv->stipple[i])
      g_object_unref (priv->stipple[i]);

  G_OBJECT_CLASS (gdk_pango_renderer_parent_class)->finalize (object);
}

static GObject*
gdk_pango_renderer_constructor (GType                  type,
				guint                  n_construct_properties,
				GObjectConstructParam *construct_params)
{
  GObject *object;
  GdkPangoRenderer *gdk_renderer;

  object = (* G_OBJECT_CLASS (gdk_pango_renderer_parent_class)->constructor) (type,
									      n_construct_properties,
									      construct_params);

  gdk_renderer = GDK_PANGO_RENDERER (object);
  
  if (!gdk_renderer->priv->screen)
    {
      g_warning ("Screen must be specified at construct time for GdkPangoRenderer");
      gdk_renderer->priv->screen = gdk_screen_get_default ();
    }

  return object;
}

/* Adjusts matrix and color for the renderer to draw the secondary
 * "shadow" copy for embossed text */
static void
emboss_context (cairo_t *cr)
{
  cairo_matrix_t tmp_matrix;

  /* The gymnastics here to adjust the matrix are because we want
   * to offset by +1,+1 in device-space, not in user-space,
   * so we can't just draw the layout at x + 1, y + 1
   */
  cairo_get_matrix (cr, &tmp_matrix);
  tmp_matrix.x0 += 1.0;
  tmp_matrix.y0 += 1.0;
  cairo_set_matrix (cr, &tmp_matrix);

  cairo_set_source_rgb (cr, 1.0, 1.0, 1.0);
}

static cairo_t *
get_cairo_context (GdkPangoRenderer *gdk_renderer,
		   PangoRenderPart   part)
{
  PangoRenderer *renderer = PANGO_RENDERER (gdk_renderer);
  GdkPangoRendererPrivate *priv = gdk_renderer->priv;

  if (!priv->cr)
    {
      const PangoMatrix *matrix;
      
      priv->cr = gdk_drawable_create_cairo_context (priv->drawable);

      matrix = pango_renderer_get_matrix (renderer);
      if (matrix)
	{
	  cairo_matrix_t cairo_matrix;
	  
	  cairo_matrix_init (&cairo_matrix,
			     matrix->xx, matrix->yx,
			     matrix->xy, matrix->yy,
			     matrix->x0, matrix->y0);
	  cairo_set_matrix (priv->cr, &cairo_matrix);
	}
    }
  
  priv->last_part = (PangoRenderPart)-1;
  if (part != priv->last_part)
    {
      PangoColor *pango_color = pango_renderer_get_color (renderer,
							  part);
      GdkColor *color = NULL;
      GdkColor tmp_color;
      if (pango_color)
	{
	  tmp_color.red = pango_color->red;
	  tmp_color.green = pango_color->green;
	  tmp_color.blue = pango_color->blue;
	  
	  color = &tmp_color;
	}

      _gdk_gc_update_context (priv->base_gc,
			      priv->cr,
			      color,
			      priv->stipple[part]);
      priv->last_part = part;
    }

  return priv->cr;
}

static void
gdk_pango_renderer_draw_glyphs (PangoRenderer    *renderer,
				PangoFont        *font,
				PangoGlyphString *glyphs,
				int               x,
				int               y)
{
  GdkPangoRenderer *gdk_renderer = GDK_PANGO_RENDERER (renderer);
  GdkPangoRendererPrivate *priv = gdk_renderer->priv;
  cairo_t *cr;

  cr = get_cairo_context (gdk_renderer, 
			  PANGO_RENDER_PART_FOREGROUND);

  if (priv->embossed)
    {
      cairo_save (cr);
      emboss_context (cr);
      cairo_move_to (cr, x / PANGO_SCALE, y / PANGO_SCALE);
      pango_cairo_show_glyph_string (cr, font, glyphs);
      cairo_restore (cr);
    }
  
  cairo_move_to (cr, x / PANGO_SCALE, y / PANGO_SCALE);
  pango_cairo_show_glyph_string (cr, font, glyphs);
}

/* Draws an error underline that looks like one of:
 *              H       E                H
 *     /\      /\      /\        /\      /\               -
 *   A/  \    /  \    /  \     A/  \    /  \              |
 *    \   \  /    \  /   /D     \   \  /    \             |
 *     \   \/  C   \/   /        \   \/   C  \            | height = HEIGHT_SQUARES * square
 *      \      /\  F   /          \  F   /\   \           | 
 *       \    /  \    /            \    /  \   \G         |
 *        \  /    \  /              \  /    \  /          |
 *         \/      \/                \/      \/           -
 *         B                         B       
 *    |----|
 *   unit_width = (HEIGHT_SQUARES - 1) * square
 *
 * The x, y, width, height passed in give the desired bounding box;
 * x/width are adjusted to make the underline a integer number of units
 * wide.
 */
#define HEIGHT_SQUARES 2.5

static void
draw_error_underline (cairo_t *cr,
		      double  x,
		      double  y,
		      double  width,
		      double  height)
{
  double square = height / HEIGHT_SQUARES;
  double unit_width = (HEIGHT_SQUARES - 1) * square;
  int width_units = (width + unit_width / 2) / unit_width;
  double y_top, y_bottom;
  int i;

  x += (width - width_units * unit_width);
  width = width_units * unit_width;

  y_top = y;
  y_bottom = y + height;
  
  /* Bottom of squiggle */
  cairo_move_to (cr, x - square / 2, y_top + square / 2); /* A */
  for (i = 0; i < width_units; i += 2)
    {
      double x_middle = x + (i + 1) * unit_width;
      double x_right = x + (i + 2) * unit_width;
    
      cairo_line_to (cr, x_middle, y_bottom); /* B */
      
      if (i + 1 == width_units)
	/* Nothing */;
      else if (i + 2 == width_units)
	cairo_line_to (cr, x_right + square / 2, y_top + square / 2); /* D */
      else
	cairo_line_to (cr, x_right, y_top + square); /* C */
    }
  
  /* Top of squiggle */
  for (i -= 2; i >= 0; i -= 2)
    {
      double x_left = x + i * unit_width;
      double x_middle = x + (i + 1) * unit_width;
      double x_right = x + (i + 2) * unit_width;
      
      if (i + 1 == width_units)
	cairo_line_to (cr, x_middle + square / 2, y_bottom - square / 2); /* G */
      else {
	if (i + 2 == width_units)
	  cairo_line_to (cr, x_right, y_top); /* E */
	cairo_line_to (cr, x_middle, y_bottom - square); /* F */
      }
      
      cairo_line_to (cr, x_left, y_top);   /* H */
    }

  cairo_close_path (cr);
  cairo_fill (cr);
}

static void
gdk_pango_renderer_draw_rectangle (PangoRenderer    *renderer,
				   PangoRenderPart   part,
				   int               x,
				   int               y,
				   int               width,
				   int               height)
{
  GdkPangoRenderer *gdk_renderer = GDK_PANGO_RENDERER (renderer);
  GdkPangoRendererPrivate *priv = gdk_renderer->priv;
  cairo_t *cr;
  
  cr = get_cairo_context (gdk_renderer, part);

  if (priv->embossed && part != PANGO_RENDER_PART_BACKGROUND)
    {
      cairo_save (cr);
      emboss_context (cr);
      cairo_rectangle (cr,
		       (double)x / PANGO_SCALE, (double)y / PANGO_SCALE,
		       (double)width / PANGO_SCALE, (double)height / PANGO_SCALE);

      cairo_fill (cr);
      cairo_restore (cr);
    }

  cairo_rectangle (cr,
		   (double)x / PANGO_SCALE, (double)y / PANGO_SCALE,
		   (double)width / PANGO_SCALE, (double)height / PANGO_SCALE);
  cairo_fill (cr);
}

static void
gdk_pango_renderer_draw_error_underline (PangoRenderer    *renderer,
					 int               x,
					 int               y,
					 int               width,
					 int               height)
{
  GdkPangoRenderer *gdk_renderer = GDK_PANGO_RENDERER (renderer);
  GdkPangoRendererPrivate *priv = gdk_renderer->priv;
  cairo_t *cr;
  
  cr = get_cairo_context (gdk_renderer, PANGO_RENDER_PART_UNDERLINE);
  
  if (priv->embossed)
    {
      cairo_save (cr);
      emboss_context (cr);
      draw_error_underline (cr,
			    (double)x / PANGO_SCALE, (double)y / PANGO_SCALE,
			    (double)width / PANGO_SCALE, (double)height / PANGO_SCALE);
      cairo_restore (cr);
    }

  draw_error_underline (cr,
			(double)x / PANGO_SCALE, (double)y / PANGO_SCALE,
			(double)width / PANGO_SCALE, (double)height / PANGO_SCALE);
}

static void
gdk_pango_renderer_part_changed (PangoRenderer   *renderer,
				 PangoRenderPart  part)
{
  GdkPangoRenderer *gdk_renderer = GDK_PANGO_RENDERER (renderer);

  if (gdk_renderer->priv->last_part == part)
    gdk_renderer->priv->last_part = (PangoRenderPart)-1;
}

static void
gdk_pango_renderer_begin (PangoRenderer *renderer)
{
  GdkPangoRenderer *gdk_renderer = GDK_PANGO_RENDERER (renderer);
  GdkPangoRendererPrivate *priv = gdk_renderer->priv;
  
  if (!priv->drawable || !priv->base_gc)
    {
      g_warning ("gdk_pango_renderer_set_drawable() and gdk_pango_renderer_set_drawable()"
		 "must be used to set the target drawable and GC before using the renderer\n");
    }
}

static void
gdk_pango_renderer_end (PangoRenderer *renderer)
{
  GdkPangoRenderer *gdk_renderer = GDK_PANGO_RENDERER (renderer);
  GdkPangoRendererPrivate *priv = gdk_renderer->priv;

  if (priv->cr)
    {
      cairo_destroy (priv->cr);
      priv->cr = NULL;
    }
  priv->last_part = (PangoRenderPart)-1;
}

static void
gdk_pango_renderer_prepare_run (PangoRenderer  *renderer,
				PangoLayoutRun *run)
{
  GdkPangoRenderer *gdk_renderer = GDK_PANGO_RENDERER (renderer);
  gboolean embossed = FALSE;
  GdkBitmap *stipple = NULL;
  GSList *l;
  int i;
  
  embossed = FALSE;
  stipple = NULL;
  
  for (l = run->item->analysis.extra_attrs; l; l = l->next)
    {
      PangoAttribute *attr = l->data;

      /* stipple_type and embossed_type aren't necessarily
       * initialized, but they are 0, which is an
       * invalid type so won't occur. 
       */
      if (attr->klass->type == gdk_pango_attr_stipple_type)
	{
	  stipple = ((GdkPangoAttrStipple*)attr)->stipple;
	}
      else if (attr->klass->type == gdk_pango_attr_embossed_type)
	{
	  embossed = ((GdkPangoAttrEmbossed*)attr)->embossed;
	}
    }

  gdk_pango_renderer_set_stipple (gdk_renderer, PANGO_RENDER_PART_FOREGROUND, stipple);
  gdk_pango_renderer_set_stipple (gdk_renderer, PANGO_RENDER_PART_BACKGROUND, stipple);
  gdk_pango_renderer_set_stipple (gdk_renderer, PANGO_RENDER_PART_UNDERLINE, stipple);
  gdk_pango_renderer_set_stipple (gdk_renderer, PANGO_RENDER_PART_STRIKETHROUGH, stipple);

  if (embossed != gdk_renderer->priv->embossed)
    {
      gdk_renderer->priv->embossed = embossed;
      pango_renderer_part_changed (renderer, PANGO_RENDER_PART_FOREGROUND);
    }

  PANGO_RENDERER_CLASS (gdk_pango_renderer_parent_class)->prepare_run (renderer, run);

  for (i = 0; i <= MAX_RENDER_PART; i++)
    {
      if (gdk_renderer->priv->override_color_set[i])
	pango_renderer_set_color (renderer, i, &gdk_renderer->priv->override_color[i]);
    }
}

static void
gdk_pango_renderer_set_property (GObject         *object,
				 guint            prop_id,
				 const GValue    *value,
				 GParamSpec      *pspec)
{
  GdkPangoRenderer *gdk_renderer = GDK_PANGO_RENDERER (object);

  switch (prop_id)
    {
    case PROP_SCREEN:
      gdk_renderer->priv->screen = g_value_get_object (value);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
    }
}

static void
gdk_pango_renderer_get_property (GObject    *object,
				 guint       prop_id,
				 GValue     *value,
				 GParamSpec *pspec)
{
  GdkPangoRenderer *gdk_renderer = GDK_PANGO_RENDERER (object);

  switch (prop_id)
    {
    case PROP_SCREEN:
      g_value_set_object (value, gdk_renderer->priv->screen);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
    }
}

static void
gdk_pango_renderer_init (GdkPangoRenderer *renderer)
{
  renderer->priv = G_TYPE_INSTANCE_GET_PRIVATE (renderer,
						GDK_TYPE_PANGO_RENDERER,
						GdkPangoRendererPrivate);

  renderer->priv->last_part = (PangoRenderPart)-1;
}

static void
gdk_pango_renderer_class_init (GdkPangoRendererClass *klass)
{
  GObjectClass *object_class = G_OBJECT_CLASS (klass);
  
  PangoRendererClass *renderer_class = PANGO_RENDERER_CLASS (klass);
  
  renderer_class->draw_glyphs = gdk_pango_renderer_draw_glyphs;
  renderer_class->draw_rectangle = gdk_pango_renderer_draw_rectangle;
  renderer_class->draw_error_underline = gdk_pango_renderer_draw_error_underline;
  renderer_class->part_changed = gdk_pango_renderer_part_changed;
  renderer_class->begin = gdk_pango_renderer_begin;
  renderer_class->end = gdk_pango_renderer_end;
  renderer_class->prepare_run = gdk_pango_renderer_prepare_run;

  object_class->finalize = gdk_pango_renderer_finalize;
  object_class->constructor = gdk_pango_renderer_constructor;
  object_class->set_property = gdk_pango_renderer_set_property;
  object_class->get_property = gdk_pango_renderer_get_property;
  
  g_object_class_install_property (object_class,
                                   PROP_SCREEN,
                                   g_param_spec_object ("screen",
                                                        P_("Screen"),
                                                        P_("the GdkScreen for the renderer"),
                                                        GDK_TYPE_SCREEN,
                                                        G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY |
							G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | 
							G_PARAM_STATIC_BLURB));

  g_type_class_add_private (object_class, sizeof (GdkPangoRendererPrivate));  
}

/**
 * gdk_pango_renderer_new:
 * @screen: a #GdkScreen
 * 
 * Creates a new #PangoRenderer for @screen. Normally you can use the
 * results of gdk_pango_renderer_get_default() rather than creating a new
 * renderer.
 * 
 * Return value: a newly created #PangoRenderer. Free with g_object_unref().
 *
 * Since: 2.6
 **/
PangoRenderer *
gdk_pango_renderer_new (GdkScreen *screen)
{
  g_return_val_if_fail (screen != NULL, NULL);
  
  return g_object_new (GDK_TYPE_PANGO_RENDERER,
		       "screen", screen,
		       NULL);
}

static void
on_renderer_display_closed (GdkDisplay       *display,
			    GdkPangoRenderer *renderer)
{
  g_signal_handlers_disconnect_by_func (renderer->priv->screen,
					(gpointer)on_renderer_display_closed,
					renderer);
  g_object_set_data (G_OBJECT (renderer->priv->screen), "gdk-pango-renderer", NULL);
}

/**
 * gdk_pango_renderer_get_default:
 * @screen: a #GdkScreen
 * 
 * Gets the default #PangoRenderer for a screen. This default renderer
 * is shared by all users of the display, so properties such as the color
 * or transformation matrix set for the renderer may be overwritten
 * by functions such as gdk_draw_layout().
 *
 * Before using the renderer, you need to call gdk_pango_renderer_set_drawable()
 * and gdk_pango_renderer_set_drawable() to set the drawable and graphics context
 * to use for drawing.
 * 
 * Return value: the default #PangoRenderer for @screen. The
 *  renderer is owned by GTK+ and will be kept around until the
 *  screen is closed.
 *
 * Since: 2.6
 **/
PangoRenderer *
gdk_pango_renderer_get_default (GdkScreen *screen)
{
  PangoRenderer *renderer;

  g_return_val_if_fail (GDK_IS_SCREEN (screen), NULL);
  
  renderer = g_object_get_data (G_OBJECT (screen), "gdk-pango-renderer");
  if (!renderer)
    {
      renderer = gdk_pango_renderer_new (screen);
      g_object_set_data_full (G_OBJECT (screen), "gdk-pango-renderer", renderer,
			      (GDestroyNotify)g_object_unref);

      g_signal_connect (gdk_screen_get_display (screen), "closed",
			G_CALLBACK (on_renderer_display_closed), renderer);
    }

  return renderer;
}

/**
 * gdk_pango_renderer_set_drawable:
 * @gdk_renderer: a #GdkPangoRenderer
 * @drawable: the new target drawable, or %NULL
 * 
 * Sets the drawable the renderer draws to.
 *
 * Since: 2.6
 **/
void
gdk_pango_renderer_set_drawable (GdkPangoRenderer *gdk_renderer,
				 GdkDrawable      *drawable)
{
  GdkPangoRendererPrivate *priv;
  
  g_return_if_fail (GDK_IS_PANGO_RENDERER (gdk_renderer));
  g_return_if_fail (drawable == NULL || GDK_IS_DRAWABLE (drawable));

  priv = gdk_renderer->priv;
  
  if (priv->drawable != drawable)
    {
      if (priv->drawable)
	g_object_unref (priv->drawable);
      priv->drawable = drawable;
      if (priv->drawable)
	g_object_ref (priv->drawable);
    }
}

/**
 * gdk_pango_renderer_set_gc:
 * @gdk_renderer: a #GdkPangoRenderer
 * @gc: the new GC to use for drawing, or %NULL
 * 
 * Sets the GC the renderer draws with. Note that the GC must not be
 * modified until it is unset by calling the function again with
 * %NULL for the @gc parameter, since GDK may make internal copies
 * of the GC which won't be updated to follow changes to the
 * original GC.
 *
 * Since: 2.6
 **/
void
gdk_pango_renderer_set_gc (GdkPangoRenderer *gdk_renderer,
			   GdkGC            *gc)
{
  GdkPangoRendererPrivate *priv;
  
  g_return_if_fail (GDK_IS_PANGO_RENDERER (gdk_renderer));
  g_return_if_fail (gc == NULL || GDK_IS_GC (gc));

  priv = gdk_renderer->priv;
  
  if (priv->base_gc != gc)
    {
      if (priv->base_gc)
	g_object_unref (priv->base_gc);
      priv->base_gc = gc;
      if (priv->base_gc)
	g_object_ref (priv->base_gc);
    }
}


/**
 * gdk_pango_renderer_set_stipple:
 * @gdk_renderer: a #GdkPangoRenderer
 * @part: the part to render with the stipple
 * @stipple: the new stipple value.
 * 
 * Sets the stipple for one render part (foreground, background, underline,
 * etc.) Note that this is overwritten when iterating through the individual
 * styled runs of a #PangoLayout or #PangoLayoutLine. This function is thus
 * only useful when you call low level functions like pango_renderer_draw_glyphs()
 * directly, or in the 'prepare_run' virtual function of a subclass of
 * #GdkPangoRenderer.
 *
 * Since: 2.6
 **/
void
gdk_pango_renderer_set_stipple (GdkPangoRenderer *gdk_renderer,
				PangoRenderPart   part,
				GdkBitmap        *stipple)
{
  g_return_if_fail (GDK_IS_PANGO_RENDERER (gdk_renderer));

  if (part > MAX_RENDER_PART)	/* Silently ignore unknown parts */
    return;

  if (stipple != gdk_renderer->priv->stipple[part])
    {
      if (gdk_renderer->priv->stipple[part])
	g_object_unref (gdk_renderer->priv->stipple[part]);

      gdk_renderer->priv->stipple[part] = stipple;
      
      if (gdk_renderer->priv->stipple[part])
	g_object_ref (gdk_renderer->priv->stipple[part]);

      pango_renderer_part_changed (PANGO_RENDERER (gdk_renderer), part);
    }
}

/**
 * gdk_pango_renderer_set_override_color:
 * @gdk_renderer: a #GdkPangoRenderer
 * @part: the part to render to set the color of
 * @color: the color to use, or %NULL to unset a previously
 *         set override color.
 * 
 * Sets the color for a particular render part (foreground,
 * background, underline, etc.), overriding any attributes on the layouts
 * renderered with this renderer.
 * 
 * Since: 2.6
 **/
void
gdk_pango_renderer_set_override_color (GdkPangoRenderer *gdk_renderer,
				       PangoRenderPart   part,
				       const GdkColor   *color)
{
  GdkPangoRendererPrivate *priv;
  
  g_return_if_fail (GDK_IS_PANGO_RENDERER (gdk_renderer));

  priv = gdk_renderer->priv;
  
  if (part > MAX_RENDER_PART)	/* Silently ignore unknown parts */
    return;

  if (color)
    {
      priv->override_color[part].red = color->red;
      priv->override_color[part].green = color->green;
      priv->override_color[part].blue = color->blue;
      priv->override_color_set[part] = TRUE;
    }
  else
    priv->override_color_set[part] = FALSE;
}

/**
 * gdk_pango_context_set_colormap:
 * @context: a #PangoContext
 * @colormap: a #GdkColormap
 *
 * This function used to set the colormap to be used for drawing with
 * @context. The colormap is now always derived from the graphics
 * context used for drawing, so calling this function is no longer
 * necessary.
 **/
void
gdk_pango_context_set_colormap (PangoContext *context,
				GdkColormap  *colormap)
{
  g_return_if_fail (PANGO_IS_CONTEXT (context));
  g_return_if_fail (colormap == NULL || GDK_IS_COLORMAP (colormap));
}

/* Gets a renderer to draw with, setting the properties of the
 * renderer and activating it. Note that since we activate the
 * renderer here, the implicit setting of the matrix that
 * pango_renderer_draw_layout_[line] normally do when they
 * activate the renderer is suppressed. */
static PangoRenderer *
get_renderer (GdkDrawable     *drawable,
	      GdkGC           *gc,
	      const GdkColor  *foreground,
	      const GdkColor  *background)
{
  GdkScreen *screen = gdk_drawable_get_screen (drawable);
  PangoRenderer *renderer = gdk_pango_renderer_get_default (screen);
  GdkPangoRenderer *gdk_renderer = GDK_PANGO_RENDERER (renderer);

  gdk_pango_renderer_set_drawable (gdk_renderer, drawable);
  gdk_pango_renderer_set_gc (gdk_renderer, gc);  

  gdk_pango_renderer_set_override_color (gdk_renderer,
					 PANGO_RENDER_PART_FOREGROUND,
					 foreground);
  gdk_pango_renderer_set_override_color (gdk_renderer,
					 PANGO_RENDER_PART_UNDERLINE,
					 foreground);
  gdk_pango_renderer_set_override_color (gdk_renderer,
					 PANGO_RENDER_PART_STRIKETHROUGH,
					 foreground);

  gdk_pango_renderer_set_override_color (gdk_renderer,
					 PANGO_RENDER_PART_BACKGROUND,
					 background);

  pango_renderer_activate (renderer);

  return renderer;
}

/* Cleans up the renderer obtained with get_renderer() */
static void
release_renderer (PangoRenderer *renderer)
{
  GdkPangoRenderer *gdk_renderer = GDK_PANGO_RENDERER (renderer);
  
  pango_renderer_deactivate (renderer);
  
  gdk_pango_renderer_set_override_color (gdk_renderer,
					 PANGO_RENDER_PART_FOREGROUND,
					 NULL);
  gdk_pango_renderer_set_override_color (gdk_renderer,
					 PANGO_RENDER_PART_UNDERLINE,
					 NULL);
  gdk_pango_renderer_set_override_color (gdk_renderer,
					 PANGO_RENDER_PART_STRIKETHROUGH,
					 NULL);
  gdk_pango_renderer_set_override_color (gdk_renderer,
					 PANGO_RENDER_PART_BACKGROUND,
					 NULL);
  
  gdk_pango_renderer_set_drawable (gdk_renderer, NULL);
  gdk_pango_renderer_set_gc (gdk_renderer, NULL);
}

/**
 * gdk_draw_layout_line_with_colors:
 * @drawable:  the drawable on which to draw the line
 * @gc:        base graphics to use
 * @x:         the x position of start of string (in pixels)
 * @y:         the y position of baseline (in pixels)
 * @line:      a #PangoLayoutLine
 * @foreground: foreground override color, or %NULL for none
 * @background: background override color, or %NULL for none
 *
 * Render a #PangoLayoutLine onto a #GdkDrawable, overriding the
 * layout's normal colors with @foreground and/or @background.
 * @foreground and @background need not be allocated.
 *
 * If the layout's #PangoContext has a transformation matrix set, then
 * @x and @y specify the position of the left edge of the baseline
 * (left is in before-tranform user coordinates) in after-transform
 * device coordinates.
 */
void 
gdk_draw_layout_line_with_colors (GdkDrawable      *drawable,
                                  GdkGC            *gc,
                                  gint              x, 
                                  gint              y,
                                  PangoLayoutLine  *line,
                                  const GdkColor   *foreground,
                                  const GdkColor   *background)
{
  PangoRenderer *renderer;
  const PangoMatrix *matrix;
  
  g_return_if_fail (GDK_IS_DRAWABLE (drawable));
  g_return_if_fail (GDK_IS_GC (gc));
  g_return_if_fail (line != NULL);

  renderer = get_renderer (drawable, gc, foreground, background);

  /* When we have a matrix, we do positioning by adjusting the matrix, and
   * clamp just pass x=0, y=0 to the lower levels. We don't want to introduce
   * a matrix when the caller didn't provide one, however, since that adds
   * lots of floating point arithmetic for each glyph.
   */
  matrix = pango_context_get_matrix (pango_layout_get_context (line->layout));
  if (matrix)
    {
      PangoMatrix tmp_matrix;
      
      tmp_matrix = *matrix;
      tmp_matrix.x0 = x;
      tmp_matrix.y0 = y;
      pango_renderer_set_matrix (renderer, &tmp_matrix);

      x = 0;
      y = 0;
    }
  else
    pango_renderer_set_matrix (renderer, NULL);

  pango_renderer_draw_layout_line (renderer, line, x * PANGO_SCALE, y * PANGO_SCALE);

  release_renderer (renderer);
}

/* Gets the bounds of a layout in device coordinates. Note cut-and-paste
 * between here and gtklabel.c */
static void
get_rotated_layout_bounds (PangoLayout  *layout,
			   GdkRectangle *rect)
{
  PangoContext *context = pango_layout_get_context (layout);
  const PangoMatrix *matrix = pango_context_get_matrix (context);
  gdouble x_min = 0, x_max = 0, y_min = 0, y_max = 0; /* quiet gcc */
  PangoRectangle logical_rect;
  gint i, j;

  pango_layout_get_extents (layout, NULL, &logical_rect);
  
  for (i = 0; i < 2; i++)
    {
      gdouble x = (i == 0) ? logical_rect.x : logical_rect.x + logical_rect.width;
      for (j = 0; j < 2; j++)
	{
	  gdouble y = (j == 0) ? logical_rect.y : logical_rect.y + logical_rect.height;
	  
	  gdouble xt = (x * matrix->xx + y * matrix->xy) / PANGO_SCALE + matrix->x0;
	  gdouble yt = (x * matrix->yx + y * matrix->yy) / PANGO_SCALE + matrix->y0;
	  
	  if (i == 0 && j == 0)
	    {
	      x_min = x_max = xt;
	      y_min = y_max = yt;
	    }
	  else
	    {
	      if (xt < x_min)
		x_min = xt;
	      if (yt < y_min)
		y_min = yt;
	      if (xt > x_max)
		x_max = xt;
	      if (yt > y_max)
		y_max = yt;
	    }
	}
    }
  
  rect->x = floor (x_min);
  rect->width = ceil (x_max) - rect->x;
  rect->y = floor (y_min);
  rect->height = floor (y_max) - rect->y;
}

/**
 * gdk_draw_layout_with_colors:
 * @drawable:  the drawable on which to draw string
 * @gc:        base graphics context to use
 * @x:         the X position of the left of the layout (in pixels)
 * @y:         the Y position of the top of the layout (in pixels)
 * @layout:    a #PangoLayout
 * @foreground: foreground override color, or %NULL for none
 * @background: background override color, or %NULL for none
 *
 * Render a #PangoLayout onto a #GdkDrawable, overriding the
 * layout's normal colors with @foreground and/or @background.
 * @foreground and @background need not be allocated.
 *
 * If the layout's #PangoContext has a transformation matrix set, then
 * @x and @y specify the position of the top left corner of the
 * bounding box (in device space) of the transformed layout.
 *
 * If you're using GTK+, the ususal way to obtain a #PangoLayout
 * is gtk_widget_create_pango_layout().
 */
void 
gdk_draw_layout_with_colors (GdkDrawable     *drawable,
                             GdkGC           *gc,
                             int              x, 
                             int              y,
                             PangoLayout     *layout,
                             const GdkColor  *foreground,
                             const GdkColor  *background)
{
  PangoRenderer *renderer;
  const PangoMatrix *matrix;
  
  g_return_if_fail (GDK_IS_DRAWABLE (drawable));
  g_return_if_fail (GDK_IS_GC (gc));
  g_return_if_fail (PANGO_IS_LAYOUT (layout));

  renderer = get_renderer (drawable, gc, foreground, background);

  /* When we have a matrix, we do positioning by adjusting the matrix, and
   * clamp just pass x=0, y=0 to the lower levels. We don't want to introduce
   * a matrix when the caller didn't provide one, however, since that adds
   * lots of floating point arithmetic for each glyph.
   */
  matrix = pango_context_get_matrix (pango_layout_get_context (layout));
  if (matrix)
    {
      PangoMatrix tmp_matrix;
      GdkRectangle rect;

      get_rotated_layout_bounds (layout, &rect);
      
      tmp_matrix = *matrix;
      tmp_matrix.x0 += x - rect.x;
      tmp_matrix.y0 += y - rect.y;
      pango_renderer_set_matrix (renderer, &tmp_matrix);
      
      x = 0;
      y = 0;
    }
  else
    pango_renderer_set_matrix (renderer, NULL);
  
  pango_renderer_draw_layout (renderer, layout, x * PANGO_SCALE, y * PANGO_SCALE);
  
  release_renderer (renderer);
}

/**
 * gdk_draw_layout_line:
 * @drawable:  the drawable on which to draw the line
 * @gc:        base graphics to use
 * @x:         the x position of start of string (in pixels)
 * @y:         the y position of baseline (in pixels)
 * @line:      a #PangoLayoutLine
 *
 * Render a #PangoLayoutLine onto an GDK drawable
 *
 * If the layout's #PangoContext has a transformation matrix set, then
 * @x and @y specify the position of the left edge of the baseline
 * (left is in before-tranform user coordinates) in after-transform
 * device coordinates.
 */
void 
gdk_draw_layout_line (GdkDrawable      *drawable,
		      GdkGC            *gc,
		      gint              x, 
		      gint              y,
		      PangoLayoutLine  *line)
{
  g_return_if_fail (GDK_IS_DRAWABLE (drawable));
  g_return_if_fail (GDK_IS_GC (gc));
  g_return_if_fail (line != NULL);
  
  gdk_draw_layout_line_with_colors (drawable, gc, x, y, line, NULL, NULL);
}

/**
 * gdk_draw_layout:
 * @drawable:  the drawable on which to draw string
 * @gc:        base graphics context to use
 * @x:         the X position of the left of the layout (in pixels)
 * @y:         the Y position of the top of the layout (in pixels)
 * @layout:    a #PangoLayout
 *
 * Render a #PangoLayout onto a GDK drawable
 *
 * If the layout's #PangoContext has a transformation matrix set, then
 * @x and @y specify the position of the top left corner of the
 * bounding box (in device space) of the transformed layout.
 *
 * If you're using GTK+, the usual way to obtain a #PangoLayout
 * is gtk_widget_create_pango_layout().
 */
void 
gdk_draw_layout (GdkDrawable     *drawable,
		 GdkGC           *gc,
		 int              x, 
		 int              y,
		 PangoLayout     *layout)
{
  g_return_if_fail (GDK_IS_DRAWABLE (drawable));
  g_return_if_fail (GDK_IS_GC (gc));
  g_return_if_fail (PANGO_IS_LAYOUT (layout));

  gdk_draw_layout_with_colors (drawable, gc, x, y, layout, NULL, NULL);
}

static PangoAttribute *
gdk_pango_attr_stipple_copy (const PangoAttribute *attr)
{
  const GdkPangoAttrStipple *src = (const GdkPangoAttrStipple*) attr;

  return gdk_pango_attr_stipple_new (src->stipple);
}

static void
gdk_pango_attr_stipple_destroy (PangoAttribute *attr)
{
  GdkPangoAttrStipple *st = (GdkPangoAttrStipple*) attr;

  if (st->stipple)
    g_object_unref (st->stipple);
  
  g_free (attr);
}

static gboolean
gdk_pango_attr_stipple_compare (const PangoAttribute *attr1,
                                    const PangoAttribute *attr2)
{
  const GdkPangoAttrStipple *a = (const GdkPangoAttrStipple*) attr1;
  const GdkPangoAttrStipple *b = (const GdkPangoAttrStipple*) attr2;

  return a->stipple == b->stipple;
}

/**
 * gdk_pango_attr_stipple_new:
 * @stipple: a bitmap to be set as stipple
 *
 * Creates a new attribute containing a stipple bitmap to be used when
 * rendering the text.
 *
 * Return value: new #PangoAttribute
 **/

PangoAttribute *
gdk_pango_attr_stipple_new (GdkBitmap *stipple)
{
  GdkPangoAttrStipple *result;
  
  static PangoAttrClass klass = {
    0,
    gdk_pango_attr_stipple_copy,
    gdk_pango_attr_stipple_destroy,
    gdk_pango_attr_stipple_compare
  };

  if (!klass.type)
    klass.type = gdk_pango_attr_stipple_type =
      pango_attr_type_register ("GdkPangoAttrStipple");

  result = g_new (GdkPangoAttrStipple, 1);
  result->attr.klass = &klass;

  if (stipple)
    g_object_ref (stipple);
  
  result->stipple = stipple;

  return (PangoAttribute *)result;
}

static PangoAttribute *
gdk_pango_attr_embossed_copy (const PangoAttribute *attr)
{
  const GdkPangoAttrEmbossed *e = (const GdkPangoAttrEmbossed*) attr;

  return gdk_pango_attr_embossed_new (e->embossed);
}

static void
gdk_pango_attr_embossed_destroy (PangoAttribute *attr)
{
  g_free (attr);
}

static gboolean
gdk_pango_attr_embossed_compare (const PangoAttribute *attr1,
                                 const PangoAttribute *attr2)
{
  const GdkPangoAttrEmbossed *e1 = (const GdkPangoAttrEmbossed*) attr1;
  const GdkPangoAttrEmbossed *e2 = (const GdkPangoAttrEmbossed*) attr2;

  return e1->embossed == e2->embossed;
}

/**
 * gdk_pango_attr_embossed_new:
 * @embossed: a bitmap to be set as embossed
 *
 * Creates a new attribute containing a embossed bitmap to be used when
 * rendering the text.
 *
 * Return value: new #PangoAttribute
 **/

PangoAttribute *
gdk_pango_attr_embossed_new (gboolean embossed)
{
  GdkPangoAttrEmbossed *result;
  
  static PangoAttrClass klass = {
    0,
    gdk_pango_attr_embossed_copy,
    gdk_pango_attr_embossed_destroy,
    gdk_pango_attr_embossed_compare
  };

  if (!klass.type)
    klass.type = gdk_pango_attr_embossed_type =
      pango_attr_type_register ("GdkPangoAttrEmbossed");

  result = g_new (GdkPangoAttrEmbossed, 1);
  result->attr.klass = &klass;
  result->embossed = embossed;
  
  return (PangoAttribute *)result;
}

/* Get a clip region to draw only part of a layout. index_ranges
 * contains alternating range starts/stops. The region is the
 * region which contains the given ranges, i.e. if you draw with the
 * region as clip, only the given ranges are drawn.
 */

/**
 * gdk_pango_layout_line_get_clip_region:
 * @line: a #PangoLayoutLine 
 * @x_origin: X pixel where you intend to draw the layout line with this clip
 * @y_origin: baseline pixel where you intend to draw the layout line with this clip
 * @index_ranges: array of byte indexes into the layout, where even members of array are start indexes and odd elements are end indexes
 * @n_ranges: number of ranges in @index_ranges, i.e. half the size of @index_ranges
 * 
 * Obtains a clip region which contains the areas where the given
 * ranges of text would be drawn. @x_origin and @y_origin are the same
 * position you would pass to gdk_draw_layout_line(). @index_ranges
 * should contain ranges of bytes in the layout's text. The clip
 * region will include space to the left or right of the line (to the
 * layout bounding box) if you have indexes above or below the indexes
 * contained inside the line. This is to draw the selection all the way
 * to the side of the layout. However, the clip region is in line coordinates,
 * not layout coordinates.
 * 
 * Return value: a clip region containing the given ranges
 **/
GdkRegion*
gdk_pango_layout_line_get_clip_region (PangoLayoutLine *line,
                                       gint             x_origin,
                                       gint             y_origin,
                                       gint            *index_ranges,
                                       gint             n_ranges)
{
  GdkRegion *clip_region;
  gint i;
  PangoRectangle logical_rect;
  PangoLayoutIter *iter;
  gint baseline;
  
  g_return_val_if_fail (line != NULL, NULL);
  g_return_val_if_fail (index_ranges != NULL, NULL);
  
  clip_region = gdk_region_new ();

  iter = pango_layout_get_iter (line->layout);
  while (pango_layout_iter_get_line (iter) != line)
    pango_layout_iter_next_line (iter);
  
  pango_layout_iter_get_line_extents (iter, NULL, &logical_rect);
  baseline = pango_layout_iter_get_baseline (iter);
  
  pango_layout_iter_free (iter);
  
  i = 0;
  while (i < n_ranges)
    {  
      gint *pixel_ranges = NULL;
      gint n_pixel_ranges = 0;
      gint j;

      /* Note that get_x_ranges returns layout coordinates
       */
      pango_layout_line_get_x_ranges (line,
                                      index_ranges[i*2],
                                      index_ranges[i*2+1],
                                      &pixel_ranges, &n_pixel_ranges);
  
      for (j=0; j < n_pixel_ranges; j++)
        {
          GdkRectangle rect;
          
          rect.x = x_origin + pixel_ranges[2*j] / PANGO_SCALE - logical_rect.x / PANGO_SCALE;
          rect.y = y_origin - (baseline / PANGO_SCALE - logical_rect.y / PANGO_SCALE);
          rect.width = (pixel_ranges[2*j + 1] - pixel_ranges[2*j]) / PANGO_SCALE;
          rect.height = logical_rect.height / PANGO_SCALE;
          
          gdk_region_union_with_rect (clip_region, &rect);
        }

      g_free (pixel_ranges);
      ++i;
    }

  return clip_region;
}

/**
 * gdk_pango_layout_get_clip_region:
 * @layout: a #PangoLayout 
 * @x_origin: X pixel where you intend to draw the layout with this clip
 * @y_origin: Y pixel where you intend to draw the layout with this clip
 * @index_ranges: array of byte indexes into the layout, where even members of array are start indexes and odd elements are end indexes
 * @n_ranges: number of ranges in @index_ranges, i.e. half the size of @index_ranges
 * 
 * Obtains a clip region which contains the areas where the given ranges
 * of text would be drawn. @x_origin and @y_origin are the same position
 * you would pass to gdk_draw_layout_line(). @index_ranges should contain
 * ranges of bytes in the layout's text.
 * 
 * Return value: a clip region containing the given ranges
 **/
GdkRegion*
gdk_pango_layout_get_clip_region (PangoLayout *layout,
                                  gint         x_origin,
                                  gint         y_origin,
                                  gint        *index_ranges,
                                  gint         n_ranges)
{
  PangoLayoutIter *iter;  
  GdkRegion *clip_region;
  
  g_return_val_if_fail (PANGO_IS_LAYOUT (layout), NULL);
  g_return_val_if_fail (index_ranges != NULL, NULL);
  
  clip_region = gdk_region_new ();
  
  iter = pango_layout_get_iter (layout);
  
  do
    {
      PangoRectangle logical_rect;
      PangoLayoutLine *line;
      GdkRegion *line_region;
      gint baseline;
      
      line = pango_layout_iter_get_line (iter);      

      pango_layout_iter_get_line_extents (iter, NULL, &logical_rect);
      baseline = pango_layout_iter_get_baseline (iter);      

      line_region = gdk_pango_layout_line_get_clip_region (line,
                                                           x_origin + logical_rect.x / PANGO_SCALE,
                                                           y_origin + baseline / PANGO_SCALE,
                                                           index_ranges,
                                                           n_ranges);

      gdk_region_union (clip_region, line_region);
      gdk_region_destroy (line_region);
    }
  while (pango_layout_iter_next_line (iter));

  pango_layout_iter_free (iter);

  return clip_region;
}

/**
 * gdk_pango_context_get:
 * 
 * Creates a #PangoContext for the default GDK screen.
 *
 * The context must be freed when you're finished with it.
 * 
 * When using GTK+, normally you should use gtk_widget_get_pango_context()
 * instead of this function, to get the appropriate context for
 * the widget you intend to render text onto.
 * 
 * Return value: a new #PangoContext for the default display
 **/
PangoContext *
gdk_pango_context_get (void)
{
  return gdk_pango_context_get_for_screen (gdk_screen_get_default ());
}

/**
 * gdk_pango_context_get_for_screen:
 * @screen: the #GdkScreen for which the context is to be created.
 * 
 * Creates a #PangoContext for @screen.
 *
 * The context must be freed when you're finished with it.
 * 
 * When using GTK+, normally you should use gtk_widget_get_pango_context()
 * instead of this function, to get the appropriate context for
 * the widget you intend to render text onto.
 * 
 * Return value: a new #PangoContext for @screen
 *
 * Since: 2.2
 **/
PangoContext *
gdk_pango_context_get_for_screen (GdkScreen *screen)
{
  PangoFontMap *fontmap;
  
  g_return_val_if_fail (GDK_IS_SCREEN (screen), NULL);

  fontmap = pango_cairo_font_map_get_default ();
  
  return pango_cairo_font_map_create_context (PANGO_CAIRO_FONT_MAP (fontmap));
}

#define __GDK_PANGO_C__
#include "gdkaliasdef.c"