Bug 327878. Add cairo_clip_extract_rectangles, to support native theme rendering patch. r=vlad

gfx/cairo/cairo/src/cairo-clip-private.h

@@ -114,4 +114,13 @@ _cairo_clip_combine_to_surface (cairo_clip_t            *clip,
 				int                      dst_y,
 				const cairo_rectangle_t *extents);
 
+cairo_private cairo_bool_t
+_cairo_clip_has_clip (cairo_clip_t *clip);
+
+cairo_private cairo_bool_t
+_cairo_clip_extract_rectangles (cairo_clip_t *clip,
+                                 int max_rectangles,
+                                 cairo_clip_rect_t *rectangles_out,
+                                 int *num_rectangles_out);
+
 #endif /* CAIRO_CLIP_PRIVATE_H */

gfx/cairo/cairo/src/cairo-clip.c

@@ -459,3 +459,53 @@ _cairo_clip_clip (cairo_clip_t       *clip,
 
     return status;
 }
+
+cairo_bool_t
+_cairo_clip_has_clip (cairo_clip_t *clip)
+{
+    return clip->region != NULL || clip->surface != NULL || clip->path != NULL;
+}
+
+static cairo_bool_t
+_cairo_region_to_clip_rectangles (pixman_region16_t *region,
+                                  int max_rectangles,
+                                  cairo_clip_rect_t *rectangles_out,
+                                  int *num_rectangles_out)
+{
+    int n_boxes, i;
+    pixman_box16_t *boxes;
+
+    /* no region -> we can't represent it as rectangles */
+    if (region == NULL)
+        return FALSE;
+
+    n_boxes = pixman_region_num_rects (region);
+    *num_rectangles_out = n_boxes;
+    if (n_boxes > max_rectangles)
+        return FALSE;
+
+    boxes = pixman_region_rects (region);
+    
+    for (i = 0; i < n_boxes; i++) {
+        rectangles_out[i].x = boxes[i].x1;
+        rectangles_out[i].y = boxes[i].y1;
+        rectangles_out[i].width = boxes[i].x2 - boxes[i].x1;
+        rectangles_out[i].height = boxes[i].y2 - boxes[i].y1;
+    }
+
+    return TRUE;
+}
+
+cairo_bool_t
+_cairo_clip_extract_rectangles (cairo_clip_t *clip,
+                                int max_rectangles,
+                                cairo_clip_rect_t *rectangles_out,
+                                int *num_rectangles_out)
+{
+    /* can't handle paths or surfaces for now */
+    if (clip->path != NULL || clip->surface != NULL)
+        return FALSE;
+ 
+    return _cairo_region_to_clip_rectangles (clip->region,
+        max_rectangles, rectangles_out, num_rectangles_out);
+}

gfx/cairo/cairo/src/cairo-gstate.c

@@ -1183,6 +1183,24 @@ _cairo_gstate_clip (cairo_gstate_t *gstate, cairo_path_fixed_t *path)
 			     gstate->antialias, gstate->target);
 }
 
+cairo_bool_t
+_cairo_gstate_has_clip (cairo_gstate_t *gstate)
+{
+   return _cairo_clip_has_clip (&gstate->clip);
+}
+
+cairo_bool_t
+_cairo_gstate_extract_clip_rectangles (cairo_gstate_t *gstate,
+                                       int max_rectangles,
+                                       cairo_clip_rect_t *rectangles_out,
+                                       int *num_rectangles_out)
+{
+    return _cairo_clip_extract_rectangles (&gstate->clip,
+                                           max_rectangles,
+                                           rectangles_out,
+                                           num_rectangles_out);
+}
+
 static void
 _cairo_gstate_unset_scaled_font (cairo_gstate_t *gstate)
 {

gfx/cairo/cairo/src/cairo.c

@@ -2583,6 +2583,45 @@ cairo_copy_path (cairo_t *cr)
     return _cairo_path_data_create (&cr->path, cr->gstate);
 }
 
+/**
+ * cairo_has_clip
+ * @cr: a cairo context
+ * 
+ * Returns TRUE if the cairo context has any clipping active, otherwise
+ * FALSE.
+ */
+cairo_bool_t
+cairo_has_clip (cairo_t *cr)
+{
+    if (cr->status)
+        return FALSE;
+    return _cairo_gstate_has_clip (cr->gstate);
+}
+
+/**
+ * cairo_extract_clip_rectangles
+ * @cr: a cairo context
+ * @max_rectangles: the maximum number of rectangles to be returned
+ * @rectangles_out: the output buffer for the rectangles
+ * @num_rectangles_out: the number of rectangles returned
+ * 
+ * If the current clip can be expressed as the union of at most
+ * 'max_rectangles' device-coordinate rectangles, then we fill in the array
+ * with the rectangles, and return True. Otherwise we return False. When there
+ * is no clipping active, we return False.
+ */
+cairo_bool_t
+cairo_extract_clip_rectangles (cairo_t *cr,
+                               int max_rectangles,
+                               cairo_clip_rect_t *rectangles_out,
+                               int *num_rectangles_out)
+{
+    if (cr->status)
+        return FALSE;
+    return _cairo_gstate_extract_clip_rectangles (cr->gstate, max_rectangles,
+                                                  rectangles_out, num_rectangles_out);
+}
+
 /**
  * cairo_copy_path_flat:
  * @cr: a cairo context

gfx/cairo/cairo/src/cairo.h

@@ -1138,6 +1138,24 @@ cairo_append_path (cairo_t	*cr,
 cairo_public void
 cairo_path_destroy (cairo_path_t *path);
 
+/**
+ * cairo_clip_rect_t:
+ * 
+ * A data structure for holding clip rectangles.
+ */
+typedef struct _cairo_clip_rect {
+    double x, y, width, height;
+} cairo_clip_rect_t;
+
+cairo_public cairo_bool_t
+cairo_has_clip (cairo_t *cr);
+
+cairo_public cairo_bool_t
+cairo_extract_clip_rectangles (cairo_t *cr,
+                               int max_rectangles,
+                               cairo_clip_rect_t *rectangles_out,
+                               int *num_rectangles_out);
+
 /* Error status queries */
 
 cairo_public cairo_status_t

gfx/cairo/cairo/src/cairoint.h

@@ -1238,6 +1238,15 @@ _cairo_gstate_clip (cairo_gstate_t *gstate, cairo_path_fixed_t *path);
 cairo_private cairo_status_t
 _cairo_gstate_reset_clip (cairo_gstate_t *gstate);
 
+cairo_private cairo_bool_t
+_cairo_gstate_has_clip (cairo_gstate_t *gstate);
+
+cairo_private cairo_bool_t
+_cairo_gstate_extract_clip_rectangles (cairo_gstate_t *gstate,
+                                       int max_rectangles,
+                                       cairo_clip_rect_t *rectangles_out,
+                                       int *num_rectangles_out);
+
 cairo_private cairo_status_t
 _cairo_gstate_show_surface (cairo_gstate_t	*gstate,
 			    cairo_surface_t	*surface,