libview: Draw selection highlight from region

Allows a fallback for backends which can implement get_selection_region
but not render_selection.  Changes ev-pixbuf-cache so a redraw is only
done when the scale changes.

https://bugzilla.gnome.org/show_bug.cgi?id=669022

origin commit:
https://git.gnome.org/browse/evince/commit/?h=gnome-3-10&id=9e89fb1

3 files changed, 81 insertions, 40 deletions

diff --git a/libview/ev-pixbuf-cache.c b/libview/ev-pixbuf-cache.c
index 506d1316..4c890030 100644
--- a/libview/ev-pixbuf-cache.c
+++ b/libview/ev-pixbuf-cache.c
@@ -27,6 +27,7 @@ typedef struct _CacheJobInfo
 	
 	cairo_surface_t *selection;
 	cairo_region_t  *selection_region;
+	gdouble          selection_scale;
 } CacheJobInfo;
 
 struct _EvPixbufCache
@@ -287,6 +288,7 @@ copy_job_to_job_info (EvJobRender   *job_render,
 		job_info->selection_points = job_render->selection_points;
 		job_info->selection_region = cairo_region_reference (job_render->selection_region);
 		job_info->selection = cairo_surface_reference (job_render->selection);
+		job_info->selection_scale = job_render->scale;
 		set_device_scale_on_surface (job_info->selection, job_info->device_scale);
 		g_assert (job_info->selection_points.x1 >= 0);
 		job_info->points_set = TRUE;
@@ -632,21 +634,17 @@ ev_pixbuf_cache_clear_job_sizes (EvPixbufCache *pixbuf_cache,
 }
 
 static void
-get_selection_colors (GtkWidget *widget, GdkColor *text, GdkColor *base)
+get_selection_colors (EvView *view, GdkColor *text, GdkColor *base)
 {
-	GtkStyleContext *context = gtk_widget_get_style_context (widget);
-        GtkStateFlags    state = 0;
-        GdkRGBA          fg, bg;
+        GdkRGBA fg, bg;
 
-        state |= gtk_widget_has_focus (widget) ? GTK_STATE_FLAG_SELECTED : GTK_STATE_FLAG_ACTIVE;
+        _ev_view_get_selection_colors (view, &bg, &fg);
 
-        gtk_style_context_get_color (context, state, &fg);
         text->pixel = 0;
         text->red = CLAMP ((guint) (fg.red * 65535), 0, 65535);
         text->green = CLAMP ((guint) (fg.green * 65535), 0, 65535);
         text->blue = CLAMP ((guint) (fg.blue * 65535), 0, 65535);
 
-        gtk_style_context_get_background_color (context, state, &bg);
         base->pixel = 0;
         base->red = CLAMP ((guint) (bg.red * 65535), 0, 65535);
         base->green = CLAMP ((guint) (bg.green * 65535), 0, 65535);
@@ -679,7 +677,8 @@ add_job (EvPixbufCache  *pixbuf_cache,
 
 	if (new_selection_surface_needed (pixbuf_cache, job_info, page, scale)) {
 		GdkColor text, base;
-		get_selection_colors (pixbuf_cache->view, &text, &base);
+
+		get_selection_colors (EV_VIEW (pixbuf_cache->view), &text, &base);
 		ev_job_render_set_selection_info (EV_JOB_RENDER (job_info->job), 
 						  &(job_info->target_points),
 						  job_info->selection_style,
@@ -864,24 +863,8 @@ new_selection_surface_needed (EvPixbufCache *pixbuf_cache,
 			      gint           page,
 			      gfloat         scale)
 {
-	if (job_info->selection) {
-		gint width, height;
-		gint selection_width, selection_height;
-
-		_get_page_size_for_scale_and_rotation (pixbuf_cache->document,
-						       page, scale, 0,
-						       &width, &height);
-
-		selection_width = cairo_image_surface_get_width (job_info->selection);
-		selection_height = cairo_image_surface_get_height (job_info->selection);
-		
-		if (width != selection_width || height != selection_height)
-			return TRUE;
-	} else {
-		if (job_info->points_set)
-			return TRUE;
-	}
-	
+	if (job_info->selection || job_info->points_set)
+		return job_info->selection_scale != scale;
 	return FALSE;
 }
 
@@ -936,12 +919,14 @@ ev_pixbuf_cache_style_changed (EvPixbufCache *pixbuf_cache)
 		if (job_info->selection) {
 			cairo_surface_destroy (job_info->selection);
 			job_info->selection = NULL;
+			job_info->selection_points.x1 = -1;
 		}
 
 		job_info = pixbuf_cache->next_job + i;
 		if (job_info->selection) {
 			cairo_surface_destroy (job_info->selection);
 			job_info->selection = NULL;
+			job_info->selection_points.x1 = -1;
 		}
 	}
 
@@ -952,6 +937,7 @@ ev_pixbuf_cache_style_changed (EvPixbufCache *pixbuf_cache)
 		if (job_info->selection) {
 			cairo_surface_destroy (job_info->selection);
 			job_info->selection = NULL;
+			job_info->selection_points.x1 = -1;
 		}
 	}
 }
@@ -979,8 +965,11 @@ ev_pixbuf_cache_get_selection_surface (EvPixbufCache   *pixbuf_cache,
 	/* If we have a running job, we just return what we have under the
 	 * assumption that it'll be updated later and we can scale it as need
 	 * be */
-	if (job_info->job && EV_JOB_RENDER (job_info->job)->include_selection)
+	if (job_info->job && EV_JOB_RENDER (job_info->job)->include_selection) {
+		if (region)
+			*region = job_info->selection_region;
 		return job_info->selection;
+	}
 
 	/* Now, lets see if we need to resize the image.  If we do, we clear the
 	 * old one. */
@@ -1003,7 +992,6 @@ ev_pixbuf_cache_get_selection_surface (EvPixbufCache   *pixbuf_cache,
 			g_assert (job_info->selection == NULL);
 			old_points = NULL;
 		} else {
-			g_assert (job_info->selection != NULL);
 			old_points = &(job_info->selection_points);
 		}
 
@@ -1018,7 +1006,7 @@ ev_pixbuf_cache_get_selection_surface (EvPixbufCache   *pixbuf_cache,
 							   rc, job_info->selection_style,
 							   &(job_info->target_points));
 
-		get_selection_colors (pixbuf_cache->view, &text, &base);
+		get_selection_colors (EV_VIEW (pixbuf_cache->view), &text, &base);
 
 		ev_selection_render_selection (EV_SELECTION (pixbuf_cache->document),
 					       rc, &(job_info->selection),
@@ -1028,6 +1016,7 @@ ev_pixbuf_cache_get_selection_surface (EvPixbufCache   *pixbuf_cache,
 					       &text, &base);
 		set_device_scale_on_surface (job_info->selection, job_info->device_scale);
 		job_info->selection_points = job_info->target_points;
+		job_info->selection_scale = scale;
 		g_object_unref (rc);
 		ev_document_doc_mutex_unlock ();
 	}
diff --git a/libview/ev-view-private.h b/libview/ev-view-private.h
index abdd43b7..3ec1f790 100644
--- a/libview/ev-view-private.h
+++ b/libview/ev-view-private.h
@@ -278,6 +278,9 @@ void _ev_view_transform_doc_rect_to_view_rect (EvView       *view,
 					       int           page,
 					       EvRectangle  *doc_rect,
 					       GdkRectangle *view_rect);
+void _ev_view_get_selection_colors (EvView  *view,
+                                    GdkRGBA *bg_color,
+                                    GdkRGBA *fg_color);
 
 void _ev_view_set_focused_element (EvView *view,
                                    EvMapping *element_mapping,
diff --git a/libview/ev-view.c b/libview/ev-view.c
index 50838662..99604221 100644
--- a/libview/ev-view.c
+++ b/libview/ev-view.c
@@ -5469,6 +5469,45 @@ draw_surface (cairo_t 	      *cr,
 	cairo_restore (cr);
 }
 
+void
+_ev_view_get_selection_colors (EvView  *view,
+                               GdkRGBA *bg_color,
+                               GdkRGBA *fg_color)
+{
+	GtkWidget       *widget = GTK_WIDGET (view);
+	GtkStateFlags    state;
+	GtkStyleContext *context;
+
+	state = gtk_widget_has_focus (widget) ? GTK_STATE_FLAG_SELECTED : GTK_STATE_FLAG_ACTIVE;
+	context = gtk_widget_get_style_context (widget);
+
+	if (bg_color)
+		gtk_style_context_get_background_color (context, state, bg_color);
+
+	if (fg_color)
+		gtk_style_context_get_color (context, state, fg_color);
+}
+
+static void
+draw_selection_region (cairo_t        *cr,
+                       cairo_region_t *region,
+                       GdkRGBA        *color,
+                       gint            x,
+                       gint            y,
+                       gdouble         scale_x,
+                       gdouble         scale_y)
+{
+	cairo_save (cr);
+	cairo_translate (cr, x, y);
+	cairo_scale (cr, scale_x, scale_y);
+	gdk_cairo_region (cr, region);
+	cairo_set_source_rgb (cr, color->red, color->green, color->blue);
+	cairo_set_operator (cr, CAIRO_OPERATOR_MULTIPLY);
+	cairo_set_antialias (cr, CAIRO_ANTIALIAS_NONE);
+	cairo_fill (cr);
+	cairo_restore (cr);
+}
+
 static void
 draw_one_page (EvView       *view,
 	       gint          page,
@@ -5510,6 +5549,7 @@ draw_one_page (EvView       *view,
 		cairo_surface_t *page_surface = NULL;
 		cairo_surface_t *selection_surface = NULL;
 		gint offset_x, offset_y;
+		cairo_region_t *region = NULL;
 		double device_scale_x = 1, device_scale_y = 1;
 
 		page_surface = ev_pixbuf_cache_get_surface (view->pixbuf_cache, page);
@@ -5535,22 +5575,31 @@ draw_one_page (EvView       *view,
 		offset_y = overlap.y - real_page_area.y;
 
 		draw_surface (cr, page_surface, overlap.x, overlap.y, offset_x, offset_y, width, height);
-		
+
 		/* Get the selection pixbuf iff we have something to draw */
-		if (find_selection_for_page (view, page) &&
-		    view->selection_mode == EV_VIEW_SELECTION_TEXT) {
-			selection_surface =
-				ev_pixbuf_cache_get_selection_surface (view->pixbuf_cache,
-								       page,
-								       view->scale,
-								       NULL);
-		}
+		if (!find_selection_for_page (view, page))
+			return;
 
-		if (!selection_surface) {
+		selection_surface = ev_pixbuf_cache_get_selection_surface (view->pixbuf_cache,
+									   page,
+									   view->scale,
+									   &region);
+		if (selection_surface) {
+			draw_surface (cr, selection_surface, overlap.x, overlap.y, offset_x, offset_y,
+				      width, height);
 			return;
 		}
-		draw_surface (cr, selection_surface, overlap.x, overlap.y, offset_x, offset_y, width, height);
 
+		if (region) {
+			double scale_x, scale_y;
+			GdkRGBA color;
+
+			scale_x = (gdouble)width / cairo_image_surface_get_width (page_surface);
+			scale_y = (gdouble)height / cairo_image_surface_get_height (page_surface);
+			_ev_view_get_selection_colors (view, &color, NULL);
+			draw_selection_region (cr, region, &color, real_page_area.x, real_page_area.y,
+					       scale_x, scale_y);
+		}
 	}
 }