libview: use css to draw the background of presentations

With the recent changes in gtk+, widgets have to draw themselves,
causing the current use of gdk_window_set_background_rgba to fail.

https://bugzilla.gnome.org/show_bug.cgi?id=765557

view: Redraw ev-view-presentation when setting normal and black mode.

The black and normal mode are the same from the CSS point of view.
The difference is that in the draw function the page is not drawn
in black mode. Hence, we need to explicitly queue a redraw in these
cases. Since setting the white mode add a CSS class, this queues
the redraw for us.

Fixes https://bugzilla.gnome.org/show_bug.cgi?id=772390.

origin commits:
https://git.gnome.org/browse/evince/commit/?id=2b352b3
https://git.gnome.org/browse/evince/commit/?id=b3f49f4

Fixes #232

libview/ev-view-presentation.c

@@ -116,9 +116,6 @@ static void ev_view_presentation_set_cursor_for_location (EvViewPresentation *pv
 
 G_DEFINE_TYPE (EvViewPresentation, ev_view_presentation, GTK_TYPE_WIDGET)
 
-static GdkRGBA black = { 0., 0., 0., 1. };
-static GdkRGBA white = { 1., 1., 1., 1. };
-
 static void
 ev_view_presentation_set_normal (EvViewPresentation *pview)
 {
@@ -128,7 +125,8 @@ ev_view_presentation_set_normal (EvViewPresentation *pview)
 		return;
 
 	pview->state = EV_PRESENTATION_NORMAL;
-	gdk_window_set_background_rgba (gtk_widget_get_window (widget), &black);
+	gtk_style_context_remove_class (gtk_widget_get_style_context (widget),
+	                                "white-mode");
 	gtk_widget_queue_draw (widget);
 }
 
@@ -141,7 +139,8 @@ ev_view_presentation_set_black (EvViewPresentation *pview)
 		return;
 
 	pview->state = EV_PRESENTATION_BLACK;
-	gdk_window_set_background_rgba (gtk_widget_get_window (widget), &black);
+	gtk_style_context_remove_class (gtk_widget_get_style_context (widget),
+	                                "white-mode");
 	gtk_widget_queue_draw (widget);
 }
 
@@ -154,8 +153,8 @@ ev_view_presentation_set_white (EvViewPresentation *pview)
 		return;
 
 	pview->state = EV_PRESENTATION_WHITE;
-	gdk_window_set_background_rgba (gtk_widget_get_window (widget), &white);
-	gtk_widget_queue_draw (widget);
+	gtk_style_context_add_class (gtk_widget_get_style_context (widget),
+	                             "white-mode");
 }
 
 static void
@@ -1026,6 +1025,13 @@ ev_view_presentation_draw (GtkWidget *widget,
 	cairo_surface_t    *surface;
 	cairo_rectangle_int_t clip_rect;
 	GdkRectangle *area = &clip_rect;
+	GtkStyleContext    *context;
+
+	context = gtk_widget_get_style_context (GTK_WIDGET (pview));
+	gtk_render_background (context, cr,
+	                       0, 0,
+	                       gtk_widget_get_allocated_width (widget),
+	                       gtk_widget_get_allocated_height (widget));
 
 	if (!gdk_cairo_get_clip_rectangle (cr, &clip_rect))
 		return FALSE;
@@ -1413,6 +1419,8 @@ ev_view_presentation_class_init (EvViewPresentationClass *klass)
 	widget_class->motion_notify_event = ev_view_presentation_motion_notify_event;
 	widget_class->scroll_event = ev_view_presentation_scroll_event;
 
+	gtk_widget_class_set_css_name (widget_class, "evpresentationview");
+
 	gobject_class->dispose = ev_view_presentation_dispose;
 
 	gobject_class->constructor = ev_view_presentation_constructor;
@@ -1514,25 +1522,8 @@ ev_view_presentation_class_init (EvViewPresentationClass *klass)
 static void
 ev_view_presentation_init (EvViewPresentation *pview)
 {
-	static gsize initialization_value = 0;
-
 	gtk_widget_set_can_focus (GTK_WIDGET (pview), TRUE);
-         pview->is_constructing = TRUE;
-
-	if (g_once_init_enter (&initialization_value)) {
-		GtkCssProvider *provider;
-
-		provider = gtk_css_provider_new ();
-		gtk_css_provider_load_from_data (provider,
-						 "EvViewPresentation {\n"
-						 " background-color: black; }",
-						 -1, NULL);
-		gtk_style_context_add_provider_for_screen (gdk_screen_get_default (),
-							   GTK_STYLE_PROVIDER (provider),
-							   GTK_STYLE_PROVIDER_PRIORITY_APPLICATION);
-		g_object_unref (provider);
-		g_once_init_leave (&initialization_value, 1);
-	}
+	pview->is_constructing = TRUE;
 }
 
 GtkWidget *

shell/atril.css

@@ -1,3 +1,19 @@
 #ev-fullscreen-toolbar {
 
 }
+
+#ev-loading-message {
+    background-color: @theme_selected_bg_color;
+    color: @theme_selected_fg_color;
+    border-radius: 3px;
+    padding: 8px;
+}
+
+evpresentationview {
+    background-color: black;
+}
+
+evpresentationview.white-mode {
+    background-color: white;
+}
+