Convert launcher icons to cairo surfaces

This improves support for HiDPI by loading properly scaled surfaces for
launcher and drawer icons.

It also Fixes the Show Desktop wncklet to show a surface icon. Other
wncklets have their icons determined by libwnck, so they remain as
pixbufs.

Fixes mate-desktop/mate-desktop#314

3 files changed, 63 insertions, 33 deletions

diff --git a/applets/clock/clock-location-tile.c b/applets/clock/clock-location-tile.c
index 03717403..33c529ec 100644
--- a/applets/clock/clock-location-tile.c
+++ b/applets/clock/clock-location-tile.c
@@ -584,11 +584,14 @@ weather_info_setup_tooltip (WeatherInfo *info, ClockLocation *location, GtkToolt
         const gchar *sys_timezone;
         time_t sunrise_time, sunset_time;
         gchar *sunrise_str, *sunset_str;
+        gint icon_scale;
 
-        icon_name = weather_info_get_icon_name (info);
         theme = gtk_icon_theme_get_default ();
-        pixbuf = gtk_icon_theme_load_icon (theme, icon_name, 48,
-                                           GTK_ICON_LOOKUP_GENERIC_FALLBACK, NULL);
+        icon_name = weather_info_get_icon_name (info);
+        icon_scale = gdk_window_get_scale_factor (gdk_get_default_root_window ());
+
+        pixbuf = gtk_icon_theme_load_icon_for_scale (theme, icon_name, 48, icon_scale,
+                                                     GTK_ICON_LOOKUP_GENERIC_FALLBACK, NULL);
         if (pixbuf)
                 gtk_tooltip_set_icon (tooltip, pixbuf);
 
@@ -654,7 +657,7 @@ weather_info_setup_tooltip (WeatherInfo *info, ClockLocation *location, GtkToolt
 static gboolean
 weather_tooltip (GtkWidget  *widget,
                  gint        x,
-                 gint             y,
+                 gint        y,
                  gboolean    keyboard_mode,
                  GtkTooltip *tooltip,
                  gpointer    data)
@@ -681,20 +684,23 @@ update_weather_icon (ClockLocation *loc, WeatherInfo *info, gpointer data)
 {
         ClockLocationTile *tile = data;
         ClockLocationTilePrivate *priv = PRIVATE (tile);
-        GdkPixbuf *pixbuf = NULL;
+        cairo_surface_t *surface = NULL;
         GtkIconTheme *theme = NULL;
         const gchar *icon_name;
+        gint icon_scale;
 
         if (!info || !weather_info_is_valid (info))
                 return;
 
+        theme = gtk_icon_theme_get_for_screen (gtk_widget_get_screen (GTK_WIDGET (priv->weather_icon)));
         icon_name = weather_info_get_icon_name (info);
-        theme = gtk_icon_theme_get_default ();
-        pixbuf = gtk_icon_theme_load_icon (theme, icon_name, 16,
-                                           GTK_ICON_LOOKUP_GENERIC_FALLBACK, NULL);
+        icon_scale = gtk_widget_get_scale_factor (GTK_WIDGET (priv->weather_icon));
+
+        surface = gtk_icon_theme_load_surface (theme, icon_name, 16, icon_scale,
+                                               NULL, GTK_ICON_LOOKUP_GENERIC_FALLBACK, NULL);
 
-        if (pixbuf) {
-                gtk_image_set_from_pixbuf (GTK_IMAGE (priv->weather_icon), pixbuf);
+        if (surface) {
+                gtk_image_set_from_surface (GTK_IMAGE (priv->weather_icon), surface);
                 gtk_widget_set_margin_end (priv->weather_icon, 6);
         }
 }
diff --git a/applets/clock/clock.c b/applets/clock/clock.c
index ad659fe5..bfbc96bc 100644
--- a/applets/clock/clock.c
+++ b/applets/clock/clock.c
@@ -1975,7 +1975,8 @@ location_weather_updated_cb (ClockLocation *location,
         const gchar *icon_name;
         const gchar *temp;
         GtkIconTheme *theme;
-        GdkPixbuf *pixbuf;
+        cairo_surface_t *surface;
+        gint icon_size, icon_scale;
 
         if (!info || !weather_info_is_valid (info))
                 return;
@@ -1984,15 +1985,23 @@ location_weather_updated_cb (ClockLocation *location,
                 return;
 
         icon_name = weather_info_get_icon_name (info);
-        /* FIXME: mmh, screen please? Also, don't hardcode to 16 */
-        theme = gtk_icon_theme_get_default ();
-        pixbuf = gtk_icon_theme_load_icon (theme, icon_name, 16,
-                                           GTK_ICON_LOOKUP_GENERIC_FALLBACK, NULL);
+        if (icon_name == NULL)
+                return;
+
+        theme = gtk_icon_theme_get_for_screen (gtk_widget_get_screen (GTK_WIDGET (cd->applet)));
+
+        icon_size = mate_panel_applet_get_size (MATE_PANEL_APPLET (cd->applet));
+        icon_scale = gtk_widget_get_scale_factor (GTK_WIDGET (cd->applet));
+
+        surface = gtk_icon_theme_load_surface (theme, icon_name, icon_size, icon_scale,
+                                               NULL, GTK_ICON_LOOKUP_GENERIC_FALLBACK, NULL);
 
         temp = weather_info_get_temp_summary (info);
 
-        gtk_image_set_from_pixbuf (GTK_IMAGE (cd->panel_weather_icon), pixbuf);
+        gtk_image_set_from_surface (GTK_IMAGE (cd->panel_weather_icon), surface);
         gtk_label_set_text (GTK_LABEL (cd->panel_temperature_label), temp);
+
+        cairo_surface_destroy (surface);
 }
 
 static void
diff --git a/applets/wncklet/showdesktop.c b/applets/wncklet/showdesktop.c
index 72b71763..1e682fab 100644
--- a/applets/wncklet/showdesktop.c
+++ b/applets/wncklet/showdesktop.c
@@ -134,9 +134,9 @@ static void update_icon(ShowDesktopData* sdd)
 	GtkStateFlags    state;
 	GtkBorder        padding;
 	int width, height;
-	GdkPixbuf* icon;
-	GdkPixbuf* scaled;
-	int icon_size;
+	cairo_surface_t* icon;
+	cairo_surface_t* scaled;
+	int icon_size, icon_scale;
 	GError* error;
 	int thickness = 0;
 
@@ -156,17 +156,24 @@ static void update_icon(ShowDesktopData* sdd)
 		break;
 	}
 
-	icon_size = sdd->size - thickness;
+	icon_scale = gtk_widget_get_scale_factor (sdd->button);
+	icon_size = sdd->size * icon_scale - thickness;
 
 	if (icon_size < 22)
 		icon_size = 16;
-	else if (icon_size < 32)
+	else if (icon_size < 24)
 		icon_size = 22;
+	else if (icon_size < 32)
+		icon_size = 24;
 	else if (icon_size < 48)
 		icon_size = 32;
+	else if (icon_size < 64)
+		icon_size = 48;
+	else if (icon_size < 128)
+		icon_size = 64;
 
 	error = NULL;
-	icon = gtk_icon_theme_load_icon (sdd->icon_theme, SHOW_DESKTOP_ICON, icon_size, 0, &error);
+	icon = gtk_icon_theme_load_surface (sdd->icon_theme, SHOW_DESKTOP_ICON, icon_size, icon_scale, NULL, 0, &error);
 
 	if (icon == NULL)
 	{
@@ -182,8 +189,8 @@ static void update_icon(ShowDesktopData* sdd)
 		return;
 	}
 
-	width = gdk_pixbuf_get_width(icon);
-	height = gdk_pixbuf_get_height(icon);
+	width = cairo_image_surface_get_width (icon);
+	height = cairo_image_surface_get_height (icon);
 
 	scaled = NULL;
 
@@ -191,28 +198,36 @@ static void update_icon(ShowDesktopData* sdd)
 	switch (sdd->orient)
 	{
 		case GTK_ORIENTATION_HORIZONTAL:
-			width = (icon_size * width) / height;
-			height = icon_size;
+			width = (icon_size / icon_scale * width) / height;
+			height = icon_size / icon_scale;
 			break;
 		case GTK_ORIENTATION_VERTICAL:
-			height = (icon_size * height) / width;
-			width = icon_size;
+			height = (icon_size / icon_scale * height) / width;
+			width = icon_size / icon_scale;
 			break;
 	}
 
-	scaled = gdk_pixbuf_scale_simple(icon, width, height, GDK_INTERP_BILINEAR);
+	scaled = cairo_surface_create_similar (icon,
+		                               cairo_surface_get_content (icon),
+		                               width,
+		                               height);
 
 	if (scaled != NULL)
 	{
-		gtk_image_set_from_pixbuf(GTK_IMAGE(sdd->image), scaled);
-		g_object_unref(scaled);
+		cairo_t *cr;
+		cr = cairo_create (scaled);
+		cairo_scale (cr, (double) width / icon_size, (double) height / icon_size);
+		cairo_set_source_surface (cr, icon, 0, 0);
+		cairo_paint (cr);
+		gtk_image_set_from_surface (GTK_IMAGE(sdd->image), scaled);
+		cairo_surface_destroy (scaled);
 	}
 	else
 	{
-		gtk_image_set_from_pixbuf (GTK_IMAGE (sdd->image), icon);
+		gtk_image_set_from_surface (GTK_IMAGE (sdd->image), icon);
 	}
 
-	g_object_unref (icon);
+	cairo_surface_destroy (icon);
 }
 
 static const GtkActionEntry show_desktop_menu_actions[] = {