Add a small helper for loading images.

1 files changed, 143 insertions, 0 deletions

diff --git a/libindicator/indicator-image-helper.c b/libindicator/indicator-image-helper.c
new file mode 100644
index 0000000..cbbad3d
--- /dev/null
+++ b/libindicator/indicator-image-helper.c
@@ -0,0 +1,143 @@
+/*
+A little helper to make a themed image with fallbacks that
+is only constrained in the vertical dimention.
+
+Copyright 2010 Canonical Ltd.
+
+Authors:
+    Ted Gould <ted@canonical.com>
+
+This library is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+version 3.0 as published by the Free Software Foundation.
+
+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 General Public License version 3.0 for more details.
+
+You should have received a copy of the GNU General Public
+License along with this library. If not, see
+<http://www.gnu.org/licenses/>.
+*/
+
+#include <math.h>
+#include "indicator-image-helper.h"
+
+const gchar * INDICATOR_NAMES_DATA = "indicator-names-data";
+
+static void
+refresh_image (GtkImage * image)
+{
+	g_return_if_fail(GTK_IS_IMAGE(image));
+
+	GIcon * icon_names = (GIcon *)g_object_get_data(G_OBJECT(image), INDICATOR_NAMES_DATA);
+	g_return_if_fail(icon_names != NULL);
+
+	/* Get the default theme */
+	GtkIconTheme * default_theme = gtk_icon_theme_get_default();
+	g_return_if_fail(default_theme != NULL);
+
+	gint icon_size = 22;
+
+	GtkStyle * style = gtk_widget_get_style(GTK_WIDGET(image));
+	GValue styleprop = {0};
+	gtk_style_get_style_property(style, GTK_TYPE_IMAGE, "x-ayatana-indicator-dynamic", &styleprop);
+
+	if (G_VALUE_HOLDS_BOOLEAN(&styleprop) && g_value_get_boolean(&styleprop)) {
+		PangoContext * context = gtk_widget_get_pango_context(GTK_WIDGET(image));
+		PangoFontMetrics * metrics = pango_context_get_metrics(context, style->font_desc, pango_context_get_language(context));
+		icon_size = PANGO_PIXELS(pango_font_metrics_get_ascent(metrics)) + PANGO_PIXELS(pango_font_metrics_get_descent(metrics));
+		g_debug("Looking for icon size %d", icon_size);
+		pango_font_metrics_unref(metrics);
+	}
+
+	/* Look through the themes for that icon */
+	GtkIconInfo * icon_info = gtk_icon_theme_lookup_by_gicon(default_theme, icon_names, icon_size, 0);
+	if (icon_info == NULL) {
+		g_warning("Unable to find icon in theme.");
+		return;
+	}
+
+	/* Grab the filename */
+	const gchar * icon_filename = gtk_icon_info_get_filename(icon_info);
+	g_return_if_fail(icon_filename != NULL); /* An error because we shouldn't get info without a filename */
+
+	/* Build a pixbuf */
+	GError * error = NULL;
+	GdkPixbuf * pixbuf = gdk_pixbuf_new_from_file(icon_filename, &error);
+	gtk_icon_info_free(icon_info);
+
+	if (pixbuf == NULL) {
+		g_error("Unable to load icon from file '%s' because: %s", icon_filename, error == NULL ? "I don't know" : error->message);
+		return;
+	}
+
+	/* Scale icon if all we get is something too big. */
+	if (gdk_pixbuf_get_height(pixbuf) > icon_size) {
+		gfloat scale = (gfloat)icon_size / (gfloat)gdk_pixbuf_get_height(pixbuf);
+		gint width = round(gdk_pixbuf_get_width(pixbuf) * scale);
+
+		GdkPixbuf * scaled = gdk_pixbuf_scale_simple(pixbuf, width, icon_size, GDK_INTERP_BILINEAR);
+		g_object_unref(G_OBJECT(pixbuf));
+		pixbuf = scaled;
+	}
+
+	/* Put the pixbuf on the image */
+	gtk_image_set_from_pixbuf(image, pixbuf);
+	g_object_unref(G_OBJECT(pixbuf));
+
+	return;
+}
+
+/* Handles the theme changed signal to refresh the icon to make
+   sure that it changes appropriately */
+static void
+theme_changed_cb (GtkIconTheme * theme, gpointer user_data)
+{
+	GtkImage * image = GTK_IMAGE(user_data);
+	refresh_image(image);
+	return;
+}
+
+/* Removes the signal on the theme that was calling update on this
+   image. */
+static void
+image_destroyed_cb (GtkImage * image, gpointer user_data)
+{
+	g_signal_handlers_disconnect_by_func(gtk_icon_theme_get_default(), theme_changed_cb, image);
+	return;
+}
+
+GtkImage *
+indicator_image_helper (const gchar * name)
+{
+	g_return_val_if_fail(name != NULL, NULL);
+	g_return_val_if_fail(name[0] != '\0', NULL);
+
+	/* Build us a GIcon */
+	GIcon * icon_names = g_themed_icon_new_with_default_fallbacks(name);
+	g_return_val_if_fail(icon_names != NULL, NULL);
+
+	/* Build us an image */
+	GtkImage * image = GTK_IMAGE(gtk_image_new());
+
+	if (image == NULL) {
+		g_error("Unable to create image from pixbuf on icon name '%s'", name);
+		g_object_unref(icon_names);
+		return NULL;
+	}
+
+	/* Attach our names to the image */
+	g_object_set_data_full(G_OBJECT(image), INDICATOR_NAMES_DATA, icon_names, g_object_unref);
+
+	/* Put the pixbuf in */
+	refresh_image(image);
+
+	/* Connect to all changes */
+	g_signal_connect(G_OBJECT(gtk_icon_theme_get_default()), "changed", G_CALLBACK(theme_changed_cb), image);
+	g_signal_connect(G_OBJECT(image), "destroy", G_CALLBACK(image_destroyed_cb), NULL);
+
+	/* Return our built image */
+	return image;
+}