[gtk/emblem-demo: 3/3] gtk-demo: Add an emblem demo

[Matthias Clasen <matthiasc src gnome org>]

commit 71ea6192741430677147eb6b10da3d94928eb87b
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Sep 11 21:09:41 2020 -0400

    gtk-demo: Add an emblem demo
    
    Add a simple demo for adding emblems to icons
    using GdkPaintable.

 demos/gtk-demo/demo.gresource.xml |   1 +
 demos/gtk-demo/meson.build        |   1 +
 demos/gtk-demo/paintable_emblem.c | 186 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 188 insertions(+)
---
diff --git a/demos/gtk-demo/demo.gresource.xml b/demos/gtk-demo/demo.gresource.xml
index f179d9819b..551468fd1b 100644
--- a/demos/gtk-demo/demo.gresource.xml
+++ b/demos/gtk-demo/demo.gresource.xml
@@ -258,6 +258,7 @@
     <file>pagesetup.c</file>
     <file>paintable.c</file>
     <file>paintable_animated.c</file>
+    <file>paintable_emblem.c</file>
     <file>paintable_mediastream.c</file>
     <file>panes.c</file>
     <file>password_entry.c</file>
diff --git a/demos/gtk-demo/meson.build b/demos/gtk-demo/meson.build
index 9ee9777d13..07fd1b2330 100644
--- a/demos/gtk-demo/meson.build
+++ b/demos/gtk-demo/meson.build
@@ -59,6 +59,7 @@ demos = files([
   'paint.c',
   'paintable.c',
   'paintable_animated.c',
+  'paintable_emblem.c',
   'paintable_mediastream.c',
   'panes.c',
   'password_entry.c',
diff --git a/demos/gtk-demo/paintable_emblem.c b/demos/gtk-demo/paintable_emblem.c
new file mode 100644
index 0000000000..4c1ecf9b4c
--- /dev/null
+++ b/demos/gtk-demo/paintable_emblem.c
@@ -0,0 +1,186 @@
+/* Paintable/Emblems
+ *
+ * This demo shows how GdkPaintable can be used to
+ * overlay an emblem on top of an icon. The emblem
+ * can either be another icon, or an arbitrary
+ * paintable.
+ */
+
+#include <gtk/gtk.h>
+
+#include "paintable.h"
+
+static GtkWidget *window = NULL;
+
+#define DEMO_TYPE_ICON (demo_icon_get_type ())
+G_DECLARE_FINAL_TYPE (DemoIcon, demo_icon, DEMO, ICON, GObject)
+
+struct _DemoIcon
+{
+  GObject parent_instance;
+
+  GdkPaintable *icon;
+  GdkPaintable *emblem;
+  GdkPaintableFlags flags;
+};
+
+struct _DemoIconClass
+{
+  GObjectClass parent_class;
+};
+
+void
+demo_icon_snapshot (GdkPaintable *paintable,
+                    GtkSnapshot  *snapshot,
+                    double        width,
+                    double        height)
+{
+  DemoIcon *self = DEMO_ICON (paintable);
+
+  gdk_paintable_snapshot (self->icon, snapshot, width, height);
+  gtk_snapshot_save (snapshot);
+  gtk_snapshot_translate (snapshot, &GRAPHENE_POINT_INIT (0.5 * width, 0));
+  gdk_paintable_snapshot (self->emblem, snapshot, 0.5 * width, 0.5 * height);
+  gtk_snapshot_restore (snapshot);
+}
+
+static GdkPaintableFlags
+demo_icon_get_flags (GdkPaintable *paintable)
+{
+  DemoIcon *self = DEMO_ICON (paintable);
+
+  return self->flags;
+}
+
+static void
+demo_icon_paintable_init (GdkPaintableInterface *iface)
+{
+  iface->snapshot = demo_icon_snapshot;
+  iface->get_flags = demo_icon_get_flags;
+}
+
+G_DEFINE_TYPE_WITH_CODE (DemoIcon, demo_icon, G_TYPE_OBJECT,
+                         G_IMPLEMENT_INTERFACE (GDK_TYPE_PAINTABLE,
+                                                demo_icon_paintable_init))
+
+static void
+demo_icon_dispose (GObject *object)
+{
+  DemoIcon *self = DEMO_ICON (object);
+
+  g_signal_handlers_disconnect_by_func (self->emblem,
+                                        gdk_paintable_invalidate_contents,
+                                        self);
+
+  g_clear_object (&self->icon);
+  g_clear_object (&self->emblem);
+
+  G_OBJECT_CLASS (demo_icon_parent_class)->dispose (object);
+}
+
+static void
+demo_icon_class_init (DemoIconClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->dispose = demo_icon_dispose;
+}
+
+static void
+demo_icon_init (DemoIcon *self)
+{
+  self->flags = GDK_PAINTABLE_STATIC_SIZE | GDK_PAINTABLE_STATIC_CONTENTS;
+}
+
+GdkPaintable *
+demo_icon_new_with_paintable (const char   *icon_name,
+                              GdkPaintable *emblem)
+{
+  GtkIconTheme *theme;
+  GtkIconPaintable *icon;
+  DemoIcon *self;
+
+  theme = gtk_icon_theme_get_for_display (gdk_display_get_default ());
+
+  icon = gtk_icon_theme_lookup_icon (theme,
+                                     icon_name, NULL,
+                                     128, 1,
+                                     GTK_TEXT_DIR_LTR, 0);
+
+  self = g_object_new (DEMO_TYPE_ICON, NULL);
+
+  self->icon = GDK_PAINTABLE (icon);
+  self->emblem = emblem;
+
+  if ((gdk_paintable_get_flags (emblem) & GDK_PAINTABLE_STATIC_CONTENTS) == 0)
+    {
+      self->flags &= ~GDK_PAINTABLE_STATIC_CONTENTS;
+
+      g_signal_connect_swapped (emblem, "invalidate-contents",
+                                G_CALLBACK (gdk_paintable_invalidate_contents), self);
+    }
+
+  return GDK_PAINTABLE (self);
+}
+
+GdkPaintable *
+demo_icon_new (const char *icon_name,
+               const char *emblem_name)
+{
+  GtkIconTheme *theme;
+  GtkIconPaintable *emblem;
+
+  theme = gtk_icon_theme_get_for_display (gdk_display_get_default ());
+
+  emblem = gtk_icon_theme_lookup_icon (theme,
+                                       emblem_name, NULL,
+                                       128, 1,
+                                       GTK_TEXT_DIR_LTR, 0);
+
+  return GDK_PAINTABLE (demo_icon_new_with_paintable (icon_name,
+                                                      GDK_PAINTABLE (emblem)));
+}
+
+GtkWidget *
+do_paintable_emblem (GtkWidget *do_widget)
+{
+  GdkPaintable *icon;
+  GtkWidget *grid;
+  GtkWidget *image;
+
+  if (!window)
+    {
+      window = gtk_window_new ();
+      gtk_window_set_display (GTK_WINDOW (window),
+                              gtk_widget_get_display (do_widget));
+      gtk_window_set_title (GTK_WINDOW (window), "Emblems");
+      gtk_window_set_default_size (GTK_WINDOW (window), 300, 200);
+      g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
+
+      grid = gtk_grid_new ();
+
+      icon = demo_icon_new ("folder", "starred");
+      image = gtk_image_new_from_paintable (icon);
+      gtk_widget_set_hexpand (image, TRUE);
+      gtk_widget_set_vexpand (image, TRUE);
+      gtk_grid_attach (GTK_GRID (grid), image, 0, 0, 1, 1);
+
+      icon = demo_icon_new_with_paintable ("drive-multidisk",
+                                           gtk_nuclear_animation_new (FALSE));
+      image = gtk_image_new_from_paintable (icon);
+      gtk_widget_set_hexpand (image, TRUE);
+      gtk_widget_set_vexpand (image, TRUE);
+      gtk_grid_attach (GTK_GRID (grid), image, 1, 0, 1, 1);
+
+      gtk_window_set_child (GTK_WINDOW (window), grid);
+      g_object_unref (icon);
+    }
+
+  if (!gtk_widget_get_visible (window))
+    gtk_widget_show (window);
+  else
+    gtk_window_destroy (GTK_WINDOW (window));
+
+  return window;
+}
+