[gtk+] Add some copy-paste for widgets demo

[Matthias Clasen <matthiasc src gnome org>]

commit 2dae71c6192c338148bb654abfc1bf36ed382363
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Dec 5 17:45:39 2017 -0800

    Add some copy-paste for widgets demo
    
    Not sure this is quite right yet.

 demos/gtk-demo/dnd.c |  167 +++++++++++++++++++++++++++++++++++++++++++++++---
 1 files changed, 159 insertions(+), 8 deletions(-)
---
diff --git a/demos/gtk-demo/dnd.c b/demos/gtk-demo/dnd.c
index 85a4937..4f1f947 100644
--- a/demos/gtk-demo/dnd.c
+++ b/demos/gtk-demo/dnd.c
@@ -50,6 +50,109 @@ gtk_demo_widget_new (void)
   return g_object_new (GTK_TYPE_DEMO_WIDGET, NULL);
 }
 
+static double pos_x, pos_y;
+
+static void
+new_label_cb (GtkMenuItem *item,
+              gpointer     data)
+{
+  GtkFixed *fixed = data;
+  GtkWidget *widget;
+
+  widget = gtk_label_new ("Label");
+  gtk_fixed_put (fixed, widget, pos_x, pos_y);
+}
+
+static void
+new_spinner_cb (GtkMenuItem *item,
+                gpointer     data)
+{
+  GtkFixed *fixed = data;
+  GtkWidget *widget;
+
+  widget = gtk_spinner_new ();
+  gtk_spinner_start (GTK_SPINNER (widget));
+  gtk_fixed_put (fixed, widget, pos_x, pos_y);
+}
+
+static void
+new_demo_cb (GtkMenuItem *item,
+             gpointer     data)
+{
+  GtkFixed *fixed = data;
+  GtkWidget *widget;
+
+  widget = gtk_demo_widget_new ();
+  gtk_fixed_put (fixed, widget, pos_x, pos_y);
+}
+
+static void
+copy_cb (GtkMenuItem *item,
+         gpointer     data)
+{
+  GtkWidget *child = data;
+  GdkClipboard *clipboard;
+  GValue value = { 0, };
+
+  g_print ("Copy %s!\n", g_type_name_from_instance ((GTypeInstance *)child));
+
+  g_value_init (&value, G_OBJECT_TYPE (child));
+  g_value_set_object (&value, child);
+
+  clipboard = gdk_display_get_clipboard (gdk_display_get_default ());
+  gdk_clipboard_set_value (clipboard, &value);
+}
+
+static void
+value_read (GObject      *source,
+            GAsyncResult *res,
+            gpointer      data)
+{
+  GdkClipboard *clipboard = GDK_CLIPBOARD (source);
+  GError *error = NULL;
+  const GValue *value;
+  GtkWidget *widget;
+  GtkWidget *new_widget;
+
+  value = gdk_clipboard_read_value_finish (clipboard, res, &error);
+
+  if (value == NULL)
+    {
+      g_print ("error: %s\n", error->message);
+      g_error_free (error);
+      return;
+    }
+
+  widget = g_value_get_object (value);
+  if (GTK_IS_LABEL (widget))
+    new_widget = gtk_label_new (gtk_label_get_text (GTK_LABEL (widget)));
+  else if (GTK_IS_SPINNER (widget))
+    {
+      new_widget = gtk_spinner_new ();
+      gtk_spinner_start (GTK_SPINNER (new_widget));
+    }
+  else
+    {
+      return;
+    }
+
+  gtk_fixed_put (GTK_FIXED (data), new_widget, pos_x, pos_y);
+}
+static void
+paste_cb (GtkMenuItem *item,
+          gpointer     data)
+{
+  GdkClipboard *clipboard;
+
+  clipboard = gdk_display_get_clipboard (gdk_display_get_default ());
+  if (gdk_content_formats_contain_gtype (gdk_clipboard_get_formats (clipboard), GTK_TYPE_LABEL))
+    gdk_clipboard_read_value_async (clipboard, GTK_TYPE_LABEL, 0, NULL, value_read, data);
+  else if (gdk_content_formats_contain_gtype (gdk_clipboard_get_formats (clipboard), GTK_TYPE_SPINNER))
+    gdk_clipboard_read_value_async (clipboard, GTK_TYPE_SPINNER, 0, NULL, value_read, data);
+  else
+    g_print ("Don't know how to handle clipboard contents\n");
+}
+
 static void
 pressed_cb (GtkGesture *gesture,
             int         n_press,
@@ -57,14 +160,62 @@ pressed_cb (GtkGesture *gesture,
             double      y,
             gpointer    data)
 {
-  GtkWidget *widget;
+  if (gtk_gesture_single_get_current_button (GTK_GESTURE_SINGLE (gesture)) == GDK_BUTTON_SECONDARY)
+    {
+      GtkWidget *widget;
+      GdkRectangle rect;
+      GtkWidget *menu;
+      GtkWidget *item;
+      GtkWidget *child;
+      GdkClipboard *clipboard;
 
-  if (n_press < 2)
-    return;
+      widget = gtk_event_controller_get_widget (GTK_EVENT_CONTROLLER (gesture));
+      child = gtk_widget_pick (widget, x, y);
 
-  widget = gtk_demo_widget_new ();
+      pos_x = x;
+      pos_y = y;
+
+      menu = gtk_menu_new ();
+      item = gtk_menu_item_new_with_label ("New Label");
+      g_signal_connect (item, "activate", G_CALLBACK (new_label_cb), widget);
+      gtk_container_add (GTK_CONTAINER (menu), item);
+      item = gtk_menu_item_new_with_label ("New Spinner");
+      g_signal_connect (item, "activate", G_CALLBACK (new_spinner_cb), widget);
+      gtk_container_add (GTK_CONTAINER (menu), item);
+      item = gtk_menu_item_new_with_label ("New Custom");
+      g_signal_connect (item, "activate", G_CALLBACK (new_demo_cb), widget);
+      gtk_container_add (GTK_CONTAINER (menu), item);
+      item = gtk_separator_menu_item_new ();
+      gtk_container_add (GTK_CONTAINER (menu), item);
+      item = gtk_menu_item_new_with_label ("Copy");
+      gtk_widget_set_sensitive (item, child != NULL && child != widget);
+      g_signal_connect (item, "activate", G_CALLBACK (copy_cb), child);
+      gtk_container_add (GTK_CONTAINER (menu), item);
+      item = gtk_menu_item_new_with_label ("Paste");
+
+      clipboard = gdk_display_get_clipboard (gdk_display_get_default ());
+      if (gdk_content_formats_contain_gtype (gdk_clipboard_get_formats (clipboard), GTK_TYPE_LABEL) ||
+          gdk_content_formats_contain_gtype (gdk_clipboard_get_formats (clipboard), GTK_TYPE_SPINNER))
+        gtk_widget_set_sensitive (item, TRUE);
+      else
+        gtk_widget_set_sensitive (item, FALSE);
+      g_signal_connect (item, "activate", G_CALLBACK (paste_cb), child);
+      gtk_container_add (GTK_CONTAINER (menu), item);
 
-  gtk_fixed_put (GTK_FIXED (gtk_event_controller_get_widget (GTK_EVENT_CONTROLLER (gesture))), widget, x, y);
+      rect.x = x;
+      rect.y = y;
+      rect.width = 0;
+      rect.height = 0;
+
+      gtk_menu_popup_at_rect (GTK_MENU (menu),
+                              gtk_widget_get_window (widget),
+                              &rect,
+                              GDK_GRAVITY_NORTH_WEST,
+                              GDK_GRAVITY_NORTH_WEST,
+                              NULL);
+
+      return;
+    }
 }
 
 static GtkWidget *window = NULL;