[gtk/wip/otte/inspector: 4/6] recorder: Make the render nodes in the list draggable

[Benjamin Otte <otte src gnome org>]

commit a4e5f15f5104419a0d87b379fd47d58b5ed2dbad
Author: Benjamin Otte <otte redhat com>
Date:   Fri Aug 20 05:52:10 2021 +0200

    recorder: Make the render nodes in the list draggable
    
    You can (soon) drag any of the nodes directly into the node-editor.

 gtk/inspector/recorder.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)
---
diff --git a/gtk/inspector/recorder.c b/gtk/inspector/recorder.c
index 7b3ead81ee..7b9793b98a 100644
--- a/gtk/inspector/recorder.c
+++ b/gtk/inspector/recorder.c
@@ -21,6 +21,8 @@
 
 #include <gtk/gtkbinlayout.h>
 #include <gtk/gtkbox.h>
+#include <gtk/gtkdragsource.h>
+#include <gtk/gtkeventcontroller.h>
 #include <gtk/gtkfilechooserdialog.h>
 #include <gtk/gtksignallistitemfactory.h>
 #include <gtk/gtklabel.h>
@@ -344,15 +346,39 @@ node_name (GskRenderNode *node)
     }
 }
 
+static GdkContentProvider *
+prepare_render_node_drag (GtkDragSource  *source,
+                          double          x,
+                          double          y,
+                          GtkListItem    *list_item)
+{
+  GtkTreeListRow *row_item;
+  GdkPaintable *paintable;
+  GskRenderNode *node;
+
+  row_item = gtk_list_item_get_item (list_item);
+  if (row_item == NULL)
+    return NULL;
+
+  paintable = gtk_tree_list_row_get_item (row_item);
+  node = gtk_render_node_paintable_get_render_node (GTK_RENDER_NODE_PAINTABLE (paintable));
+
+  return gdk_content_provider_new_typed (GSK_TYPE_RENDER_NODE, node);
+}
+
 static void
 setup_widget_for_render_node (GtkSignalListItemFactory *factory,
                               GtkListItem              *list_item)
 {
   GtkWidget *expander, *box, *child;
+  GtkDragSource *source;
 
   /* expander */
   expander = gtk_tree_expander_new ();
   gtk_list_item_set_child (list_item, expander);
+  source = gtk_drag_source_new ();
+  g_signal_connect (source, "prepare", G_CALLBACK (prepare_render_node_drag), list_item);
+  gtk_widget_add_controller (expander, GTK_EVENT_CONTROLLER (source));
 
   box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 3);
   gtk_tree_expander_set_child (GTK_TREE_EXPANDER (expander), box);