[libdazzle] tree: track drag action for applying DnD

[Christian Hergert <chergert src gnome org>]

commit 77bfba2366738610ea6f9fe8a7654ef50e697f0e
Author: Christian Hergert <chergert redhat com>
Date:   Tue Dec 5 17:22:14 2017 -0800

    tree: track drag action for applying DnD
    
    We need this for the builders to ensure they propagate the
    proper action (such as move instead of copy).

 src/tree/dzl-tree-private.h |    1 +
 src/tree/dzl-tree.c         |   34 ++++++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 0 deletions(-)
---
diff --git a/src/tree/dzl-tree-private.h b/src/tree/dzl-tree-private.h
index 5683fbd..a0c949d 100644
--- a/src/tree/dzl-tree-private.h
+++ b/src/tree/dzl-tree-private.h
@@ -45,6 +45,7 @@ void          _dzl_tree_remove                          (DzlTree
 DzlTreeNode  *_dzl_tree_get_drop_node                   (DzlTree                *self,
                                                          DzlTreeDropPosition    *pos);
 GPtrArray    *_dzl_tree_get_builders                    (DzlTree                *self);
+GdkDragAction _dzl_tree_get_drag_action                 (DzlTree                *self);
 gboolean      _dzl_tree_get_iter                        (DzlTree                *self,
                                                          DzlTreeNode            *node,
                                                          GtkTreeIter            *iter);
diff --git a/src/tree/dzl-tree.c b/src/tree/dzl-tree.c
index e09d9fd..ee43e11 100644
--- a/src/tree/dzl-tree.c
+++ b/src/tree/dzl-tree.c
@@ -42,6 +42,7 @@ typedef struct
   GtkCellRenderer         *cell_text;
 
   GtkTreeViewDropPosition  last_drop_pos;
+  GdkDragAction            drag_action;
 
   GdkRGBA                  dim_foreground;
 
@@ -962,6 +963,28 @@ _dzl_tree_get_drop_node (DzlTree             *self,
 }
 
 static void
+dzl_tree_drag_data_received (GtkWidget        *widget,
+                             GdkDragContext   *context,
+                             gint              x,
+                             gint              y,
+                             GtkSelectionData *data,
+                             guint             info,
+                             guint             time_)
+{
+  DzlTree *self = (DzlTree *)widget;
+  DzlTreePrivate *priv = dzl_tree_get_instance_private (self);
+
+  g_assert (DZL_IS_TREE (widget));
+  g_assert (GDK_IS_DRAG_CONTEXT (context));
+  g_assert (data != NULL);
+
+  /* Drag the drag action for use in dispatch */
+  priv->drag_action = gdk_drag_context_get_selected_action (context);
+
+  GTK_WIDGET_CLASS (dzl_tree_parent_class)->drag_data_received (widget, context, x, y, data, info, time_);
+}
+
+static void
 dzl_tree_style_updated (GtkWidget *widget)
 {
   DzlTree *self = (DzlTree *)widget;
@@ -1094,6 +1117,7 @@ dzl_tree_class_init (DzlTreeClass *klass)
   widget_class->style_updated = dzl_tree_style_updated;
 
   widget_class->drag_motion = dzl_tree_drag_motion;
+  widget_class->drag_data_received = dzl_tree_drag_data_received;
   widget_class->drag_end = dzl_tree_drag_end;
 
   tree_view_class->row_activated = dzl_tree_row_activated;
@@ -1943,3 +1967,13 @@ _dzl_tree_get_builders (DzlTree *self)
 
   return priv->builders;
 }
+
+GdkDragAction
+_dzl_tree_get_drag_action (DzlTree *self)
+{
+  DzlTreePrivate *priv = dzl_tree_get_instance_private (self);
+
+  g_return_val_if_fail (DZL_IS_TREE (self), 0);
+
+  return priv->drag_action;
+}