[gtk/wip/chergert/fix-textview-dnd-move-same-view] textview: remove drag selection after dnd move action

[Christian Hergert <chergert src gnome org>]

commit e14d6fe9d5398b0e0edc82ffece1f1726445758a
Author: Christian Hergert <chergert redhat com>
Date:   Thu Jan 6 16:30:34 2022 -0800

    textview: remove drag selection after dnd move action
    
    If we have a GDK_ACTION_MOVE, we need to delete the selection. However,
    previously this only worked when the drop target and drag source were
    different applications, as the selection would get messed up along the
    way.
    
    Instead, we stash marks for the duration of the operation so that we can
    delete the appropriate selection when completing the move.

 gtk/gtktextview.c | 40 ++++++++++++++++++++++++++++++++++++++--
 1 file changed, 38 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtktextview.c b/gtk/gtktextview.c
index db23e9ad86..44fd7c7576 100644
--- a/gtk/gtktextview.c
+++ b/gtk/gtktextview.c
@@ -231,8 +231,13 @@ struct _GtkTextViewPrivate
   guint first_validate_idle;        /* Idle to revalidate onscreen portion, runs before resize */
   guint incremental_validate_idle;  /* Idle to revalidate offscreen portions, runs after redraw */
 
+  /* Mark for drop target */
   GtkTextMark *dnd_mark;
 
+  /* Mark for selection of drag source */
+  GtkTextMark *dnd_drag_begin_mark;
+  GtkTextMark *dnd_drag_end_mark;
+
   GtkIMContext *im_context;
   GtkWidget *popup_menu;
   GMenuModel *extra_menu;
@@ -8056,8 +8061,26 @@ static void
 dnd_finished_cb (GdkDrag     *drag,
                  GtkTextView *self)
 {
-  if (gdk_drag_get_selected_action (drag) == GDK_ACTION_MOVE)
-    gtk_text_buffer_delete_selection (self->priv->buffer, TRUE, self->priv->editable);
+  GtkTextBuffer *buffer = self->priv->buffer;
+
+  if (self->priv->dnd_drag_begin_mark)
+    {
+      if (gdk_drag_get_selected_action (drag) == GDK_ACTION_MOVE)
+        {
+            {
+              GtkTextIter begin, end;
+
+              gtk_text_buffer_get_iter_at_mark (buffer, &begin, self->priv->dnd_drag_begin_mark);
+              gtk_text_buffer_get_iter_at_mark (buffer, &end, self->priv->dnd_drag_end_mark);
+              gtk_text_buffer_delete (buffer, &begin, &end);
+            }
+        }
+
+      gtk_text_buffer_delete_mark (buffer, self->priv->dnd_drag_begin_mark);
+      gtk_text_buffer_delete_mark (buffer, self->priv->dnd_drag_end_mark);
+      self->priv->dnd_drag_begin_mark = NULL;
+      self->priv->dnd_drag_end_mark = NULL;
+    }
 
   self->priv->drag = NULL;
 }
@@ -8067,6 +8090,16 @@ dnd_cancel_cb (GdkDrag *drag,
                GdkDragCancelReason reason,
                GtkTextView *self)
 {
+  GtkTextBuffer *buffer = self->priv->buffer;
+
+  if (self->priv->dnd_drag_begin_mark)
+    {
+      gtk_text_buffer_delete_mark (buffer, self->priv->dnd_drag_begin_mark);
+      gtk_text_buffer_delete_mark (buffer, self->priv->dnd_drag_end_mark);
+      self->priv->dnd_drag_begin_mark = NULL;
+      self->priv->dnd_drag_end_mark = NULL;
+    }
+
   self->priv->drag = NULL;
 }
 
@@ -8108,6 +8141,9 @@ gtk_text_view_start_selection_dnd (GtkTextView       *text_view,
       paintable = gtk_text_util_create_rich_drag_icon (widget, buffer, &start, &end);
       gtk_drag_icon_set_from_paintable (drag, paintable, 0, 0);
       g_object_unref (paintable);
+
+      text_view->priv->dnd_drag_begin_mark = gtk_text_buffer_create_mark (buffer, NULL, &start, TRUE);
+      text_view->priv->dnd_drag_end_mark = gtk_text_buffer_create_mark (buffer, NULL, &end, TRUE);
     }
 
   text_view->priv->drag = drag;