textview: Avoid usage of gdk_window_get_device_position() during DnD

Just use the last coordinates given on XdndPosition/drag_motion() in
order to trigger scrolling.

When running on Xwayland, the pointer position is unknown at this
stage on the X11 side, so the coordinates given here are bogus.
This change avoids both roundtrips and this situation.

https://bugzilla.gnome.org/show_bug.cgi?id=749679

1 files changed, 16 insertions, 35 deletions

diff --git a/gtk/gtktextview.c b/gtk/gtktextview.c
index a2475868c6..bbc033ac94 100644
--- a/gtk/gtktextview.c
+++ b/gtk/gtktextview.c
@@ -136,7 +136,9 @@ struct _GtkTextViewPrivate
   guint blink_time;  /* time in msec the cursor has blinked since last user event */
   guint im_spot_idle;
   gchar *im_module;
-  GdkDevice *dnd_device;
+
+  gint dnd_x;
+  gint dnd_y;
 
   GtkTextHandle *text_handle;
   GtkWidget *selection_bubble;
@@ -6837,33 +6839,6 @@ gtk_text_view_unselect (GtkTextView *text_view)
 }
 
 static void
-get_iter_at_pointer (GtkTextView *text_view,
-                     GdkDevice   *device,
-                     GtkTextIter *iter,
-		     gint        *x,
-		     gint        *y)
-{
-  GtkTextViewPrivate *priv;
-  gint xcoord, ycoord;
-  GdkModifierType state;
-
-  priv = text_view->priv;
-
-  gdk_window_get_device_position (priv->text_window->bin_window,
-                                  device, &xcoord, &ycoord, &state);
-
-  gtk_text_layout_get_iter_at_pixel (priv->layout,
-                                     iter,
-                                     xcoord + priv->xoffset,
-                                     ycoord + priv->yoffset);
-  if (x)
-    *x = xcoord;
-
-  if (y)
-    *y = ycoord;
-}
-
-static void
 move_mark_to_pointer_and_scroll (GtkTextView    *text_view,
                                  const gchar    *mark_name)
 {
@@ -6923,20 +6898,22 @@ drag_scan_timeout (gpointer data)
   GtkTextView *text_view;
   GtkTextViewPrivate *priv;
   GtkTextIter newplace;
-  gint x, y;
   gdouble pointer_xoffset, pointer_yoffset;
 
   text_view = GTK_TEXT_VIEW (data);
   priv = text_view->priv;
 
-  get_iter_at_pointer (text_view, priv->dnd_device, &newplace, &x, &y);
+  gtk_text_layout_get_iter_at_pixel (priv->layout,
+                                     &newplace,
+                                     priv->dnd_x + priv->xoffset,
+                                     priv->dnd_y + priv->yoffset);
 
   gtk_text_buffer_move_mark (get_buffer (text_view),
                              priv->dnd_mark,
                              &newplace);
 
-  pointer_xoffset = (gdouble) x / gdk_window_get_width (priv->text_window->bin_window);
-  pointer_yoffset = (gdouble) y / gdk_window_get_height (priv->text_window->bin_window);
+  pointer_xoffset = (gdouble) priv->dnd_x / gdk_window_get_width (priv->text_window->bin_window);
+  pointer_yoffset = (gdouble) priv->dnd_y / gdk_window_get_height (priv->text_window->bin_window);
 
   if (check_scroll (pointer_xoffset, priv->hadjustment) ||
       check_scroll (pointer_yoffset, priv->vadjustment))
@@ -7782,6 +7759,10 @@ static void
 gtk_text_view_drag_end (GtkWidget        *widget,
                         GdkDragContext   *context)
 {
+  GtkTextView *text_view;
+
+  text_view = GTK_TEXT_VIEW (widget);
+  text_view->priv->dnd_x = text_view->priv->dnd_y = -1;
 }
 
 static void
@@ -7868,8 +7849,7 @@ gtk_text_view_drag_leave (GtkWidget        *widget,
 
   gtk_text_mark_set_visible (priv->dnd_mark, FALSE);
 
-  if (priv->dnd_device)
-    priv->dnd_device = NULL;
+  priv->dnd_x = priv->dnd_y = -1;
 
   if (priv->scroll_timeout != 0)
     g_source_remove (priv->scroll_timeout);
@@ -7966,7 +7946,8 @@ gtk_text_view_drag_motion (GtkWidget        *widget,
       gtk_text_mark_set_visible (priv->dnd_mark, FALSE);
     }
 
-  priv->dnd_device = gdk_drag_context_get_device (context);
+  priv->dnd_x = x;
+  priv->dnd_y = y;
 
   if (!priv->scroll_timeout)
   {