[gtk+/multitouch-for-3.4: 49/89] gtk, scrolledwindow: Ensure the view snaps back when overshooting

[Carlos Garnacho <carlosg src gnome org>]

commit f48fdd2b432dbe13d29bc2c47578821ff29e7bbb
Author: Carlos Garnacho <carlosg gnome org>
Date:   Wed Jan 4 23:58:13 2012 +0100

    gtk,scrolledwindow: Ensure the view snaps back when overshooting
    
    Instead of just stopping the acceleration source ID, check whether
    it's overshooting, and let it snap back if needed after ::grab-notify
    and ::button-release-event

 gtk/gtkscrolledwindow.c |   35 +++++++++++++----------------------
 1 files changed, 13 insertions(+), 22 deletions(-)
---
diff --git a/gtk/gtkscrolledwindow.c b/gtk/gtkscrolledwindow.c
index 98aaaec..d0bde13 100644
--- a/gtk/gtkscrolledwindow.c
+++ b/gtk/gtkscrolledwindow.c
@@ -2351,24 +2351,6 @@ gtk_scrolled_window_cancel_deceleration (GtkScrolledWindow *scrolled_window)
       g_source_remove (priv->deceleration_id);
       priv->deceleration_id = 0;
     }
-
-  /* Ensure the overshoot window is clamped to the adjustments' limits */
-  if (_gtk_scrolled_window_get_overshoot (scrolled_window, NULL, NULL))
-    {
-      GtkAdjustment *vadjustment, *hadjustment;
-
-      vadjustment = gtk_range_get_adjustment (GTK_RANGE (priv->vscrollbar));
-      hadjustment = gtk_range_get_adjustment (GTK_RANGE (priv->hscrollbar));
-
-      _gtk_scrolled_window_set_adjustment_value (scrolled_window,
-                                                 vadjustment,
-                                                 gtk_adjustment_get_value (vadjustment),
-                                                 FALSE, TRUE);
-      _gtk_scrolled_window_set_adjustment_value (scrolled_window,
-                                                 hadjustment,
-                                                 gtk_adjustment_get_value (hadjustment),
-                                                 FALSE, TRUE);
-    }
 }
 
 static void
@@ -2430,6 +2412,9 @@ gtk_scrolled_window_release_captured_event (GtkScrolledWindow *scrolled_window)
       priv->button_press_event = NULL;
     }
 
+  if (_gtk_scrolled_window_get_overshoot (scrolled_window, NULL, NULL))
+    gtk_scrolled_window_start_deceleration (scrolled_window);
+
   return FALSE;
 }
 
@@ -2476,6 +2461,7 @@ gtk_scrolled_window_captured_button_release (GtkWidget *widget,
   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
   GtkWidget *child;
   GdkEventButton *event;
+  gboolean overshoot;
 
   event = (GdkEventButton *)_event;
 
@@ -2495,6 +2481,8 @@ gtk_scrolled_window_captured_button_release (GtkWidget *widget,
       priv->release_timeout_id = 0;
     }
 
+  overshoot = _gtk_scrolled_window_get_overshoot (scrolled_window, NULL, NULL);
+
   if (priv->in_drag)
     gdk_device_ungrab (event->device, event->time);
   else
@@ -2504,7 +2492,8 @@ gtk_scrolled_window_captured_button_release (GtkWidget *widget,
        */
       gtk_scrolled_window_release_captured_event (scrolled_window);
 
-      return FALSE;
+      if (!overshoot)
+        return FALSE;
     }
   priv->in_drag = FALSE;
 
@@ -2522,8 +2511,7 @@ gtk_scrolled_window_captured_button_release (GtkWidget *widget,
   if (!priv->vscrollbar_visible)
     priv->y_velocity = 0;
 
-  if (priv->x_velocity != 0 || priv->y_velocity != 0 ||
-      _gtk_scrolled_window_get_overshoot (scrolled_window, NULL, NULL))
+  if (priv->x_velocity != 0 || priv->y_velocity != 0 || overshoot)
     {
       gtk_scrolled_window_start_deceleration (scrolled_window);
       priv->x_velocity = priv->y_velocity = 0;
@@ -3310,7 +3298,10 @@ gtk_scrolled_window_grab_notify (GtkWidget *widget,
           priv->release_timeout_id = 0;
         }
 
-      gtk_scrolled_window_cancel_deceleration (scrolled_window);
+      if (_gtk_scrolled_window_get_overshoot (scrolled_window, NULL, NULL))
+        gtk_scrolled_window_start_deceleration (scrolled_window);
+      else
+        gtk_scrolled_window_cancel_deceleration (scrolled_window);
 
       priv->last_button_event_x_root = -TOUCH_BYPASS_CAPTURED_THRESHOLD;
       priv->last_button_event_y_root = -TOUCH_BYPASS_CAPTURED_THRESHOLD;