Make touch-resizing windows to screen edge possible

ash/wm/workspace/workspace_window_resizer.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/wm/workspace/workspace_window_resizer.h"
 
 #include <algorithm>
 #include <cmath>
 #include <utility>
 #include <vector>
@@ skipping 62 matching lines @@
 }
 
 namespace internal {
 
 namespace {
 
 // Distance in pixels that the cursor must move past an edge for a window
 // to move or resize beyond that edge.
 const int kStickyDistancePixels = 64;
 
+// Snapping distance used instead of WorkspaceWindowResizer::kScreenEdgeInset
+// when resizing a window using touchscreen.
+const int kScreenEdgeInsetForTouchResize = 16;
+
 // Returns true if the window should stick to the edge.
 bool ShouldStickToEdge(int distance_from_edge, int sticky_size) {
   if (CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kAshEnableStickyEdges)) {
     return distance_from_edge < 0 &&
            distance_from_edge > -sticky_size;
   }
   return distance_from_edge < sticky_size &&
                               distance_from_edge > -sticky_size * 2;
 }
@@ skipping 227 matching lines @@
                                   int event_flags) {
   last_mouse_location_ = location_in_parent;
 
   int sticky_size;
   if (event_flags & ui::EF_CONTROL_DOWN) {
     sticky_size = 0;
   } else if (CommandLine::ForCurrentProcess()->HasSwitch(
       switches::kAshEnableStickyEdges)) {
     sticky_size = kStickyDistancePixels;
   } else {
-    sticky_size = kScreenEdgeInset;
+    if ((details_.bounds_change & kBoundsChange_Resizes) && details_.is_touch)
+      sticky_size = kScreenEdgeInsetForTouchResize;
+    else
+      sticky_size = kScreenEdgeInset;
   }
   // |bounds| is in |window()->parent()|'s coordinates.
   gfx::Rect bounds = CalculateBoundsForDrag(details_, location_in_parent);
 
   if (wm::IsWindowNormal(window()))
     AdjustBoundsForMainWindow(sticky_size, &bounds);
 
   if (bounds != window()->bounds()) {
     if (!did_move_or_resize_) {
       if (!details_.restore_bounds.IsEmpty())
@@ skipping 503 matching lines @@
   gfx::Rect area(ScreenAsh::GetDisplayBoundsInParent(window()));
   if (location.x() <= area.x())
     return SNAP_LEFT_EDGE;
   if (location.x() >= area.right() - 1)
     return SNAP_RIGHT_EDGE;
   return SNAP_NONE;
 }
 
 }  // namespace internal
 }  // namespace ash