Add gesture target fuzzing to views

ui/views/view.h

 // 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.
 
 #ifndef UI_VIEWS_VIEW_H_
 #define UI_VIEWS_VIEW_H_
 
 #include <algorithm>
 #include <map>
 #include <set>
@@ skipping 482 matching lines @@
 
   // Enable/Disable accelerated compositing.
   static void set_use_acceleration_when_possible(bool use);
   static bool get_use_acceleration_when_possible();
 
   // Input ---------------------------------------------------------------------
   // The points (and mouse locations) in the following functions are in the
   // view's coordinates, except for a RootView.
 
   // Returns the deepest visible descendant that contains the specified point.
   virtual View* GetEventHandlerForPoint(const gfx::Point& point);

[sky, 2012/08/02 15:52:08]

Add a comment to this that if overriding GetEventHandlerForPoint you'll need to
override this GetEventHandlerForRect.

[tdanderson, 2012/08/02 18:11:37]

Done.

 
+  // Considers the bounding rectangles of all leaf descendant views that have
+  // at least views::kFuzzingOverlapPercentage of their area covered by
+  // |touch_rect|. Among these rectangles, choose one that is closest to the

[sky, 2012/08/02 15:52:08]

touch_rect -> rect

Why is the rect in screen coordinates? It should be location coordinates as is
GetEventHandleForPoint and most other methods.

[tdanderson, 2012/08/02 18:11:37]

Done.
I decided to keep everything in screen coordinates because
GetEventHandlerForRect makes calls to PercentCoveredBy and
DistanceSquaredFromCenterLineToPoint, which both require a common coordinate
system for their parameters. This way seems to require less work in switching
back and forth between different coordinate systems.

+  // center line of |touch_rect| and return its corresponding View. If there
+  // are no such rectangles, NULL is returned. Note that |touch_rect| is in
+  // screen coordinates.
+  virtual View* GetEventHandlerForRect(const gfx::Rect& touch_rect);
+
   // Return the cursor that should be used for this view or the default cursor.
   // The event location is in the receiver's coordinate system. The caller is
   // responsible for managing the lifetime of the returned object, though that
   // lifetime may vary from platform to platform. On Windows and Aura,
   // the cursor is a shared resource.
   virtual gfx::NativeCursor GetCursor(const MouseEvent& event);
 
   // Convenience to test whether a point is within this view's bounds
   virtual bool HitTest(const gfx::Point& l) const;
 
@@ skipping 953 matching lines @@
   base::win::ScopedComPtr<NativeViewAccessibilityWin>
       native_view_accessibility_win_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(View);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_VIEW_H_