MacViews: Allow ui::EventLocationFromNative to handle native titlebars

ui/events/cocoa/events_mac.mm

 // Copyright 2014 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 "ui/events/event_utils.h"
 
 #include <Cocoa/Cocoa.h>
 
 #include "base/logging.h"
 #include "base/time/time.h"
@@ skipping 69 matching lines @@
   NSTimeInterval since_system_startup = [native_event timestamp];
   // Truncate to extract seconds before doing floating point arithmetic.
   int64_t seconds = since_system_startup;
   since_system_startup -= seconds;
   int64_t microseconds = since_system_startup * 1000000;
   return base::TimeDelta::FromSeconds(seconds) +
       base::TimeDelta::FromMicroseconds(microseconds);
 }
 
 gfx::Point EventLocationFromNative(const base::NativeEvent& native_event) {
-  if (![native_event window]) {
+  NSWindow* window = [native_event window];
+  if (!window) {
     NOTIMPLEMENTED();  // Point will be in screen coordinates.
     return gfx::Point();
   }
   NSPoint location = [native_event locationInWindow];
-  return gfx::Point(location.x,
-                    NSHeight([[native_event window] frame]) - location.y);
+  NSRect content_rect = [window contentRectForFrameRect:[window frame]];
+  return gfx::Point(location.x, NSHeight(content_rect) - location.y);
 }

[tapted, 2014/06/05 07:33:35]

Note most of my local branches have been using a "ui/gfx/mac/point_utils.mm".
I'm not yet sure if it will be widely used, so haven't tried to land it. But
it's another possible approach for this stuff. Example in another CL:
https://codereview.chromium.org/303543004/diff/20001/ui/gfx/mac/point_utils.mm 

e.g. we could put a function in ui/gfx which was like

gfx::Point WindowPointFromNSPoint(NSWindow* window, const NSPoint& point) {
  if (!window)
    return ScreenPointFromNSPoint(point);
  NSRect content_rect = [window contentRectForFrameRect:[window frame]];
  return gfx::Point(location.x, NSHeight(content_rect) - location.y);
}

and here do

return gfx::WindowPointFromNSPoint([native_event window],
                                   [native_event locationInWindow]);

let me know if that approach sounds better.

[Robert Sesek, 2014/06/05 14:08:27]

I think I like extracting this information directly from the NSEvent better than
requiring the caller to pass the window.

 
 gfx::Point EventSystemLocationFromNative(
     const base::NativeEvent& native_event) {
   NOTIMPLEMENTED();
   return gfx::Point();
 }
 
 int EventButtonFromNative(const base::NativeEvent& native_event) {
   NOTIMPLEMENTED();
   return 0;
@@ skipping 110 matching lines @@
 
 KeyboardCode KeyboardCodeFromNative(const base::NativeEvent& native_event) {
   return KeyboardCodeFromNSEvent(native_event);
 }
 
 const char* CodeFromNative(const base::NativeEvent& native_event) {
   return CodeFromNSEvent(native_event);
 }
 
 }  // namespace ui