MacViews: Create abstraction for event monitoring

ui/views/event_monitor_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/views/event_monitor_mac.h"
+
+#include "base/logging.h"
+#include "ui/events/event.h"
+#include "ui/events/event_handler.h"
+#include "ui/events/event_utils.h"
+
+namespace views {
+
+// static
+EventMonitor* EventMonitor::Create(ui::EventHandler* event_handler) {
+  return new EventMonitorMac(event_handler);
+}
+
+// static
+gfx::Point EventMonitor::GetLastMouseLocation() {
+  NSPoint mouseLocation = [NSEvent mouseLocation];
+  // Flip coordinates to gfx (0,0 in top-left corner) using primary screen.
+  NSScreen* screen = [[NSScreen screens] objectAtIndex:0];
+  mouseLocation.y = NSMaxY([screen frame]) - mouseLocation.y;
+  return gfx::Point(mouseLocation.x, mouseLocation.y);
+}
+
+EventMonitorMac::EventMonitorMac(ui::EventHandler* event_handler) {
+  DCHECK(event_handler);
+  monitor_ = [NSEvent addLocalMonitorForEventsMatchingMask:NSAnyEventMask
+      handler:^NSEvent*(NSEvent* event){
+                  scoped_ptr<ui::Event> ui_event = ui::EventFromNative(event);
+                  event_handler->OnEvent(ui_event.get());
+                  return event;
+              }];
+}
+
+EventMonitorMac::~EventMonitorMac() {
+  [NSEvent removeMonitor:monitor_];
+}
+
+}  // namespace views