MacViews: Implement event monitoring for a specific window

ui/views/event_monitor_aura.cc

 // 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_aura.h"
 
 #include "base/logging.h"
 #include "ui/aura/env.h"
+#include "ui/aura/window.h"
+#include "ui/events/event_target.h"
 
 namespace views {
 
 // static
 EventMonitor* EventMonitor::Create(ui::EventHandler* event_handler) {
-  return new EventMonitorAura(event_handler);
+  return new EventMonitorAura(event_handler, aura::Env::GetInstance());

[tapted, 2014/11/20 22:39:02]

Seems almost odd that aura::Env::GetInstance() works here. GetEventTargeter()
just does NOTREACHED. Do we need the one-argument Create at all? Aura should
probably pass a RootWindow if it doesn't have a specific window in mind.

On Mac, we can say "pass nil to monitor all events sent to the application"

[Andre, 2014/11/21 00:28:28]

It seems to be the current pattern to use aura::Env to monitor app events.
Will RootWindow have the same effect?

[tapted, 2014/11/21 00:57:34]

Ah, I poked around in http://crrev.com/678823002 . Yeah -
aura::Env::GetInstance() seems like the way it's done. And requiring the second
argument would make encapsulation harder. So if it works ignore me :).

But maybe it could be clearer with something like

EventMonitor::CreateApplicaitonMonitor(ui::EventHandler*)
EventMonitor::CreateWindowMonitor(ui::EventHandler*, gfx::NativeWindow)

WDYT?

[Andre, 2014/12/10 00:18:13]

Done.

 }
 
 // static
+EventMonitor* EventMonitor::Create(ui::EventHandler* event_handler,
+                                   gfx::NativeWindow target_window) {
+  return new EventMonitorAura(event_handler, target_window);
+}
+
+// static
 gfx::Point EventMonitor::GetLastMouseLocation() {
   return aura::Env::GetInstance()->last_mouse_location();
 }
 
-EventMonitorAura::EventMonitorAura(ui::EventHandler* event_handler)
-    : event_handler_(event_handler) {
+EventMonitorAura::EventMonitorAura(ui::EventHandler* event_handler,
+                                   ui::EventTarget* event_target)
+    : event_handler_(event_handler),
+      event_target_(event_target) {
   DCHECK(event_handler_);
-  aura::Env::GetInstance()->AddPreTargetHandler(event_handler_);
+  DCHECK(event_target_);
+  event_target_->AddPreTargetHandler(event_handler_);
 }
 
 EventMonitorAura::~EventMonitorAura() {
-  aura::Env::GetInstance()->RemovePreTargetHandler(event_handler_);
+  event_target_->RemovePreTargetHandler(event_handler_);
 }
 
 }  // namespace views