Only block internal touchpad and allow external mice to continue working in maximize mode.

ash/wm/maximize_mode/maximize_mode_event_blocker.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 "ash/wm/maximize_mode/maximize_mode_event_blocker.h"
 
 #include "ash/shell.h"
+#include "ash/wm/maximize_mode/internal_input_device_list.h"
 #include "base/memory/scoped_ptr.h"
 #include "ui/aura/client/cursor_client.h"
+#include "ui/aura/window_event_dispatcher.h"
+#include "ui/aura/window_tree_host.h"
 #include "ui/events/event_targeter.h"
 #include "ui/events/keycodes/keyboard_codes.h"
+#include "ui/gfx/point.h"
+
+#if defined(USE_X11)
+#include "ash/wm/maximize_mode/internal_input_device_list_x11.h"
+#endif
 
 namespace ash {
 
 namespace {
 
 // Event targeter to prevent delivery of mouse and touchpad events while
 // maximize mode is active. Other events such as touch are passed on to the
 // default targeter.
-// TODO(flackr): This should only stop events from the internal keyboard and
-// touchpad.
 class BlockKeyboardAndTouchpadTargeter : public ui::EventTargeter {
  public:
-  BlockKeyboardAndTouchpadTargeter();
+  BlockKeyboardAndTouchpadTargeter(
+      aura::Window* root_window,
+      MaximizeModeEventBlocker* event_blocker);
   virtual ~BlockKeyboardAndTouchpadTargeter();
 
   // Sets the default targeter to use when the event is not being blocked.
   void SetDefaultTargeter(EventTargeter* default_targeter);
 
   // Overridden from ui::EventTargeter:
   virtual ui::EventTarget* FindTargetForEvent(ui::EventTarget* root,
                                               ui::Event* event) OVERRIDE;
 
  private:
+  // A weak pointer to the root window on which this targeter will be set. The
+  // root window owns this targeter.
+  aura::Window* root_window_;
+
+  // A weak pointer to the event blocker which owns the scoped targeter owning
+  // this targeter.
+  MaximizeModeEventBlocker* event_blocker_;
+
   // A weak pointer to the targeter this targeter is wrapping. The
   // default_targeter is owned by the ScopedWindowTargeter which will be valid
   // as long as this targeter is alive.
   ui::EventTargeter* default_targeter_;
 
+  // The last known mouse location to lock the cursor in place to when events
+  // come from the internal touchpad.
+  gfx::Point last_mouse_location_;
+
   DISALLOW_COPY_AND_ASSIGN(BlockKeyboardAndTouchpadTargeter);
 };
 
-BlockKeyboardAndTouchpadTargeter::BlockKeyboardAndTouchpadTargeter()
-    : default_targeter_(NULL) {
+BlockKeyboardAndTouchpadTargeter::BlockKeyboardAndTouchpadTargeter(
+    aura::Window* root_window,
+    MaximizeModeEventBlocker* event_blocker)
+    : root_window_(root_window),
+      event_blocker_(event_blocker),
+      default_targeter_(NULL),
+      last_mouse_location_(root_window->GetHost()->dispatcher()->
+          GetLastMouseLocationInRoot()) {
 }
 
 BlockKeyboardAndTouchpadTargeter::~BlockKeyboardAndTouchpadTargeter() {
 }
 
 void BlockKeyboardAndTouchpadTargeter::SetDefaultTargeter(
     ui::EventTargeter* default_targeter) {
   default_targeter_ = default_targeter;
 }
 
 ui::EventTarget* BlockKeyboardAndTouchpadTargeter::FindTargetForEvent(
     ui::EventTarget* root,
     ui::Event* event) {
-  if (event->IsMouseEvent() ||
-      event->IsMouseWheelEvent() ||
-      event->IsScrollEvent()) {
+  bool internal_device = event_blocker_->internal_devices() &&
+      event_blocker_->internal_devices()->IsEventFromInternalDevice(event);
+  if (event->IsMouseEvent()) {
+    if (internal_device) {
+      // The cursor movement is handled at a lower level which is not blocked.
+      // Move the mouse cursor back to its last known location resulting from
+      // an external mouse to prevent the internal touchpad from moving it.
+      root_window_->GetHost()->MoveCursorToHostLocation(
+          last_mouse_location_);
+      return NULL;
+    } else {
+      // Track the last location seen from an external mouse event.
+      last_mouse_location_ =
+          static_cast<ui::MouseEvent*>(event)->root_location();
+      root_window_->GetHost()->ConvertPointToHost(&last_mouse_location_);
+    }
+  } else if (internal_device && (event->IsMouseWheelEvent() ||
+                                 event->IsScrollEvent())) {
     return NULL;
-  }
-  if (event->IsKeyEvent() && event->HasNativeEvent()) {
+  } else if (event->IsKeyEvent() && event->HasNativeEvent()) {
+    // TODO(flackr): Disable events only from the internal keyboard device
+    // when we begin using XI2 events for keyboard events
+    // (http://crbug.com/368750) and can tell which device the event is
+    // coming from, http://crbug.com/362881.
     // TODO(bruthig): Fix this to block rewritten volume keys
     // (i.e. F9 and F10)  from the device's keyboard. https://crbug.com/368669
     ui::KeyEvent* key_event = static_cast<ui::KeyEvent*>(event);
     if (key_event->key_code() != ui::VKEY_VOLUME_DOWN &&
         key_event->key_code() != ui::VKEY_VOLUME_UP
 #if defined(OS_CHROMEOS)
-        && key_event->key_code() != ui::VKEY_POWER
+      && key_event->key_code() != ui::VKEY_POWER
 #endif
         ) {
       return NULL;
     }
   }
   return default_targeter_->FindTargetForEvent(root, event);
 }
 
 }  // namespace
 
-MaximizeModeEventBlocker::MaximizeModeEventBlocker() {
+MaximizeModeEventBlocker::MaximizeModeEventBlocker()
+#if defined(USE_X11)
+    : internal_devices_(new InternalInputDeviceListX11)
+#endif
+    {
   Shell::GetInstance()->AddShellObserver(this);
 
   // Hide the cursor as mouse events will be blocked.
   aura::client::CursorClient* cursor_client_ =
       aura::client::GetCursorClient(Shell::GetTargetRootWindow());
   if (cursor_client_)
     cursor_client_->HideCursor();
 
   // Block keyboard and mouse events on all existing and new root windows for
   // the lifetime of this class.
   aura::Window::Windows root_windows(Shell::GetAllRootWindows());
   for (aura::Window::Windows::iterator iter = root_windows.begin();
        iter != root_windows.end(); ++iter) {
     AddEventTargeterOn(*iter);
   }
 }
 
 MaximizeModeEventBlocker::~MaximizeModeEventBlocker() {
   Shell::GetInstance()->RemoveShellObserver(this);
 }
 
 void MaximizeModeEventBlocker::OnRootWindowAdded(aura::Window* root_window) {
   AddEventTargeterOn(root_window);
 }
 
 void MaximizeModeEventBlocker::AddEventTargeterOn(
     aura::Window* root_window) {
   BlockKeyboardAndTouchpadTargeter* targeter =
-      new BlockKeyboardAndTouchpadTargeter();
+      new BlockKeyboardAndTouchpadTargeter(root_window, this);
   aura::ScopedWindowTargeter* scoped_targeter = new aura::ScopedWindowTargeter(
       root_window, scoped_ptr<ui::EventTargeter>(targeter));
   targeter->SetDefaultTargeter(scoped_targeter->old_targeter());
   targeters_.push_back(scoped_targeter);
 }
 
 }  // namespace ash