Refactors maximize mode event handling into its own class

ash/wm/maximize_mode/maximize_mode_window_manager.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_window_manager.h"
 
 #include "ash/aura/wm_window_aura.h"
 #include "ash/common/ash_switches.h"
 #include "ash/common/session/session_state_delegate.h"
 #include "ash/common/shell_window_ids.h"
+#include "ash/common/wm/maximize_mode/maximize_mode_event_handler.h"
 #include "ash/common/wm/mru_window_tracker.h"
 #include "ash/common/wm/overview/window_selector_controller.h"
 #include "ash/common/wm/window_state.h"
 #include "ash/common/wm/wm_event.h"
 #include "ash/common/wm_shell.h"
 #include "ash/root_window_controller.h"
 #include "ash/shell.h"
 #include "ash/wm/maximize_mode/maximize_mode_window_state.h"
 #include "ash/wm/maximize_mode/workspace_backdrop_delegate.h"
 #include "ash/wm/window_state_aura.h"
 #include "ash/wm/window_util.h"
 #include "ash/wm/workspace_controller.h"
 #include "base/command_line.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/window.h"
 #include "ui/display/screen.h"
 
 namespace ash {
 
 namespace {
 
-// The height of the area in which a touch operation leads to exiting the
-// full screen mode.
-const int kLeaveFullScreenAreaHeightInPixel = 2;
-
 // Exits overview mode if it is currently active.
 void CancelOverview() {
   WindowSelectorController* controller =
       WmShell::Get()->window_selector_controller();
   if (controller->IsSelecting())
     controller->OnSelectionEnded();
 }
 
 }  // namespace
 
 MaximizeModeWindowManager::~MaximizeModeWindowManager() {
   // Overview mode needs to be ended before exiting maximize mode to prevent
   // transforming windows which are currently in
   // overview: http://crbug.com/366605
   CancelOverview();
 
-  Shell::GetInstance()->RemovePreTargetHandler(this);
   WmShell::Get()->RemoveShellObserver(this);
   display::Screen::GetScreen()->RemoveObserver(this);
   EnableBackdropBehindTopWindowOnEachDisplay(false);
   RemoveWindowCreationObservers();
   RestoreAllWindows();
 }
 
 int MaximizeModeWindowManager::GetNumberOfManagedWindows() {
   return window_state_map_.size();
 }
@@ skipping 96 matching lines @@
 void MaximizeModeWindowManager::OnDisplayRemoved(
     const display::Display& display) {
   DisplayConfigurationChanged();
 }
 
 void MaximizeModeWindowManager::OnDisplayMetricsChanged(const display::Display&,
                                                         uint32_t) {
   // Nothing to do here.
 }
 
-void MaximizeModeWindowManager::OnTouchEvent(ui::TouchEvent* event) {
-  const SessionStateDelegate* delegate =
-      Shell::GetInstance()->session_state_delegate();
-
-  if (delegate->IsScreenLocked())
-    return;
-
-  switch (delegate->GetSessionState()) {
-    case SessionStateDelegate::SESSION_STATE_LOGIN_PRIMARY:
-      return;
-    case SessionStateDelegate::SESSION_STATE_ACTIVE:
-      break;
-    case SessionStateDelegate::SESSION_STATE_LOGIN_SECONDARY:
-      return;
-  }
-
-  if (event->type() != ui::ET_TOUCH_PRESSED)
-    return;
-
-  // Find the active window (from the primary screen) to un-fullscreen.
-  aura::Window* window = wm::GetActiveWindow();
-  if (!window)
-    return;
-
-  wm::WindowState* window_state = wm::GetWindowState(window);
-  if (!window_state->IsFullscreen() || window_state->in_immersive_fullscreen())
-    return;
-
-  // Test that the touch happened in the top or bottom lines.
-  int y = event->y();
-  if (y >= kLeaveFullScreenAreaHeightInPixel &&
-      y < (window->bounds().height() - kLeaveFullScreenAreaHeightInPixel)) {
-    return;
-  }
-
-  // Leave full screen mode.
-  event->StopPropagation();
-  wm::WMEvent toggle_fullscreen(wm::WM_EVENT_TOGGLE_FULLSCREEN);
-  window_state->OnWMEvent(&toggle_fullscreen);
-}
-
 MaximizeModeWindowManager::MaximizeModeWindowManager()
     : backdrops_hidden_(false) {
   // The overview mode needs to be ended before the maximize mode is started. To
   // guarantee the proper order, it will be turned off from here.
   CancelOverview();
 
   MaximizeAllWindows();
   AddWindowCreationObservers();
   EnableBackdropBehindTopWindowOnEachDisplay(true);
   display::Screen::GetScreen()->AddObserver(this);
   WmShell::Get()->AddShellObserver(this);
-  Shell::GetInstance()->AddPreTargetHandler(this);
+  event_handler_ = WmShell::Get()->CreateMaximizeModeEventHandler();
 }
 
 void MaximizeModeWindowManager::MaximizeAllWindows() {
   MruWindowTracker::WindowList windows = ash::Shell::GetInstance()
                                              ->mru_window_tracker()
                                              ->BuildWindowListIgnoreModal();
   // Add all existing Mru windows.
   for (WmWindow* window : windows)
     MaximizeAndTrackWindow(WmWindowAura::GetAuraWindow(window));
 }
@@ skipping 112 matching lines @@
     aura::Window* container = Shell::GetContainer(
         controller->GetRootWindow(), kShellWindowId_DefaultContainer);
     controller->workspace_controller()->SetMaximizeBackdropDelegate(
         std::unique_ptr<WorkspaceLayoutManagerBackdropDelegate>(
             enable ? new WorkspaceBackdropDelegate(WmWindowAura::Get(container))
                    : nullptr));
   }
 }
 
 }  // namespace ash