Full-screen Magnifier: Support warping the cursor on the edge

ash/accelerators/accelerator_controller.cc

 // Copyright (c) 2012 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/accelerators/accelerator_controller.h"
 
+#include <cmath>
+
 #include "ash/accelerators/accelerator_table.h"
 #include "ash/ash_switches.h"
 #include "ash/caps_lock_delegate.h"
 #include "ash/desktop_background/desktop_background_controller.h"
 #include "ash/focus_cycler.h"
 #include "ash/ime_control_delegate.h"
 #include "ash/launcher/launcher.h"
 #include "ash/launcher/launcher_delegate.h"
 #include "ash/launcher/launcher_model.h"
+#include "ash/magnifier/magnification_controller.h"
 #include "ash/monitor/monitor_controller.h"
 #include "ash/monitor/multi_monitor_manager.h"
 #include "ash/root_window_controller.h"
 #include "ash/screenshot_delegate.h"
 #include "ash/shell.h"
 #include "ash/shell_delegate.h"
 #include "ash/shell_window_ids.h"
 #include "ash/system/brightness/brightness_control_delegate.h"
 #include "ash/system/tray/system_tray.h"
 #include "ash/volume_control_delegate.h"
@@ skipping 14 matching lines @@
 #include "ui/compositor/screen_rotation.h"
 #include "ui/oak/oak.h"
 
 #if defined(OS_CHROMEOS)
 #include "chromeos/monitor/output_configurator.h"
 #endif  // defined(OS_CHROMEOS)
 
 namespace ash {
 namespace {
 
+// Factor of magnification scale. For example, when this value is 1.189, scale
+// value will be changed x1.000, x1.189, x1.414, x1.681, x2.000, ...
+// Note: this value is 2.0 ^ (1 / 4).
+const float kMagnificationFactor = 1.18920712;
+
 bool HandleCycleWindowMRU(WindowCycleController::Direction direction,
                           bool is_alt_down) {
   Shell::GetInstance()->
       window_cycle_controller()->HandleCycleWindow(direction, is_alt_down);
   // Always report we handled the key, even if the window didn't change.
   return true;
 }
 
 void HandleCycleWindowLinear(CycleDirection direction) {
   Shell::GetInstance()->launcher()->CycleWindowLinear(direction);
@@ skipping 148 matching lines @@
 
 bool HandlePrintWindowHierarchy() {
   DLOG(INFO) << "Window hierarchy:";
   aura::Window* container =
       Shell::GetPrimaryRootWindowController()->GetContainer(
           internal::kShellWindowId_DefaultContainer);
   PrintWindowHierarchy(container, 0);
   return true;
 }
 
+// Magnify the screen
+bool HandleMagnifyScreen(int delta_index) {
+  float scale =
+       ash::Shell::GetInstance()->magnification_controller()->GetScale();
+  // Calculate rounded logarithm (base kMagnificationFactor) of scale.
+  int scale_index =
+      std::floor(std::log(scale) / std::log(kMagnificationFactor) + 0.5);
+
+  int new_scale_index = std::max(0, std::min(8, scale_index + delta_index));
+
+  ash::Shell::GetInstance()->magnification_controller()->
+      SetScale(std::pow(kMagnificationFactor, new_scale_index), true);
+
+  return true;
+}
+
 #endif  // !defined(NDEBUG)
 
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 // AcceleratorController, public:
 
 AcceleratorController::AcceleratorController()
     : accelerator_manager_(new ui::AcceleratorManager) {
   Init();
@@ skipping 290 matching lines @@
       return HandlePrintWindowHierarchy();
     case MONITOR_ADD_REMOVE:
       internal::MultiMonitorManager::AddRemoveMonitor();
       return true;
     case MONITOR_CYCLE:
       internal::MultiMonitorManager::CycleMonitor();
       return true;
     case MONITOR_TOGGLE_SCALE:
       internal::MultiMonitorManager::ToggleMonitorScale();
       return true;
+    case MAGNIFY_SCREEN_ZOOM_IN:
+      return HandleMagnifyScreen(1);
+    case MAGNIFY_SCREEN_ZOOM_OUT:
+      return HandleMagnifyScreen(-1);
 #endif
     default:
       NOTREACHED() << "Unhandled action " << action;
   }
   return false;
 }
 
 void AcceleratorController::SetBrightnessControlDelegate(
     scoped_ptr<BrightnessControlDelegate> brightness_control_delegate) {
   brightness_control_delegate_.swap(brightness_control_delegate);
@@ skipping 56 matching lines @@
     // Then set this one as active.
     Shell::GetInstance()->launcher()->ActivateLauncherItem(found_index);
   }
 }
 
 bool AcceleratorController::CanHandleAccelerators() const {
   return true;
 }
 
 }  // namespace ash