2nd try

Add shortcut keys to ui scaling
- Round root window size because it can be fractional size
  when root_window_scale_ is specified.
- Remove scaling option from about:flags.
- Rotate display where the mouse is in.

BUG=179997,119268

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=188324

Review URL: https://codereview.chromium.org/12848004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@188362 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 56 insertions, 8 deletions

diff --git a/ash/accelerators/accelerator_controller.cc b/ash/accelerators/accelerator_controller.cc
index 8194d90..a2656cf 100644
--- a/ash/accelerators/accelerator_controller.cc
+++ b/ash/accelerators/accelerator_controller.cc
@@ -154,7 +154,7 @@ bool HandleRotateActiveWindow() {
   return true;
 }
 
-const gfx::Display::Rotation GetNextRotation(gfx::Display::Rotation current) {
+gfx::Display::Rotation GetNextRotation(gfx::Display::Rotation current) {
   switch (current) {
     case gfx::Display::ROTATE_0:
       return gfx::Display::ROTATE_90;
@@ -169,13 +169,40 @@ const gfx::Display::Rotation GetNextRotation(gfx::Display::Rotation current) {
   return gfx::Display::ROTATE_0;
 }
 
+float GetNextScale(float scale, int next) {
+  // These scales are equivalent to 1024, 1280, 1600 and 1920 pixel width
+  // respectively on 2560 pixel width 2x density display.
+  static const float kScales[] = {0.8f, 1.0f, 1.25f, 1.5f};
+  static const int kScaleTableSize = arraysize(kScales);
+  const float* location = std::find(kScales, kScales + kScaleTableSize, scale);
+  // Fallback to 1.0f if the |scale| wasn't in the list.
+  if (location == kScales + kScaleTableSize)
+    return 1.0f;
+  int index = std::distance(kScales, location) + next;
+  return kScales[std::min(kScaleTableSize - 1, std::max(0, index))];
+}
+
+bool HandleScaleUI(bool up) {
+  // UI Scaling is effective only on internal display.
+  int64 display_id = gfx::Display::InternalDisplayId();
+#if defined(OS_CHROMEOS)
+  // On linux desktop, allow ui scalacing on the first dislpay.
+  if (!base::chromeos::IsRunningOnChromeOS())
+    display_id = Shell::GetInstance()->display_manager()->first_display_id();
+#endif
+  const gfx::Display& display = Shell::GetInstance()->display_manager()->
+      GetDisplayForId(display_id);
+  const DisplayInfo& display_info = Shell::GetInstance()->display_manager()->
+      GetDisplayInfo(display);
+  Shell::GetInstance()->display_manager()->SetDisplayUIScale(
+      display.id(), GetNextScale(display_info.ui_scale(), up ? 1 : -1));
+  return true;
+}
+
 // Rotates the screen.
 bool HandleRotateScreen() {
-  aura::Window* active_window = wm::GetActiveWindow();
-  if (!active_window)
-    return false;
-  const gfx::Display& display =
-      Shell::GetScreen()->GetDisplayNearestWindow(active_window);
+  gfx::Point point = Shell::GetScreen()->GetCursorScreenPoint();
+  gfx::Display display = Shell::GetScreen()->GetDisplayNearestPoint(point);
   const DisplayInfo& display_info =
       Shell::GetInstance()->display_manager()->GetDisplayInfo(display);
   Shell::GetInstance()->display_manager()->SetDisplayRotation(
@@ -758,6 +785,10 @@ bool AcceleratorController::PerformAction(int action,
       }
       break;
     }
+    case SCALE_UI_UP:
+      return HandleScaleUI(true /* up */);
+    case SCALE_UI_DOWN:
+      return HandleScaleUI(false /* down */);
     case ROTATE_WINDOW:
       return HandleRotateActiveWindow();
     case ROTATE_SCREEN:
@@ -767,7 +798,7 @@ bool AcceleratorController::PerformAction(int action,
     case TOGGLE_ROOT_WINDOW_FULL_SCREEN:
       return HandleToggleRootWindowFullScreen();
     case DISPLAY_TOGGLE_SCALE:
-      internal::DisplayManager::ToggleDisplayScale();
+      internal::DisplayManager::ToggleDisplayScaleFactor();
       return true;
     case MAGNIFY_SCREEN_ZOOM_IN:
       return HandleMagnifyScreen(1);
diff --git a/ash/accelerators/accelerator_table.cc b/ash/accelerators/accelerator_table.cc
index 54e4c5b..02de15d 100644
--- a/ash/accelerators/accelerator_table.cc
+++ b/ash/accelerators/accelerator_table.cc
@@ -77,7 +77,11 @@ const AcceleratorData kAcceleratorData[] = {
   // Extra shortcut to lock the screen on linux desktop.
   { true, ui::VKEY_POWER, ui::EF_SHIFT_DOWN, LOCK_PRESSED },
   { false, ui::VKEY_POWER, ui::EF_SHIFT_DOWN, LOCK_RELEASED },
+  // Extra shortcut to rotate/scale up/down the screen on linux desktop.
   { true, ui::VKEY_F3, ui::EF_SHIFT_DOWN | ui::EF_CONTROL_DOWN, ROTATE_SCREEN },
+  { true, ui::VKEY_F2, ui::EF_CONTROL_DOWN , SCALE_UI_UP },
+  { true, ui::VKEY_F2,
+    ui::EF_CONTROL_DOWN | ui::EF_SHIFT_DOWN, SCALE_UI_DOWN },
 #endif  // !defined(NDEBUG)
   { true, ui::VKEY_O, ui::EF_CONTROL_DOWN, OPEN_FILE_DIALOG },
   { true, ui::VKEY_M, ui::EF_SHIFT_DOWN | ui::EF_ALT_DOWN,
@@ -101,6 +105,10 @@ const AcceleratorData kAcceleratorData[] = {
     NEW_INCOGNITO_WINDOW },
   { true, ui::VKEY_N, ui::EF_CONTROL_DOWN, NEW_WINDOW },
   { true, ui::VKEY_T, ui::EF_CONTROL_DOWN, NEW_TAB },
+  { true, ui::VKEY_BROWSER_BACK,
+    ui::EF_CONTROL_DOWN | ui::EF_SHIFT_DOWN, SCALE_UI_UP },
+  { true, ui::VKEY_BROWSER_FORWARD,
+    ui::EF_CONTROL_DOWN | ui::EF_SHIFT_DOWN, SCALE_UI_DOWN },
   { true, ui::VKEY_BROWSER_REFRESH,
     ui::EF_CONTROL_DOWN | ui::EF_SHIFT_DOWN, ROTATE_SCREEN },
   { true, ui::VKEY_BROWSER_REFRESH,
@@ -129,7 +137,8 @@ const AcceleratorData kAcceleratorData[] = {
   { true, ui::VKEY_F14, ui::EF_NONE, SHOW_KEYBOARD_OVERLAY },
   { true, ui::VKEY_N, ui::EF_SHIFT_DOWN | ui::EF_ALT_DOWN,
     SHOW_MESSAGE_CENTER_BUBBLE },
-  { true, ui::VKEY_BROWSER_BACK, ui::EF_SHIFT_DOWN | ui::EF_CONTROL_DOWN,
+  { true, ui::VKEY_BROWSER_BACK,
+    ui::EF_SHIFT_DOWN | ui::EF_CONTROL_DOWN | ui::EF_ALT_DOWN,
     SHOW_OAK },
   { true, ui::VKEY_S, ui::EF_SHIFT_DOWN | ui::EF_ALT_DOWN,
     SHOW_SYSTEM_TRAY_BUBBLE },
@@ -228,6 +237,8 @@ const AcceleratorAction kActionsAllowedAtLoginOrLockScreen[] = {
   VOLUME_UP,
   ROTATE_SCREEN,
   ROTATE_WINDOW,
+  SCALE_UI_UP,
+  SCALE_UI_DOWN,
 #if !defined(NDEBUG)
   PRINT_LAYER_HIERARCHY,
   PRINT_VIEW_HIERARCHY,
@@ -294,6 +305,8 @@ const AcceleratorAction kNonrepeatableActions[] = {
   CYCLE_FORWARD_MRU,
   ROTATE_SCREEN,
   ROTATE_WINDOW,
+  SCALE_UI_UP,
+  SCALE_UI_DOWN,
   TOGGLE_MAXIMIZED,
   WINDOW_MINIMIZE,
 };
@@ -321,6 +334,8 @@ const AcceleratorAction kActionsAllowedInAppMode[] = {
   POWER_RELEASED,
   PREVIOUS_IME,
   ROTATE_SCREEN,
+  SCALE_UI_UP,
+  SCALE_UI_DOWN,
   SWAP_PRIMARY_DISPLAY,
   SWITCH_IME,  // Switch to another IME depending on the accelerator.
   TOGGLE_CAPS_LOCK,
diff --git a/ash/accelerators/accelerator_table.h b/ash/accelerators/accelerator_table.h
index f8d99ac..c95a048 100644
--- a/ash/accelerators/accelerator_table.h
+++ b/ash/accelerators/accelerator_table.h
@@ -47,6 +47,8 @@ enum AcceleratorAction {
   RESTORE_TAB,
   ROTATE_SCREEN,
   ROTATE_WINDOW,
+  SCALE_UI_DOWN,
+  SCALE_UI_UP,
   SELECT_LAST_WIN,
   SELECT_WIN_0,
   SELECT_WIN_1,