ash/accelerators/magnifier_key_scroller.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "ash/accelerators/magnifier_key_scroller.h"
   6
   7 #include "ash/accelerators/key_hold_detector.h"
   8 #include "ash/ash_switches.h"
   9 #include "ash/magnifier/magnification_controller.h"
  10 #include "ash/shell.h"
  11 #include "base/command_line.h"
  12 #include "ui/events/event.h"
  13
  14 namespace ash {
  15 namespace {
  16 bool magnifier_key_scroller_enabled = false;
  17 }
  18
  19 // static
  20 bool MagnifierKeyScroller::IsEnabled() {
  21   bool has_switch = false;
  22 #if defined(OS_CHROMEOS)
  23   has_switch = base::CommandLine::ForCurrentProcess()->HasSwitch(
  24       switches::kAshEnableMagnifierKeyScroller);
  25 #endif
  26
  27   return (magnifier_key_scroller_enabled || has_switch) &&
  28       ash::Shell::GetInstance()->magnification_controller()->IsEnabled();
  29 }
  30
  31 // static
  32 void MagnifierKeyScroller::SetEnabled(bool enabled) {
  33   magnifier_key_scroller_enabled = enabled;
  34 }
  35
  36 // static
  37 scoped_ptr<ui::EventHandler> MagnifierKeyScroller::CreateHandler() {
  38   scoped_ptr<KeyHoldDetector::Delegate> delegate(new MagnifierKeyScroller());
  39   return scoped_ptr<ui::EventHandler>(new KeyHoldDetector(delegate.Pass()));
  40 }
  41
  42 bool MagnifierKeyScroller::ShouldProcessEvent(const ui::KeyEvent* event) const {
  43   return IsEnabled() &&
  44       (event->key_code() == ui::VKEY_UP ||
  45        event->key_code() == ui::VKEY_DOWN ||
  46        event->key_code() == ui::VKEY_LEFT ||
  47        event->key_code() == ui::VKEY_RIGHT);
  48 }
  49
  50 bool MagnifierKeyScroller::IsStartEvent(const ui::KeyEvent* event) const {
  51   return event->type() == ui::ET_KEY_PRESSED &&
  52       event->flags() & ui::EF_SHIFT_DOWN;
  53 }
  54
  55 bool MagnifierKeyScroller::ShouldStopEventPropagation() const {
  56   return true;
  57 }
  58
  59 void MagnifierKeyScroller::OnKeyHold(const ui::KeyEvent* event) {
  60   MagnificationController* controller =
  61       Shell::GetInstance()->magnification_controller();
  62   switch (event->key_code()) {
  63     case ui::VKEY_UP:
  64       controller->SetScrollDirection(MagnificationController::SCROLL_UP);
  65       break;
  66     case ui::VKEY_DOWN:
  67       controller->SetScrollDirection(MagnificationController::SCROLL_DOWN);
  68       break;
  69     case ui::VKEY_LEFT:
  70       controller->SetScrollDirection(MagnificationController::SCROLL_LEFT);
  71       break;
  72     case ui::VKEY_RIGHT:
  73       controller->SetScrollDirection(MagnificationController::SCROLL_RIGHT);
  74       break;
  75     default:
  76       NOTREACHED() << "Unknown keyboard_code:" << event->key_code();
  77   }
  78 }
  79
  80 void MagnifierKeyScroller::OnKeyUnhold(const ui::KeyEvent* event) {
  81   MagnificationController* controller =
  82       Shell::GetInstance()->magnification_controller();
  83   controller->SetScrollDirection(MagnificationController::SCROLL_NONE);
  84 }
  85
  86 MagnifierKeyScroller::MagnifierKeyScroller() {}
  87
  88 MagnifierKeyScroller::~MagnifierKeyScroller() {}
  89
  90 }  // namespace ash