Long press menu (shift+f6) to toggle spoken feedback.

ash/accelerators/key_hold_detector.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/magnifier/magnifier_key_scroller.h"
+#include "ash/accelerators/key_hold_detector.h"
 
 #include <X11/Xlib.h>
 
 #undef RootWindow
 #undef Status
 
-#include "ash/ash_switches.h"
-#include "ash/magnifier/magnification_controller.h"
 #include "ash/shell.h"
-#include "base/command_line.h"
 #include "base/message_loop/message_loop.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/window_tracker.h"
+#include "ui/events/event_dispatcher.h"
 
 namespace ash {
 namespace {
 
-bool magnifier_key_scroller_enabled = false;
-
-void ScrollScreen(ui::KeyEvent* event) {
-  MagnificationController* controller =
-      Shell::GetInstance()->magnification_controller();
-  switch (event->key_code()) {
-    case ui::VKEY_UP:
-      controller->SetScrollDirection(MagnificationController::SCROLL_UP);
-      break;
-    case ui::VKEY_DOWN:
-      controller->SetScrollDirection(MagnificationController::SCROLL_DOWN);
-      break;
-    case ui::VKEY_LEFT:
-      controller->SetScrollDirection(MagnificationController::SCROLL_LEFT);
-      break;
-    case ui::VKEY_RIGHT:
-      controller->SetScrollDirection(MagnificationController::SCROLL_RIGHT);
-      break;
-    default:
-      NOTREACHED() << "Unknown keyboard_code:" << event->key_code();
-  }
-}
-
 void DispatchPressedEvent(XEvent native_event,
                           scoped_ptr<aura::WindowTracker> tracker) {
   // The target window may be gone.
   if (tracker->windows().empty())
     return;
   aura::Window* target = *(tracker->windows().begin());
   ui::KeyEvent event(&native_event, false);
   event.set_flags(event.flags() | ui::EF_IS_SYNTHESIZED);
   ui::EventDispatchDetails result ALLOW_UNUSED =
       target->GetDispatcher()->OnEventFromSource(&event);
 }
 
 void PostPressedEvent(ui::KeyEvent* event) {
   // Modify RELEASED event to PRESSED event.
   XEvent xkey = *(event->native_event());
   xkey.xkey.type = KeyPress;
   xkey.xkey.state |= ShiftMask;
   scoped_ptr<aura::WindowTracker> tracker(new aura::WindowTracker);
   tracker->Add(static_cast<aura::Window*>(event->target()));
 
   base::MessageLoopForUI::current()->PostTask(
       FROM_HERE,
       base::Bind(&DispatchPressedEvent, xkey, base::Passed(&tracker)));
 }
 
 }  // namespace
 
-// static
-bool MagnifierKeyScroller::IsEnabled() {
-  return (magnifier_key_scroller_enabled ||
-          CommandLine::ForCurrentProcess()->HasSwitch(
-              switches::kAshEnableMagnifierKeyScroller)) &&
-      ash::Shell::GetInstance()->magnification_controller()->IsEnabled();
-}
+KeyHoldDetector::KeyHoldDetector(scoped_ptr<Delegate> delegate)
+    : state_(INITIAL),
+      delegate_(delegate.Pass()) {}
 
-// static
-void MagnifierKeyScroller::SetEnabled(bool enabled) {
-  magnifier_key_scroller_enabled = enabled;
-}
+KeyHoldDetector::~KeyHoldDetector() {}
 
-MagnifierKeyScroller::MagnifierKeyScroller()
-    : state_(INITIAL) {}
-
-MagnifierKeyScroller::~MagnifierKeyScroller() {}
-
-void MagnifierKeyScroller::OnKeyEvent(
-    ui::KeyEvent* event) {
-  if (!IsEnabled())
+void KeyHoldDetector::OnKeyEvent(ui::KeyEvent* event) {
+  if (!delegate_->ShouldProcessEvent(event))
     return;
 
-  if (event->key_code() != ui::VKEY_UP &&
-      event->key_code() != ui::VKEY_DOWN &&
-      event->key_code() != ui::VKEY_LEFT &&
-      event->key_code() != ui::VKEY_RIGHT) {
-    return;
-  }
-
-  if (event->type() == ui::ET_KEY_PRESSED &&
-      event->flags() & ui::EF_SHIFT_DOWN) {
+  if (delegate_->IsStartEvent(event)) {
     switch (state_) {
       case INITIAL:
         // Pass through posted event.
         if (event->flags() & ui::EF_IS_SYNTHESIZED) {
           event->set_flags(event->flags() & ~ui::EF_IS_SYNTHESIZED);
           return;
         }
         state_ = PRESSED;
         // Don't process ET_KEY_PRESSED event yet. The ET_KEY_PRESSED
         // event will be generated upon ET_KEY_RELEASEED event below.
         event->StopPropagation();
         break;
       case PRESSED:
         state_ = HOLD;
         // pass through
       case HOLD:
-        ScrollScreen(event);
+        delegate_->OnKeyHold(event);
         event->StopPropagation();
         break;
       }
   } else if (event->type() == ui::ET_KEY_RELEASED) {
     switch (state_) {
       case INITIAL:
         break;
       case PRESSED: {
         PostPressedEvent(event);
         event->StopPropagation();
         break;
       }
       case HOLD: {
-        MagnificationController* controller =
-            Shell::GetInstance()->magnification_controller();
-        controller->SetScrollDirection(MagnificationController::SCROLL_NONE);
+        delegate_->OnKeyUnhold(event);
+        // controller->SetScrollDirection(MagnificationController::SCROLL_NONE);

[xiyuan, 2014/02/14 01:50:21]

nit: remove this?

[oshima, 2014/02/14 18:03:25]

Done.

         event->StopPropagation();
         break;
       }
     }
     state_ = INITIAL;
   }
 }
 
 }  // namespace ash