ash/accelerators/key_hold_detector.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/key_hold_detector.h"
   6
   7 #include <X11/Xlib.h>
   8
   9 #undef RootWindow
  10 #undef Status
  11
  12 #include "ash/shell.h"
  13 #include "base/message_loop/message_loop.h"
  14 #include "ui/aura/window_tracker.h"
  15 #include "ui/aura/window_tree_host.h"
  16 #include "ui/events/event_dispatcher.h"
  17 #include "ui/events/event_processor.h"
  18
  19 namespace ash {
  20 namespace {
  21
  22 void DispatchPressedEvent(const ui::KeyEvent& key_event,
  23                           scoped_ptr<aura::WindowTracker> tracker) {
  24   // The target window may be gone.
  25   if (tracker->windows().empty())
  26     return;
  27   ui::KeyEvent event(key_event);
  28   aura::Window* target = *(tracker->windows().begin());
  29   ignore_result(
  30       target->GetHost()->event_processor()->OnEventFromSource(&event));
  31 }
  32
  33 void PostPressedEvent(ui::KeyEvent* event) {
  34   // Modify RELEASED event to PRESSED event.
  35   const ui::KeyEvent pressed_event(
  36       ui::ET_KEY_PRESSED,
  37       event->key_code(),
  38       event->code(),
  39       event->flags() | ui::EF_SHIFT_DOWN | ui::EF_IS_SYNTHESIZED);
  40   scoped_ptr<aura::WindowTracker> tracker(new aura::WindowTracker);
  41   tracker->Add(static_cast<aura::Window*>(event->target()));
  42
  43   base::MessageLoopForUI::current()->PostTask(
  44       FROM_HERE,
  45       base::Bind(&DispatchPressedEvent, pressed_event, base::Passed(&tracker)));
  46 }
  47
  48 }  // namespace
  49
  50 KeyHoldDetector::KeyHoldDetector(scoped_ptr<Delegate> delegate)
  51     : state_(INITIAL),
  52       delegate_(delegate.Pass()) {}
  53
  54 KeyHoldDetector::~KeyHoldDetector() {}
  55
  56 void KeyHoldDetector::OnKeyEvent(ui::KeyEvent* event) {
  57   if (!delegate_->ShouldProcessEvent(event))
  58     return;
  59
  60   if (delegate_->IsStartEvent(event)) {
  61     switch (state_) {
  62       case INITIAL:
  63         // Pass through posted event.
  64         if (event->flags() & ui::EF_IS_SYNTHESIZED) {
  65           event->set_flags(event->flags() & ~ui::EF_IS_SYNTHESIZED);
  66           return;
  67         }
  68         state_ = PRESSED;
  69         // Don't process ET_KEY_PRESSED event yet. The ET_KEY_PRESSED
  70         // event will be generated upon ET_KEY_RELEASEED event below.
  71         event->StopPropagation();
  72         break;
  73       case PRESSED:
  74         state_ = HOLD;
  75         // pass through
  76       case HOLD:
  77         delegate_->OnKeyHold(event);
  78         event->StopPropagation();
  79         break;
  80       }
  81   } else if (event->type() == ui::ET_KEY_RELEASED) {
  82     switch (state_) {
  83       case INITIAL:
  84         break;
  85       case PRESSED: {
  86         PostPressedEvent(event);
  87         event->StopPropagation();
  88         break;
  89       }
  90       case HOLD: {
  91         delegate_->OnKeyUnhold(event);
  92         event->StopPropagation();
  93         break;
  94       }
  95     }
  96     state_ = INITIAL;
  97   }
  98 }
  99
 100 }  // namespace ash