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(XEvent native_event,
  23                           scoped_ptr<aura::WindowTracker> tracker) {
  24   // The target window may be gone.
  25   if (tracker->windows().empty())
  26     return;
  27   aura::Window* target = *(tracker->windows().begin());
  28   ui::KeyEvent event(&native_event);
  29   event.set_flags(event.flags() | ui::EF_IS_SYNTHESIZED);
  30   ui::EventDispatchDetails result ALLOW_UNUSED =
  31       target->GetHost()->event_processor()->OnEventFromSource(&event);
  32 }
  33
  34 void PostPressedEvent(ui::KeyEvent* event) {
  35   // Modify RELEASED event to PRESSED event.
  36   XEvent xkey = *(event->native_event());
  37   xkey.xkey.type = KeyPress;
  38   xkey.xkey.state |= ShiftMask;
  39   scoped_ptr<aura::WindowTracker> tracker(new aura::WindowTracker);
  40   tracker->Add(static_cast<aura::Window*>(event->target()));
  41
  42   base::MessageLoopForUI::current()->PostTask(
  43       FROM_HERE,
  44       base::Bind(&DispatchPressedEvent, xkey, base::Passed(&tracker)));
  45 }
  46
  47 }  // namespace
  48
  49 KeyHoldDetector::KeyHoldDetector(scoped_ptr<Delegate> delegate)
  50     : state_(INITIAL),
  51       delegate_(delegate.Pass()) {}
  52
  53 KeyHoldDetector::~KeyHoldDetector() {}
  54
  55 void KeyHoldDetector::OnKeyEvent(ui::KeyEvent* event) {
  56   if (!delegate_->ShouldProcessEvent(event))
  57     return;
  58
  59   if (delegate_->IsStartEvent(event)) {
  60     switch (state_) {
  61       case INITIAL:
  62         // Pass through posted event.
  63         if (event->flags() & ui::EF_IS_SYNTHESIZED) {
  64           event->set_flags(event->flags() & ~ui::EF_IS_SYNTHESIZED);
  65           return;
  66         }
  67         state_ = PRESSED;
  68         // Don't process ET_KEY_PRESSED event yet. The ET_KEY_PRESSED
  69         // event will be generated upon ET_KEY_RELEASEED event below.
  70         event->StopPropagation();
  71         break;
  72       case PRESSED:
  73         state_ = HOLD;
  74         // pass through
  75       case HOLD:
  76         delegate_->OnKeyHold(event);
  77         event->StopPropagation();
  78         break;
  79       }
  80   } else if (event->type() == ui::ET_KEY_RELEASED) {
  81     switch (state_) {
  82       case INITIAL:
  83         break;
  84       case PRESSED: {
  85         PostPressedEvent(event);
  86         event->StopPropagation();
  87         break;
  88       }
  89       case HOLD: {
  90         delegate_->OnKeyUnhold(event);
  91         event->StopPropagation();
  92         break;
  93       }
  94     }
  95     state_ = INITIAL;
  96   }
  97 }
  98
  99 }  // namespace ash