ozone: evdev: Make cancellation of repeats on key up more robust

ui/events/ozone/evdev/keyboard_evdev.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 "ui/events/ozone/evdev/keyboard_evdev.h"
 
+#include "base/single_thread_task_runner.h"
+#include "base/thread_task_runner_handle.h"
 #include "ui/events/event.h"
 #include "ui/events/event_constants.h"
 #include "ui/events/event_utils.h"
 #include "ui/events/keycodes/dom4/keycode_converter.h"
 #include "ui/events/ozone/evdev/event_modifiers_evdev.h"
 #include "ui/events/ozone/evdev/keyboard_util_evdev.h"
 #include "ui/events/ozone/layout/keyboard_layout_engine.h"
 #include "ui/events/ozone/layout/keyboard_layout_engine_manager.h"
 #include "ui/events/ozone/layout/layout_util.h"
 
@@ skipping 35 matching lines @@
 
 }  // namespace
 
 KeyboardEvdev::KeyboardEvdev(EventModifiersEvdev* modifiers,
                              KeyboardLayoutEngine* keyboard_layout_engine,
                              const EventDispatchCallback& callback)
     : callback_(callback),
       modifiers_(modifiers),
       keyboard_layout_engine_(keyboard_layout_engine),
       repeat_enabled_(true),
-      repeat_key_(KEY_RESERVED) {
+      repeat_key_(KEY_RESERVED),
+      repeat_sequence_(0),
+      weak_ptr_factory_(this) {
   repeat_delay_ = base::TimeDelta::FromMilliseconds(kRepeatDelayMs);
   repeat_interval_ = base::TimeDelta::FromMilliseconds(kRepeatIntervalMs);
 }
 
 KeyboardEvdev::~KeyboardEvdev() {
 }
 
 void KeyboardEvdev::OnKeyChange(unsigned int key,
                                 bool down,
                                 base::TimeDelta timestamp) {
@@ skipping 66 matching lines @@
   if (!repeat_enabled_)
     StopKeyRepeat();
   else if (key != repeat_key_ && down)
     StartKeyRepeat(key);
   else if (key == repeat_key_ && !down)
     StopKeyRepeat();
 }
 
 void KeyboardEvdev::StartKeyRepeat(unsigned int key) {
   repeat_key_ = key;
-  repeat_delay_timer_.Start(
-      FROM_HERE, repeat_delay_,
-      base::Bind(&KeyboardEvdev::OnRepeatDelayTimeout, base::Unretained(this)));
-  repeat_interval_timer_.Stop();
+  repeat_sequence_++;
+
+  ScheduleKeyRepeat(repeat_delay_);
 }
 
 void KeyboardEvdev::StopKeyRepeat() {
-  repeat_key_ = KEY_RESERVED;
-  repeat_delay_timer_.Stop();
-  repeat_interval_timer_.Stop();
+  repeat_sequence_++;
 }
 
-void KeyboardEvdev::OnRepeatDelayTimeout() {
-  DispatchKey(repeat_key_, true /* down */, true /* repeat */,
-              EventTimeForNow());
-
-  repeat_interval_timer_.Start(
-      FROM_HERE, repeat_interval_,
-      base::Bind(&KeyboardEvdev::OnRepeatIntervalTimeout,
-                 base::Unretained(this)));
+void KeyboardEvdev::ScheduleKeyRepeat(const base::TimeDelta& delay) {
+  base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
+      FROM_HERE, base::Bind(&KeyboardEvdev::OnRepeatTimeout,
+                            weak_ptr_factory_.GetWeakPtr(), repeat_sequence_),
+      delay);
 }
 
-void KeyboardEvdev::OnRepeatIntervalTimeout() {
+void KeyboardEvdev::OnRepeatTimeout(unsigned int sequence) {
+  if (repeat_sequence_ != sequence)
+    return;
+
+  DispatchKeyRepeat(repeat_key_);

[alexst (slow to review), 2015/04/07 18:20:58]

Probably worth just moving DispatchKey from DispatchKeyRepeat here since it's
only used in one place.

[spang, 2015/04/07 18:28:49]

Done.

+  ScheduleKeyRepeat(repeat_interval_);
+}
+
+void KeyboardEvdev::DispatchKeyRepeat(unsigned int key) {
   DispatchKey(repeat_key_, true /* down */, true /* repeat */,
               EventTimeForNow());
 }
 
 void KeyboardEvdev::DispatchKey(unsigned int key,
                                 bool down,
                                 bool repeat,
                                 base::TimeDelta timestamp) {
   DomCode dom_code =
       KeycodeConverter::NativeKeycodeToDomCode(EvdevCodeToNativeCode(key));
@@ skipping 14 matching lines @@
     UpdateModifier(ModifierDomKeyToEventFlag(dom_key), down);
 
   KeyEvent event(down ? ET_KEY_PRESSED : ET_KEY_RELEASED, key_code, dom_code,
                  modifiers_->GetModifierFlags(), dom_key, character, timestamp);
   if (platform_keycode)
     event.set_platform_keycode(platform_keycode);
   callback_.Run(&event);
 }
 
 }  // namespace ui