| // Copyright 2016 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/accessibility/touch_accessibility_enabler.h" |
| |
| #include <math.h> |
| |
| #include <utility> |
| |
| #include "base/logging.h" |
| #include "base/metrics/user_metrics.h" |
| #include "base/time/default_tick_clock.h" |
| #include "ui/aura/window.h" |
| #include "ui/aura/window_event_dispatcher.h" |
| #include "ui/aura/window_tree_host.h" |
| #include "ui/events/event.h" |
| #include "ui/events/event_processor.h" |
| #include "ui/events/event_utils.h" |
| |
| namespace ash { |
| |
| namespace { |
| |
| // Delay between timer callbacks. Each one plays a tick sound. |
| constexpr int kTimerDelayInMS = 500; |
| |
| // The number of ticks of the timer before the first sound is generated. |
| constexpr int kTimerTicksOfFirstSoundFeedback = 6; |
| |
| // The number of ticks of the timer before toggling spoken feedback. |
| constexpr int kTimerTicksToToggleSpokenFeedback = 10; |
| |
| } // namespace |
| |
| TouchAccessibilityEnabler::TouchAccessibilityEnabler( |
| aura::Window* root_window, |
| TouchAccessibilityEnablerDelegate* delegate) |
| : root_window_(root_window), |
| delegate_(delegate), |
| state_(NO_FINGERS_DOWN), |
| tick_clock_(nullptr), |
| weak_factory_(this) { |
| DCHECK(root_window); |
| DCHECK(delegate); |
| AddEventHandler(); |
| } |
| |
| TouchAccessibilityEnabler::~TouchAccessibilityEnabler() { |
| RemoveEventHandler(); |
| } |
| |
| void TouchAccessibilityEnabler::RemoveEventHandler() { |
| if (event_handler_installed_) { |
| root_window_->RemovePreTargetHandler(this); |
| event_handler_installed_ = false; |
| ResetToNoFingersDown(); |
| } |
| } |
| |
| void TouchAccessibilityEnabler::AddEventHandler() { |
| if (!event_handler_installed_) { |
| root_window_->AddPreTargetHandler(this); |
| event_handler_installed_ = true; |
| ResetToNoFingersDown(); |
| } |
| } |
| |
| void TouchAccessibilityEnabler::OnTouchEvent(ui::TouchEvent* event) { |
| DCHECK(!(event->flags() & ui::EF_TOUCH_ACCESSIBILITY)); |
| HandleTouchEvent(*event); |
| } |
| |
| void TouchAccessibilityEnabler::HandleTouchEvent(const ui::TouchEvent& event) { |
| DCHECK(!(event.flags() & ui::EF_TOUCH_ACCESSIBILITY)); |
| const ui::EventType type = event.type(); |
| const gfx::PointF& location = event.location_f(); |
| const int touch_id = event.pointer_details().id; |
| |
| if (type == ui::ET_TOUCH_PRESSED) { |
| touch_locations_.insert(std::pair<int, gfx::PointF>(touch_id, location)); |
| } else if (type == ui::ET_TOUCH_RELEASED || type == ui::ET_TOUCH_CANCELLED) { |
| auto iter = touch_locations_.find(touch_id); |
| |
| // Can happen if this object is constructed while fingers were down. |
| if (iter == touch_locations_.end()) |
| return; |
| |
| touch_locations_.erase(touch_id); |
| } else if (type == ui::ET_TOUCH_MOVED) { |
| auto iter = touch_locations_.find(touch_id); |
| |
| // Can happen if this object is constructed while fingers were down. |
| if (iter == touch_locations_.end()) |
| return; |
| |
| float delta = (location - iter->second).Length(); |
| if (delta > gesture_detector_config_.double_tap_slop) { |
| state_ = WAIT_FOR_NO_FINGERS; |
| CancelTimer(); |
| return; |
| } |
| } else { |
| NOTREACHED() << "Unexpected event type received: " << event.GetName(); |
| return; |
| } |
| |
| if (touch_locations_.size() == 0) { |
| state_ = NO_FINGERS_DOWN; |
| CancelTimer(); |
| return; |
| } |
| |
| if (touch_locations_.size() > 2) { |
| state_ = WAIT_FOR_NO_FINGERS; |
| CancelTimer(); |
| return; |
| } |
| |
| if (state_ == NO_FINGERS_DOWN && event.type() == ui::ET_TOUCH_PRESSED) { |
| state_ = ONE_FINGER_DOWN; |
| } else if (state_ == ONE_FINGER_DOWN && |
| event.type() == ui::ET_TOUCH_PRESSED) { |
| state_ = TWO_FINGERS_DOWN; |
| two_finger_start_time_ = Now(); |
| StartTimer(); |
| delegate_->OnTwoFingerTouchStart(); |
| } |
| } |
| |
| base::WeakPtr<TouchAccessibilityEnabler> |
| TouchAccessibilityEnabler::GetWeakPtr() { |
| return weak_factory_.GetWeakPtr(); |
| } |
| |
| base::TimeTicks TouchAccessibilityEnabler::Now() { |
| if (tick_clock_) { |
| // This is the same as what EventTimeForNow() does, but here we do it |
| // with a clock that can be replaced with a simulated clock for tests. |
| return tick_clock_->NowTicks(); |
| } |
| return ui::EventTimeForNow(); |
| } |
| |
| void TouchAccessibilityEnabler::StartTimer() { |
| if (timer_.IsRunning()) |
| return; |
| |
| timer_.Start(FROM_HERE, base::TimeDelta::FromMilliseconds(kTimerDelayInMS), |
| this, &TouchAccessibilityEnabler::OnTimer); |
| } |
| |
| void TouchAccessibilityEnabler::CancelTimer() { |
| if (timer_.IsRunning()) { |
| timer_.Stop(); |
| delegate_->OnTwoFingerTouchStop(); |
| } |
| } |
| |
| void TouchAccessibilityEnabler::OnTimer() { |
| base::TimeTicks now = Now(); |
| double tick_count_f = |
| (now - two_finger_start_time_).InMillisecondsF() / kTimerDelayInMS; |
| int tick_count = roundf(tick_count_f); |
| |
| if (tick_count == kTimerTicksOfFirstSoundFeedback) { |
| base::RecordAction( |
| base::UserMetricsAction("Accessibility.TwoFingersHeldDown")); |
| } |
| |
| if (tick_count >= kTimerTicksOfFirstSoundFeedback && |
| tick_count < kTimerTicksToToggleSpokenFeedback) { |
| delegate_->PlaySpokenFeedbackToggleCountdown(tick_count); |
| } |
| if (tick_count == kTimerTicksToToggleSpokenFeedback) { |
| delegate_->ToggleSpokenFeedback(); |
| state_ = WAIT_FOR_NO_FINGERS; |
| } |
| } |
| |
| void TouchAccessibilityEnabler::ResetToNoFingersDown() { |
| state_ = NO_FINGERS_DOWN; |
| touch_locations_.clear(); |
| CancelTimer(); |
| } |
| |
| } // namespace ash |