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// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "ash/accessibility/chromevox/touch_accessibility_enabler.h"
#include <math.h>
#include <utility>
#include "base/check.h"
#include "base/metrics/user_metrics.h"
#include "base/notreached.h"
#include "base/numerics/safe_conversions.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 which triggers toggling ChromeVox.
// CFM expects 2 seconds.
constexpr auto kTimerDelay = base::Seconds(2);
} // namespace
TouchAccessibilityEnabler::TouchAccessibilityEnabler(
aura::Window* root_window,
TouchAccessibilityEnablerDelegate* delegate)
: root_window_(root_window),
delegate_(delegate),
state_(NO_FINGERS_DOWN),
tick_clock_(nullptr) {
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::EventType::kTouchPressed) {
touch_locations_.insert(std::pair<int, gfx::PointF>(touch_id, location));
} else if (type == ui::EventType::kTouchReleased ||
type == ui::EventType::kTouchCancelled) {
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::EventType::kTouchMoved) {
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();
}
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::EventType::kTouchPressed) {
state_ = ONE_FINGER_DOWN;
} else if (state_ == ONE_FINGER_DOWN &&
event.type() == ui::EventType::kTouchPressed) {
state_ = TWO_FINGERS_DOWN;
StartTimer();
}
}
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, kTimerDelay, this,
&TouchAccessibilityEnabler::OnTimer);
}
void TouchAccessibilityEnabler::CancelTimer() {
if (timer_.IsRunning()) {
timer_.Stop();
}
}
void TouchAccessibilityEnabler::OnTimer() {
delegate_->ToggleSpokenFeedback();
if (state_ != NO_FINGERS_DOWN) {
state_ = WAIT_FOR_NO_FINGERS;
}
}
void TouchAccessibilityEnabler::ResetToNoFingersDown() {
state_ = NO_FINGERS_DOWN;
touch_locations_.clear();
CancelTimer();
}
} // namespace ash
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