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ash / components / arc / compat_mode / touch_mode_mouse_rewriter.cc [blame]
// Copyright 2021 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/components/arc/compat_mode/touch_mode_mouse_rewriter.h"
#include <tuple>
#include "ash/components/arc/compat_mode/metrics.h"
#include "ash/shell.h"
#include "base/functional/bind.h"
#include "base/task/sequenced_task_runner.h"
#include "ui/aura/window_tree_host.h"
#include "ui/events/base_event_utils.h"
namespace arc {
namespace {
// In Android, the default long press threshold is 500ms.
constexpr base::TimeDelta kLongPressInterval = base::Milliseconds(700);
// The scale from MouseWheelEvent's |y_offset| to ScrollEvent's |y_offset|.
// TODO(b/202679170): Verify that this value is working well, as the value was
// chosen tentatively.
constexpr int kWheelToSmoothScrollScale = 3;
// The total time from the first simulated smooth scroll event to the last one.
constexpr base::TimeDelta kSmoothScrollTimeout = base::Milliseconds(500);
// The interval between simulated smooth scroll events.
constexpr base::TimeDelta kSmoothScrollEventInterval = base::Milliseconds(20);
} // namespace
TouchModeMouseRewriter::TouchModeMouseRewriter() = default;
TouchModeMouseRewriter::~TouchModeMouseRewriter() {
std::set<aura::WindowTreeHost*> unique_hosts(hosts_.begin(), hosts_.end());
for (aura::WindowTreeHost* host : unique_hosts)
host->GetEventSource()->RemoveEventRewriter(this);
}
void TouchModeMouseRewriter::EnableForWindow(aura::Window* window) {
if (window_observations_.IsObservingSource(window))
return;
enabled_windows_.insert(window);
OnWindowAddedToRootWindow(window);
window_observations_.AddObservation(window);
}
void TouchModeMouseRewriter::DisableForWindow(aura::Window* window) {
OnWindowDestroying(window);
}
void TouchModeMouseRewriter::OnWindowDestroying(aura::Window* window) {
if (!window_observations_.IsObservingSource(window))
return;
window_observations_.RemoveObservation(window);
OnWindowRemovingFromRootWindow(window, nullptr);
enabled_windows_.erase(window);
}
void TouchModeMouseRewriter::OnWindowAddedToRootWindow(aura::Window* window) {
aura::WindowTreeHost* host = window->GetHost();
if (!host)
return;
// |hosts_| is a multiset, so if this is the first one, add the EventRewriter
// to that WindowTreeHost.
if (hosts_.count(host) == 0)
host->GetEventSource()->AddEventRewriter(this);
hosts_.insert(host);
}
void TouchModeMouseRewriter::OnWindowRemovingFromRootWindow(
aura::Window* window,
aura::Window* new_root) {
aura::WindowTreeHost* host = window->GetHost();
if (!host)
return;
auto it = hosts_.find(host);
DCHECK(it != hosts_.end());
hosts_.erase(it);
// |hosts_| is a multiset, so if this is the last one, remove the
// EventRewriter from that WindowTreeHost.
if (hosts_.count(host) == 0)
host->GetEventSource()->RemoveEventRewriter(this);
}
ui::EventDispatchDetails TouchModeMouseRewriter::RewriteEvent(
const ui::Event& event,
const Continuation continuation) {
if (!event.IsMouseEvent())
return SendEvent(continuation, &event);
auto* screen = display::Screen::GetScreen();
aura::Window* target =
screen->GetWindowAtScreenPoint(screen->GetCursorScreenPoint());
// Only handle clicks to the content area of an Exo window i.e. exclude the
// caption bar.
if (!target || target->GetType() != aura::client::WINDOW_TYPE_CONTROL)
return SendEvent(continuation, &event);
const bool in_resize_locked = IsInResizeLockedWindow(target);
if (event.IsMouseWheelEvent()) {
if (!in_resize_locked)
return SendEvent(continuation, &event);
return RewriteMouseWheelEvent(*event.AsMouseWheelEvent(), continuation);
}
const ui::MouseEvent& mouse_event = *event.AsMouseEvent();
if (mouse_event.IsRightMouseButton() || mouse_event.IsLeftMouseButton()) {
if (!in_resize_locked) {
return SendEvent(continuation, &event);
}
return RewriteMouseClickEvent(mouse_event, continuation);
}
return SendEvent(continuation, &event);
}
void TouchModeMouseRewriter::SendReleaseEvent(
const ui::MouseEvent& original_event,
const Continuation continuation) {
release_event_scheduled_ = false;
ui::MouseEvent release_event(
ui::EventType::kMouseReleased, original_event.location(),
original_event.root_location(), ui::EventTimeForNow(),
ui::EF_LEFT_MOUSE_BUTTON, ui::EF_LEFT_MOUSE_BUTTON);
std::ignore = SendEvent(continuation, &release_event);
}
void TouchModeMouseRewriter::SendScrollEvent(
const ui::MouseWheelEvent& original_event,
const Continuation continuation) {
if (scroll_timeout_.is_zero())
return;
const int y_step =
scroll_y_offset_ * (kSmoothScrollEventInterval / scroll_timeout_);
const int x_step =
scroll_x_offset_ * (kSmoothScrollEventInterval / scroll_timeout_);
ui::ScrollEvent scroll_event(
ui::EventType::kScroll, original_event.location_f(),
original_event.root_location_f(), ui::EventTimeForNow(), 0, x_step,
y_step, x_step, y_step, 1);
std::ignore = SendEvent(continuation, &scroll_event);
scroll_y_offset_ -= y_step;
scroll_x_offset_ -= x_step;
scroll_timeout_ -= kSmoothScrollEventInterval;
if (scroll_timeout_.is_zero()) {
ui::ScrollEvent fling_start_event(ui::EventType::kScrollFlingStart,
original_event.location_f(),
original_event.root_location_f(),
ui::EventTimeForNow(), 0, 0, 0, 0, 0, 0);
std::ignore = SendEvent(continuation, &fling_start_event);
} else {
base::SequencedTaskRunner::GetCurrentDefault()->PostDelayedTask(
FROM_HERE,
base::BindOnce(&TouchModeMouseRewriter::SendScrollEvent,
weak_ptr_factory_.GetWeakPtr(), original_event,
continuation),
kSmoothScrollEventInterval);
}
}
ui::EventDispatchDetails TouchModeMouseRewriter::RewriteMouseWheelEvent(
const ui::MouseWheelEvent& event,
const Continuation continuation) {
const bool started = !scroll_timeout_.is_zero();
scroll_y_offset_ += kWheelToSmoothScrollScale * event.y_offset();
scroll_x_offset_ += kWheelToSmoothScrollScale * event.x_offset();
scroll_timeout_ = kSmoothScrollTimeout;
if (!started) {
ui::ScrollEvent fling_cancel_event(
ui::EventType::kScrollFlingCancel, event.location_f(),
event.root_location_f(), event.time_stamp(), 0, 0, 0, 0, 0, 0);
base::SequencedTaskRunner::GetCurrentDefault()->PostTask(
FROM_HERE,
base::BindOnce(&TouchModeMouseRewriter::SendScrollEvent,
weak_ptr_factory_.GetWeakPtr(), event, continuation));
return SendEvent(continuation, &fling_cancel_event);
}
return DiscardEvent(continuation);
}
ui::EventDispatchDetails TouchModeMouseRewriter::RewriteMouseClickEvent(
const ui::MouseEvent& event,
const Continuation continuation) {
if (event.IsRightMouseButton()) {
// 1. If there is already an ongoing simulated long press, discard the
// subsequent right click.
// 2. If the left button is currently pressed, discard the right click.
// 3. Discard events that is not a right press.
if (release_event_scheduled_ || left_pressed_ ||
event.type() != ui::EventType::kMousePressed) {
return DiscardEvent(continuation);
}
// Schedule the release event after |kLongPressInterval|.
release_event_scheduled_ = true;
base::SequencedTaskRunner::GetCurrentDefault()->PostDelayedTask(
FROM_HERE,
base::BindOnce(&TouchModeMouseRewriter::SendReleaseEvent,
weak_ptr_factory_.GetWeakPtr(), event, continuation),
kLongPressInterval);
// Send the press event now.
ui::MouseEvent press_event(
ui::EventType::kMousePressed, event.location(), event.root_location(),
event.time_stamp(), ui::EF_LEFT_MOUSE_BUTTON, ui::EF_LEFT_MOUSE_BUTTON);
return SendEvent(continuation, &press_event);
} else if (event.IsLeftMouseButton()) {
if (event.type() == ui::EventType::kMousePressed) {
left_pressed_ = true;
} else if (event.type() == ui::EventType::kMouseReleased) {
left_pressed_ = false;
}
// Discard a release event that corresponds to a previously discarded press
// event.
if (discard_next_left_release_ &&
event.type() == ui::EventType::kMouseReleased) {
discard_next_left_release_ = false;
return DiscardEvent(continuation);
}
// Discard the left click if there is an ongoing simulated long press.
if (release_event_scheduled_) {
if (event.type() == ui::EventType::kMousePressed) {
discard_next_left_release_ = true;
}
return DiscardEvent(continuation);
}
return SendEvent(continuation, &event);
}
return SendEvent(continuation, &event);
}
bool TouchModeMouseRewriter::IsInResizeLockedWindow(
const aura::Window* window) const {
// TODO(b/202679170): Verify that it does not affect performance before
// flipping the flag, and fix it if necessary.
while (window != nullptr) {
if (enabled_windows_.count(window))
return true;
window = window->parent();
}
return false;
}
} // namespace arc