blob: 80f32170baefaafb2e699ad3db01d9d7bf831e1b [file] [log] [blame]
// Copyright 2019 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 "components/exo/wayland/serial_tracker.h"
#include <wayland-server-core.h>
namespace exo {
namespace wayland {
namespace {
// Number of previous events to retain information about.
constexpr uint32_t kMaxEventsTracked = 1024;
} // namespace
SerialTracker::SerialTracker(struct wl_display* display)
: display_(display), events_(kMaxEventsTracked) {}
SerialTracker::~SerialTracker() {}
uint32_t SerialTracker::GetNextSerial(EventType type) {
uint32_t serial = wl_display_next_serial(display_);
events_[serial % kMaxEventsTracked] = type;
max_event_ = serial + 1;
if ((max_event_ - min_event_) > kMaxEventsTracked)
min_event_ = max_event_ - kMaxEventsTracked;
switch (type) {
case EventType::POINTER_BUTTON_DOWN:
pointer_down_serial_ = serial;
break;
case EventType::POINTER_BUTTON_UP:
pointer_down_serial_ = base::nullopt;
break;
case EventType::TOUCH_DOWN:
touch_down_serial_ = serial;
break;
case EventType::TOUCH_UP:
touch_down_serial_ = base::nullopt;
break;
default:
break;
}
return serial;
}
base::Optional<SerialTracker::EventType> SerialTracker::GetEventType(
uint32_t serial) const {
if (max_event_ < min_event_) {
// The valid range has partially overflowed the 32 bit space, so we should
// only reject if the serial number is in neither the upper nor lower parts
// of the space.
if (!((serial < max_event_) || (serial >= min_event_)))
return base::nullopt;
} else {
// Normal, non-overflowed case. Reject the serial number if it isn't in the
// interval.
if (!((serial < max_event_) && (serial >= min_event_)))
return base::nullopt;
}
return events_[serial % kMaxEventsTracked];
}
base::Optional<uint32_t> SerialTracker::GetPointerDownSerial() {
return pointer_down_serial_;
}
base::Optional<uint32_t> SerialTracker::GetTouchDownSerial() {
return touch_down_serial_;
}
void SerialTracker::ResetTouchDownSerial() {
touch_down_serial_ = base::nullopt;
}
} // namespace wayland
} // namespace exo