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/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ANDROID_GUI_DISPLAY_EVENT_H
#define ANDROID_GUI_DISPLAY_EVENT_H
#include <stdint.h>
#include <sys/types.h>
#include <utils/Errors.h>
#include <utils/RefBase.h>
#include <utils/Timers.h>
#include <binder/IInterface.h>
// ----------------------------------------------------------------------------
namespace android {
// ----------------------------------------------------------------------------
class BitTube;
class IDisplayEventConnection;
// ----------------------------------------------------------------------------
class DisplayEventReceiver {
public:
enum {
DISPLAY_EVENT_VSYNC = 'vsyn',
DISPLAY_EVENT_HOTPLUG = 'plug'
};
struct Event {
struct Header {
uint32_t type;
uint32_t id;
nsecs_t timestamp __attribute__((aligned(8)));
};
struct VSync {
uint32_t count;
};
struct Hotplug {
bool connected;
};
Header header;
union {
VSync vsync;
Hotplug hotplug;
};
};
public:
/*
* DisplayEventReceiver creates and registers an event connection with
* SurfaceFlinger. VSync events are disabled by default. Call setVSyncRate
* or requestNextVsync to receive them.
* Other events start being delivered immediately.
*/
DisplayEventReceiver();
/*
* ~DisplayEventReceiver severs the connection with SurfaceFlinger, new events
* stop being delivered immediately. Note that the queue could have
* some events pending. These will be delivered.
*/
~DisplayEventReceiver();
/*
* initCheck returns the state of DisplayEventReceiver after construction.
*/
status_t initCheck() const;
/*
* getFd returns the file descriptor to use to receive events.
* OWNERSHIP IS RETAINED by DisplayEventReceiver. DO NOT CLOSE this
* file-descriptor.
*/
int getFd() const;
/*
* getEvents reads events from the queue and returns how many events were
* read. Returns 0 if there are no more events or a negative error code.
* If NOT_ENOUGH_DATA is returned, the object has become invalid forever, it
* should be destroyed and getEvents() shouldn't be called again.
*/
ssize_t getEvents(Event* events, size_t count);
static ssize_t getEvents(const sp<BitTube>& dataChannel,
Event* events, size_t count);
/*
* sendEvents write events to the queue and returns how many events were
* written.
*/
static ssize_t sendEvents(const sp<BitTube>& dataChannel,
Event const* events, size_t count);
/*
* setVsyncRate() sets the Event::VSync delivery rate. A value of
* 1 returns every Event::VSync. A value of 2 returns every other event,
* etc... a value of 0 returns no event unless requestNextVsync() has
* been called.
*/
status_t setVsyncRate(uint32_t count);
/*
* requestNextVsync() schedules the next Event::VSync. It has no effect
* if the vsync rate is > 0.
*/
status_t requestNextVsync();
private:
sp<IDisplayEventConnection> mEventConnection;
sp<BitTube> mDataChannel;
};
// ----------------------------------------------------------------------------
}; // namespace android
#endif // ANDROID_GUI_DISPLAY_EVENT_H
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