2 * Copyright (C) 2011 The Android Open Source Project
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 #ifndef ANDROID_GUI_DISPLAY_EVENT_H
18 #define ANDROID_GUI_DISPLAY_EVENT_H
21 #include <sys/types.h>
23 #include <utils/Errors.h>
24 #include <utils/RefBase.h>
25 #include <utils/Timers.h>
27 #include <binder/IInterface.h>
29 // ----------------------------------------------------------------------------
33 // ----------------------------------------------------------------------------
36 class IDisplayEventConnection;
38 // ----------------------------------------------------------------------------
40 class DisplayEventReceiver {
43 DISPLAY_EVENT_VSYNC = 'vsyn',
44 DISPLAY_EVENT_HOTPLUG = 'plug'
72 * DisplayEventReceiver creates and registers an event connection with
73 * SurfaceFlinger. VSync events are disabled by default. Call setVSyncRate
74 * or requestNextVsync to receive them.
75 * Other events start being delivered immediately.
77 DisplayEventReceiver();
80 * ~DisplayEventReceiver severs the connection with SurfaceFlinger, new events
81 * stop being delivered immediately. Note that the queue could have
82 * some events pending. These will be delivered.
84 ~DisplayEventReceiver();
87 * initCheck returns the state of DisplayEventReceiver after construction.
89 status_t initCheck() const;
92 * getFd returns the file descriptor to use to receive events.
93 * OWNERSHIP IS RETAINED by DisplayEventReceiver. DO NOT CLOSE this
99 * getEvents reads events from the queue and returns how many events were
100 * read. Returns 0 if there are no more events or a negative error code.
101 * If NOT_ENOUGH_DATA is returned, the object has become invalid forever, it
102 * should be destroyed and getEvents() shouldn't be called again.
104 ssize_t getEvents(Event* events, size_t count);
105 static ssize_t getEvents(const sp<BitTube>& dataChannel,
106 Event* events, size_t count);
109 * sendEvents write events to the queue and returns how many events were
112 static ssize_t sendEvents(const sp<BitTube>& dataChannel,
113 Event const* events, size_t count);
116 * setVsyncRate() sets the Event::VSync delivery rate. A value of
117 * 1 returns every Event::VSync. A value of 2 returns every other event,
118 * etc... a value of 0 returns no event unless requestNextVsync() has
121 status_t setVsyncRate(uint32_t count);
124 * requestNextVsync() schedules the next Event::VSync. It has no effect
125 * if the vsync rate is > 0.
127 status_t requestNextVsync();
130 sp<IDisplayEventConnection> mEventConnection;
131 sp<BitTube> mDataChannel;
134 // ----------------------------------------------------------------------------
135 }; // namespace android
137 #endif // ANDROID_GUI_DISPLAY_EVENT_H