Add support for sending VSYNC events to the framework
use gui/DisplayEvent to receive the events. Events are
dispatched through a unix pipe, so the API is compatible
with utils/Looper. see gui/DisplayEvent.h for more info.
Bug: 1475048
Change-Id: Ia720f64d1b950328b47b22c6a86042e481d35f09
diff --git a/include/gui/DisplayEventReceiver.h b/include/gui/DisplayEventReceiver.h
new file mode 100644
index 0000000..8d07c0e
--- /dev/null
+++ b/include/gui/DisplayEventReceiver.h
@@ -0,0 +1,105 @@
+/*
+ * 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'
+ };
+
+ struct Event {
+
+ struct Header {
+ uint32_t type;
+ nsecs_t timestamp;
+ };
+
+ struct VSync {
+ uint32_t count;
+ };
+
+ Header header;
+ union {
+ VSync vsync;
+ };
+ };
+
+public:
+ /*
+ * DisplayEventReceiver creates and registers an event connection with
+ * SurfaceFlinger. 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 event 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);
+
+private:
+ sp<IDisplayEventConnection> mEventConnection;
+ sp<BitTube> mDataChannel;
+};
+
+// ----------------------------------------------------------------------------
+}; // namespace android
+
+#endif // ANDROID_GUI_DISPLAY_EVENT_H