package com.limelight.binding.input.evdev;
import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import com.limelight.LimeLog;
public class EvdevReader {
private static void readAll(InputStream in, ByteBuffer bb) throws IOException {
byte[] buf = bb.array();
int ret;
int offset = 0;
while (offset < buf.length) {
ret = in.read(buf, offset, buf.length-offset);
if (ret <= 0) {
throw new IOException("Read failed: "+ret);
}
offset += ret;
}
}
// Takes a byte buffer to use to read the output into.
// This buffer MUST be in native byte order and at least
// EVDEV_MAX_EVENT_SIZE bytes long.
public static EvdevEvent read(InputStream input) throws IOException {
ByteBuffer bb;
int packetLength;
// Read the packet length
bb = ByteBuffer.allocate(4).order(ByteOrder.nativeOrder());
readAll(input, bb);
packetLength = bb.getInt();
if (packetLength < EvdevEvent.EVDEV_MIN_EVENT_SIZE) {
LimeLog.warning("Short read: "+packetLength);
return null;
}
// Read the rest of the packet
bb = ByteBuffer.allocate(packetLength).order(ByteOrder.nativeOrder());
readAll(input, bb);
// Throw away the time stamp
if (packetLength == EvdevEvent.EVDEV_MAX_EVENT_SIZE) {
bb.getLong();
bb.getLong();
} else {
bb.getInt();
bb.getInt();
}
return new EvdevEvent(bb.getShort(), bb.getShort(), bb.getInt());
}
}