package com.genymobile.scrcpy; import java.io.EOFException; import java.io.IOException; import java.io.InputStream; import java.nio.ByteBuffer; import java.nio.charset.StandardCharsets; public class ControlEventReader { private static final int KEYCODE_PAYLOAD_LENGTH = 9; private static final int MOUSE_PAYLOAD_LENGTH = 13; private static final int SCROLL_PAYLOAD_LENGTH = 16; private static final int COMMAND_PAYLOAD_LENGTH = 1; public static final int TEXT_MAX_LENGTH = 300; private static final int RAW_BUFFER_SIZE = 1024; private final byte[] rawBuffer = new byte[RAW_BUFFER_SIZE]; private final ByteBuffer buffer = ByteBuffer.wrap(rawBuffer); private final byte[] textBuffer = new byte[TEXT_MAX_LENGTH]; public ControlEventReader() { // invariant: the buffer is always in "get" mode buffer.limit(0); } public boolean isFull() { return buffer.remaining() == rawBuffer.length; } public void readFrom(InputStream input) throws IOException { if (isFull()) { throw new IllegalStateException("Buffer full, call next() to consume"); } buffer.compact(); int head = buffer.position(); int r = input.read(rawBuffer, head, rawBuffer.length - head); if (r == -1) { throw new EOFException("Event controller socket closed"); } buffer.position(head + r); buffer.flip(); } public ControlEvent next() { if (!buffer.hasRemaining()) { return null; } int savedPosition = buffer.position(); int type = buffer.get(); ControlEvent controlEvent; switch (type) { case ControlEvent.TYPE_KEYCODE: controlEvent = parseKeycodeControlEvent(); break; case ControlEvent.TYPE_TEXT: controlEvent = parseTextControlEvent(); break; case ControlEvent.TYPE_MOUSE: controlEvent = parseMouseControlEvent(); break; case ControlEvent.TYPE_SCROLL: controlEvent = parseScrollControlEvent(); break; case ControlEvent.TYPE_COMMAND: controlEvent = parseCommandControlEvent(); break; default: Ln.w("Unknown event type: " + type); controlEvent = null; break; } if (controlEvent == null) { // failure, reset savedPosition buffer.position(savedPosition); } return controlEvent; } private ControlEvent parseKeycodeControlEvent() { if (buffer.remaining() < KEYCODE_PAYLOAD_LENGTH) { return null; } int action = toUnsigned(buffer.get()); int keycode = buffer.getInt(); int metaState = buffer.getInt(); return ControlEvent.createKeycodeControlEvent(action, keycode, metaState); } private ControlEvent parseTextControlEvent() { if (buffer.remaining() < 1) { return null; } int len = toUnsigned(buffer.getShort()); if (buffer.remaining() < len) { return null; } buffer.get(textBuffer, 0, len); String text = new String(textBuffer, 0, len, StandardCharsets.UTF_8); return ControlEvent.createTextControlEvent(text); } private ControlEvent parseMouseControlEvent() { if (buffer.remaining() < MOUSE_PAYLOAD_LENGTH) { return null; } int action = toUnsigned(buffer.get()); int buttons = buffer.getInt(); Position position = readPosition(buffer); return ControlEvent.createMotionControlEvent(action, buttons, position); } private ControlEvent parseScrollControlEvent() { if (buffer.remaining() < SCROLL_PAYLOAD_LENGTH) { return null; } Position position = readPosition(buffer); int hScroll = buffer.getInt(); int vScroll = buffer.getInt(); return ControlEvent.createScrollControlEvent(position, hScroll, vScroll); } private ControlEvent parseCommandControlEvent() { if (buffer.remaining() < COMMAND_PAYLOAD_LENGTH) { return null; } int action = toUnsigned(buffer.get()); return ControlEvent.createCommandControlEvent(action); } private static Position readPosition(ByteBuffer buffer) { int x = toUnsigned(buffer.getShort()); int y = toUnsigned(buffer.getShort()); int screenWidth = toUnsigned(buffer.getShort()); int screenHeight = toUnsigned(buffer.getShort()); return new Position(x, y, screenWidth, screenHeight); } @SuppressWarnings("checkstyle:MagicNumber") private static int toUnsigned(short value) { return value & 0xffff; } @SuppressWarnings("checkstyle:MagicNumber") private static int toUnsigned(byte value) { return value & 0xff; } }