AbstractXboxController.java

package com.limelight.binding.input.driver;

import android.hardware.usb.UsbConstants;
import android.hardware.usb.UsbDevice;
import android.hardware.usb.UsbDeviceConnection;
import android.hardware.usb.UsbEndpoint;
import android.hardware.usb.UsbInterface;

import com.limelight.LimeLog;
import com.limelight.binding.video.MediaCodecHelper;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;

public abstract class AbstractXboxController extends AbstractController {
    protected final UsbDevice device;
    protected final UsbDeviceConnection connection;

    private Thread inputThread;
    private boolean stopped;

    protected UsbEndpoint inEndpt, outEndpt;

    public AbstractXboxController(UsbDevice device, UsbDeviceConnection connection, int deviceId, UsbDriverListener listener) {
        super(deviceId, listener);
        this.device = device;
        this.connection = connection;
    }

    private Thread createInputThread() {
        return new Thread() {
            public void run() {
                while (!isInterrupted() && !stopped) {
                    byte[] buffer = new byte[64];

                    int res;

                    //
                    // There's no way that I can tell to determine if a device has failed
                    // or if the timeout has simply expired. We'll check how long the transfer
                    // took to fail and assume the device failed if it happened before the timeout
                    // expired.
                    //

                    do {
                        // Read the next input state packet
                        long lastMillis = MediaCodecHelper.getMonotonicMillis();
                        res = connection.bulkTransfer(inEndpt, buffer, buffer.length, 3000);

                        // If we get a zero length response, treat it as an error
                        if (res == 0) {
                            res = -1;
                        }

                        if (res == -1 && MediaCodecHelper.getMonotonicMillis() - lastMillis < 1000) {
                            LimeLog.warning("Detected device I/O error");
                            AbstractXboxController.this.stop();
                            break;
                        }
                    } while (res == -1 && !isInterrupted() && !stopped);

                    if (res == -1 || stopped) {
                        break;
                    }

                    if (handleRead(ByteBuffer.wrap(buffer, 0, res).order(ByteOrder.LITTLE_ENDIAN))) {
                        // Report input if handleRead() returns true
                        reportInput();
                    }
                }
            }
        };
    }

    public boolean start() {
        // Force claim all interfaces
        for (int i = 0; i < device.getInterfaceCount(); i++) {
            UsbInterface iface = device.getInterface(i);

            if (!connection.claimInterface(iface, true)) {
                LimeLog.warning("Failed to claim interfaces");
                return false;
            }
        }

        // Find the endpoints
        UsbInterface iface = device.getInterface(0);
        for (int i = 0; i < iface.getEndpointCount(); i++) {
            UsbEndpoint endpt = iface.getEndpoint(i);
            if (endpt.getDirection() == UsbConstants.USB_DIR_IN) {
                if (inEndpt != null) {
                    LimeLog.warning("Found duplicate IN endpoint");
                    return false;
                }
                inEndpt = endpt;
            }
            else if (endpt.getDirection() == UsbConstants.USB_DIR_OUT) {
                if (outEndpt != null) {
                    LimeLog.warning("Found duplicate OUT endpoint");
                    return false;
                }
                outEndpt = endpt;
            }
        }

        // Make sure the required endpoints were present
        if (inEndpt == null || outEndpt == null) {
            LimeLog.warning("Missing required endpoint");
            return false;
        }

        // Run the init function
        if (!doInit()) {
            return false;
        }

        // Report that we're added _before_ starting the input thread
        notifyDeviceAdded();

        // Start listening for controller input
        inputThread = createInputThread();
        inputThread.start();

        return true;
    }

    public void stop() {
        if (stopped) {
            return;
        }

        stopped = true;

        // Stop the input thread
        if (inputThread != null) {
            inputThread.interrupt();
            inputThread = null;
        }

        // Close the USB connection
        connection.close();

        // Report the device removed
        notifyDeviceRemoved();
    }

    protected abstract boolean handleRead(ByteBuffer buffer);
    protected abstract boolean doInit();
}