Java tutorial
/*** Copyright (c) 2015 CommonsWare, LLC 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. Covered in detail in the book _The Busy Coder's Guide to Android Development_ https://commonsware.com/Android */ package com.commonsware.andprojector; import android.app.PendingIntent; import android.content.Intent; import android.content.res.Configuration; import android.hardware.display.DisplayManager; import android.hardware.display.VirtualDisplay; import android.media.projection.MediaProjection; import android.media.projection.MediaProjectionManager; import android.os.Handler; import android.os.HandlerThread; import android.os.SystemClock; import android.support.v4.app.NotificationCompat; import android.view.WindowManager; import com.commonsware.android.webserver.WebServerService; import com.koushikdutta.async.http.WebSocket; import com.koushikdutta.async.http.server.AsyncHttpServer; import com.koushikdutta.async.http.server.AsyncHttpServerRequest; import com.koushikdutta.async.http.server.AsyncHttpServerResponse; import com.koushikdutta.async.http.server.HttpServerRequestCallback; import java.io.ByteArrayInputStream; import java.util.concurrent.atomic.AtomicReference; public class ProjectorService extends WebServerService { static final String EXTRA_RESULT_CODE = "resultCode"; static final String EXTRA_RESULT_INTENT = "resultIntent"; static final int VIRT_DISPLAY_FLAGS = DisplayManager.VIRTUAL_DISPLAY_FLAG_OWN_CONTENT_ONLY | DisplayManager.VIRTUAL_DISPLAY_FLAG_PUBLIC; private MediaProjection projection; private VirtualDisplay vdisplay; final private HandlerThread handlerThread = new HandlerThread(getClass().getSimpleName(), android.os.Process.THREAD_PRIORITY_BACKGROUND); private Handler handler; private AtomicReference<byte[]> latestPng = new AtomicReference<byte[]>(); private MediaProjectionManager mgr; private WindowManager wmgr; private ImageTransmogrifier it; @Override public void onCreate() { super.onCreate(); mgr = (MediaProjectionManager) getSystemService(MEDIA_PROJECTION_SERVICE); wmgr = (WindowManager) getSystemService(WINDOW_SERVICE); handlerThread.start(); handler = new Handler(handlerThread.getLooper()); } @Override public int onStartCommand(Intent i, int flags, int startId) { projection = mgr.getMediaProjection(i.getIntExtra(EXTRA_RESULT_CODE, -1), (Intent) i.getParcelableExtra(EXTRA_RESULT_INTENT)); it = new ImageTransmogrifier(this); MediaProjection.Callback cb = new MediaProjection.Callback() { @Override public void onStop() { vdisplay.release(); } }; vdisplay = projection.createVirtualDisplay("andprojector", it.getWidth(), it.getHeight(), getResources().getDisplayMetrics().densityDpi, VIRT_DISPLAY_FLAGS, it.getSurface(), null, handler); projection.registerCallback(cb, handler); return (START_NOT_STICKY); } @Override public void onDestroy() { projection.stop(); super.onDestroy(); } @Override public void onConfigurationChanged(Configuration newConfig) { super.onConfigurationChanged(newConfig); ImageTransmogrifier newIt = new ImageTransmogrifier(this); if (newIt.getWidth() != it.getWidth() || newIt.getHeight() != it.getHeight()) { ImageTransmogrifier oldIt = it; it = newIt; vdisplay.resize(it.getWidth(), it.getHeight(), getResources().getDisplayMetrics().densityDpi); vdisplay.setSurface(it.getSurface()); oldIt.close(); } } @Override protected boolean configureRoutes(AsyncHttpServer server) { serveWebSockets("/ss", null); server.get(getRootPath() + "/screen/.*", new ScreenshotRequestCallback()); return (true); } @Override protected int getPort() { return (4999); } @Override protected int getMaxIdleTimeSeconds() { return (120); } @Override protected int getMaxSequentialInvalidRequests() { return (10); } WindowManager getWindowManager() { return (wmgr); } Handler getHandler() { return (handler); } void updateImage(byte[] newPng) { latestPng.set(newPng); for (WebSocket socket : getWebSockets()) { socket.send("screen/" + Long.toString(SystemClock.uptimeMillis())); } } @Override protected void buildForegroundNotification(NotificationCompat.Builder b) { Intent iActivity = new Intent(this, MainActivity.class); PendingIntent piActivity = PendingIntent.getActivity(this, 0, iActivity, 0); b.setContentTitle(getString(R.string.app_name)).setContentIntent(piActivity) .setSmallIcon(R.mipmap.ic_launcher).setTicker(getString(R.string.app_name)); } private class ScreenshotRequestCallback implements HttpServerRequestCallback { @Override public void onRequest(AsyncHttpServerRequest request, AsyncHttpServerResponse response) { response.setContentType("image/png"); byte[] png = latestPng.get(); ByteArrayInputStream bais = new ByteArrayInputStream(png); response.sendStream(bais, png.length); } } }