Java tutorial
/*** Copyright (c) 2013 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.android.preso.fragment; import android.media.MediaRouter; import android.media.MediaRouter.RouteInfo; import android.media.MediaRouter.SimpleCallback; import android.os.Bundle; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentActivity; import android.util.Log; import android.view.Display; import android.view.View; import android.widget.TextView; public class MainActivity extends FragmentActivity { MediaRouter router = null; PresentationFragment preso = null; SimpleCallback cb = null; View inline = null; TextView prose = null; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); inline = findViewById(R.id.preso); prose = findViewById(R.id.prose); } @Override protected void onStart() { super.onStart(); if (cb == null) { cb = new RouteCallback(); router = (MediaRouter) getSystemService(MEDIA_ROUTER_SERVICE); } handleRoute(router.getSelectedRoute(MediaRouter.ROUTE_TYPE_LIVE_VIDEO)); router.addCallback(MediaRouter.ROUTE_TYPE_LIVE_VIDEO, cb); } @Override protected void onStop() { clearPreso(false); if (router != null) { router.removeCallback(cb); } super.onStop(); } private void handleRoute(RouteInfo route) { if (route == null) { clearPreso(true); } else { Display display = route.getPresentationDisplay(); if (route.isEnabled() && display != null) { if (preso == null) { showPreso(route); Log.d(getClass().getSimpleName(), "enabled route"); } else if (preso.getDisplay().getDisplayId() != display.getDisplayId()) { clearPreso(true); showPreso(route); Log.d(getClass().getSimpleName(), "switched route"); } else { // no-op: should already be set } } else { clearPreso(true); Log.d(getClass().getSimpleName(), "disabled route"); } } } private void clearPreso(boolean switchToInline) { if (switchToInline) { inline.setVisibility(View.VISIBLE); prose.setText(R.string.primary); getSupportFragmentManager().beginTransaction().add(R.id.preso, buildPreso(null)).commit(); } if (preso != null) { preso.dismiss(); preso = null; } } private void showPreso(RouteInfo route) { if (inline.getVisibility() == View.VISIBLE) { inline.setVisibility(View.GONE); prose.setText(R.string.secondary); Fragment f = getSupportFragmentManager().findFragmentById(R.id.preso); getSupportFragmentManager().beginTransaction().remove(f).commit(); } preso = buildPreso(route.getPresentationDisplay()); preso.show(getSupportFragmentManager(), "preso"); } private PresentationFragment buildPreso(Display display) { return (SamplePresentationFragment.newInstance(this, display, "https://commonsware.com")); } private class RouteCallback extends SimpleCallback { @Override public void onRoutePresentationDisplayChanged(MediaRouter router, RouteInfo route) { handleRoute(route); } } }