Added background playback notification to prevent killing the app

app/src/main/java/cz/martykan/webtube/MainActivity.java

@@ -1,6 +1,7 @@
 package cz.martykan.webtube;
 
 import android.app.ActionBar;
+import android.app.NotificationManager;
 import android.content.Context;
 import android.content.DialogInterface;
 import android.content.Intent;
@@ -13,6 +14,7 @@
 import android.preference.PreferenceManager;
 import android.support.design.widget.NavigationView;
 import android.support.design.widget.Snackbar;
+import android.support.v4.app.NotificationCompat;
 import android.support.v4.widget.DrawerLayout;
 import android.support.v7.app.AlertDialog;
 import android.support.v7.app.AppCompatActivity;
@@ -25,6 +27,7 @@
 import android.view.Window;
 import android.view.WindowManager;
 import android.webkit.CookieManager;
+import android.webkit.JavascriptInterface;
 import android.webkit.ValueCallback;
 import android.webkit.WebChromeClient;
 import android.webkit.WebSettings;
@@ -198,7 +201,6 @@ public boolean shouldOverrideUrlLoading(WebView view, String url) {
 
             public void onLoadResource(WebView view, String url) {
                 if (!url.contains(".jpg") && !url.contains(".ico") && !url.contains(".css") && !url.contains(".js") && !url.contains("complete/search")) {
-                    Log.i("URL", url);
                     // Remove all iframes (to prevent WebRTC exploits)
                     webView.loadUrl("javascript:(function() {" +
                             "var iframes = document.getElementsByTagName('iframe');" +
@@ -319,6 +321,45 @@ public boolean onNavigationItemSelected(MenuItem menuItem) {
         }
     }
 
+    @Override
+    public void onPause() {
+        super.onPause();
+        if(webView.getUrl().contains("/watch")) {
+            if(Integer.valueOf(Build.VERSION.SDK_INT) >= 19) {
+                webView.evaluateJavascript("(function() { if(document.getElementsByTagName('video')[0].paused == false) { return 'playing'; } else { return 'stopped'; } })();", new ValueCallback<String>() {
+                    @Override
+                    public void onReceiveValue(String value) {
+                        Log.i("VALUE", value);
+                        if(value.equals("\"playing\"")) {
+                            showBackgroundPlaybackNotification();
+                        }
+                    }
+                });
+            }
+            else {
+                showBackgroundPlaybackNotification();
+            }
+        }
+    }
+
+    public void showBackgroundPlaybackNotification() {
+        NotificationCompat.Builder builder = new NotificationCompat.Builder(this)
+                .setSmallIcon(R.drawable.ic_headphones_white_24dp)
+                .setOngoing(true)
+                .setColor(Color.parseColor("#E62118"))
+                .setContentTitle(getString(R.string.app_name))
+                .setContentText(webView.getTitle().replace(" - YouTube", ""));
+        NotificationManager manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
+        manager.notify(1337 - 420 * 69, builder.build());
+    }
+
+    @Override
+    public void onResume() {
+        super.onResume();
+        NotificationManager manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
+        manager.cancel(1337 - 420 * 69);
+    }
+
     @Override
     protected void onNewIntent(final Intent intent) {
         super.onNewIntent(intent);

app/src/main/res/drawable/headphones.xml

@@ -0,0 +1,8 @@
+<!-- drawable/headphones.xml -->
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:height="24dp"
+    android:width="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path android:fillColor="#000" android:pathData="M12,1C7,1 3,5 3,10V17A3,3 0 0,0 6,20H9V12H5V10A7,7 0 0,1 12,3A7,7 0 0,1 19,10V12H15V20H18A3,3 0 0,0 21,17V10C21,5 16.97,1 12,1Z" />
+</vector>