Collaborative attempt to initialize the background webview on startup

app/src/main/AndroidManifest.xml

@@ -281,6 +281,10 @@
             android:name=".activities.DiscoveryActivity"
             android:label="@string/title_activity_discovery"
             android:parentActivityName=".activities.ControlCenter" />
+        <activity
+            android:name=".activities.BackgroundWebViewActivity"
+            android:label="@string/activity_web_view"
+            android:parentActivityName=".activities.ControlCenter" />
         <activity
             android:name=".activities.AndroidPairingActivity"
             android:label="@string/title_activity_android_pairing" />

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/GBApplication.java

@@ -27,6 +27,7 @@ import java.util.concurrent.TimeUnit;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
 
+import nodomain.freeyourgadget.gadgetbridge.activities.BackgroundWebViewActivity;
 import nodomain.freeyourgadget.gadgetbridge.database.DBHandler;
 import nodomain.freeyourgadget.gadgetbridge.database.DBHelper;
 import nodomain.freeyourgadget.gadgetbridge.database.DBOpenHelper;
@@ -124,6 +125,8 @@ public class GBApplication extends Application {
 
         deviceManager = new DeviceManager(this);
 
+        createWebViewActivity();
+
         deviceService = createDeviceService();
         loadBlackList();
 
@@ -132,6 +135,10 @@ public class GBApplication extends Application {
         }
     }
 
+    private void createWebViewActivity() {
+        startActivity(new Intent(getContext(), BackgroundWebViewActivity.class));
+    }
+
     @Override
     public void onTrimMemory(int level) {
         super.onTrimMemory(level);

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/BackgroundWebViewActivity.java

@@ -0,0 +1,16 @@
+package nodomain.freeyourgadget.gadgetbridge.activities;
+
+import android.app.Activity;
+import android.os.Bundle;
+import android.os.PersistableBundle;
+
+import nodomain.freeyourgadget.gadgetbridge.util.WebViewSingleton;
+
+public class BackgroundWebViewActivity extends Activity {
+    @Override
+    public void onCreate(Bundle savedInstanceState, PersistableBundle persistentState) {
+        super.onCreate(savedInstanceState, persistentState);
+        WebViewSingleton.createWebView(this);
+        setVisible(false);
+    }
+}

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/ExternalPebbleJSActivity.java

@@ -48,8 +48,8 @@ public class ExternalPebbleJSActivity extends GBActivity {
 
         setContentView(R.layout.activity_external_pebble_js);
 
-        myWebView = WebViewSingleton.getorInitWebView(this, mGBDevice, appUuid);
+        WebViewSingleton.updateActivityContext(this);
-        myWebView.setWillNotDraw(false);
+        myWebView = WebViewSingleton.getWebView();
         myWebView.addJavascriptInterface(new ActivityJSInterface(ExternalPebbleJSActivity.this), "GBActivity");
         FrameLayout fl = (FrameLayout) findViewById(R.id.webview_placeholder);
         fl.addView(myWebView);

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/appmanager/AbstractAppManagerFragment.java

@@ -338,8 +338,6 @@ public abstract class AbstractAppManagerFragment extends Fragment {
 
         view.performHapticFeedback(HapticFeedbackConstants.LONG_PRESS);
         popupMenu.show();
-        //TODO: replace with local broadcast on app start
-        WebViewSingleton.getorInitWebView(getActivity(), mGBDevice, selectedApp.getUUID());
         return true;
     }
 

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/pebble/PebbleIoThread.java

@@ -82,7 +82,7 @@ class PebbleIoThread extends GBDeviceIoThread {
     private int mBytesWritten = -1;
 
     private void sendAppMessageJS(GBDeviceEventAppMessage appMessage) {
-        WebViewSingleton.getorInitWebView(getContext(), gbDevice, appMessage.appUUID);
+//        WebViewSingleton.runJavascriptInterface(gbDevice, appMessage.appUUID);
         WebViewSingleton.appMessage(appMessage.message);
     }
 
@@ -487,8 +487,7 @@ class PebbleIoThread extends GBDeviceIoThread {
                     break;
                 case START:
                     LOG.info("got GBDeviceEventAppManagement START event for uuid: " + appMgmt.uuid);
-                    WebViewSingleton.getorInitWebView(getContext(), gbDevice, appMgmt.uuid);
+                    WebViewSingleton.runJavascriptInterface(gbDevice, appMgmt.uuid);
-                    //TODO: the method call above will not work the first time as we need an activity. Either we find a way to have one here, or replace it with a local broadcast
                     break;
                 default:
                     break;

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/util/WebViewSingleton.java

@@ -13,6 +13,7 @@ import android.net.Uri;
 import android.os.Build;
 import android.os.Handler;
 import android.os.Looper;
+import android.support.annotation.NonNull;
 import android.support.v4.app.ActivityCompat;
 import android.webkit.ConsoleMessage;
 import android.webkit.JavascriptInterface;
@@ -58,37 +59,9 @@ public class WebViewSingleton extends Activity {
     private WebViewSingleton() {
     }
 
-    public static WebView getorInitWebView(Context context, final GBDevice device, final UUID uuid) {
+    public static synchronized WebView createWebView(Context context) {
-
-        if (jsInterface == null || (jsInterface != null && (!device.equals(jsInterface.device) || !uuid.equals(jsInterface.mUuid)))) {
-            jsInterface = new JSInterface(device, uuid);
-            new Handler(Looper.getMainLooper()).post(new Runnable() {
-                @Override
-                public void run() {
-                    if (instance != null) {
-                        instance.removeJavascriptInterface("GBjs");
-                        instance.addJavascriptInterface(jsInterface, "GBjs");
-                        instance.loadUrl("file:///android_asset/app_config/configure.html");
-                    }
-                }
-            });
-        } else {
-            LOG.debug("Not replacing the JS in the webview. JS uuid " + jsInterface.mUuid.toString());
-        }
-
-        if (context instanceof Activity) {
-            if (contextWrapper != null) {
-                contextWrapper.setBaseContext(context);
-            } else {
-                contextWrapper = new MutableContextWrapper(context);
-            }
-
         if (instance == null) {
-                LOG.debug("WEBV: creating webview");
+            contextWrapper = new MutableContextWrapper(context);
-
-                new Handler(Looper.getMainLooper()).post(new Runnable() {
-                    @Override
-                    public void run() {
             instance = new WebView(contextWrapper);
             instance.setWillNotDraw(true);
             instance.clearCache(true);
@@ -101,20 +74,35 @@ public class WebViewSingleton extends Activity {
             webSettings.setDomStorageEnabled(true);
             //needed for localstorage
             webSettings.setDatabaseEnabled(true);
-                        if (jsInterface != null) {
+        }
-                            LOG.debug("Attaching the existing jsInterface to the new webview instance");
+        return instance;
+    }
+
+    public static void updateActivityContext(Context context) {
+        if (context instanceof Activity) {
+            contextWrapper.setBaseContext(context);
+        }
+    }
+
+    @NonNull
+    public static WebView getWebView() {
+        return instance;
+    }
+
+    public static void runJavascriptInterface(final GBDevice device, final UUID uuid) {
+        if (jsInterface == null || !device.equals(jsInterface.device) || !uuid.equals(jsInterface.mUuid)) {
+            jsInterface = new JSInterface(device, uuid);
+            new Handler(Looper.getMainLooper()).post(new Runnable() {
+                @Override
+                public void run() {
+                    instance.removeJavascriptInterface("GBjs");
                     instance.addJavascriptInterface(jsInterface, "GBjs");
                     instance.loadUrl("file:///android_asset/app_config/configure.html");
                 }
-                    }
             });
-            }
-
         } else {
-            LOG.debug("WEBV: not using the passed context, as it is not an activity");
+            LOG.debug("Not replacing the JS in the webview. JS uuid " + jsInterface.mUuid.toString());
         }
-
-        return instance;
     }
 
     public static void appMessage(final String message) {

app/src/main/res/values/strings.xml

@@ -393,4 +393,5 @@
     <string name="timeformat_24h">24H</string>
     <string name="timeformat_am_pm">AM/PM</string>
     <string name="pref_screen_notification_profile_alarm_clock">Alarm Clock</string>
+    <string name="activity_web_view">Web View Activity</string>
 </resources>