Only start the webview when needed

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

@@ -37,6 +37,7 @@ import nodomain.freeyourgadget.gadgetbridge.impl.GBDevice;
 import nodomain.freeyourgadget.gadgetbridge.impl.GBDeviceService;
 import nodomain.freeyourgadget.gadgetbridge.model.ActivityUser;
 import nodomain.freeyourgadget.gadgetbridge.model.DeviceService;
+import nodomain.freeyourgadget.gadgetbridge.util.DeviceHelper;
 import nodomain.freeyourgadget.gadgetbridge.util.FileUtils;
 import nodomain.freeyourgadget.gadgetbridge.util.GB;
 import nodomain.freeyourgadget.gadgetbridge.util.GBPrefs;
@@ -136,9 +137,11 @@ public class GBApplication extends Application {
     }
 
     private void createWebViewActivity() {
-        Intent intent = new Intent(getContext(), BackgroundWebViewActivity.class);
+        if (DeviceHelper.getInstance().needsBackgroundWebView(this)) {
-        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+            Intent intent = new Intent(getContext(), BackgroundWebViewActivity.class);
-        startActivity(intent);
+            intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+            startActivity(intent);
+        }
     }
 
     @Override

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

@@ -3,14 +3,9 @@ package nodomain.freeyourgadget.gadgetbridge.activities;
 import android.app.Activity;
 import android.os.Bundle;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import nodomain.freeyourgadget.gadgetbridge.util.WebViewSingleton;
 
 public class BackgroundWebViewActivity extends Activity {
-    private static Logger LOG = LoggerFactory.getLogger(BackgroundWebViewActivity.class);
-
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/devices/AbstractDeviceCoordinator.java

@@ -103,4 +103,9 @@ public abstract class AbstractDeviceCoordinator implements DeviceCoordinator {
         }
         return false;
     }
+
+    @Override
+    public boolean needsBackgroundWebView(GBDevice device) {
+        return false;
+    }
 }

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/devices/DeviceCoordinator.java

@@ -186,4 +186,12 @@ public interface DeviceCoordinator {
      * @return
      */
     Class<? extends Activity> getAppsManagementActivity();
+
+    /**
+     * Returns true if the given device needs a background webview for
+     * executing javascript or configuration, for example.
+     *
+     * @param device
+     */
+    boolean needsBackgroundWebView(GBDevice device);
 }

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/devices/pebble/PebbleCoordinator.java

@@ -137,4 +137,9 @@ public class PebbleCoordinator extends AbstractDeviceCoordinator {
     public Class<? extends Activity> getAppsManagementActivity() {
         return AppManagerActivity.class;
     }
+
+    @Override
+    public boolean needsBackgroundWebView(GBDevice device) {
+        return true;
+    }
 }

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

@@ -255,4 +255,20 @@ public class DeviceHelper {
         }
         return false;
     }
+
+    /**
+     * Returns true if the background webview for executing javascript is needed
+     * for any of the known/available devices.
+     * @param context
+     */
+    public boolean needsBackgroundWebView(Context context) {
+        Set<GBDevice> availableDevices = getAvailableDevices(context);
+        for (GBDevice device : availableDevices) {
+            DeviceCoordinator coordinator = getCoordinator(device);
+            if (coordinator.needsBackgroundWebView(device)) {
+                return true;
+            }
+        }
+        return false;
+    }
 }