Pebble background webview: bring back the mutableContextWrapper, otherwise inputs aren't working.

Reliably go back to first step of the configuration page when closing (this causes a Toast when closing the activity while in the clay settings page)

app/src/main/assets/app_config/js/gadgetbridge_boilerplate.js

@@ -109,6 +109,7 @@ function gbPebble() {
 
     this.actuallySendData = function() {
         GBjs.sendAppMessage(self.configurationValues);
+        showStep("step1");
         GBActivity.closeActivity();
     }
 
@@ -209,6 +210,7 @@ if (jsConfigFile != null) {
             Pebble.evaluate('showConfiguration');
         } else {
             window.onfocus = function () {
+                showStep("step1");
                 GBjs.gbLog("window focused!!!");
                 Pebble.evaluate('showConfiguration');
             };

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

@@ -8,6 +8,7 @@ import android.support.v4.app.NavUtils;
 import android.view.MenuItem;
 import android.view.View;
 import android.webkit.JavascriptInterface;
+import android.webkit.ValueCallback;
 import android.webkit.WebView;
 import android.widget.FrameLayout;
 import android.widget.Toast;
@@ -70,6 +71,12 @@ public class ExternalPebbleJSActivity extends GBActivity {
             public void onViewDetachedFromWindow(View v) {
                 myWebView.removeJavascriptInterface("GBActivity");
                 myWebView.setWillNotDraw(true);
+                myWebView.evaluateJavascript("showStep('step1')", new ValueCallback<String>() {
+                    @Override
+                    public void onReceiveValue(String s) {
+                        LOG.debug("Callback from window detach: " + s);
+                    }
+                });
                 FrameLayout fl = (FrameLayout) findViewById(R.id.webview_placeholder);
                 fl.removeAllViews();
             }

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

@@ -4,12 +4,15 @@ import android.Manifest;
 import android.app.Activity;
 import android.content.Context;
 import android.content.Intent;
+import android.content.MutableContextWrapper;
 import android.content.pm.PackageManager;
 import android.location.Criteria;
 import android.location.Location;
 import android.location.LocationManager;
 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;
@@ -58,7 +61,8 @@ public class WebViewSingleton {
     private static final Logger LOG = LoggerFactory.getLogger(WebViewSingleton.class);
 
     private static WebView instance = null;
-    private Activity contextWrapper;
+    private MutableContextWrapper contextWrapper;
+    private Looper mainLooper;
     private static WebViewSingleton webViewSingleton = new WebViewSingleton();
     private static UUID currentRunningUUID;
 
@@ -67,8 +71,9 @@ public class WebViewSingleton {
 
     public static synchronized WebView createWebView(Activity context) {
         if (instance == null) {
-            webViewSingleton.contextWrapper = context;
+            webViewSingleton.contextWrapper = new MutableContextWrapper(context);
-            instance = new WebView(context);
+            webViewSingleton.mainLooper = context.getMainLooper();
+            instance = new WebView(webViewSingleton.contextWrapper);
             instance.setWillNotDraw(true);
             instance.clearCache(true);
             instance.setWebViewClient(new GBWebClient());
@@ -86,7 +91,7 @@ public class WebViewSingleton {
 
     public static void updateActivityContext(Activity context) {
         if (context instanceof Activity) {
-            webViewSingleton.contextWrapper = context;
+            webViewSingleton.contextWrapper.setBaseContext(context);
         }
     }
 
@@ -104,7 +109,7 @@ public class WebViewSingleton {
         } else {
             LOG.debug("WEBVIEW uuid changed, restarting");
             currentRunningUUID = uuid;
-            webViewSingleton.contextWrapper.runOnUiThread(new Runnable() {
+            new Handler(webViewSingleton.mainLooper).post(new Runnable() {
                 @Override
                 public void run() {
                     instance.removeJavascriptInterface("GBjs");
@@ -125,8 +130,7 @@ public class WebViewSingleton {
 
         final String appMessage = parseIncomingAppMessage(message.message, message.appUUID);
         LOG.debug("to WEBVIEW: " + appMessage);
-
+        new Handler(webViewSingleton.mainLooper).post(new Runnable() {
-        webViewSingleton.contextWrapper.runOnUiThread(new Runnable() {
             @Override
             public void run() {
                 instance.evaluateJavascript("Pebble.evaluate('appmessage',[" + appMessage + "]);", new ValueCallback<String>() {
@@ -141,7 +145,7 @@ public class WebViewSingleton {
     }
 
     public static void disposeWebView() {
-        webViewSingleton.contextWrapper.runOnUiThread(new Runnable() {
+        new Handler(webViewSingleton.mainLooper).post(new Runnable() {
             @Override
             public void run() {
                 if (instance != null) {