Pebble: webview. Implement two way communication with JS.

The support within JS is a bit hacky and sometimes conflicts with the configuration page.

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

@@ -141,7 +141,11 @@ function gbPebble() {
     this.sendAppMessage = function (dict, callbackAck, callbackNack){
         try {
             self.configurationValues = JSON.stringify(dict);
-            document.getElementById("jsondata").innerHTML=self.configurationValues;
+            if (document.getElementById("step2").style.display == 'block') { //intercept the values
+                document.getElementById("jsondata").innerHTML=self.configurationValues;
+            } else { //pass them silently
+                GBjs.sendAppMessage(JSON.stringify(dict));
+            }
             return callbackAck;
         }
         catch (e) {
@@ -179,8 +183,8 @@ function gbPebble() {
         if (str.split(needle)[1] !== undefined) {
             var t = new Object();
             t.response = decodeURIComponent(str.split(needle)[1]);
-            self.evaluate('webviewclosed',[t]);
             showStep("step2");
+            self.evaluate('webviewclosed',[t]);
         } else {
             console.error("No valid configuration found in the entered string.");
         }

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

@@ -140,6 +140,11 @@ class PebbleIoThread extends GBDeviceIoThread {
         }
     };
 
+    private void sendAppMessageJS(GBDeviceEventAppMessage appMessage) {
+        WebViewSingleton.getorInitWebView(getContext(), gbDevice, appMessage.appUUID);
+        WebViewSingleton.appMessage(appMessage.message);
+    }
+
     private void sendAppMessageIntent(GBDeviceEventAppMessage appMessage) {
         Intent intent = new Intent();
         intent.setAction(PEBBLEKIT_ACTION_APP_RECEIVE);
@@ -582,6 +587,7 @@ class PebbleIoThread extends GBDeviceIoThread {
             setInstallSlot(appInfoEvent.freeSlot);
             return false;
         } else if (deviceEvent instanceof GBDeviceEventAppMessage) {
+            sendAppMessageJS((GBDeviceEventAppMessage) deviceEvent);
             if (mEnablePebblekit) {
                 LOG.info("Got AppMessage event");
                 sendAppMessageIntent((GBDeviceEventAppMessage) deviceEvent);

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

@@ -19,6 +19,7 @@ import android.webkit.WebView;
 import android.webkit.WebViewClient;
 import android.widget.Toast;
 
+import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
 import org.slf4j.Logger;
@@ -32,6 +33,7 @@ import java.io.UnsupportedEncodingException;
 import java.io.Writer;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
+import java.util.HashMap;
 import java.util.Iterator;
 import java.util.Scanner;
 import java.util.UUID;
@@ -107,18 +109,22 @@ public class WebViewSingleton extends Activity {
     }
 
     public static void appMessage(final String message) {
+
+        final String appMessage = jsInterface.parseIncomingAppMessage(message);
+        LOG.debug("to WEBVIEW: " + appMessage);
+
         new Handler(Looper.getMainLooper()).post(new Runnable() {
             @Override
             public void run() {
                 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
-                    instance.evaluateJavascript("Pebble.evaluate('appmessage',[{'payload':" + message + "}]);", new ValueCallback<String>() {
+                    instance.evaluateJavascript("Pebble.evaluate('appmessage',[" + appMessage + "]);", new ValueCallback<String>() {
                         @Override
                         public void onReceiveValue(String s) {
                             LOG.debug("Callback from showConfiguration", s);
                         }
                     });
                 } else {
-                    instance.loadUrl("javascript:Pebble.evaluate('appmessage',[{'payload':" + message + "}]);");
+                    instance.loadUrl("javascript:Pebble.evaluate('appmessage',[" + appMessage + "]);");
                 }
             }
         });
@@ -129,6 +135,13 @@ public class WebViewSingleton extends Activity {
             @Override
             public void run() {
                 if (instance != null) {
+                    instance.setWebChromeClient(null);
+                    instance.setWebViewClient(null);
+                    instance.clearHistory();
+                    instance.clearCache(true);
+                    instance.loadUrl("about:blank");
+                    instance.freeMemory();
+                    instance.pauseTimers();
                     instance.destroy();
                     instance = null;
                     contextWrapper = null;
@@ -202,6 +215,48 @@ public class WebViewSingleton extends Activity {
             this.mUuid = mUuid;
         }
 
+        public String parseIncomingAppMessage(String msg) {
+            JSONObject jsAppMessage = new JSONObject();
+
+            JSONObject knownKeys = getAppConfigurationKeys(this.mUuid);
+            HashMap<Integer, String> appKeysMap = new HashMap<Integer, String>();
+
+            String inKey, outKey;
+            //knownKeys contains "name"->"index", we need to reverse that
+            for (Iterator<String> key = knownKeys.keys(); key.hasNext(); ) {
+                inKey = key.next();
+                appKeysMap.put(knownKeys.optInt(inKey), inKey);
+            }
+
+            try {
+                JSONArray incoming = new JSONArray(msg);
+                JSONObject outgoing = new JSONObject();
+                for (int i = 0; i < incoming.length(); i++) {
+                    JSONObject in = incoming.getJSONObject(i);
+                    outKey = null;
+                    Object outValue = null;
+                    for (Iterator<String> key = in.keys(); key.hasNext(); ) {
+                        inKey = key.next();
+                        switch (inKey) {
+                            case "key":
+                                outKey = appKeysMap.get(in.optInt(inKey));
+                                break;
+                            case "value":
+                                outValue = in.get(inKey);
+                        }
+                    }
+                    if (outKey != null && outValue != null) {
+                        outgoing.put(outKey, outValue);
+                    }
+                }
+                jsAppMessage.put("payload", outgoing);
+
+            } catch (JSONException e) {
+                e.printStackTrace();
+            }
+            return jsAppMessage.toString();
+        }
+
         @JavascriptInterface
         public void gbLog(String msg) {
             LOG.debug("WEBVIEW", msg);