Develop Reference

PocketSphinx is not listening

I would like to implement the library PocketSphinx in my Android project but I fail with it since nothing happens. It doesn't work and I don't get any errors.
This is how I tried it:
Added pocketsphinx-android-5prealpha-release.aar to /app/libs
Added assets.xml to /app
Aded the following to /app/build.gradle:
ant.importBuild 'assets.xml'
preBuild.dependsOn(list, checksum)
clean.dependsOn(clean_assets)
Added sync (with all sub-files) into /app/assets
Cloned the following repos into my root-directory:
git clone https://github.com/cmusphinx/sphinxbase
git clone https://github.com/cmusphinx/pocketsphinx
git clone https://github.com/cmusphinx/pocketsphinx-android
Executed gradle build
This is how my code looks like:
import android.app.Service;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.IBinder;
import android.util.Log;
import androidx.annotation.Nullable;
import java.io.File;
import java.io.IOException;
import java.lang.ref.WeakReference;
import java.util.HashMap;
import ch.yourclick.kitt.R;
import edu.cmu.pocketsphinx.Assets;
import edu.cmu.pocketsphinx.Hypothesis;
import edu.cmu.pocketsphinx.RecognitionListener;
import edu.cmu.pocketsphinx.SpeechRecognizer;
import edu.cmu.pocketsphinx.SpeechRecognizerSetup;
public class SttService extends Service implements RecognitionListener {
private static final String TAG = "SstService";
/* Named searches allow to quickly reconfigure the decoder */
private static final String KWS_SEARCH = "wakeup";
private static final String FORECAST_SEARCH = "forecast";
private static final String DIGITS_SEARCH = "digits";
private static final String PHONE_SEARCH = "phones";
private static final String MENU_SEARCH = "menu";
/* Keyword we are looking for to activate menu */
private static final String KEYPHRASE = "oh mighty computer";
/* Used to handle permission request */
private static final int PERMISSIONS_REQUEST_RECORD_AUDIO = 1;
private SpeechRecognizer recognizer;
private HashMap<String, Integer> captions;
public SttService() {
// Prepare the data for UI
captions = new HashMap<>();
captions.put(KWS_SEARCH, R.string.kws_caption);
captions.put(MENU_SEARCH, R.string.menu_caption);
captions.put(DIGITS_SEARCH, R.string.digits_caption);
captions.put(PHONE_SEARCH, R.string.phone_caption);
captions.put(FORECAST_SEARCH, R.string.forecast_caption);
Log.e(TAG, "SttService: Preparing the recognition");
// Recognizer initialization is a time-consuming and it involves IO,
// so we execute it in async task
new SetupTask(this).execute();
}
private static class SetupTask extends AsyncTask<Void, Void, Exception> {
WeakReference<SttService> activityReference;
SetupTask(SttService activity) {
this.activityReference = new WeakReference<>(activity);
}
#Override
protected Exception doInBackground(Void... params) {
try {
Assets assets = new Assets(activityReference.get());
File assetDir = assets.syncAssets();
activityReference.get().setupRecognizer(assetDir);
} catch (IOException e) {
return e;
}
return null;
}
#Override
protected void onPostExecute(Exception result) {
if (result != null) {
Log.e(TAG, "onPostExecute: Failed to init recognizer " + result);
} else {
activityReference.get().switchSearch(KWS_SEARCH);
}
}
}
#Override
public void onDestroy() {
super.onDestroy();
if (recognizer != null) {
recognizer.cancel();
recognizer.shutdown();
}
}
#Nullable
#Override
public IBinder onBind(Intent intent) {
return null;
}
/**
* In partial result we get quick updates about current hypothesis. In
* keyword spotting mode we can react here, in other modes we need to wait
* for final result in onResult.
*/
#Override
public void onPartialResult(Hypothesis hypothesis) {
if (hypothesis == null)
return;
String text = hypothesis.getHypstr();
if (text.equals(KEYPHRASE))
switchSearch(MENU_SEARCH);
else if (text.equals(DIGITS_SEARCH))
switchSearch(DIGITS_SEARCH);
else if (text.equals(PHONE_SEARCH))
switchSearch(PHONE_SEARCH);
else if (text.equals(FORECAST_SEARCH))
switchSearch(FORECAST_SEARCH);
else
Log.e(TAG, "onPartialResult: " + text);
}
/**
* This callback is called when we stop the recognizer.
*/
#Override
public void onResult(Hypothesis hypothesis) {
if (hypothesis != null) {
String text = hypothesis.getHypstr();
Log.e(TAG, "onResult: " + text);
}
}
#Override
public void onBeginningOfSpeech() {
}
/**
* We stop recognizer here to get a final result
*/
#Override
public void onEndOfSpeech() {
if (!recognizer.getSearchName().equals(KWS_SEARCH))
switchSearch(KWS_SEARCH);
}
private void switchSearch(String searchName) {
recognizer.stop();
// If we are not spotting, start listening with timeout (10000 ms or 10 seconds).
if (searchName.equals(KWS_SEARCH))
recognizer.startListening(searchName);
else
recognizer.startListening(searchName, 10000);
String caption = getResources().getString(captions.get(searchName));
Log.e(TAG, "switchSearch: "+ caption);
}
private void setupRecognizer(File assetsDir) throws IOException {
// The recognizer can be configured to perform multiple searches
// of different kind and switch between them
recognizer = SpeechRecognizerSetup.defaultSetup()
.setAcousticModel(new File(assetsDir, "en-us-ptm"))
.setDictionary(new File(assetsDir, "cmudict-en-us.dict"))
.setRawLogDir(assetsDir) // To disable logging of raw audio comment out this call (takes a lot of space on the device)
.getRecognizer();
recognizer.addListener(this);
/* In your application you might not need to add all those searches.
They are added here for demonstration. You can leave just one.
*/
// Create keyword-activation search.
recognizer.addKeyphraseSearch(KWS_SEARCH, KEYPHRASE);
// Create grammar-based search for selection between demos
File menuGrammar = new File(assetsDir, "menu.gram");
recognizer.addGrammarSearch(MENU_SEARCH, menuGrammar);
// Create grammar-based search for digit recognition
File digitsGrammar = new File(assetsDir, "digits.gram");
recognizer.addGrammarSearch(DIGITS_SEARCH, digitsGrammar);
// Create language model search
File languageModel = new File(assetsDir, "weather.dmp");
recognizer.addNgramSearch(FORECAST_SEARCH, languageModel);
// Phonetic search
File phoneticModel = new File(assetsDir, "en-phone.dmp");
recognizer.addAllphoneSearch(PHONE_SEARCH, phoneticModel);
}
#Override
public void onError(Exception error) {
Log.e(TAG, "onError: " + error.getMessage());
}
#Override
public void onTimeout() {
switchSearch(KWS_SEARCH);
}
}
My code is almost the same as pocketsphinx-android-demo. The only differences are that I am doing this in a service class, instead of an Activity and I am not asking the user for microphone permission since I do that in the MainActity already. Well, my code has some warnings but no errors.
When I run my app, I get this message (see the full stack trace):
E/SstService: switchSearch: To start demonstration say "oh mighty
computer".
But when I say "oh mighty computer" (or anything else), nothing happens. I don't even get an error. So I have no idea where I am stuck and what I am doing wrong.
If there is someone familiar with that library, any help will be appreciated!

FFmpeg - cannot find ExecuteBinaryResponseHandler - Android/Java

I am trying to make a module for react-native that will change a video into a gif. I have little to no experience with android studios/java, but I would love to learn more! I am using this library to convert the video to a gif. Here is my code:
package com.reactlibrary;
import android.widget.Toast;
import com.facebook.react.bridge.ReactApplicationContext;
import com.facebook.react.bridge.ReactContextBaseJavaModule;
import com.facebook.react.bridge.ReactMethod;
import com.github.hiteshsondhi88.libffmpeg.FFmpeg;
public class RNGifMakerModule extends ReactContextBaseJavaModule {
private final ReactApplicationContext reactContext;
public RNGifMakerModule(ReactApplicationContext reactContext) {
super(reactContext);
this.reactContext = reactContext;
}
#Override
public String getName() {
return "RNGifMakerModule";
}
#ReactMethod
public void alert(String message) {
Toast.makeText(getReactApplicationContext(), "Error", Toast.LENGTH_LONG).show();
String[] cmd = {"-i"
, message
, "Image.gif"};
conversion(cmd);
}
public void conversion(String[] cmd) {
FFmpeg ffmpeg = FFmpeg.getInstance(this.reactContext);
try {
// to execute "ffmpeg -version" command you just need to pass "-version"
ffmpeg.execute(cmd, new ExecuteBinaryResponseHandler() {
#Override
public void onStart() {
}
#Override
public void onProgress(String message) {
}
#Override
public void onFailure(String message) {
}
#Override
public void onSuccess(String message) {
}
#Override
public void onFinish() {
}
});
} catch (FFmpegCommandAlreadyRunningException e) {
// Handle if FFmpeg is already running
e.printStackTrace();
}
}
}
And I get this error:
Error:(43, 31) error: cannot find symbol class ExecuteBinaryResponseHandler
This seems odd to be, because in the documentation for ffmpeg-android-java it says to use almost exactly the same code.
Bounty
The bounty will be awarded to you if you can find a way to convert a video.mp4 into a gif. You do not necessarily have to use FFmpeg, but your solution has to work with java/android studios.

First of all you should init ffmpeg correctly.
FFmpeg ffmpeg = FFmpeg.getInstance(this.reactContext);
// please add following method after
ffmpeg.loadBinary(new FFmpegLoadBinaryResponseHandler() {
#Override
public void onFailure() {
// probably your device not supported
}
#Override
public void onSuccess() {
// you should init flag here (isLoaded, isReady etc.)
}
Only after onSuccess() you can work with commands.
Then please check following answer by LordNeckbeard.
So your code should be something like this:
if (isFFmpegLoaded) {
// ffmpeg.execute(commands from link from the answer)
}
Please do not forget to remove all spaces from command's string and "ffmpeg" word.
To keep command more readable I will recommend to build command like this:
final String[] command = new String[11]; // example of the first command in the answer
command[0] = "-y";
command[1] = "-ss";
command[2] = "30";
command[3] = "-t";
command[4] = "3";
command[5] = "-i";
command[6] = "-t";
command[7] = "filePath";
command[8] = "-vf";
command[9] = "fps=10,scale=320:-1:flags=lanczos,palettegen";
command[10] = "palette.png";
Please make sure that you have storage permission to work with file just in case you are working on external storage.
Based on this strategy ffmpeg works well for me. Thanks and good luck!

First of all, you should use: File - Invalidate Caches/Restart - Invalidate and Restart and try to reimport ExecuteBinaryResponseHan‌dler. If the problem hasn't been resolved you can try the small hack. Inside your project create package com.github.hiteshsondhi88.libffmpeg and class:
public class ExecuteBinaryResponseHandler implements FFmpegExecuteResponseHandler {
#Override
public void onSuccess(String message) {
}
#Override
public void onProgress(String message) {
}
#Override
public void onFailure(String message) {
}
#Override
public void onStart() {
}
#Override
public void onFinish() {
}
}
It should be as on image:
Then inside your build.gradle file in defaultConfig block add multiDexEnabled true
Then you will be able to use that class

Updating JavaFX GUI from a service thread

How can I safely update the widgets on a JavaFX GUI from within a JavaFX Service. I remember when I was developing with Swing, I used to 'invoke later' and other various swing worker utilities to ensure that all updates to the UI were handled safely in the Java Event Thread. Here is an example of a simple service thread that handles datagram messages. The bit that is missing is where the datagram message is parsed and corresponding UI widgets are updated. As you can see the service class is very simplistic.
I'm not sure if I need to use simple binding properties (like message) or alternatively should I should pass widgets to the constructor of my StatusListenerService (which is probably not the best thing to do). Can someone give me a good similar example that I would work from.
public class StatusListenerService extends Service<Void> {
private final int mPortNum;
/**
*
* #param aPortNum server listen port for inbound status messages
*/
public StatusListenerService(final int aPortNum) {
this.mPortNum = aPortNum;
}
#Override
protected Task<Void> createTask() {
return new Task<Void>() {
#Override
protected Void call() throws Exception {
updateMessage("Running...");
try {
DatagramSocket serverSocket = new DatagramSocket(mPortNum);
// allocate space for received datagrams
byte[] bytes = new byte[512];
//message.setByteBuffer(ByteBuffer.wrap(bytes), 0);
DatagramPacket packet = new DatagramPacket(bytes, bytes.length);
while (!isCancelled()) {
serverSocket.receive(packet);
SystemStatusMessage message = new SystemStatusMessage();
message.setByteBuffer(ByteBuffer.wrap(bytes), 0);
}
} catch (Exception ex) {
System.out.println(ex.getMessage());
}
updateMessage("Cancelled");
return null;
}
};
}
}

The "low-level" approach is to use Platform.runLater(Runnable r) to update the UI. This will execute r on the FX Application Thread, and is the equivalent of Swing's SwingUtilities.invokeLater(...). So one approach is simply to call Platform.runLater(...) from inside your call() method and update the UI. As you point out, though, this essentially requires the service knowing details of the UI, which is undesirable (though there are patterns that work around this).
Task defines some properties and has corresponding updateXXX methods, such as the updateMessage(...) method you call in your example code. These methods are safe to call from any thread, and result in an update to the corresponding property to be executed on the FX Application Thread. (So, in your example, you can safely bind the text of a label to the messageProperty of the service.) As well as ensuring the updates are performed on the correct thread, these updateXXX methods also throttle the updates, so that you can essentially call them as often as you like without flooding the FX Application Thread with too many events to process: updates that occur within a single frame of the UI will be coalesced so that only the last such update (within a given frame) is visible.
You could leverage this to update the valueProperty of the task/service, if it is appropriate for your use case. So if you have some (preferably immutable) class that represents the result of parsing the packet (let's call it PacketData; but maybe it is as simple as a String), you make
public class StatusListener implements Service<PacketData> {
// ...
#Override
protected Task<PacketData> createTask() {
return new Task<PacketData>() {
// ...
#Override
public PacketData call() {
// ...
while (! isCancelled()) {
// receive packet, parse data, and wrap results:
PacketData data = new PacketData(...);
updateValue(data);
}
return null ;
}
};
}
}
Now you can do
StatusListener listener = new StatusListener();
listener.valueProperty().addListener((obs, oldValue, newValue) -> {
// update UI with newValue...
});
listener.start();
Note that the value is updated to null by the code when the service is cancelled, so with the implementation I outlined you need to make sure that your listener on the valueProperty() handles this case.
Also note that this will coalesce consecutive calls to updateValue() if they occur within the same frame rendering. So this is not an appropriate approach if you need to be sure to process every data in your handler (though typically such functionality would not need to be performed on the FX Application Thread anyway). This is a good approach if your UI is only going to need to show the "most recent state" of the background process.
SSCCE showing this technique:
import java.util.Random;
import javafx.application.Application;
import javafx.beans.binding.Bindings;
import javafx.concurrent.Service;
import javafx.concurrent.Task;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.CheckBox;
import javafx.scene.control.Label;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
public class LongRunningTaskExample extends Application {
#Override
public void start(Stage primaryStage) {
CheckBox enabled = new CheckBox("Enabled");
enabled.setDisable(true);
CheckBox activated = new CheckBox("Activated");
activated.setDisable(true);
Label name = new Label();
Label value = new Label();
Label serviceStatus = new Label();
StatusService service = new StatusService();
serviceStatus.textProperty().bind(service.messageProperty());
service.valueProperty().addListener((obs, oldValue, newValue) -> {
if (newValue == null) {
enabled.setSelected(false);
activated.setSelected(false);
name.setText("");
value.setText("");
} else {
enabled.setSelected(newValue.isEnabled());
activated.setSelected(newValue.isActivated());
name.setText(newValue.getName());
value.setText("Value: "+newValue.getValue());
}
});
Button startStop = new Button();
startStop.textProperty().bind(Bindings
.when(service.runningProperty())
.then("Stop")
.otherwise("Start"));
startStop.setOnAction(e -> {
if (service.isRunning()) {
service.cancel() ;
} else {
service.restart();
}
});
VBox root = new VBox(5, serviceStatus, name, value, enabled, activated, startStop);
root.setAlignment(Pos.CENTER);
Scene scene = new Scene(root, 400, 400);
primaryStage.setScene(scene);
primaryStage.show();
}
private static class StatusService extends Service<Status> {
#Override
protected Task<Status> createTask() {
return new Task<Status>() {
#Override
protected Status call() throws Exception {
Random rng = new Random();
updateMessage("Running");
while (! isCancelled()) {
// mimic sporadic data feed:
try {
Thread.sleep(rng.nextInt(2000));
} catch (InterruptedException exc) {
Thread.currentThread().interrupt();
if (isCancelled()) {
break ;
}
}
Status status = new Status("Status "+rng.nextInt(100),
rng.nextInt(100), rng.nextBoolean(), rng.nextBoolean());
updateValue(status);
}
updateMessage("Cancelled");
return null ;
}
};
}
}
private static class Status {
private final boolean enabled ;
private final boolean activated ;
private final String name ;
private final int value ;
public Status(String name, int value, boolean enabled, boolean activated) {
this.name = name ;
this.value = value ;
this.enabled = enabled ;
this.activated = activated ;
}
public boolean isEnabled() {
return enabled;
}
public boolean isActivated() {
return activated;
}
public String getName() {
return name;
}
public int getValue() {
return value;
}
}
public static void main(String[] args) {
launch(args);
}
}

Adobe Air ANE for android with java native extension trying to receive broadcast

I'm trying to create a native extension which can receive broadcasts, sent from a native android am as intent broadcasts.
The sending part works, I've tested this with a native app that has a broadcast receiver, but I cant get it to work in the native extension.
Here's what I have so far:
Here the java side of the ANE
public class ReceiverPhidget extends BroadcastReceiver {
private FREContext mFREContext;
public ReceiverPhidget(FREContext mFREContext) {
this.mFREContext = mFREContext;
}
#Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (action.equals(IntentsKeys.INTENT_PHIDGET_CONNECTED)){
//Send listener in ANE project with message that phidget connected (not must)
System.out.println("Phidget connected");
mFREContext.dispatchStatusEventAsync("Yes", Keys.KEY_CONNECTED);
} else
if (action.equals(IntentsKeys.INTENT_PHIDGET_DISCONNECTED)){
//Send listener in ANE project with message that phidget disconnected (not must)
System.out.println("Phidget disconnected");
mFREContext.dispatchStatusEventAsync("Yes", Keys.KEY_DISCONNECTED);
} else
if (action.equals(IntentsKeys.INTENT_PHIDGET_GAIN_TAG)){
//Send listener with data in ANE project with message that phidget gain receive
String message = intent.getStringExtra(IntentsKeys.INTENT_PHIDGET_EXTRA_DATA);
System.out.println("Phidget gain message: " + message);
Log.d("TAG FOUND", message);
mFREContext.dispatchStatusEventAsync(message, Keys.KEY_TAG_GAIN);
}
}
public static IntentFilter getIntentFilter(){
final IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(IntentsKeys.INTENT_PHIDGET_CONNECTED);
intentFilter.addAction(IntentsKeys.INTENT_PHIDGET_DISCONNECTED);
intentFilter.addAction(IntentsKeys.INTENT_PHIDGET_GAIN_TAG);
return intentFilter;
}
}
And the FREExtension
public class ReceiverExtension implements FREExtension {
private ReceiverPhidget mReceiverPhidget;
private ReceiverExtensionContext mContext;
#Override
public void initialize() {
mReceiverPhidget = new ReceiverPhidget(mContext);
mContext.getActivity().registerReceiver(mReceiverPhidget, ReceiverPhidget.getIntentFilter());
}
#Override
public FREContext createContext(String s) {
return mContext = new ReceiverExtensionContext();
}
#Override
public void dispose() {
mContext.getActivity().unregisterReceiver(mReceiverPhidget);
}
}
And here is the flash library side of the ANE
package nl.mediaheads.anetest.extension {
import flash.events.EventDispatcher;
import flash.events.StatusEvent;
import flash.external.ExtensionContext;
public class RFIDController extends EventDispatcher {
private var extContext:ExtensionContext;
private var channel:int;
private var scannedChannelList:Vector.<int>;
public function RFIDController() {
extContext = ExtensionContext.createExtensionContext(
"nl.mediaheads.anetest.exntension.RFIDController", "");
extContext.addEventListener(StatusEvent.STATUS, onStatus);
}
private function onStatus(event:StatusEvent):void {
if (event.level == EventKeys.KEY_TAG_GAIN) {
dispatchEvent (new TagEvent(TagEvent.TAG_GAINED, event.code) );
}
}
}
}
And here is my test mobile project class to test the ANE
package
{
import flash.display.Sprite;
import flash.display.StageAlign;
import flash.display.StageScaleMode;
import flash.events.Event;
import flash.text.TextField;
import nl.mediaheads.anetest.extension.RFIDController;
[SWF(width="1280", height="800", frameRate="60", backgroundColor="#ffffff")]
public class AneTestApp extends Sprite
{
private var tf:TextField;
private var rc:RFIDController;
public function AneTestApp()
{
super();
// support autoOrients
stage.align = StageAlign.TOP_LEFT;
stage.scaleMode = StageScaleMode.NO_SCALE;
stage.color = 0xFFFFFF;
addEventListener(Event.ADDED_TO_STAGE, onAdded);
}
private function onAdded(event:Event):void {
//
tf = new TextField();
tf.width = 200;
tf.height = 50;
tf.x = 10;
tf.y = 64;
tf.mouseEnabled = false;
tf.background = true;
tf.backgroundColor = 0xF50000;
addChild(tf);
rc = new RFIDController();
tf.text = "test 1";
this.addEventListener( TagEvent.TAG_GAINED , onTagAdded);
tf.text = "test 2";
//
}
private function onTagAdded(event:TagEvent):void
{
tf.text = event.params;
}
}
}
I have signed the ANE accordingly, I also signed the test app it's self.
I have a Log.d in the java part of the ANE which should pop up on log cat but it doesn't, also the textfield just becomes blank as soon as I initialized the RFIDController even without added the event listener.
If you need any more code or information to help me solve this problem feel free to ask.
I could really use some help because I'm completely lost, I've followed multiple tutorials and guide on how to do this, I should have done everything correctly, but I clearly have not.
UPDATE: 1
The extension xml
<extension xmlns="http://ns.adobe.com/air/extension/3.5">
<id>nl.mediaheads.anetest.exntension.RFIDController</id>
<versionNumber>0.0.1</versionNumber>
<platforms>
<platform name="Android-ARM">
<applicationDeployment>
<nativeLibrary>AneTest.jar</nativeLibrary>
<initializer>nl.mediaheads.anetest.ReceiverExtension</initializer>
<finalizer>nl.mediaheads.anetest.ReceiverExtension</finalizer>
</applicationDeployment>
</platform>
</platforms>
</extension>
UPDATE 2:
I fixed it, it was an context issue together with that flash somehow clean my custom event so I used status event to parse from the flash side of the ANE to the air application itself.

Currently you are creating your receiver at the initialisation point of the extension which will most likely be called before the context creation, so your context may be null at that point and causing your errors.
Try moving the creation of your ReceiverPhidget to the constructor of your ReceiverExtensionContext. Something like the following (I haven't tested this):
public class ReceiverExtensionContext extends FREContext
{
private ReceiverPhidget mReceiverPhidget;
public ReceiverExtensionContext()
{
mReceiverPhidget = new ReceiverPhidget( this );
getActivity().registerReceiver( mReceiverPhidget, ReceiverPhidget.getIntentFilter() );
}
#Override
public Map<String, FREFunction> getFunctions()
{
Map<String, FREFunction> functionMap = new HashMap<String, FREFunction>();
return functionMap;
}
#Override
public void dispose()
{
getActivity().unregisterReceiver( mReceiverPhidget );
}
}

Hooking a GWT event onto an element in an external iframe

I am writing a GWT app that involves interacting with an external document in an iframe. As a proof of concept, I am trying to attach a click handler to a button.
The following works in javascript
var iframe = document.getElementById("rawJSIFrame");
var doc = iframe.contentDocument;
var body = doc.body;
var button = doc.getElementsByTagName("input").namedItem("submit");
button.onclick = function() {
alert("Clicked!");
};
Trying to do the equivalent in GWT, I did the following:
public void addClickHandlerToSubmitButton(String buttonElementName, ClickHandler clickHandler) {
IFrameElement iframe = IFrameElement.as(frame.getElement());
Document frameDocument = getIFrameDocument(iframe);
if (frameDocument != null) {
Element buttonElement = finder(frameDocument).tag("input").name(buttonElementName).findOne();
ElementWrapper wrapper = new ElementWrapper(buttonElement);
HandlerRegistration handlerRegistration = wrapper.addClickHandler(clickHandler);
}
}
private native Document getIFrameDocument(IFrameElement iframe)/*-{
return iframe.contentDocument;
}-*/;
The following is the ElementWrapper class:
public class ElementWrapper extends Widget implements HasClickHandlers {
public ElementWrapper(Element theElement) {
setElement(theElement);
}
public HandlerRegistration addClickHandler(ClickHandler handler) {
return addDomHandler(handler, ClickEvent.getType());
}
}
The code to find the button works fine but the actual click event handler is not getting invoked. Has anybody had a similar issue before, and how did you resolve it?
Thanks in advance,
Tin

Hilbrand is right about the problem being that the GWT method onAttach() was not called.
I implemented your original solution, adding the following method to ElementWrapper:
public void onAttach() {
super.onAttach();
}
And called added wrapper.onAttach() after the ElementWrapper is created. Works like a charm!

I expect the problem is that the GWT method onAttach() is not called when you use the wrapping as in your first example. You can try to use the static wrap method on the Button widget. Although to use this the input must be of type button. Or have a look at the implementation of the wrap method. Here is the modified code when using the wrap method:
Element buttonElement = finder(frameDocument).tag("input").name(buttonElementName).findOne();
Button button = Button.wrap(buttonElement);
HandlerRegistration handlerRegistration = button.addClickHandler(clickHandler);

After researching this further, I found that the iframe is irrelevant. The same behaviour doesn't work on a normal button on the host page.
I basically fixed it by using JSNI to replicate part of GWT's event handling mechanism. The following works:
Element buttonElement = DOM.getElementById("externalButton");
new CustomElementWrapper(buttonElement).addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
Window.alert("GWT hooked into button");
}
});
Where CustomElementWrapper is:
public class CustomElementWrapper extends Widget implements HasClickHandlers {
private ClickEventManager clickEventManager;
public CustomElementWrapper(Element theElement) {
setElement(theElement);
clickEventManager = new ClickEventManager(theElement);
}
public HandlerRegistration addClickHandler(ClickHandler handler) {
//The 'right' way of doing this would be the code below. However, this doesn't work
// A bug in GWT?
//
// return addDomHandler(handler, ClickEvent.getType());
return clickEventManager.registerClickHandler(handler);
}
void invokeClickHandler() {
clickEventManager.invokeClickHandler();
}
public boolean isClickHandlerRegistered() {
return clickEventManager.isClickHandlerRegistered();
}
}
Finally, the ClickEventManager, where the actual work happens is:
public class ClickEventManager {
private boolean clickHandlerRegistered = false;
private ClickHandler clickHandler;
private Element element;
public ClickEventManager(Element element) {
this.element = element;
}
public void invokeClickHandler() {
//This shouldn't really be null but we are bypassing GWT's native event mechanism
//so we can't create an event
clickHandler.onClick(null);
}
public boolean isClickHandlerRegistered() {
return clickHandlerRegistered;
}
HandlerRegistration registerClickHandler(ClickHandler handler) {
clickHandler = handler;
if (!clickHandlerRegistered) {
registerClickHandlerInJS(element);
clickHandlerRegistered = true;
}
return new HandlerRegistration() {
public void removeHandler() {
//For now, we don't support the removal of handlers
throw new UnsupportedOperationException();
}
};
}
private native void registerClickHandlerInJS(Element element)/*-{
element.__clickManager = this;
element.onclick
= function() {
var cm = this.__clickManager;
cm.#com.talktactics.agent2.client.widgets.ClickEventManager::invokeClickHandler()();
}
}-*/;
}
Personally, I hate this solution because I appear to be duplicating GWT's event handling and quite possibly introducing nasty javascript memory leaks. Any ideas on why my first post doesn't work (remembering that the iframe aspect is a red herring), would be appreciated.
Thanks,
Tin

You may find this helpful:
import com.google.gwt.dom.client.Element;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.dom.client.HasClickHandlers;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.user.client.ui.AbsolutePanel;
public class DirectPanel extends AbsolutePanel implements HasClickHandlers {
public DirectPanel(Element elem) {
super(elem.<com.google.gwt.user.client.Element> cast());
onAttach();
}
#Override
public HandlerRegistration addClickHandler(ClickHandler handler) {
return addDomHandler(handler, ClickEvent.getType());
}
}
You will then be able to make arbitrary containers into widget containers:
Element root = Document.get().getElementById("target");
DirectPanel p = new DirectPanel(root);
Button register = new Button("Register");
register.addClickHandler(new ClickHandler() {
#Override
public void onClick(ClickEvent event) {
// ...
}
});
p.add(register);
And bind events to arbitrary elements:
Element root = Document.get().getElementById("target");
DirectPanel p = new DirectPanel(root);
p.addClickHandler(new ClickHandler() {
#Override
public void onClick(ClickEvent event) {
// ...
}
});
Specifically in your case, try this:
IFrameElement frm = Document.get().createIFrameElement();
Document d = frm.getContentDocument();
NodeList<Element> inputs = d.getElementsByTagName("input");
InputElement target = null;
for(int i = 0; i < inputs.getLength(); ++i) {
Element e = inputs.getItem(0);
if (e.getNodeName().equals("submit")) {
target = InputElement.as(e);
break;
}
}
if (target != null) {
DirectPanel p = new DirectPanel(target);
p.addClickHandler(new ClickHandler() {
#Override
public void onClick(ClickEvent event) {
// TODO Auto-generated method stub
}
});
}
It's always mystified me that GWT makes doing this so difficult and poorly documented.

Instead of using iframes i suggest you simply make a http request from GWT via com.google.gwt.http.client.RequestBuilder. Like so:
private void getHtml(String url) {
RequestBuilder rb = new RequestBuilder(RequestBuilder.GET, url);
rb.setCallback(new RequestCallback() {
#Override
public void onResponseReceived(Request request, Response response) {
HTMLPanel html = new HTMLPanel(response.getText());
// Now you have a widget with the requested page
// thus you may do whatever you want with it.
}
#Override
public void onError(Request request, Throwable exception) {
Log.error("error " + exception);
}
});
try {
rb.send();
} catch (RequestException e) {
Log.error("error " + e);
}
}

You could use JSNI to reuse your JavaScript piece of code. Your javascript code would call a gwt method on an object that would throw it on behalf of the button in the iframe.
As to why GWT code does not work -- I guess that is because they use some layer on top of regular browser events that probably cannot span more than 1 frame. That's just a guess though. You could file this as a feature/bug request agains GWT team. If I am right your code looks just fine.

Please see my previous answer. A slight modification to your original solution will make it work.