Help With Chromecast Extension

bartmathijssen · April 14, 2020, 8:28pm

To convert a List to a YailList you could do something like the following:

YailList chromeCasts = YailList.makeList(ChromeCasts.get());

Alexander · April 14, 2020, 8:41pm

Indeed it compiled without problems, but it returns an empty List

What I see also is that in ChromeCasts.java (from the Library) it says “return new ArrayList”

Will it be related?

github.com

vitalidze/chromecast-java-api-v2/blob/master/src/main/java/su/litvak/chromecast/api/v2/ChromeCasts.java#L46




private final List<ChromeCastsListener> listeners = new ArrayList<ChromeCastsListener>();
private final List<ChromeCast> chromeCasts = Collections.synchronizedList(new ArrayList<ChromeCast>());


private ChromeCasts() {
}


/** Returns a copy of the currently seen chrome casts.
 * @return a copy of the currently seen chromecast devices.
 */
public static List<ChromeCast> get() {
    return new ArrayList<ChromeCast>(INSTANCE.chromeCasts);
}


/** Hidden service listener to receive callbacks.
 * Is hidden to avoid messing with it.
 */
private class MyServiceListener implements ServiceListener {
    @Override
    public void serviceAdded(ServiceEvent se) {
        if (se.getInfo() != null) {

#Off-Topic

@Peter your son is a genius, don’t do this to him

ewpatton · April 14, 2020, 9:36pm

You can return a straight List type from a method, you don’t need to return YailList. The runtime will coerce the List into a YailList. However, we generally don’t try to expose non-YAIL types in the blocks since one can’t do anything with them. Instead we provide methods to access information about the internal objects (cf. BluetoothClient). You may want to consider a similar pattern.

Alexander · April 15, 2020, 12:33pm

Ok, @Krishjha07 has helped me solve some problems, however it still returns an empty list

I found this Issue in the Repository of the used library, but I think it affects only computers, since I have seen other Android projects using this library

ewpatton · April 15, 2020, 2:25pm

@Alexander Are you able to build a very basic app in Android Studio using the library? At least that would allow us to ensure that you have code that works, in which case it’s just a matter of figuring out how to integrate it into an extension.

Alexander · April 15, 2020, 3:26pm

I have never used Android Studio before, but I guess I can try it

I will install it

Alexander · April 30, 2020, 3:01am

After several days of research and help received, I think we reached the cause of the error

When implementing a .OnError block it shows us that the StartingDeviceDiscovery process stops due to android.os.NetworkOnMainThreadException

I did a little more research and came to the conclusion that this process should be done asynchronously

I will report the results when I do more tests

Thanks Evan and Bart for the kind attention!

vknow360 · April 30, 2020, 3:58am

I don't think it will work.
AsyncTask is the best option.

Alexander · April 30, 2020, 4:02am

Yes, I saw your post on Kodular Community about this recommendation @vknow360

I’ll do a little more research since I’m not very knowledgeable about it

vknow360 · April 30, 2020, 4:04am

It is quite easy to implement once you have learnt about its usage.
This can be helpful:

vknow360 · April 30, 2020, 6:59am

Can you give me a working example?

...without any meaningful reason. I have no idea that why some developers hate it so much.

ewpatton · April 30, 2020, 1:33pm

@Alexander I would recommend that you make use of the AsynchUtil class:

github.com

mit-cml/appinventor-sources/blob/master/appinventor/components/src/com/google/appinventor/components/runtime/util/AsynchUtil.java

// -*- mode: java; c-basic-offset: 2; -*-
// Copyright 2009-2011 Google, All Rights reserved
// Copyright 2011-2012 MIT, All rights reserved
// Released under the Apache License, Version 2.0
// http://www.apache.org/licenses/LICENSE-2.0

package com.google.appinventor.components.runtime.util;

import android.os.Handler;

/**
 * Utilities for handling asynchronous calls.
 *
 * @author markf@google.com (Mark Friedman)
 */

public class AsynchUtil {

  /**
   * Make an asynchronous call in a separate thread.

This file has been truncated. show original

You can see uses of it in other components that do network activity, such as the Web component.

Alexander · April 30, 2020, 1:39pm

Apparently at least in Kodular Creator this might sometimes not work and closed the app

Although apparently it works fine now

I think I will make the repository public so that those interested can help

Alexander · April 30, 2020, 2:00pm

I have used the Extensions template and GitHub Actions

ewpatton · April 30, 2020, 2:20pm

Unfortunately, I can’t really speak to any stability issues in Kodular w.r.t. to the use of AsynchUtil there. In App Inventor, we use AsynchUtil in many different components in App Inventor, so if there were an actual problem with it I would expect that we’d be seeing a lot of reports (we had almost 650k users in the last 30 days). For example, it’s used as part of the WebRTC negotiation when you connect your companion to the browser.

According to an analysis with IntelliJ, AsynchUtil is used in the following components:

BluetoothServer
File
Map
FeatureCollection
MediaUtil; for loading images from the web and called from a plethora of components, including:
- ButtonBase and its associated subclasses (Button and all Picker elements)
- Canvas
- Form (Screen)
- Image
- ImageSprite
Navigation
TinyWebDB
Twitter
Web
WebRTCMgr (companion connection management)
YandexTranslate

Alexander · April 30, 2020, 2:28pm

vknow360 · April 30, 2020, 3:42pm

Hi @ewpatton
First of all thanks for sharing so much knowledge.
Honestly I haven’t used most of the AI2 components.
I mostly use AI2 for testing my extensions.So I am aware of those uses of AsychUtil.
But recently I have experienced a lot of issues by using AsynchUtill such as unexpected closing of application.
That’s is why I wrote above post on Kodular Community.
I also thought to report bug here but somehow I was able overcome the issues using AsyncTask so didn’t reported bug here.And I am feeling very sorry for that.
But I don’t know how it is working now

ewpatton · April 30, 2020, 3:45pm

Do you experience issues in App Inventor, Kodular, or both? Did you capture any stack traces via adb logcat for the crashes?

vknow360 · April 30, 2020, 3:51pm

I experienced issues on both builders.First on Kodular because users reported bugs there then I tested on App Inventor and found that it is not working on both.

Sorry I use android 4.4 so either I have not so much options for debugging or I don't have proper knowledge about debugging.
Can I get logcat now?

ewpatton · April 30, 2020, 4:00pm

@Hossein has a post on the AppyBuilder forum about how to use adb logcat to collect crash information:

https://community.appybuilder.com/t/capturing-device-logs-using-adb/83?u=taifun