Calling reset on Media Player after calling setDataSource, Freezes UI - java

Im working on a Music Player app, and all the music handled by the app are from streaming resources.
Everytime the user changes songs, i need to call reset and set a new dataSource. If the user rapidly switches songs, and the MediaPlayer is on the preparing state, the UI from my app freezes.
This only happens if i call reset and the media player is in the preparing state.
How can i prevent my app UI from freezing and getting an ANR?
PS: Im using prepareAsync(), not prepare().

See setOnPreparedListener. You can keep track of the state in your class through various listeners and avoid calling prepareAsync().
You might have better luck also calling stop() before reset().
http://developer.android.com/reference/android/media/MediaPlayer.html#setOnPreparedListener%28android.media.MediaPlayer.OnPreparedListener%29

Related

Why does an activity playing a sound disturb the user interface?

I would like to show a notification and play a sound when the user taps onto that notification. It works somehow when I use an activity to play the sound, as I have written in my own answer to this question: How can I create a notification that plays an audio file when being tapped? (in this question and answer there is also the source code showing how I create the notification and how my PlaySoundActivity looks like.
Yet, I have realized, that while the sound is playing, the appearance of my main application changes and it will not be restored without closing the application.
I have created my application from the "Tabbed Activity" project template.
This is how it looks after being started:
And this is how it looks when I have tapped onto the sound notification (the sections are gone):
Can anyone explain why this happens? Is it a wrong approach to play sound using an activity? But it does not work here when I use a service, I hear nothing! How to solve that?
According to the Android developer reference, "almost all activities interact with the user, so the Activity class takes care of creating a window for you in which you can place your UI with setContentView(View)".
I had not done this. Therefore a new window was displayed, but there was no content.
The better solution for playing a sound is to use a PlaySoundService (service!!!) instead of an activity. It contains almost the same code as an activity would do, but the pending intent is created with PendingIntent.getService(...) instead of PendingIntent.getActivity(...). Using the wrong method does not result in an obvious error message, but the service won't work as expected.

Loading Images,Videos in background

I am trying to make an App which is going to display Some Images and Videos. So I am planning to add a splash screen of around 2seconds. After 2 seconds the user will be taken to the Main Screen of the App.
I want to start the loading of the Images, Video when then user is at the splash screen itself so that the user should wait for the least time when he is at the Main Screen.
So the loading will be started at the Splash Screen and then after two second the user will be taken to main screen irrespective of the completion of the loading.
Now since this involves two activities should I use a Async task or should I Use a service with an Async Task(For the callback of completion of code) within it?
Which one would be better. Also in Android 8.0 are there any restriction in using Services?
I think using a Async Task between two screens may cause Memory leak if not coded properly.
Any help would be really grateful.
EDIT: My app is having one more feature hence cannot make the user wait in the Splash Screen till the loading is over.
It is not very good to use AsyncTask for sharing results between 2 activities, because AsyncTack created in Splash activity will be destoyed (stopped) when switched to Main activity. Better to use service in this case and Main screen will subscribe for result.
So basically you want to start the download in the splash screen and continue the download in the activity that follows. In this way, you still have to implement a loading animation. In your case, I would recommend finishing your splash screen, as soon as everything is downloaded. In that way, you don't have to download anything anymore inside the app's lifecycle.
AsyncTasks continue to run even after switching to a new activity. You can try the following flow:
1. Splash screen
2. Trigger Async Task
3. Main Activity
4. Show Images/Videos
The only catch is, you will not be able to fix a time for #2 to complete to be able to start #4. This is the nature of AsyncTasks. You can workaround by using the OnPostExecute within AsyncTask.
Example: OnPostExecute call another method that will enable a button. Users can click on the button to view Images/Videos. But then, this might not be a good user experience to see some button suddenly getting enabled.
In that case I would rather create some Singleton with own Handler (that works in separate Thread), that will be started at Splash screen. After Main screen will start, it should ask that Singleton about respective data or should sign himself for receiving that data.

How to execute code everytime app opens Android

I want to execute a piece of code (say, for example, display a Toast) every time that the app is opened. So far I have managed to do this every time the app is launched by putting the code into my MyApp.java file that extends Application.
However, if I press the homescreen or back out of the app and then go into it, the message doesn't reappear. It only does when I relaunch the app. Any idea how to do this?
EDIT:
basically im asking how to execute code everytime the whole APP is brought to foreground (this can be first time open, after another app was used, after user backed out of app, etc). Where would I place onResume code? It wouldn't be in a particular activity, would it, since I want it to apply when entire app appears in foreground, not just particular activity.
You can try writing that code in your activity's #Override-d onResume() method.
The only way to do this is,
Determine which app is currently in the foreground
.Follow this discussion for getting an idea for the best way to do it.
[Determining the current foreground application from a background task or service
Suppose, if the function name is 'getCurrentForgroundApp()',
You need a service to execute getCurrentForgroundApp(); every one second
(1-second interval is depending on your purpose, can be lower or higher).
Now, you can identify which app is running foreground in every second.
So, check if your app is the one running foreground. If true, then execute the toast or code you need.
This is how app-locker apps showing lock screen over selected apps, whenever they come to the foreground.
You have to use the onResume callback:
Android API
Example of use from previous SO question
In activity class:
#Override
protected void onResume() {
super.onResume();
//your code here
}

Android Sound Resetting

My app plays a coin sound every time a button is pressed.
coin_sound.start();
You can easily press faster than the coin sound. When this happens I want the coin sound to start from the beginning ever time the button is pressed.
if(coin_sound.isPlaying()){
coin_sound.reset();
coin_sound = MediaPlayer.create(getContext(), R.raw.coin02);
}
coin_sound.start();
The problem with this is that loading a media file tiny as it may be is still a relatively slow process. When you start to click the button really fast the app lags hard.
Are there any solutions to my problem? The only idea I have is to do something with an array of coin_sounds, but this method seems like it will be messy and gross...
The other answer posted here is somewhat correct. You should not call create over and over.
The code in that answer has a problem, though. The reset method sends the MediaPlayer into the idle state, where it is illegal to call most other methods. If you were to go that route, you have to call methods in the following order:
coin_sound.reset();
coin_sound.setDataSource(...);
coin_sound.prepare();
coin_sound.start();
The difference between calling create and the previous sequence of method calls is simply the creation of a new instance. That, however, is not the quickest way to do what should be done.
You should simply call coin_sound.seekTo(0); when you want the current playing sound to restart. So do something like:
if (coin_sound.isPlaying()) coin_sound.seekTo(0);
else coin_sound.start();
That assumes you have left the MediaPlayer in the prepared state so start can be called. You can accomplish that by calling reset, setDataSource, and prepare in the onCompletion listener. Also, make sure to call release when the sound is no longer needed.
It is because you are initiating coin_sound in the button click event, try this
initiate this variable in your oncreate method
coin_sound = MediaPlayer.create(getContext(), R.raw.coin02);
then make this your code for your button
if(coin_sound.isPlaying()){
coin_sound.reset();
}
coin_sound.start();
the problem is you are recreating a new media player each time the button is clicked so the new media player doesnt think there is a sound
and do you need to start it again with coin_sound.start();? doesnt restart stop then start the sound for you?

How to resume video playback after the surface was destroyed?

I'm working with the media player on a streaming application (RTSP):
Video and sound are played great but when an incoming call pauses the Activity, the Surface is destroyed (I know this because of traces in SurfaceHolder.Callback).
Once the call finishes, the activity is resumed and a new Surface is created. I've tried to assign it to the player via setDisplay(SurfaceHolder sh) method but so far, only the sound of the video can be heard.
The work around to resume a video stream is:
Restart the MediaPlayer object.
Wait for the buffer to fill.
Perform a seek via the mediaPlayer.
Wait for the buffer to fill.
This is annoying as the player should be able to be paused when a call is received, bind the new surface when the call completed and the Activity resume and play the video with no buffering at all.
Have you tried overriding "onStop" or even "onDestroy" and somehow make the player persitent?
Edith just showed me the timestamp of this question. Is it of any interest still?

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