Hello everyone,
For a while now, I had been trying to figure out how to download and display a web page's HTML file in a WebView. Why, you ask? Well, because this app is probably going to be used offline. More importantly, it is just another thing that you can learn to do and have in your skillset.
A long time passed from my initial Googling efforts, and I forgot about this for a bit. After a couple of weeks, I picked this up again and got it to work correctly.
Since so many different tutorials and explanations exist, I wanted to give a clear and detailed explanation, as well as try to help anyone who attempts to implement this.
So, here we go!
Step 1:
Of course, you need to have specified a button that executes an action.
I chose to have an ActionBar item that checks whether or not the SD card is accessible to your app. It also calls the ASyncTask that downloads the file.
To do this, I used:
Code:
case R.id.save: // Save item
if (Environment.getExternalStorageState().equals(
Environment.MEDIA_MOUNTED)) {
// execute this when the downloader must be fired
DownloadFile downloadFile = new DownloadFile();
downloadFile.execute(downloadUrl);
} else {
Toast.makeText(this, "Can't write to internal storage",
Toast.LENGTH_LONG).show();
}
This checks whether the internal SD card is mounted. If it is, it starts a new download, and gets the file at the webpage with the URL downloadUrl.
If the SD card cannot be accessed, it will show so in a Toast.
Step 2:
For part 2, we will set up the actual download of the file. This is done by an ASyncTask. You can, should you want to, show a progress indicator. However, since I only download small files, I have chosen not to do so.
To download the file:
Code:
private class DownloadFile extends AsyncTask<String, Integer, String> {
[user=439709]@override[/user]
protected String doInBackground(String... sUrl) {
try {
URL url = new URL(downloadUrl);
URLConnection connection = url.openConnection();
connection.connect();
// download the file
InputStream input = new BufferedInputStream(url.openStream());
OutputStream output = new FileOutputStream(Environment
.getExternalStorageDirectory().getPath()
+ "/data/"
+ getPackageName() + "/webpage.html");
byte data[] = new byte[1024];
int count;
try {
while ((count = input.read(data)) != -1)
output.write(data, 0, count);
} catch (IOException e) {
e.printStackTrace();
}
output.flush();
output.close();
input.close();
Toast.makeText(MyWebView.this, "File downloaded", Toast.LENGTH_SHORT).show();
} catch (IOException ioe) {
ioe.printStackTrace();
}
return null;
}
}
So, what do we see here?
Firstly, make a new ASyncTask class. This has a number of standard methods, including one that executes everything in it in a separate background thread: doInBackground.
Now, you want to open a new connection to the site's server, with the downloadUrl, and connect to it. This is easily done with a standard class called URLConnection.
To download and write the file to a specific location on the SD, open a new InputStream. This will download the file from the downloadURL.
Once you have done that, make a new OutputStream to open a connection to the internal storage. In my case, I am writing to what would be /sdcard/data/<mypackagename>/webpage.html, because every new download overwrites the file that was downloaded last.
To actually write the file to the SD, byte by byte, create a new bit array and a counter. As long as there's still data to be read from the file, write the data.
As the last step here, you want to clean and close your in- and output streams, etc. Just do this with the standard commands.
Then show the user a short Toast, to let them know the file has been downloaded correctly.
Should an IOException occur, I print the stack trace.
It would be good to notify the user of the error, though you shouldn't do it in an obtrusive way.
Step 3:
Now, we're almost done. I know you want to know what else is to be done, since the hard parts have been coded already.
This is true, but placement is very important. You want to have the ASyncTask placed correctly in your code.
So, where does it go? Just put it at the bottom of your original class. Subclasses of ASyncTask are usually inside the main Activity class. This ensures you can still easily modify the UI thread (foreground thread, which we use for the Toasts).
Everything should now work, just code a nice little Button (or something else) that triggers the download.
Step 4:
Now, we want to display this web page in the WebView. You should have the HTML file downloaded locally, after which it is quite easy to get it to show in a WebView. This does not automatically show images and other external files! However, I think that kind of defeats the purpose, which is saving on internet costs.
If anyone wants to know how I would do this, please ask in this thread!
To open and display the downloaded HTML in your WebView:
Code:
mWebView.loadUrl("file://"
+ Environment
.getExternalStorageDirectory()
.getPath() + "/data/"
+ getPackageName()
+ "/webpage.html");
Very easy, as I said. Just add file:// to the front of your downloaded file's location, and the WebView will do all the work.
You should make sure, though, that the app doesn't have an Internet connection available. I check this when the WebView starts, but that's material for another guide.
I hope this tutorial helped you. Should you still have questions or see something wrong, please do tell me!
Regards,
bassie1995
Cool guide.
Thanks.
nikwen said:
Cool guide.
Thanks.
Click to expand...
Click to collapse
I might have killed your 444 thanks count .
Is there any advantage of using an URLConnection instead of HttpGet?
I usually do this using a HttpGet object which I execute using a HttpClient.
nikwen said:
Is there any advantage of using an URLConnection instead of HttpGet?
I usually do this using a HttpGet object which I execute using a HttpClient.
Click to expand...
Click to collapse
Honestly, I wouldn't know right now. I'll go and look it up, but have some things to do for school :-\
Sent from my Nexus 7 using Tapatalk HD
bassie1995 said:
Honestly, I wouldn't know right now. I'll go and look it up, but have some things to do for school :-\
Sent from my Nexus 7 using Tapatalk HD
Click to expand...
Click to collapse
Ok, I will look it up later and tell you.
nikwen said:
Ok, I will look it up later and tell you.
Click to expand...
Click to collapse
Didn't find too much quickly, but this might help?
http://www.tbray.org/ongoing/When/201x/2012/01/17/HttpURLConnection
Sent from my Nexus 7 using Tapatalk HD
bassie1995 said:
Didn't find too much quickly, but this might help?
http://www.tbray.org/ongoing/When/201x/2012/01/17/HttpURLConnection
Sent from my Nexus 7 using Tapatalk HD
Click to expand...
Click to collapse
I will search for it later.
I do not use a HttpURLConnection. I can post my code later. (It is working.)
nikwen said:
I will search for it later.
I do not use a HttpURLConnection. I can post my code later. (It is working.)
Click to expand...
Click to collapse
I'd like to see .
Sent from my GT-I9300 using Tapatalk 4 Beta
bassie1995 said:
I'd like to see .
Sent from my GT-I9300 using Tapatalk 4 Beta
Click to expand...
Click to collapse
That is my code:
Code:
try {
HttpParams params = new BasicHttpParams();
HttpConnectionParams.setConnectionTimeout(params, 4000);
HttpConnectionParams.setSoTimeout(params, 5000);
HttpClient client = new DefaultHttpClient(params);
HttpGet request = new HttpGet("www.google.com");
HttpResponse response = client.execute(request);
InputStream is = response.getEntity().getContent();
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
String line = null;
while((line = reader.readLine()) != null) {
//do something with the line
}
is.close();
} catch (Exception e) {
e.printStackTrace();
}
My sources were http://stackoverflow.com/questions/...-source-of-a-page-from-a-html-link-in-android and http://stackoverflow.com/questions/6503574/how-to-get-html-source-code-from-url-in-android
Sweet guide!
Sent from my GT-S5830M using Tapatalk 2
This thread has evrything i had been looking for ....
Thanks a lot
Sent from my GT-S5360 using xda app-developers app
are you still open for questions ? nice thread btw
Thank you, this helped me so much!
Hello, very nice article provided. I want to open html file from sdcard path like "file:///storage/emulated/0/hensler_bone_press/index.html"
How can we achieve this using webview ?
Just stumbled upon this again...
Pannam said:
are you still open for questions ? nice thread btw
Click to expand...
Click to collapse
Did you get an answer? I assume so, 2 years later?
hardikjoshi8689 said:
Hello, very nice article provided. I want to open html file from sdcard path like "file:///storage/emulated/0/hensler_bone_press/index.html"
How can we achieve this using webview ?
Click to expand...
Click to collapse
Same here, have you got this working?
I'm not working with Android, especially not WebView, right now, but I suspect that you use the line in the last step to normally just load a URL.
Instead of supplying the URL wherever you tell the WebView what page to load, you can probably do what I did in the OP and specify your file path. Be sure to use the correct methods to get the path to your file instead of hard-coding it!
Beginner developers, beware! This guide isn't beginner-friendly at all and it's targeted at developers who have some knowledge about Android development.
Or you can use my new library - Remote Metadata Provider, it's MUCH simplier to use.
0. The Introduction
You guys probably seen my apps - Floating Music Widget and Android Control Center.
They both share one feature - good music player integration. They can show you metadata and Floating Music Widget even shows album art. While some players provide API for external music controls(like PowerAmp), the others just somehow integrate with lockscreen. How? Sit down, get a cup of tea, and listen to me.
With the API Level 14 Google introduced class called RemoteControlClient. Citing Google API Reference:
RemoteControlClient enables exposing information meant to be consumed by remote controls capable of displaying metadata, artwork and media transport control buttons.
Click to expand...
Click to collapse
I won't explain how this works - you may go and read some tutorials around the web, there are plenty of them.
Or check API Reference here.
But. Well, we send metadata and album art. Oh, and on 4.3 we can even send playback position. However...how do we receive it? Well, by some reason, I don't know exactly why, Google has hidden this part of API. Maybe they think it's unsere to let you consume other app data, or maybe they just forgot about it. I've asked them multiple times, why did they hid this part of API, but they just ignored me.
So, by posting this article, I hope to maybe somehow make them change their minds and publish this API after all.
1. Getting started
Please note that this guide won't give you Activity examples, or any other things. It will give you the bare bones of the implementation of your own media controls. It's NOT intended to be used by Android/Java newbies.
PLEASE NOTE THAT IT'S A CLOSED API! IT MAY MALFUNCTION OR NOT WORK AT ALL!
Of course, you will need Eclipse IDE.
Also you will need modified Android build platform with hidden and internal API enabled.
There's an excellent guide on how to do this:
Using internal (com.android.internal) and hidden (@hide) APIs
Read it, do all five steps, then come back here for a read.
Please note that you will need to enable hidden APIs for API Level 18(4.3) and one API from 14 to 17. I recommend doing 17.
So, you've enabled hidden and internal API, hacked your ADT plugin, and you're craving for knowledge? Good.
Now some theory.
When the metadata is sent by RemoteControlClient, it is consumed by object called RemoteControlDisplay.
But the problem is, there's no explicit RemoteControlDisplay class, but there is only AIDL interface called IRemoteControlDisplay.
2. Understanding IRemoteControlDisplay
So, let's check which methods this interface has.
void setCurrentClientId(int clientGeneration, in PendingIntent clientMediaIntent, boolean clearing);
This method is used to connect music player to your RemoteControlDisplay.
First parameter is an internal ID of current player.
Second parameter is PendingIntent which will be used for controlling the playback - this is the "address" where you will send commands like "stop playback", "switch to next", etc.
About third parameter...my guess is that it's used when the RemoteControlDisplay is disconnected from current music player. You don't really ned this one.
For next methods I will explain only useful parameters.
void setPlaybackState(int generationId, int state, long stateChangeTimeMs);
This method is called when playback state has changed. For example, it's called when you pause your music.
"state" is obviously the current state of your music player.
It can be one of the following values:
Rarely used:
RemoteControlClient.PLAYSTATE_ERROR - well, there was some kind of error. Normally, you won't get this one.
RemoteControlClient.PLAYSTATE_BUFFERING - the music is buffering and will start playing very-very soon.
Normally used:
RemoteControlClient.PLAYSTATE_PAUSED - the music is paused
RemoteControlClient.PLAYSTATE_PLAYING - the music is playing.
You can check other PLAYSTATE_ constant in RemoteControlClient API reference.
void setTransportControlFlags(int generationId, int transportControlFlags);
In lockscreen it is used for toggling the widget visibility. I couldn't find any appliance for this method in my apps. Well, it sets flags
void setMetadata(int generationId, in Bundle metadata);
Well, that's obvious. It is called when RemoteControlDisplay have to update current track metadata.
The Bundle which we are receiving containing some metadata.
The keys for them are all in class MediaMetadataRetriever.
So, for example, to extract song title, you have to do it this way:
Code:
String title=metadata.getString(Integer.toString(MediaMetadataRetriever.METADATA_KEY_TITLE));
From my research I've found that this Bundle can have the following entries:
Those are for "String" entries:
MediaMetadataRetriever.METADATA_KEY_ALBUMARTIST
MediaMetadataRetriever.METADATA_KEY_ARTIST
MediaMetadataRetriever.METADATA_KEY_ALBUM
MediaMetadataRetriever.METADATA_KEY_TITLE
And this one is "long":
MediaMetadataRetriever.METADATA_KEY_DURATION
void setArtwork(int generationId, in Bitmap artwork);
This one is way too obvious. It gives you the Bitmap with artwork of current song. If there is no artwork, the "artwork" parameter will be null.
void setAllMetadata(int generationId, in Bundle metadata, in Bitmap artwork);
This call just combines previous two.
3. Implementing IRemoteControlDisplay
Hey, I now know everything about RemoteControlDisplay, I will implement my own in split second.
Code:
public class MyRemoteControlDisplay implements IRemoteControlDisplay
Please note that IT WON'T WORK THIS WAY!
As IRemoteControlDisplay is actually a AIDL interface, we need to somehow handle marshalling and unmarshalling of data. But luckily, we don't need to think about it. There is a class which handles basic IPC operations - IRemoteControlDisplay$Stub. We just need to extend it.
So, the right way to implement your own RemoteControlDisplayClass is:
Code:
public class MyRemoteControlDisplay extends IRemoteControlDisplay.Stub
Then you will have to implement methods of IRemoteControlDisplay. However, now listen to me carefully. Please, don't try to write your own super-cool implementation.
Just copy and paste the following code
Code:
public MyRemoteControlDisplay extends IRemoteControlDisplay.Stub {
static final int MSG_SET_ARTWORK = 104;
static final int MSG_SET_GENERATION_ID = 103;
static final int MSG_SET_METADATA = 101;
static final int MSG_SET_TRANSPORT_CONTROLS = 102;
static final int MSG_UPDATE_STATE = 100;
private WeakReference<Handler> mLocalHandler;
MyRemoteControlDisplay(Handler handler) {
mLocalHandler = new WeakReference<Handler>(handler);
}
public void setAllMetadata(int generationId, Bundle metadata, Bitmap bitmap) {
Handler handler = mLocalHandler.get();
if (handler != null) {
handler.obtainMessage(MSG_SET_METADATA, generationId, 0, metadata).sendToTarget();
handler.obtainMessage(MSG_SET_ARTWORK, generationId, 0, bitmap).sendToTarget();
}
}
public void setArtwork(int generationId, Bitmap bitmap) {
Handler handler = mLocalHandler.get();
if (handler != null) {
handler.obtainMessage(MSG_SET_ARTWORK, generationId, 0, bitmap).sendToTarget();
}
}
public void setCurrentClientId(int clientGeneration, PendingIntent mediaIntent,
boolean clearing) throws RemoteException {
Handler handler = mLocalHandler.get();
if (handler != null) {
handler.obtainMessage(MSG_SET_GENERATION_ID, clientGeneration, (clearing ? 1 : 0), mediaIntent).sendToTarget();
}
}
public void setMetadata(int generationId, Bundle metadata) {
Handler handler = mLocalHandler.get();
if (handler != null) {
handler.obtainMessage(MSG_SET_METADATA, generationId, 0, metadata).sendToTarget();
}
}
public void setPlaybackState(int generationId, int state, long stateChangeTimeMs) {
Handler handler = mLocalHandler.get();
if (handler != null) {
handler.obtainMessage(MSG_UPDATE_STATE, generationId, state).sendToTarget();
}
}
public void setTransportControlFlags(int generationId, int flags) {
Handler handler = mLocalHandler.get();
if (handler != null) {
handler.obtainMessage(MSG_SET_TRANSPORT_CONTROLS, generationId, flags).sendToTarget();
}
}
}
Why we have to implement it this way?
Well, it's because those methods calls arrive asynchronously, so, to correctly process them all, we need a Handler. Then we send messages to this Handler with necessary parameters, and it processes them.
But why use this weird WeakReference? Well, I can't explain it better than Google Developers. Citing the source code comment:
/**
* This class is required to have weak linkage
* because the remote process can hold a strong reference to this binder object and
* we can't predict when it will be GC'd in the remote process. Without this code, it
* would allow a heavyweight object to be held on this side of the binder when there's
* no requirement to run a GC on the other side.
*/
Click to expand...
Click to collapse
Tl;dr it's just a clever usage of memory resources.
So, my congratulations! We've implemented hidden IRemoteControlDisplay interface. But now it doesn't actually do anything.
4. Using our RCD implementation
As you can see, the constructor requires a Handler to be passed to it.
But any Handler just won't do, as we have to process messages.
So, you can't just write
Code:
MyRemoteControlDisplay display=new MyRemoteControlDisplay(new Handler());
Then, let's implement our Handler.
Again, I recommend you to use the following code, as it's doing it's job fine. This is the code used by default lockscreen with slight modifications. You can try and implement your own Handler, but this is strongly discouraged, as it can get glitchy. Don't worry, we'll soon get to the part where you can use your imagination
Code:
private int mClientGeneration;
private PendingIntent mClientIntent;
private Bitmap mArtwork;
public static final int MSG_SET_ARTWORK = 104;
public static final int MSG_SET_GENERATION_ID = 103;
public static final int MSG_SET_METADATA = 101;
public static final int MSG_SET_TRANSPORT_CONTROLS = 102;
public static final int MSG_UPDATE_STATE = 100;
Handler myHandler = new Handler(new Handler.Callback() {
[user=439709]@override[/user]
public boolean handleMessage(Message msg) {
switch (msg.what) {
case MSG_UPDATE_STATE:
//if client generation is correct(our client is still active), we do some stuff to indicate change of playstate
if (mClientGeneration == msg.arg1) updatePlayPauseState(msg.arg2);
break;
//if client generation is correct(our client is still active), we do some stuff to update our metadata
case MSG_SET_METADATA:
if (mClientGeneration == msg.arg1) updateMetadata((Bundle) msg.obj);
break;
case MSG_SET_TRANSPORT_CONTROLS:
break;
//if our client has changed, we update the PendingIntent to control it and save new generation id
case MSG_SET_GENERATION_ID:
mClientGeneration = msg.arg1;
mClientIntent = (PendingIntent) msg.obj;
break;
//if client generation is correct(our client is still active), we do some stuff to update our artwork
//while recycling the old one to reduce memory usage
case MSG_SET_ARTWORK:
if (mClientGeneration == msg.arg1) {
if (mArtwork != null) {
mArtwork.recycle();
}
mArtwork = (Bitmap)msg.obj;
setArtwork(mArtwork);
}
break;
}
return true;
}
});
I think you can probably guess what do we do here, but I'll explain anyway.
updatePlayPauseState(msg.arg2) - it's the method where you actually handle the change of playstate.
msg.arg2 is an Integer(or, more correcly, int), which indicates current play state. Please refer to section 2 to see possible play states. For example, you may do check like this:
Code:
updatePlayState(int state) {
if(state==RemoteControlClient.PLAYSTATE_PLAYING) {
setButtonImage(R.drawable.play);
} else {
setButtonImage(R.drawable.pause);
}
}
setArtwork(mArtwork);
It's pretty obvious, do whatever you like with this bitmap, just remember that it can be null.
updateMetadata((Bundle) msg.obj)
That one isn't very easy to handle. There is a bundle containing all of available metadata. So, you can deal with it as you please(you know how to extract data from Bundle, right?), but here's how I do it(modified Google version):
Code:
private void updateMetadata(Bundle data) {
String artist = getMdString(data, MediaMetadataRetriever.METADATA_KEY_ALBUMARTIST);
//if we failed to get artist, then we should try another field
if(artist==null) {
artist=getMdString(data, MediaMetadataRetriever.METADATA_KEY_ARTIST);
}
if(artist==null) {
//if we still failed to get artist, we will return a string containing "Unknown"
artist=mContext.getResources().getString(R.string.unknown);
}
//same idea for title
String title = getMdString(data, MediaMetadataRetriever.METADATA_KEY_TITLE);
if(title==null) {
title=mContext.getResources().getString(R.string.unknown);
}
//album isn't that necessary, so I just ignore it if it's null
String album=getMdString(data, MediaMetadataRetriever.METADATA_KEY_ALBUM);
if((artist!=null)&&(title!=null)) {
setMetadata(artist, title, album);
}
}
private void updatePlayPauseState(int state) {
mPlayButtonState=state;
mService.setPlayButtonState(state);
}
public void setMetadata(String artist, String title, String album) {
mMetadataArtistTextView.setText(artist);
mMetadataTitleTextView.setText(title);
if(album!=null) {
mMetadataAlbumTextView.setText(album);
} else {
mMetadataAlbumTextView.setText("");
}
}
}
private String getMdString(Bundle data, int id) {
return data.getString(Integer.toString(id));
}
You've got the idea.
Okay. So you've implemented your Handler, and created MyRemoteControlDisplayObject. What's next?
5. Registering and unregistering RemoteControlDisplay
In order for your RemoteControlDisplay to be able to receive metadata and album arts, it has to be registered via AudioManager.
You have to get the instance of AudioManager and then call Audiomanager#registerRemoteControlDisplay().
Code:
MyHandler myHandler=new MyHandler();
MyRemoteControlDisplay remoteDisplay=new MyRemoteControlDisplay(myHandler);
AudioManager manager=((AudioManager)mContext.getSystemService("audio"));
mAudioManager.registerRemoteControlDisplay(remoteDisplay);
So, that's it. You've succesfully registered your display. Now it will receive metadata and album art.
However, that's not all.
When the metadata isn't visible to user, you should unregister your RemoteControlDisplay by using this code:
Code:
audioManager.unregisterRemoteControlDisplay(remoteDisplay);
remoteDisplay=null;
mHandler.removeMessages(MSG_SET_GENERATION_ID);
mHandler.removeMessages(MSG_SET_METADATA);
mHandler.removeMessages(MSG_SET_TRANSPORT_CONTROLS);
mHandler.removeMessages(MSG_UPDATE_STATE);
This way you will unregister your RemoteControlDisplay, destroy it(or, actually, just give it garbage collector), and remove all unprocessed messages. This is the correct way to unregister your RemoteControlDisplay.
Please note! You must register your RemoteControlDisplay every time when the View which displays metadata is shown to the user. This is because 4.2.2 and lower versions support only one RemoteControlDisplay, and if system will decide to register it's own RCD, your RCD will be unregistered automatically.
When you're compiling, you have to compile with 4.2.2 modified library for 4.2.2 and lower, and compile with 4.3 modified library for 4.3. That is very important, because if you'll try to launch 4.2.2 implementation on device running 4.3, it will give you AbstractMethodError.
If you have any question regarding the implementation, please ask here. Don't ask "How do I start Eclipse", or anything like that.
And please, if you use this, at least give me a credit. Finding this out was a really hard job.
To understand how it works, I've used source code from Android GitHub repository:
KeyguardTransportControlView.java
Or donate to me, whatever you like more. However, it would be the best if you give me credit and donate to me
Reserved for Android 4.3 implementation.
So, in 4.3 Google change some IRemoteControlDisplay methods.
1. Implementing IRemoteControlDisplay
Those are:
void setTransportControlFlags(int generationId, int transportControlFlags); is replaced by
void setTransportControlInfo(int generationId, int transportControlFlags, int posCapabilities)
The new parameter - posCapabilities - is indicating whether the RemoteControlClient provides information about playback position. It is a bit mask for those (public, but hidden) constants:
0 - no info about playback position
RemoteControlClient.MEDIA_POSITION_WRITABLE - playback position can be changed
RemoteControlClient.MEDIA_POSITION_READABLE - playback position can be read
void setPlaybackState(int generationId, int state, long stateChangeTimeMs); is replaced by
void setPlaybackState(int generationId, int state, long stateChangeTimeMs, long currentPosMs,float speed);
New parameters:
currentPosMs - current playback position in milliseconds.
If it's positive, it's the current playback position.
Negative values means that the position is unknown.
RemoteControlClient.PLAYBACK_POSITION_INVALID means that position is unknown, like if you're listening to live radio.
RemoteControlClient.PLAYBACK_POSITION_ALWAYS_UNKNOWN - that means the music player doesn't provide current position at all, because it's using legacy API(from 4.2.2).
speed - is the playback speed. 1.0 is normal, 0.5 is slower, 2.0 is 2x faster.
The rest stays the same.
However, the IRemoteControlDisplay implementation in my first post doesn't send this kind of data. So, if you want to send this data to your Handler, you may want to pack it into Bundle and send it as Message.obj.
2. Registering RemoteControlDisplay
Now there are two methods:
registerRemoteControlDisplay(IRemoteControlDisplay rcd)
RemoteControlDisplay registered with this method will NOT receive any artwork bitmaps.
Use this method only if you DO NOT NEED ARTWORK.
registerRemoteControlDisplay(IRemoteControlDisplay rcd, int w, int h)
w and h are maximum width and height of expected artwork bitmap. Use this method if you NEED ARTWORK.
3. Multiple RemoteControlDisplays
(FOLLOWING TEXT MAY BE NOT WORKING, AS THIS IS ONLY A THEORY BASED FROM STUDYING OF ANDROID SOURCE CODE)
Until API 18 there could be only one active RemoteControlDisplay. So, that means if you register your RCD, and then system decides to do the same, then your RemoteControlDisplay will be unregistered automatically.
However, this is not the case in 4.3, as from API 18 it does support multiple RemoteControlDisplay. So, in theory, you can just fire AudioManager#registerRemoteControlDisplay. Didn't tried that, however.
And, of course, you have to compile with Android 4.3 library.
Really cool guide. :good:
Thank you.
nikwen said:
Really cool guide. :good:
Thank you.
Click to expand...
Click to collapse
Thanks! I just hope it will have the desired effect and Google will release RemoteControlDisplay API to public, 'cause, you know, now I made it public, there's no reason to hide it now. Now I only need it to be featured on the main page...
How about making it sticky or something?
Dr.Alexander_Breen said:
Thanks! I just hope it will have the desired effect and Google will release RemoteControlDisplay API to public, 'cause, you know, now I made it public, there's no reason to hide it now. Now I only need it to be featured on the main page...
How about making it sticky or something?
Click to expand...
Click to collapse
I voted for it.
The sticky: Contact a mod and if it is relevant to the majority of the users, it will be made sticky.
Those are the mods for the Java development forum: diestarbucks, poyensa, justmpm, mark manning, crachel, Archer
I was looking for this undocumented api's and customized transparent lock screen that can listen for events.
Thank you. I will close my other open thread now.
God is great.
@Dr.Alexander_Breen thanks a lot for this, almost spent the day trying to get this to work with reflection.
Anyway, I still can't get it to work.
I'm trying to do this for my S-View cover mod http://forum.xda-developers.com/showthread.php?t=2368665
But the methods aren't called at all.
I've never used handlers before, so I'm guessing there's a problem with those.
Can you take a look at the source code? Since it's an Xposed module, and you might not know Xposed, I'll state a few things about it
https://github.com/MohammadAG/Xpose...ewpowerampmetadata/SViewPowerampMetadata.java
The mod is not a subclass of Activity, so there's no Context, but I do get the Context used by the S-View widget.
After getting the Context, and the Handler used by the S-View classes, I register the RemoteControlDisplay (method initializeRemoteControlDisplay(Looper))
The rest is mostly your code.
If you're wondering why I construct the Handler in such a weird way, it's because I can't create one on the Xposed module thread (something about Looper.prepare()).
Anyway, any help would be appreciated, if the code seems fine, I guess I'll have to use a service and make the module communicate with that instead, though I can't imagine media buttons being any slower.
@MohammadAG:
Your code looks fine to me, but there is one thing.
You register your RemoteControlDisplay in handleLoadPackage() method. I suppose that this method is called only once, but RemoteControlDisplay needs to be registered every time the metadata view is show to user.
Also, added 4.3 implementation.
Dr.Alexander_Breen said:
@MohammadAG:
Your code looks fine to me, but there is one thing.
You register your RemoteControlDisplay in handleLoadPackage() method. I suppose that this method is called only once, but RemoteControlDisplay needs to be registered every time the metadata view is show to user.
Also, added 4.3 implementation.
Click to expand...
Click to collapse
But that's only if I unregister it right? I'll see about it, maybe I need to do the Handler bit different in Xposed.
Thanks
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MohammadAG said:
But that's only if I unregister it right? I'll see about it, maybe I need to do the Handler bit different in Xposed.
Thanks
Sent from my GT-I9500 using xda app-developers app
Click to expand...
Click to collapse
Actually, no. As in 4.2 and lower, there can be only one active RCD. So, in case your system decides to register it's own RCD, it automatically unregisters yours.
Dr.Alexander_Breen said:
Actually, no. As in 4.2 and lower, there can be only one active RCD. So, in case your system decides to register it's own RCD, it automatically unregisters yours.
Click to expand...
Click to collapse
Oh, so that explains why your app displayed Unknown at some point. I guess that was my RCD being registered.
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And it's on the portal: Implement Lock Screen-Style Music Controls in Your App
MohammadAG said:
Oh, so that explains why your app displayed Unknown at some point. I guess that was my RCD being registered.
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Click to expand...
Click to collapse
So, have you managed to make your app working?
Dr.Alexander_Breen said:
So, have you managed to make your app working?
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Click to collapse
No, actually I haven't :/
I register the display each time the S View screen shows, which is when I want to show metadata, but that doesn't work, the handler's handleMessage method is never called.
MohammadAG said:
No, actually I haven't :/
I register the display each time the S View screen shows, which is when I want to show metadata, but that doesn't work, the handler's handleMessage method is never called.
Click to expand...
Click to collapse
Hmm. I'm afraid this is something with Handler in Xposed. You can, however, move IRemoteControlDisplay implementation to service, which will connect with your Xposed part via AIDL or smth like that.
Also, check, if methods of IRemoteControlDisplay are being called. Like, fire a log message when method is called.
Dr.Alexander_Breen said:
Hmm. I'm afraid this is something with Handler in Xposed. You can, however, move IRemoteControlDisplay implementation to service, which will connect with your Xposed part via AIDL or smth like that.
Also, check, if methods of IRemoteControlDisplay are being called. Like, fire a log message when method is called.
Click to expand...
Click to collapse
I thought about that, but I'm pretty sure it'll use up more memory and introduce a bit of lag (if the service was killed for example).
I was thinking of hooking registerRemoteControlClient and keeping the registered remote(s). Then I can simply get the data from their methods, do you know if they're kept in memory for as long as the app lives?
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MohammadAG said:
I thought about that, but I'm pretty sure it'll use up more memory and introduce a bit of lag (if the service was killed for example).
I was thinking of hooking registerRemoteControlClient and keeping the registered remote(s). Then I can simply get the data from their methods, do you know if they're kept in memory for as long as the app lives?
Sent from my GT-I9500 using xda app-developers app
Click to expand...
Click to collapse
Again, please check, if methods of RemoteControlDisplay are being called. Write message to debug log(Log.d) in setMetadata or setAllMetadata methods.
As a workaround, I have this idea.
If I understand correctly, Xposed can hook the method of the class, not the instance. Then you can hook RemoteControlClient methods to get the metadata directly from the clients. Check the API reference to RCC to get necessary methods.
really cool tutorial
Thanks a lot !
Could you post one for implimemtation of IBatteryStats...... etc private battery APIs ??
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sak-venom1997 said:
really cool tutorial
Thanks a lot !
Could you post one for implimemtation of IBatteryStats...... etc private battery APIs ??
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Click to expand...
Click to collapse
Well, I think the answer is "no", because I'm no Google Software Engineer. I'll look into this, however, as it will be simplier, I think.
Something like connecting remote service with IBatteryStats.Stub.asInterface. I'll look into it, however.
Dr.Alexander_Breen said:
Well, I think the answer is "no", because I'm no Google Software Engineer. I'll look into this, however, as it will be simplier, I think.
Something like connecting remote service with IBatteryStats.Stub.asInterface. I'll look into it, however.
Click to expand...
Click to collapse
Connecting to serivice and obtaining data i could manage by diging into source but parsing the info is causing trouble
thanks
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