[Q] Extract live wallpaper - Xposed Framework Modules

Does anyone know where I can find code handling the current live wallpaper engine / view? I am trying to extract the live wallpaper for further processing (e.g. blurring).
I already found an entrance point: If the LWP used the standard com.android.internal.view.BaseSurfaceHolder supplied by the base class android.service.wallpaper.WallpaperService.Engine i can hook into lockCanvas and unlockCanvas to grab the image. But most LWPs do not use this, so I need another (more general) solution.
I thought about hooking all subclasses of android.service.wallpaper.WallpaperService, but AFAIK that's not possible without loading every single class and check if it's a subclass.
Any ideas?
Implementation for reference:
Code:
public class Hook implements IXposedHookLoadPackage {
@Override
public void handleLoadPackage(XC_LoadPackage.LoadPackageParam loadPackageParam) throws Throwable {
final Class<?> engingeClass = findClass("android.service.wallpaper.WallpaperService.Engine", loadPackageParam.classLoader);
final String packageName = loadPackageParam.packageName;
final Class<?> surfaceHolderClass = findClass("com.android.internal.view.BaseSurfaceHolder",loadPackageParam.classLoader);
findAndHookMethod(engingeClass, "getSurfaceHolder", new XC_MethodHook() {
private boolean isFirstCall = true;
@Override
protected void afterHookedMethod(MethodHookParam param) throws Throwable {
Field field = findField(param.thisObject.getClass(), "this$0");
WallpaperService service = (WallpaperService) field.get(param.thisObject);
WallpaperManager wallpaperManager = WallpaperManager.getInstance(service);
if (isFirstCall && wallpaperManager.getWallpaperInfo().getPackageName().equals(packageName)) {
isFirstCall = false;
XposedBridge.log("Got context. Set up hooks...");
hook(surfaceHolderClass,service);
}
}
});
}
Bitmap bitmap;
Canvas internalCanvas;
Canvas originalCanvas;
private void hook(Class<?> clazz, final Context context) {
hookAllMethods(clazz, "lockCanvas", new XC_MethodHook() {
@Override
protected void afterHookedMethod(MethodHookParam param) throws Throwable {
originalCanvas = (Canvas) param.getResult();
bitmap = Bitmap.createBitmap(originalCanvas.getWidth(),originalCanvas.getHeight(), Bitmap.Config.ARGB_8888);
internalCanvas = new Canvas(bitmap);
param.setResult(internalCanvas);
XposedBridge.log("Locked Canvas");
}
});
findAndHookMethod(clazz, "unlockCanvasAndPost", Canvas.class, new XC_MethodHook() {
@Override
protected void beforeHookedMethod(MethodHookParam param) throws Throwable {
originalCanvas.drawBitmap(bitmap,0,0,null);
param.args[0] = originalCanvas;
Intent intent = new Intent("com.faendir.lwpextractor.WALLPAPER_CHANGE");
ByteArrayOutputStream bs = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.PNG,100,bs);
intent.putExtra("bmp",bs.toByteArray());
context.sendBroadcast(intent, "com.faendir.lwpextractor.RECEIVE_WALLPAPER_CHANGE");
XposedBridge.log("Unlocked Canvas");
}
});
}
}

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bump

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anyone?

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Try asking in the Xposed Development forum, that's a better place for code-related questions.