Develop Reference

Android: Save XWalkView - Crosswalk state

I am using XWalkView to show a mobile web site as an application. My problem is when application goes background and comes back it reloads the page it shows. I want to keep it state and continue from that state when it comes from background. Here is my code:
public class MainActivity extends AppCompatActivity {
static final String URL = "https://www.biletdukkani.com.tr";
static final int MY_PERMISSIONS_REQUEST_ACCESS_LOCATION = 55;
static final String SHOULD_ASK_FOR_LOCATION_PERMISSION = "shouldAskForLocationPermission";
static final String TAG = "MainActivity";
static final String COMMAND = "/system/bin/ping -c 1 185.22.184.184";
static XWalkView xWalkWebView;
TextView noInternet;
static Bundle stateBundle;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d(TAG, "onCreate");
// Check whether we're recreating a previously destroyed instance
if (savedInstanceState != null) {
// Restore value of members from saved state
stateBundle = savedInstanceState.getBundle("xwalk");
}
setContentView(R.layout.activity_main);
initNoInternetTextView();
}
public void onRestoreInstanceState(Bundle savedInstanceState) {
// Always call the superclass so it can restore the view hierarchy
super.onRestoreInstanceState(savedInstanceState);
stateBundle = savedInstanceState.getBundle("xwalk");
Log.d(TAG, "onRestoreInstanceState");
}
/**
* İnternet yok mesajı gösteren TextVidew'i ayarlar.
*/
private void initNoInternetTextView() {
Log.d(TAG, "initNoInternetTextView");
noInternet = (TextView) findViewById(R.id.no_internet);
if (noInternet != null) {
noInternet.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
checkInternetConnection();
}
});
}
}
/**
* WebView'i ayarlar.
*/
private void initWebView() {
Log.d(TAG, "initWebView");
if (xWalkWebView == null) {
ProgressBar progressBar = (ProgressBar) findViewById(R.id.progressBar);
xWalkWebView = (XWalkView) findViewById(R.id.webView);
//xWalkWebView.clearCache(true);
xWalkWebView.load(URL, null);
xWalkWebView.setResourceClient(new BDResourceClient(xWalkWebView, progressBar));
}
}
#Override
protected void onResume() {
super.onResume();
Log.d(TAG, "onResume");
checkLocationPermissions();
checkInternetConnection();
if (xWalkWebView != null && stateBundle != null) {
xWalkWebView.restoreState(stateBundle);
}
}
#Override
protected void onPause() {
super.onPause();
Log.d(TAG, "onPause");
if (xWalkWebView != null) {
stateBundle = new Bundle();
xWalkWebView.saveState(stateBundle);
}
}
public void onSaveInstanceState(Bundle savedInstanceState) {
Log.d(TAG, "onSaveInstanceState");
// Save the user's current game state
savedInstanceState.putBundle("xwalk", stateBundle);
// Always call the superclass so it can save the view hierarchy state
super.onSaveInstanceState(savedInstanceState);
}
#Override
public void onBackPressed() {
Log.d(TAG, "onBackPressed");
if (xWalkWebView != null && xWalkWebView.getNavigationHistory().canGoBack()) {
xWalkWebView.getNavigationHistory().navigate(XWalkNavigationHistory.Direction.BACKWARD, 1);
} else {
super.onBackPressed();
}
}
}
I have also tried to add following lines to manifest but didn't work.
android:launchMode="singleTask"
android:alwaysRetainTaskState="true"
How can i do that?
Thanks in advcance.

One way would be to initialize the view inside a fragment which is set to retain it's instance.

What causes a fragment to get detached from an Activity?

I have a SignupActivity which will go through several fragments as users go through a signup process. On the last fragment, I'm calling
getActivity().setResult(Activity.RESULT_OK)
since SingupActivity intent was started for result. Some users are crashing at this point, because getActivity() is producing a NPE. I'm not able to figure out what is causing this. Screen rotation is disabled, so there is no reason that I know of for the fragment to detach from the Activity.
Any insight as to what may be causing this, and how I can resolve it?
public class SignupConfirmationFragment extends Fragment {
public static final String TAG = SignupConfirmationFragment.class.getSimpleName();
private User mNewUser;
private myAppClient mmyAppClient;
private Animation rotateAnimation;
private ImageView avatar;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mNewUser = ((SignUpActivity) getActivity()).getNewUser();
mmyAppClient = ((SignUpActivity) getActivity()).getmyAppClient();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
final View v = inflater.inflate(R.layout.fragment_signup_confirmation, null);
((TextView) v.findViewById(R.id.username_textView)).setText(((SignUpActivity) getActivity()).getNewUser().getName());
avatar = (ImageView) v.findViewById(R.id.avatar);
if (mNewUser.getAvatarImage() != null) {
avatar.setImageBitmap(mNewUser.getAvatarImage());
}
rotateAnimation = AnimationUtils.loadAnimation(getActivity(), R.anim.progress_rotate);
v.findViewById(R.id.progress_loading).startAnimation(rotateAnimation);
if (mNewUser.getAvatarImage() != null) {
startAvatarUpload();
} else if (mNewUser.getNewsletter()) {
setNewsletterStatus();
} else {
pauseForOneSecond();
}
return v;
}
private void startAvatarUpload() {
mmyAppClient.uploadUserAvatar(mNewUser.getAvatarImage(), new FutureCallback<JsonObject>() {
#Override
public void onCompleted(Exception e, JsonObject result) {
if (mNewUser.getNewsletter()) {
setNewsletterStatus();
} else {
updateFragment();
}
}
},
null,
null);
}
private void setNewsletterStatus() {
mmyAppClient.setNewsletter(mNewUser.getEmail(), mNewUser.getFirstName(), mNewUser.getLastName(), new FutureCallback<String>() {
#Override
public void onCompleted(Exception e, String result) {
//Log.d(TAG, "Result: " + result);
updateFragment();
}
});
}
private void pauseForOneSecond() {
final Handler handler = new Handler();
handler.postDelayed(new Runnable() {
#Override
public void run() {
updateFragment();
}
}, 1000);
}
private void updateFragment() {
rotateAnimation.cancel();
if (isAdded()) {
getActivity().setResult(Activity.RESULT_OK);
AnalyticsManager.logUIEvent("sign up completed");
getActivity().finish();
} else {
AnalyticsManager.logUIEvent("sign up failed");
}
}
}

According to Fragment lifecycle in Android OS, you cannot get the Activity associated with the fragment in the onCreateView, because the Activity with which the Fragment is associated will not be created at that stage.
See the figure below:
Also, refer to this link, http://developer.android.com/guide/components/fragments.html
As you can see the Activity is created in onActivityCreated which is after onCreateView, hence you'll get null if you try to call the Activity in the onCreateView. Try to call it in onActivityCreated or in onStart that should solve your problem.
I hope this helps.

YouTube Player plays for 2 seconds and stop in full screen

I'm currently facing 2 major problems,
I'm using a youtube player and when it gets on full screen, It plays for 1-2 seconds and stop.
When I click the "Play" button in the middle, it's buffering all over again. even if the gray bar filled to it's center.
those problems aren't occurring in portrait mode.
here is my class, like the youtube api demo with a bit defference
public class Video extends YouTubeFailureRecoveryActivity implements YouTubePlayer.OnFullscreenListener, Utils.OnGetUrlListener, View.OnClickListener {
static int AUTO_PLAY_DELAY = 1000;
static final int PORTRAIT_ORIENTATION = Build.VERSION.SDK_INT < 9
? ActivityInfo.SCREEN_ORIENTATION_PORTRAIT
: ActivityInfo.SCREEN_ORIENTATION_SENSOR_PORTRAIT;
private LinearLayout mRootLayout;
/**
* * Youtube ***
*/
YouTubePlayerView mPlayerView;
YouTubePlayer mPlayer;
boolean mIsFullscreen;
String urlID;
/**
* * My ***
*/
RelativeLayout mContainer;
ImageView mBtPlay;
boolean mIsNeedSetFlags;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Utils.getInstance().setActivity(this);
setContentView(R.layout.video_main);
mIsNeedSetFlags = true;
mRootLayout = (LinearLayout) findViewById(R.id.video_root_layout);
mContainer = (RelativeLayout) findViewById(R.id.container);
mBtPlay = (ImageView) findViewById(R.id.video_play);
mBtPlay.setVisibility(View.INVISIBLE);
mPlayerView = (YouTubePlayerView) findViewById(R.id.player);
Intent intent = getIntent();
doLayout();
}
#Override
public void onInitializationSuccess(YouTubePlayer.Provider provider, YouTubePlayer player, boolean wasRestored) {
mPlayer = player;
player.addFullscreenControlFlag(YouTubePlayer.FULLSCREEN_FLAG_CUSTOM_LAYOUT);
player.setOnFullscreenListener(this);
if (mIsNeedSetFlags) {
mIsNeedSetFlags = false;
int controlFlags = player.getFullscreenControlFlags();
setRequestedOrientation(PORTRAIT_ORIENTATION);
controlFlags |= YouTubePlayer.FULLSCREEN_FLAG_ALWAYS_FULLSCREEN_IN_LANDSCAPE;
player.setFullscreenControlFlags(controlFlags);
}
if (!wasRestored) {
player.cueVideo(urlID);
}
}
#Override
protected YouTubePlayer.Provider getYouTubePlayerProvider() {
return mPlayerView;
}
private void doLayout() {
LinearLayout.LayoutParams playerParams = (LinearLayout.LayoutParams) mPlayerView.getLayoutParams();
if (mIsFullscreen) {
playerParams.width = LinearLayout.LayoutParams.MATCH_PARENT;
playerParams.height = LinearLayout.LayoutParams.MATCH_PARENT;
mParallaxScrollView.setVisibility(View.GONE);
} else {
mParallaxScrollView.setVisibility(View.VISIBLE);
if (getResources().getConfiguration().orientation != Configuration.ORIENTATION_LANDSCAPE) {
ViewGroup.LayoutParams otherViewsParams = mParallaxScrollView.getLayoutParams();
playerParams.width = otherViewsParams.width = MATCH_PARENT;
playerParams.height = WRAP_CONTENT;
mRootLayout.setOrientation(LinearLayout.VERTICAL);
}
}
mPlayerView.setLayoutParams(playerParams);
}
#Override
public void onFullscreen(boolean isFullscreen) {
mIsFullscreen = isFullscreen;
showPlayerAndPlay();
doLayout();
}
#Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
doLayout();
}
#Override
public void onGetUrlFinished(String videoUrl) {
urlID = videoUrl;
mBtPlay.setVisibility(View.VISIBLE);
mBtPlay.setOnClickListener(this);
mPlayerView.initialize(Utils.YOU_TUBE_DEV_KEY, this);
}
#Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.video_play:
showPlayerAndPlay();
break;
}
}
private void showPlayerAndPlay() {
mPlayerView.setVisibility(View.VISIBLE);
mBtPlay.setVisibility(View.INVISIBLE);
if (!mPlayer.isPlaying())
new android.os.Handler().postDelayed(new Runnable() {
#Override
public void run() {
mPlayer.play();
}
}, AUTO_PLAY_DELAY);
}
}

YouTube does not allow other views to be overlayed on top of its player view.
If you check the logs, you will also see a warning message that specifies this very limitation, plus more information on which view (its ID) and the overlapping region.

A good alternative is to used Exoplayer, to overlay your video with view. It is not part of the android sdk, but it's recommended by google and included in android developer documentation :
http://google.github.io/ExoPlayer/ https://developer.android.com/guide/topics/media/exoplayer.html
Exoplayer allow you to stream any kind of video, not only Youtubes videos.
It's also good to mention that Exoplayer is used in Youtube application.

As the answer marked as correct explained: the problem is overlaying a view over the Youtube player view. If you need to keep those views will the Youtube is initializing then this will do the trick.
I was doing a loading animation with crossfade for the involved views. Setting alpha to 0 won't fix the issue because the view is still there. But setting visibility to GONE or INVISIBLE does work. For what I understand a View is not computed if is not VISIBLE, well at least it will not be taken into consideration after the visibility changed. Finally, I did something like this:
myView.animate().alpha(0).setDuration(800).setListener(
new Animator.AnimatorListener() {
#Override
public void onAnimationStart(Animator animator) {
}
#Override
public void onAnimationEnd(Animator animator) {
myView.setVisibility(View.GONE);
}
#Override
public void onAnimationCancel(Animator animator) {
}
#Override
public void onAnimationRepeat(Animator animator) {
}
}).start();

how to set listview's position after configuration change

I'm struggling to recover my position in a listview on screen rotation configuration change.
Amongst the many things I've tried I came to this:
#Override
public void onActivityCreated(#Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
if (savedInstanceState == null) {
...
mVisibleItem = -1;
} else {
if (savedInstanceState.containsKey(LV_VISIBLE_ITEM)) {
mVisibleItem = savedInstanceState.getInt(LV_VISIBLE_ITEM);
}
}
setRetainInstance(true);
}
and here I'm trying to set the position in the listview
#Override
public void onResume() {
super.onResume();
if (mVisibleItem > 0) {
mlvDictionaryIndex.setSelectionFromTop(mVisibleItem, 0);
}
}
However, much to my surprise, after rotating the screen and watching mVisibleItem gets set with the correct value, in onResume I see that mVisibleItem equals -1. How come?

use onSavedInstanceState to write in the bundle the returned value of ListView.onSaveInstanceState(), and restored it onActivityCreated
#Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
if (mListView != null) {
outState.putParcelable(LISTVIEW_INTERNAL_STATE_KEY, mListView.onSaveInstanceState());
}
}
after the data are reload then you can call
mListView.onRestoreInstanceState(savedInstanceState.getParcelable(LISTVIEW_INTERNAL_STATE_KEY));

Override onSaveInstanceState such as below"
#Override
public void onSaveInstanceState(Bundle savedInstanceState) {
super.onSaveInstanceState(savedInstanceState);
savedInstanceState.putInt("pos", pos);
}
Then in your onCreate method have read the savedInstanceState to check if this is an orientation change or a new activity.
private int pos = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
//This is a new activity
}else{
pos = savedInstanceState.getInt("");
}
Now you have the position in the list, and you can scroll to this in configuration change.

Maybe after the data in the listview is reloaded，the code below will work.
mlvDictionaryIndex.setSelectionFromTop(mVisibleItem, 0);
So you can use post() method, just like below:
post(new Runnable() {
public void run() {
mlvDictionaryIndex.setSelectionFromTop(mVisibleItem, 0);
}
});

Video is not pausing in fragment ViewPager

I am using View Pager with fragment to showing image and video, I am able to show image and video properly but I have problem, when I swipe for video, then video is playing, but I swipe next or previous then video is still playing on just next or previous screen but when I move two slide next or previous then video is being stop, but why not on next or previous slide.
I search it more but I did not get any solution, any help will be appreciable.
Thanks in advance.
Here is my code:
This is Fragment Class
public class ContentFragment extends Fragment {
private final String imageResourceId;
private String type;
public ContentFragment(String imageResourceId,String type) {
System.out.println("Path In cons="+imageResourceId+"and type is="+type);
this.imageResourceId = imageResourceId;
this.type= type;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.e("Test", "hello");
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.content_layout, container, false);
TouchImageView imageView = (TouchImageView) view.findViewById(R.id.touchImage);
imageView.setImageResource(R.id.touchImage);
imageView.setMaxZoom(10f);
VideoView videoView =(VideoView) view.findViewById(R.id.videoView1);
if(type.equals("image")) {
imageView.invalidate();
imageView.setVisibility(View.VISIBLE);
videoView.setVisibility(View.GONE);
try {
System.out.println("IN Content Fragment"+imageResourceId.toString());
Bitmap bmp = BitmapFactory.decodeFile(imageResourceId.toString());
imageView.setImageBitmap(bmp);
} catch(Exception e) {
System.out.println("Error Of image File"+e);
}
} else
try {
if(type.equals("video")){
videoView.invalidate();
videoView.setVisibility(View.VISIBLE);
imageView.setVisibility(View.GONE);
String path = imageResourceId.toString();
videoView.setVideoURI(Uri.parse(path));
videoView.setMediaController(new MediaController(getActivity()));
videoView.setFocusable(true);
videoView.start();
}
} catch(Exception e) {
e.printStackTrace();
}
return view;
}
}
This is pager adapter activity
public class MediaActivity extends FragmentActivity {
private MyAdapter mAdapter;
private ViewPager mPager;
public ArrayList<Content> contentList;
Context context;
LinearLayout numberOfPageLayout;
SharedPreferences sharedPreferences;
Handler progressHandler;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_media);
context=(Context) getApplicationContext();
mPager = (ViewPager) findViewById(R.id.pager);
progressHandler = new Handler();
contentList=new ArrayList<Content>();
new AsyncTask<Void, Void, Void>() {
#Override
protected Void doInBackground(Void... params) {
// TODO Auto-generated method stub
contentList=new ContentDBAdapter(context).getAllContent();
}
return null;
}
#Override
protected void onPostExecute(Void result) {
// TODO Auto-generated method stub
super.onPostExecute(result);
mAdapter = new MyAdapter(getSupportFragmentManager(),contentList);
mPager.setAdapter(mAdapter);
}
}.execute();
mPager.setOnPageChangeListener(new OnPageChangeListener() {
#Override
public void onPageSelected(int arg0) {
// TODO Auto-generated method stub
}
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
// TODO Auto-generated method stub
}
#Override
public void onPageScrollStateChanged(int arg0) {
// TODO Auto-generated method stub
}
});
}
public static class MyAdapter extends FragmentPagerAdapter {
ArrayList <Content>contList=new ArrayList<Content>();
public MyAdapter(FragmentManager fm,ArrayList<Content> cont) {
super(fm);
this.contList=cont;
}
#Override
public int getCount() {
totalPage=contList.size();
return contList.size();
}
#Override
public Fragment getItem(int position) {
Content con=contList.get(position);
return new ContentFragment(con.getPath(),con.getType());
}
}
}

It is because ViewPager keeps offscreen fragments started. For instance you have a fragment visible to the user. ViewPager will try to keep the previous fragment (on the left side) and the next fragment (on the right side) started. This allows ViewPager performing smooth sliding when user decides to change the page, because the next and the previous pages are already prepared.
In your case the video player is not visible (offscreen), but ViewPager keeps it started as due to the behaviour described above. You can use setOffscreenPageLimit() method to change this behaviour. If you set page limit to 0, then offscreen fragments will be paused immediately. Unfortunately they will not only be paused, but stopped and detached from the activity too. This means when you return back to your fragment, it will recreate the whole layout anew. That's why you can try to override either Fragment.setUserVisibleHint() or Fragment.onHiddenChanged() and execute your pause/play logic there. ViewPager will update hidden state of a fragment depending on whether the fragment is actually visible to user or not.
Hope this helps.

You have to override setUserVisibleHint method in a fragment where u play video.
public void setUserVisibleHint(boolean isVisibleToUser) {
super.setUserVisibleHint(isVisibleToUser);
if (this.isVisible())
{
if (!isVisibleToUser) // If we are becoming invisible, then...
{
//pause or stop video
}
if (isVisibleToUser)
{
//play your video
}
}
}

I handle the problem like this:
boolean isVisible = false;
#Override
public void setUserVisibleHint(boolean isVisibleToUser) {
isVisible = isVisibleToUser;
if(player!=null)
player.pause();
super.setUserVisibleHint(isVisibleToUser);
}
then in onCreateView method:
SimpleExoPlayer player;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_screen_slide_page, container, false);
PlayerView playerView = v.findViewById(R.id.playerView);
playerView.getLayoutParams().width = ListPager.widthPixels;
playerView.getLayoutParams().height = ListPager.widthPixels;
if(player!=null)
player.release();
player = new SimpleExoPlayer.Builder(App.applicationContext).build();
playerView.setPlayer(player);
MediaItem mediaItem = MediaItem.fromUri(url);
player.setMediaItem(mediaItem);
player.prepare();
//---------The following code is important because if you remove the following if
// then if the next page is displaying, android will automatically initiate the
// previous and the next page, and the player will start playing :|
if(isVisible)
player.play();
}