How To refresh Data Of middle Page of ViewPager in Android - android

I am using view pager. In this view pager i have 3 page. When i am running the app. view pager create left center and right fragment instance and all life cycle method are called. my problem is that i need to show some data when i select middle page. but i am not able to get any callback method to do. please help me. thanks in advance.
Adapter
public class ViewPagerFragmentPageAdapter extends FragmentPagerAdapter {
Context mContext;
public ViewPagerFragmentPageAdapter(Context context, FragmentManager fm) {
super(fm);
mContext = context;
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return BusinessCategoryFragment.getInstance();
case 1:
return FavoriteFragment.getInstance(mContext.getResources().getString(R.string.favorite));
case 2:
return RecentFragment.getInstance(mContext.getResources().getString(R.string.recent));
default:
return BusinessCategoryFragment.getInstance();
}
}
#Override
public int getCount() {
return 3;
}
}
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewFragmentPageAdapter = new ViewPagerFragmentPageAdapter(
HomeActivity.this, getSupportFragmentManager());
mViewPager.setAdapter(mViewFragmentPageAdapter);

You can use the onPageChangelistener and handle data refreshing code in the overrided methods of the listener.
vPager.setOnPageChangeListener(new OnPageChangeListener() {
#Override
public void onPageSelected(int position) {
// here u can add necessary code for refreshing data
}
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) {}
#Override
public void onPageScrollStateChanged(int arg0) {}
});

Related

getItem in FragmentStatePagerAdapter never called when instantiating from a Fragment

I'm using a Fragment on my Activity that will have a picture "swiper". I've created a FragmentStatePagerAdapter which I'm trying to call from this Fragment and for some reason my getItem() method is never being called.
I've searched and found that I need to use getChildFragmentManager() when instantiating my FragmentStatePagerAdapter because I'm calling it from a Fragment. I've tried this as well as getSupportFragmentManager() with no luck from either.
Any ideas?
here's my Fragment that I'm using on my MainActivity with the method that shoudl setup the FragmentStatePagerAdapter:
public class PhotoFlipper extends Fragment {
// properties and fields
// primitive types
String currentImage;
int friendShareType = 0;
ImageView share;
ViewPager pager;
PhotoFlipperItemAdapter pagerAdapter;
LatLng itemPosition;
Activity activity;
FragmentActivity fragActivity;
public ArrayList<MarkerModel> picsAndVids;
// end properties and fields
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View photoFlipperFragmentView = inflater.inflate(R.layout.photo_flipper_layout, container, false);
InitializeFragment(photoFlipperFragmentView);
return photoFlipperFragmentView;
}
private void InitializeFragment(View photoFlipperFragmentView) {
activity = getActivity();
fragActivity = (FragmentActivity)activity;
pager = (ViewPager)photoFlipperFragmentView.findViewById(R.id.photoflipper_pager);
share = (ImageView)photoFlipperFragmentView.findViewById(R.id.photoflipper_share);
share.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
IPictureFlipper iPictureFlipper = (IPictureFlipper)activity;
iPictureFlipper.ShareVideoOrImage(friendShareType, itemPosition, currentImage);
}
});
}
#Override
public void onHiddenChanged(boolean hidden) {
super.onHiddenChanged(hidden);
if (hidden) {
pager.setVisibility(View.GONE);
}
}
public void SetTappedPicture(int index) {
pagerAdapter = new PhotoFlipperItemAdapter(getChildFragmentManager(), picsAndVids, picsAndVids.size());
pager.setAdapter(pagerAdapter);
pager.setCurrentItem(index);
pager.addOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
#Override
public void onPageSelected(int position) {
}
});
}
}
And here's my FragmentStatePagerAdapter:
public class PhotoFlipperItemAdapter extends FragmentStatePagerAdapter {
ArrayList<MarkerModel> _markers;
int NUM_PAGES;
String TAG = "home";
public PhotoFlipperItemAdapter(FragmentManager fm, ArrayList<MarkerModel> markers, int numpages){
super(fm);
Log.d(TAG,"in adapter in constructor");
_markers = markers;
NUM_PAGES = numpages;
}
#Override
public Fragment getItem(int position) {
Log.d(TAG,"in adapter in get item");
Fragment fragment = PhotoFlipperItemFragment.create(position, _markers);
return fragment;
}
#Override
public int getCount() {
Log.d(TAG,"in adapter in get count: "+NUM_PAGES);
return NUM_PAGES;
}
}
logcat is showing me that NUM_PAGES is > 0 so that's not my issue. I see my log in the constructor and in getCount() but nothing in getItem().
TIA
I got this sorted out. I was hiding my fragment in my InitializeActivity() right after I added it to my FragmentManager so it was never fully building the Fragment with the ViewPager etc.
I'm going to have to come up with a different solution for hiding/showing the fragment but that was my problem.

Fragments not updating in viewpager

I am pretty new to ViewPager and adapter world in android. I have seen this issue asked many times but did not quite understand so hoping for a simplified answer :).
I have a ViewPager with 3 tabs and each tab has a fragment. By default the user first sees tab2 where he gives some imput to generate a string. this string then needs to be taken in tab3 which generates a qr code from it.
the string from tab 2 is updated to a class and tab3 takes the string from there.
My Problem is that when i move from tab2->tab3 the qr code is not generated. But when i go tab2->tab1->tab3 it is generated. I am guessing it retains my old fragment .
Below are my class codes. Could you please let me know why is this viewpager behaviour so.
my FragementActivity class:
public class ConfigExchangeMain extends FragmentActivity {
FragmentPagerAdapter adapterViewPager;
SampleFragementPagerAdapterExchange adapter;
String sent;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.config_exchange_main);
final ViewPager viewPager = (ViewPager) findViewById(R.id.viewpager);
adapter=new SampleFragementPagerAdapterExchange(getSupportFragmentManager());
viewPager.setAdapter(adapter);
viewPager.setCurrentItem(1);
// Give the TabLayout the ViewPager
TabLayout tabLayout = (TabLayout) findViewById(R.id.sliding_tabs);
tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
tabLayout.setupWithViewPager(viewPager);
}
}
My Pager Adapter looks like
public class SampleFragementPagerAdapterExchange extends FragmentStatePagerAdapter {
final int PAGE_COUNT = 3;
private String tabTitles[] = new String[]{"CONTACTS", "HOME", "QR+SCAN"};
private ConfigDetail context;
public SampleFragementPagerAdapterExchange(FragmentManager fm) {
super(fm);
//this.context = context;
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 1:
return new ConfigExchangeNFR();
case 0:
return new ConfigExchangeHome();
case 2:
return new ConfigExchangeQR();
default:
return new ConfigExchangeQR();
}
}
#Override
public int getCount() {
return PAGE_COUNT;
}
public CharSequence getPageTitle(int position) {
// Generate title based on item position
return tabTitles[position];
}
#Override
public int getItemPosition(Object object) {
return POSITION_NONE;
}
}
and my fragment in tab3 that is not updating:
public class ConfigExchangeQR extends Fragment {
ImageView iQRCode ;
int iQRDimension;
Button bScan;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
FacebookSdk.sdkInitialize(getActivity().getApplicationContext());
View view1 = inflater.inflate(R.layout.config_exchange_qr, container, false);
iQRCode = (ImageView)view1.findViewById(R.id.qrCode);
iQRDimension = 900;
String FinalQRCode = KeyValueDb.getPrefFinalVCard(getActivity());
QRCodeEncoder qrCodeEncoder = new QRCodeEncoder(FinalQRCode, null,
contents.Type.TEXT, BarcodeFormat.QR_CODE.toString(), iQRDimension);
try {
Bitmap bitmap = qrCodeEncoder.encodeAsBitmap();
iQRCode.setImageBitmap(bitmap);
} catch (WriterException e) {
e.printStackTrace();
}
bScan = (Button)view1.findViewById(R.id.scan_qr);
bScan.setOnClickListener(new View.OnClickListener() {
public void onClick(View paramAnonymousView) {
Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");
startActivityForResult(intent, 0);
}
});
return view1;
}
}
In ConfigExchangeMain class:
viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
Fragment fragment= adapter.getItem(position);
if(fragment instanceof ConfigExchangeQR ){
((ConfigExchangeQR)fragment).update();
}
}
#Override
public void onPageScrollStateChanged(int state) {
}
});
#Override
public void onDestroy() {
super.onDestroy();
viewPager.clearOnPageChangeListeners();
}
Add this method to your ConfigExchangeQR fragment
public class ConfigExchangeQR extends Fragment {
...
public void update(){
String FinalQRCode = KeyValueDb.getPrefFinalVCard(getActivity());
QRCodeEncoder qrCodeEncoder = new QRCodeEncoder(FinalQRCode, null,
contents.Type.TEXT, BarcodeFormat.QR_CODE.toString(), iQRDimension);
try {
Bitmap bitmap = qrCodeEncoder.encodeAsBitmap();
iQRCode.setImageBitmap(bitmap);
} catch (WriterException e) {
}
}
}
When you are currently in your second tab. The first and the third tab are preloaded (because the animation is smoother). When you switch to the first tab the third tab is unloaded -> so after switching back to the third tab it is recreated and it works for you.
The 3rd tab onCreateView is called before the 2nd tab is done, thats why it is not working. Try implementing logic inside the onResume() - to make sure it is always called when the focus is back on the fragment.
Hope this helps...
Cheers

ViewPager recreate fragments all the time

I am using ViewPager with my fragments. All fragments has animation and it does not work when switching back maybe because ViewPager saves somehow state of near Fragments, do you have some idea how to avoid it?
getItemPosition() doesn't make anything in this case
private class MyFragmentPagerAdapter extends FragmentPagerAdapter {
public MyFragmentPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public CharSequence getPageTitle(int position) {
return null;
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return GetStartedOneFragment.newInstance();
case 1:
return GetStartedTwoFragment.newInstance();
case 2:
return GetStartedThreeFragment.newInstance();
case 3:
return GetStartedFourFragment.newInstance();
case 4:
return GetStartedFiveFragment.newInstance();
case 5:
return GetStartedSixFragment.newInstance();
default:
return GetStartedOneFragment.newInstance();
}
}
#Override
public int getCount() {
return PAGE_COUNT;
}
#Override
public int getItemPosition(Object object) {
return POSITION_NONE;
}
}
I used a Fragment as a slider content, see the sample code below. Feel free to ask more details if required.
I have 4 flight modes in the example. The ViewPager is used with the associated adapter (ScreenSlidePagerAdapter).
You can see the app in the Play Store to see the slider (search "Flight Recorder 24").
// In the main fragment java code
private View headerView;
private ViewPager mPager;
public ScreenSlidePagerAdapter mPagerAdapter;
// ...
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState)
{
super.onCreateView(inflater, container, savedInstanceState);
View mainView = inflater.inflate(R.layout.monitoring_fragment,container, false);
// The header of the list
View view = inflater.inflate(R.layout.header_monitoring_fragment, mListView, false);
headerView = view;
//...
mPager = (ViewPager) view.findViewById(R.id.pager);
FragmentManager fm = getChildFragmentManager();
mPagerAdapter = new ScreenSlidePagerAdapter(fm);
mPager.setAdapter(mPagerAdapter);
mPager.setCurrentItem(UserConfiguration.getUserConf().getPositionFromFlightMode());
// Attach the page change listener inside the activity
mPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener()
{
// This method will be invoked when a new page becomes selected.
#Override
public void onPageSelected(int position)
{
int flight_mode = UserConfiguration.getFlightModeFromPosition(position);
UserConfiguration.getUserConf().setFlightMode(flight_mode);
}
// This method will be invoked when the current page is scrolled
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels)
{
// Code goes here
}
// Called when the scroll state changes:
// SCROLL_STATE_IDLE, SCROLL_STATE_DRAGGING, SCROLL_STATE_SETTLING
#Override
public void onPageScrollStateChanged(int state)
{
// Code goes here
}
});
// ...
}
// ...
// Slider adapter
private class ScreenSlidePagerAdapter extends FragmentPagerAdapter
{
public ScreenSlidePagerAdapter(FragmentManager fm)
{
super(fm);
}
#Override
public Fragment getItem(int position)
{
// position to flight mode
int flight_mode = UserConfiguration.getFlightModeFromPosition(position);
FlightModeFragment flightModeFragment = FlightModeFragment.newInstance(flight_mode);
return flightModeFragment;
}
public int getItemPosition(Object object)
{
return POSITION_NONE;
}
#Override
public int getCount()
{
return 4;
}
}
Then you have to create a Fragment with your slider content (here the class FlightModeFragment), it will be instanciated with an integer to identify the page embedded into a Bundle savedInstanceState (I have 4 pages).
public class FlightModeFragment extends Fragment
{
LinearLayout mainLayout;
ImageView live15minImageView;
ImageView modeImageView;
ImageView imageViewLeft;
ImageView imageViewRight;
private TextView textViewRecord;
private TextView textViewGps;
int flight_mode = UserConfiguration.AC_LISTENER_TRAVEL_RECORDER_MODE;
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
// handle fragment arguments
Bundle arguments = getArguments();
if(arguments != null)
{
flight_mode = arguments.getInt("flight_mode");
}
}
// ...
}

Android ViewPager in Fragment not updating

I have a Fragment for a ViewPager. The ViewPager is updated based on an action fired by the user. Well when the Fragment is recreated so to speak, the page of a ViewPager is not updated as should be, or even shown for that matter! When I swipe over to other pages and then back to that one, it loads?
Here is the Fragment:
public static class CardFrontFragment extends Fragment {
public CardFrontFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = null;
rootView = inflater.inflate(R.layout.activity_dashboard, container, false);
TextView textviewLocation = (TextView)rootView.findViewById(R.id.textview_location);
TextView textviewConditions = (TextView)rootView.findViewById(R.id.textview_points);
ViewPager viewPagerDashboard = (ViewPager)rootView.findViewById(R.id.viewPager_Dashboard);
if(overviewData != null) {
textviewLocation.setText(overviewData.getLocation());
textviewPoints.setText(overviewData.getPoints());
viewPagerDashboard.setAdapter(adapterSectionsPager);
adapterSectionsPager.notifyDataSetChanged();
viewPagerDashboard.destroyDrawingCache();
textviewLocation.setText(overviewData.getWeathersLocation());
textviewPoints.setText(overviewData.getWeathersConditions());
}
return rootView;
}
}
Here is the adapter:
public class SectionsPagerAdapter extends FragmentStatePagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public android.support.v4.app.Fragment getItem(int position) {
return DashboardSectionFragment.create
(uiContext, position, overviewData, forecastData, hourlyData, radarData);
}
#Override
public int getCount() {
// Show 4 total pages:
return 4;
}
#Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return getString(R.string.title_section_1).toUpperCase(l);
case 1:
return getString(R.string.title_section_2).toUpperCase(l);
case 2:
return getString(R.string.title_section_3).toUpperCase(l);
case 3:
// Radar Page:
return getString(R.string.title_section_4).toUpperCase(l);
}
return null;
}
}
I heard I am extending the correct one FragmentStatePagerAdapter over FragmentPagerAdapter. Yet nothing is working. I have called many methods of the ViewPager and adapter in the Fragment when the ViewPager is recreated but it still does not load initially till it appears off screen then back on...
Thanks!
try overriding the following like this and update the viewpager and pageradapater instance
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
viewPager.invalidate();
pagerAdapter.notifyDataSetChanged();
}
or else depending upon the specific location of the Fragment you can do the following
#Override
public void onPageSelected(int arg0) {
if(int == 2)// In which specifi fragment you want to update the view
{
viewPager.invalidate();
pagerAdapter.notifyDataSetChanged();
}
}
I hope this would help you
Try to update view when fragment get visible to user as follows:
public class MyFragment extends Fragment
#Override
public void setMenuVisibility(final boolean visible) {
super.setMenuVisibility(visible);
if (visible) {
**//Update views here**
}
}

How to update views of viewpager on swipe - android

I am using view-pager.In that I have three tabs : 1. History , 2. Main , 3. Map .
I have stopwatch into main activity.When I press the start and then after stop at that time value of the stopwatch add into the sqlite DB. And into history activity I am fetching the value of stopwatch from DB and store into the listview. It's working perfect.
But now I want the update the History activity when I swipe from the Main > History so After press the stop button,I got the last value into listview of history activity.
My question is how can I update the view on swipe the viewpager?
public class SwipeyTabsSampleActivity extends FragmentActivity {
private static final String [] TITLES = {
"HISTORY",
"MAIN",
"MAP"
};
private SwipeyTabs mTabs;
private ViewPager mViewPager;
//Handler handler=new Handler();
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_swipeytab);
mViewPager = (ViewPager) findViewById(R.id.viewpager);
mTabs = (SwipeyTabs) findViewById(R.id.swipeytabs);
SwipeyTabsPagerAdapter adapter = new SwipeyTabsPagerAdapter(this,
getSupportFragmentManager());
mViewPager.setAdapter(adapter);
mTabs.setAdapter(adapter);
mViewPager.setOnPageChangeListener(mTabs);
mViewPager.setCurrentItem(1);
mViewPager.setOffscreenPageLimit(3);
}
private class SwipeyTabsPagerAdapter extends FragmentPagerAdapter implements
SwipeyTabsAdapter, ViewPager.OnPageChangeListener {
private final Context mContext;
ViewPager viewpager;
public SwipeyTabsPagerAdapter(Context context, FragmentManager fm, ViewPager mViewPager) {
super(fm);
this.mContext = context;
viewpager = mViewPager;
//viewpager.setAdapter(this);
viewpager.setOnPageChangeListener(this);
}
#Override
public Fragment getItem(int position) {
Fragment f = new Fragment();
switch (position) {
case 0:
f = History.newInstance(position);
break;
case 1:
f = Main.newInstance(position);
break;
case 2:
f = Map.newInstance(position);
break;
}
return f;
}
#Override
public int getCount() {
return TITLES.length;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
ViewPager pager = (ViewPager) container;
View view = (View) object;
pager.removeView(view);
}
public TextView getTab(final int position, SwipeyTabs root) {
TextView view = (TextView) LayoutInflater.from(mContext).inflate(
R.layout.swipey_tab_indicator, root, false);
view.setText(TITLES[position]);
view.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
mViewPager.setCurrentItem(position);
}
});
return view;
}
#Override
public void onPageScrollStateChanged(int state) {
// TODO Auto-generated method stub
}
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
// TODO Auto-generated method stub
}
#Override
public void onPageSelected(int positiion) {
// TODO Auto-generated method stub
}
}
}
Add ViewPager OnPageChangeListener:
mViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
// your code here
}
#Override
public void onPageScrollStateChanged(int state) {
}
});
This will affect the changes from one page to another page in view pager.
OnPageChangeListener pagechangelistener =new OnPageChangeListener() {
#Override
public void onPageSelected(int arg0) {
Logger.logMessage("Called first");
pageAdapter.notifyDataSetChanged();
indicator.setCurrentItem(arg0);
}
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
Logger.logMessage("Called second");
}
#Override
public void onPageScrollStateChanged(int arg0) {
Logger.logMessage("Called third");
}
};
myViewPager.setOnPageChangeListener(pagechangelistener);
Use this in your page adapter.
#Override
public int getItemPosition(Object object) {
return POSITION_NONE;
}
Take one string and add the Getters and setters into your FragmentActivity class.
Like...
String HistoryFragment;
public String getHistoryFragment() {
return HistoryFragment;
}
public void setHistoryFragment(String historyFragment) {
HistoryFragment = historyFragment;
}
Then after we can access another fragment from our current fragment by calling findFragmentByTag(<tag of target fragment>).
For the more information check the link Communication between Fragments in ViewPager.
Have you tried implementing OnPageChanged`? You can capture when the user start swiping.
do pager.setOnPageChanged(new ....) and Eclipse will show you the methods you can override.
Then you can override onPageScrollStateChanged(int state)
onPageScrollStateChanged(int state){
if (state==OnPageChangeListener.SCROLL_STATE_DRAGGING){
// update here
}
}

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