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I have a ViewPager with 3 tabs.
I'm loading big data in every fragments.
The app load every fragments but I want to load fragment only when its selected.
How can I do that? I have no idea.
I'm waiting for your help. Thank you
my code:
public class Fragments extends AppCompatActivity {
private TabLayout tabLayout;
private ViewPager viewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_tabs);
viewPager = (ViewPager) findViewById(R.id.viewpager);
setupViewPager(viewPager);
tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(viewPager);
}
private void setupViewPager(ViewPager viewPager) {
ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
adapter.addFragment(new FirstFragment(), "1");
adapter.addFragment(new SecondFragment(), "2");
adapter.addFragment(new ThirdFragment(), "3");
viewPager.setAdapter(adapter);
}
class ViewPagerAdapter extends FragmentPagerAdapter {
private final List<Fragment> mFragmentList = new ArrayList<>();
private final List<String> mFragmentTitleList = new ArrayList<>();
public ViewPagerAdapter(FragmentManager manager) {
super(manager);
}
#Override
public Fragment getItem(int position) {
return mFragmentList.get(position);
}
#Override
public int getCount() {
return mFragmentList.size();
}
public void addFragment(Fragment fragment, String title) {
mFragmentList.add(fragment);
mFragmentTitleList.add(title);
}
#Override
public CharSequence getPageTitle(int position) {
return mFragmentTitleList.get(position);
}
}
}
If no one has given you a good answer I know this is 5 years later, but anyone reading this. I'm actually having the opposite problem. I need to load all tabs at the same time. What is happening to me now is only one tab is loading at a time. I need to use this adapter for viewpager2 with tablayout so that I can disable the viewpager swiping left to right for my specific usecase.
Here is my code:
WARNING CODE IS IN KOTLIN NOT JAVA
class RecipeTabAdapter internal constructor(fm: FragmentManager, lifecycle: Lifecycle) : FragmentStateAdapter(fm, lifecycle) {
val fragmentsList: ArrayList<Fragment> = arrayListOf()
fun addFragment(fragment: Fragment) {
fragmentsList.add(fragment)
}
override fun getItemCount(): Int {
return fragmentsList.size
}
override fun createFragment(position: Int): Fragment {
when (position) {
position -> fragmentsList[position]
position -> fragmentsList[position]
}
return fragmentsList[position]
}
}
Is it possible to disable the offscreen page limit?
No. It is already set to the minimum possible value: one page to each side of the viewed page. This is necessary to have the animation effects work -- you see parts of two fragments (original and new) at the same time.
In
OncreateView(){
//.... dont initialize your view here
if(isMenuVisible()) { // menu should be visible if current fragment is visible right now
setUserVisibleHint(true); // manually set value to true
}
}
in
oncreate(){
setHasOptionsMenu(true);
}
Finally there is method called setuservisiblehint() which is only called when the fragment is visible to the user this is the only method where you shud initialize all your views.
#Override
public void setUserVisibleHint(boolean isVisibleToUser) {
super.setUserVisibleHint(isVisibleToUser);
if(isVisibleToUser && v != null) {
// initialize your view here and call you fetch_data_function()
}
Here's my solution and it works as expected. In all of your child fragments create a boolean variable:
private boolean loadFragmentExecuted = false;
in the child fragments create a generic method called loadFragment and move all of the logic you added in onCreateView to that method:
public void loadFragment()
{
if(!loadFragmentExecuted)
{
//Add your logic to manipulate the UI or load data etc...
loadFragmentExecuted = true;
}
}
in your pageview logic create the fragments dynamically like:
//add the fragment
String fragmentName = "com.something." + fragmentId;
//check if the class exists
try
{
Class myFragmentClass = Class.forName(fragmentName);
Fragment myFragment = (Fragment) myFragmentClass.newInstance();
mFragments.add(myFragment);
}
catch (ClassNotFoundException e)
{
e.printStackTrace();
}
catch (IllegalAccessException e)
{
e.printStackTrace();
}
catch (InstantiationException e)
{
e.printStackTrace();
}
then set your pager adapter and attach a tablayout with it:
//set our pager adapter that contains different fragments
mPagerAdapter = new BasePagerAdapter(mFragmentManager, mFragments);
//link the adapter to the viewpager
mViewPager.setAdapter(mPagerAdapter);
//cache fragments
int limit = (mPagerAdapter.getCount() > 0 ? mPagerAdapter.getCount() : 1);
mViewPager.setOffscreenPageLimit(limit);
//add the page listner to the viewPager and link it to the tabLayout
mViewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(mTabLayout));
//on tab selected select current viewpager item
mTabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener()
{
#Override
public void onTabSelected(TabLayout.Tab tab)
{
mViewPager.setCurrentItem(tab.getPosition());
//get fragment for the selected tab
Fragment f = mPagerAdapter.getItem(tab.getPosition());
//load the content of the fragment
try
{
Class c = f.getClass();
Method loadFragment = c.getMethod("loadFragment");
loadFragment.invoke(f);
}
catch (IllegalAccessException e){}
catch (InvocationTargetException e){}
catch (NoSuchMethodException e){}
}
#Override
public void onTabUnselected(TabLayout.Tab tab)
{
}
#Override
public void onTabReselected(TabLayout.Tab tab)
{
}
});
I have a solution that does not require subclassing, and it's easy to introduce into existing projects. It uses the child fragment mechanism.
The basic idea is to replace your content fragment with an almost empty fragment, and add your content fragment as a child fragment when it is really visible to the user
The gist of the code is like this
#Override
public void onViewCreated(#NonNull View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
boolean hasFragment = getChildFragmentManager().findFragmentById(R.id.container) != null;
if (hasFragment) {
return;
}
if (getUserVisibleHint()) {
addFragment("onViewCreated");
}
}
#Override
public void onResume() {
super.onResume();
if (getUserVisibleHint()) {
addFragment("onResume");
}
}
#Override
public void setUserVisibleHint(boolean isVisibleToUser) {
super.setUserVisibleHint(isVisibleToUser);
if (isVisibleToUser && isResumed()) {
addFragment("setUserVisibleHint");
}
}
private void addFragment(String cause) {
if (getChildFragmentManager().findFragmentById(R.id.container) == null) {
getChildFragmentManager().beginTransaction()
.setCustomAnimations(android.R.animator.fade_in, android.R.animator.fade_out)
.add(R.id.container, createFragment()).commit();
}
}
Check out my full solution here, which also contains a progressbar, and the option to automatically start loading of background fragments with a specified delay: Lazy Load Fragment
How should I select a tab in TabLayout programmatically?
TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(viewPager);
If you know the index of the tab you want to select, you can do it like so:
TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
TabLayout.Tab tab = tabLayout.getTabAt(someIndex);
tab.select();
This technique works even if you're using the TabLayout by itself without a ViewPager (which is atypical, and probably bad practice, but I've seen it done).
This is how I solved it:
void selectPage(int pageIndex){
tabLayout.setScrollPosition(pageIndex,0f,true);
viewPager.setCurrentItem(pageIndex);
}
Use this:
tabs.getTabAt(index).select();
Keep in mind that, if currentTabIndex and index are same then this sends your flow to onTabReselected and not onTabSelected.
Use this:
<android.support.design.widget.TabLayout
android:id="#+id/patienthomescreen_tabs"
android:layout_width="match_parent"
android:layout_height="72sp"
app:tabGravity="fill"
app:tabMode="fixed"
app:tabIndicatorColor="#android:color/white"
app:tabSelectedTextColor="#color/green"/>
After in OnClickListener:
TabLayout tabLayout = (TabLayout) findViewById(R.id.patienthomescreen_tabs);
TabLayout.Tab tab = tabLayout.getTabAt(someIndex);
tab.select();
Keep in mind that, if currentTabIndex and index are same then this sends your flow to onTabReselected and not onTabSelected.
This is probably not the ultimate solution, and it requires that you use the TabLayout together with a ViewPager, but this is how I solved it:
void selectPage(int pageIndex)
{
viewPager.setCurrentItem(pageIndex);
tabLayout.setupWithViewPager(viewPager);
}
I tested how big the performance impact of using this code is by first looking at the CPU- and memory monitors in Android Studio while running the method, then comparing it to the load that was put on the CPU and memory when I navigated between the pages myself (using swipe gestures), and the difference isn't significantly big, so at least it's not a horrible solution...
Hope this helps someone!
Just set viewPager.setCurrentItem(index) and the associated TabLayout would select the respective tab.
With the TabLayout provided by the Material Components Library just use the selectTab method:
TabLayout tabLayout = findViewById(R.id.tab_layout);
tabLayout.selectTab(tabLayout.getTabAt(index));
It requires version 1.1.0.
If you can't use tab.select() and you don't want to use a ViewPager, you can still programmatically select a tab. If you're using a custom view through TabLayout.Tab setCustomView(android.view.View view) it is simpler. Here's how to do it both ways.
// if you've set a custom view
void updateTabSelection(int position) {
// get the position of the currently selected tab and set selected to false
mTabLayout.getTabAt(mTabLayout.getSelectedTabPosition()).getCustomView().setSelected(false);
// set selected to true on the desired tab
mTabLayout.getTabAt(position).getCustomView().setSelected(true);
// move the selection indicator
mTabLayout.setScrollPosition(position, 0, true);
// ... your logic to swap out your fragments
}
If you aren't using a custom view then you can do it like this
// if you are not using a custom view
void updateTabSelection(int position) {
// get a reference to the tabs container view
LinearLayout ll = (LinearLayout) mTabLayout.getChildAt(0);
// get the child view at the position of the currently selected tab and set selected to false
ll.getChildAt(mTabLayout.getSelectedTabPosition()).setSelected(false);
// get the child view at the new selected position and set selected to true
ll.getChildAt(position).setSelected(true);
// move the selection indicator
mTabLayout.setScrollPosition(position, 0, true);
// ... your logic to swap out your fragments
}
Use a StateListDrawable to toggle between selected and unselected drawables or something similar to do what you want with colors and/or drawables.
A bit late but might be a useful solution.
I am using my TabLayout directly in my Fragment and trying to select a tab quite early in the Fragment's Lifecycle.
What worked for me was to wait until the TabLayout finished drawing its child views by using android.view.View#post method. i.e:
int myPosition = 0;
myFilterTabLayout.post(() -> { filterTabLayout.getTabAt(myPosition).select(); });
You can try solving it with this:
TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(mViewPager);
TabLayout.Tab tab = tabLayout.getTabAt(pos);
if (tab != null) {
tab.select();
}
Newest simple solution worked for me:
binding.tablayout.selectTab(binding.tablayout.getTabAt(tabPosisiton))
or
with(binding.tablayout) {
selectTab(getTabAt(tabPosisiton))
}
and tabPosition start from 0
try this
new Handler().postDelayed(
new Runnable(){
#Override
public void run() {
if (i == 1){
tabLayout.getTabAt(0).select();
} else if (i == 2){
tabLayout.getTabAt(1).select();
}
}
}, 100);
Kotlin Users:
Handler(Looper.getMainLooper()).postDelayed(
{ tabLayout.getTabAt(position).select() }, 100
)
This will also scroll your tab layout in case if it needs to scroll.
you should use a viewPager to use viewPager.setCurrentItem()
viewPager.setCurrentItem(n);
tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
#Override
public void onTabSelected(TabLayout.Tab tab) {
viewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(TabLayout.Tab tab) {
}
#Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
A combined solution from different answers is:
new Handler().postDelayed(() -> {
myViewPager.setCurrentItem(position, true);
myTabLayout.setScrollPosition(position, 0f, true);
},
100);
I am using TabLayout to switch fragments. It works for the most part, except whenever I tried to select a tab programmatically using tab.select(), my TabLayout.OnTabSelectedListener would trigger the onTabSelected(TabLayout.Tab tab), which would cause me much grief. I was looking for a way to do programmatic selection without triggering the listener.
So I adapted #kenodoggy 's answer to my use. I was further facing a problem where some of the internal objects would return null (because they weren't created yet, because I was answering onActivityResult() from my fragment, which occurs before onCreate() in the case the activity is singleTask or singleInstance) so I wrote up a detailed if/else sequence which would report the error and fall through without the NullPointerException that would otherwise trigger. I use Timber for logging, if you're not using that substitute with Log.e().
void updateSelectedTabTo(int position) {
if (tabLayout != null){
int selected = tabLayout.getSelectedTabPosition();
if (selected != -1){
TabLayout.Tab oldTab = tabLayout.getTabAt(0);
if (oldTab != null){
View view = oldTab.getCustomView();
if (view != null){
view.setSelected(false);
}
else {
Timber.e("oldTab customView is null");
}
}
else {
Timber.e("oldTab is null");
}
}
else {
Timber.e("selected is -1");
}
TabLayout.Tab newTab = tabLayout.getTabAt(position);
if (newTab != null){
View view = newTab.getCustomView();
if (view != null){
view.setSelected(false);
}
else {
Timber.e("newTab customView is null");
}
}
else {
Timber.e("newTab is null");
}
}
else {
Timber.e("tablayout is null");
}
}
Here, tabLayout is my memory variable bound to the TabLayout object in my XML. And I don't use the scrolling tab feature so I removed that as well.
If you are using TabLayout with viewPager then this helps you. You set the TabLayout with ViewPager in addOnpagelistener.
if you want to set the TabLayout position directly(not click on the Tab individual) try below code tabLayout.getTabAt(position_you_want_to_set).select()
/* will be invoked whenever the page changes or is incrementally scrolled*/
viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
tabLayout.getTabAt(position).select();
}
#Override
public void onPageScrollStateChanged(int state) {
}
});
This won't work for app that has ViewPager2 Implemented, For that, you need to use
viewPager2.setCurrentItem(position);
inside onConfigureTab, onConfigureTab if found when we use TabLayoutMediator
i.e
TabLayoutMediator tabLayoutMediator = new TabLayoutMediator(
tabLayout, viewPager2, new TabLayoutMediator.TabConfigurationStrategy() {
#Override
public void onConfigureTab(#NonNull TabLayout.Tab tab, int position) {
switch (position){
case 0 : tab.setIcon(getResources().getDrawable(R.drawable.camera));
break;
case 1 : tab.setText("CHAT");
viewPager2.setCurrentItem(position); // when app starts this will be the selected tab
break;
case 2 : tab.setText("STATUS");
break;
case 3 : tab.setText("CALL");
break;
}
}
}
);
tabLayoutMediator.attach();
add for your viewpager:
viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageSelected(int position) {
array.clear();
switch (position) {
case 1:
//like a example
setViewPagerByIndex(0);
break;
}
}
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageScrollStateChanged(int state) {
}
});
//on handler to prevent crash outofmemory
private void setViewPagerByIndex(final int index){
Application.getInstance().getHandler().post(new Runnable() {
#Override
public void run() {
viewPager.setCurrentItem(index);
}
});
}
By default if you select a tab it will be highlighted. If you want to select Explicitly means use the given commented code under onTabSelected(TabLayout.Tab tab) with your specified tab index position. This code will explains about change fragment on tab selected position using viewpager.
public class GalleryFragment extends Fragment implements TabLayout.OnTabSelectedListener
{
private ViewPager viewPager;public ViewPagerAdapter adapter;private TabLayout tabLayout;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_gallery, container, false);
viewPager = (ViewPager) rootView.findViewById(R.id.viewpager);
adapter = new ViewPagerAdapter(getChildFragmentManager());
adapter.addFragment(new PaymentCardFragment(), "PAYMENT CARDS");
adapter.addFragment(new LoyaltyCardFragment(), "LOYALTY CARDS");
viewPager.setAdapter(adapter);
tabLayout = (TabLayout) rootView.findViewById(R.id.tabs);
tabLayout.setupWithViewPager(viewPager);
tabLayout.setOnTabSelectedListener(this);
}
#Override
public void onTabSelected(TabLayout.Tab tab) {
//This will be called 2nd when you select a tab or swipe using viewpager
final int position = tab.getPosition();
Log.i("card", "Tablayout pos: " + position);
//TabLayout.Tab tabdata=tabLayout.getTabAt(position);
//tabdata.select();
tabLayout.post(new Runnable() {
#Override
public void run() {
if (position == 0) {
PaymentCardFragment paymentCardFragment = getPaymentCardFragment();
if (paymentCardFragment != null) {
VerticalViewpager vp = paymentCardFragment.mypager;
if(vp!=null)
{
//vp.setCurrentItem(position,true);
vp.setCurrentItem(vp.getAdapter().getCount()-1,true);
}
}
}
if (position == 1) {
LoyaltyCardFragment loyaltyCardFragment = getLoyaltyCardFragment();
if (loyaltyCardFragment != null) {
VerticalViewpager vp = loyaltyCardFragment.mypager;
if(vp!=null)
{
vp.setCurrentItem(position);
}
}
}
}
});
}
#Override
public void onTabUnselected(TabLayout.Tab tab) {
//This will be called 1st when you select a tab or swipe using viewpager
}
#Override
public void onTabReselected(TabLayout.Tab tab) {
//This will be called only when you select the already selected tab(Ex: selecting 3rd tab again and again)
}
private PaymentCardFragment getLoyaltyCardFragment() {
Fragment f = adapter.mFragmentList.get(viewPager.getCurrentItem());
if(f instanceof PaymentCardFragment)
{
return (PaymentCardFragment) f;
}
return null;
}
private LoyaltyCardFragment getPaymentCardFragment() {
Fragment f = adapter.mFragmentList.get(viewPager.getCurrentItem());
if(f instanceof LoyaltyCardFragment)
{
return (LoyaltyCardFragment) f;
}
return null;
}
class ViewPagerAdapter extends FragmentPagerAdapter {
public List<Fragment> mFragmentList = new ArrayList<>();
private final List<String> mFragmentTitleList = new ArrayList<>();
public void addFragment(Fragment fragment, String title) {
mFragmentList.add(fragment);
mFragmentTitleList.add(title);
}
}
}
This can help too
viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageScrolled(int i, float v, int i1) {
}
#Override
public void onPageSelected(int i) {
tablayout.getTabAt(i).select();
}
#Override
public void onPageScrollStateChanged(int i) {
}
});
You can set TabLayout position using following functions
public void setTab(){
tabLayout.setScrollPosition(YOUR_SCROLL_INDEX,0,true);
tabLayout.setSelected(true);
}
If it so happens that your default tab is the first one(0) and you happen to switch to a fragment, then you must manually replace the fragment for the first time. This is because the tab is selected before the listener gets registered.
private TabLayout mTabLayout;
...
#Override
public View onCreateView(#NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_tablayout, container, false);
mTabLayout = view.findViewById(R.id.sliding_tabs);
mTabLayout.addOnTabSelectedListener(mOnTabSelectedListener);
getActivity().getSupportFragmentManager().beginTransaction()
.replace(R.id.tabContent, MyFirstFragment.newInstance()).commit();
return view;
}
Alternatively, you can consider calling getTabAt(0).select() and overriding onTabReselected like so:
#Override
public void onTabReselected(TabLayout.Tab tab) {
// Replace the corresponding tab fragment.
}
This would work because you are essentially replacing the fragment on every tab reselect.
If you have trouble understanding, this code can help you
private void MyTabLayout(){
TabLayout.Tab myTab = myTabLayout.newTab(); // create a new tab
myTabLayout.addTab(myTab); // add my new tab to myTabLayout
myTab.setText("new tab");
myTab.select(); // select the new tab
}
You can also add this to your code:
myTabLayout.setTabTextColors(getColor(R.color.colorNormalTab),getColor(R.color.colorSelectedTab));
Try this way.
tabLayout.setTabTextColors(getResources().getColor(R.color.colorHintTextLight),
getResources().getColor(R.color.colorPrimaryTextLight));
if u are using TabLayout without viewPager this helps
mTitles = getResources().getStringArray(R.array.tabItems);
mIcons = getResources().obtainTypedArray(R.array.tabIcons);
for (int i = 0; i < mTitles.length; i++) {
tabs.addTab(tabs.newTab().setText(mTitles[i]).setIcon(mIcons.getDrawable(i)));
if (i == 0) {
/*For setting selected position 0 at start*/
Objects.requireNonNull(Objects.requireNonNull(tabs.getTabAt(i)).getIcon()).setColorFilter(ContextCompat.getColor(getApplicationContext(), R.color.colorPrimary), PorterDuff.Mode.SRC_IN);
}
}
tabs.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
#Override
public void onTabSelected(TabLayout.Tab tab) {
Objects.requireNonNull(tab.getIcon()).setColorFilter(ContextCompat.getColor(getApplicationContext(), R.color.colorPrimary), PorterDuff.Mode.SRC_IN);
}
#Override
public void onTabUnselected(TabLayout.Tab tab) {
Objects.requireNonNull(tab.getIcon()).setColorFilter(ContextCompat.getColor(getApplicationContext(), R.color.white), PorterDuff.Mode.SRC_IN);
}
#Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
Kotlin fix
viewPager.currentItem = 0
tabs.setupWithViewPager(viewPager)
TabLayout jobTabs = v.findViewById(R.id.jobTabs);
ViewPager jobFrame = v.findViewById(R.id.jobPager);
jobFrame.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(jobTabs));
this will select tab as view pager swipe page
With Viewpager2, Kotlin none of the other answers helped, only this worked below. position is from fragment result listener in my case:
TabLayoutMediator(binding.tabLayout, binding.viewPager2) { _, _ ->
binding.viewPager2 = position
}.attach()
I am scracthing my head for past 1 day but unable to find the solution.
In mine application there are two tabs under the toolbar
First tab is USER-TAB
the second one is ADMIN-TAB
In both the tabs there are the listView. When a ListItem on the USER-TAB is clicked a dialog appears and user take some action.
Now after this when the ADMIN-TAB is Selected the Admin should get refreshed with new sets of data. But It's not. On selecting the ADMIN-TAB the onResume() method and everyting is getting called but it is not able to update the list.
I wont be able to write the Whole code, I am giving some snippet.
Basically I have taken the code from this link
https://github.com/codepath/android_guides/wiki/Sliding-Tabs-with-PagerSlidingTabStrip
In My Main Activity I have written the OpPageChangeListener.
public class MaterialTab extends FragmentActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.material_main_sample);
// Get the ViewPager and set it's PagerAdapter so that it can display items
ViewPager viewPager = (ViewPager) findViewById(R.id.viewpager);
viewPager.setAdapter(new SampleFragmentPagerAdapter(getSupportFragmentManager()));
// Give the PagerSlidingTabStrip the ViewPager
PagerSlidingTabStrip tabsStrip = (PagerSlidingTabStrip) findViewById(R.id.tabs);
// Attach the view pager to the tab strip
tabsStrip.setViewPager(viewPager);
tabsStrip.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
if(position == 0){
MileUserFragment userFragment = new MileUserFragment();
final FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.detach(userFragment);
ft.attach(userFragment);
ft.commit();
} if(position == 1){
MileAdminFragment adminFragment = new MileAdminFragment();
final FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.detach(adminFragment);
ft.attach(adminFragment);
ft.commit();
}
}
#Override
public void onPageScrollStateChanged(int state) {
}
});
}
}
OnPageSelected You can see I am detaching and reattaching the fragment.Everything is working fine. Both Fragments OnResume() are getting called but the List is not getting changed. I don't undrstand why
For additional assistance i am adding snippet one Fragment. Hope this will give some Idea where i might be going wrong
public class MileUserFragment extends Fragment {
#Override
public void onResume() {
super.onResume();
new GetAdminDbTask().execute();
if(!internetUtil.isConnectedToInternet(getActivity())){
mSwipeRefreshLayout.setRefreshing(false);
mSwipeRefreshLayout.setEnabled(false);
}
}
public class GetAdminDbTask extends AsyncTask<Admin, Void, String> {
#Override
protected String doInBackground(Admin... parmas) {
_adminList = shipmentDbHandler.getAllAdmin();
return "";
}
#Override
protected void onPostExecute(String str) {
mAdminAdapter = new AdminAdapter(getActivity(), _adminList);
adminListView.setAdapter(mAdminAdapter);
mAdminAdapter.notifyDataSetChanged();
// Set the refresh Listener to false after the list has been loaded with new set of data
if (mSwipeRefreshLayout.isRefreshing()) {
mSwipeRefreshLayout.setRefreshing(false);
}
if(_adminList.size() > 0 ){
mAdminAdapter = new AdminAdapter(getActivity(), _adminList);
adminListView.setAdapter(mAdminAdapter);
mAdminAdapter.notifyDataSetChanged();
}
}
}
}
public class SampleFragmentPagerAdapter extends FragmentPagerAdapter {
final int PAGE_COUNT = 2;
private String tabTitles[] = new String[] { "Tab1", "Tab2" };
private FragmentManager fragmentManager;
public SampleFragmentPagerAdapter(FragmentManager fm) {
super(fm);
this.fragmentManager = fm;
}
#Override
public int getCount() {
return PAGE_COUNT;
}
#Override
public Fragment getItem(int position) {
FragmentTransaction ft = null;
if(position == 0){
MileUserFragment userFragment = new MileUserFragment();
return userFragment;
}
if(position == 1){
MileAdminFragment adminFragment = new MileAdminFragment();
return archiveFragment;
}
}
#Override
public CharSequence getPageTitle(int position) {
// Generate title based on item position
return tabTitles[position];
}
}
Haah.. Finally i got an answer to after an heck of losing almost 1 and half days. It might be not completely good answer but atleast it is one of the closest I got.
First of all MainActivity.java looks like:
tabs.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
int scrollPosition = 0;
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
if(position == 0){
scrollPosition = 0;
}
if(position == 1){
scrollPosition = 1;
}
}
#Override
public void onPageSelected(int position) {
}
#Override
public void onPageScrollStateChanged(int state) {
if(state == pager.SCROLL_STATE_IDLE){
if(scrollPosition == 0 && application.isActiveAction()){
viewPagerAdapter.notifyDataSetChanged();
application.setActiveAction(false);
}
if(scrollPosition == 1 && application.isArchiveAction()){
viewPagerAdapter.notifyDataSetChanged();
application.setArchiveAction(false);
}
}
}
});
Now what I have done here is I have set OnPageChangeListener and in this I am keeping track of the position whenever the tabs are changing. For my needs what i have done is i have created two boolean variables and setting it when any content on those tab are changing in Application scope. Now when the contents on one tab has been changed or some Action are done I am calling
viewPagerAdapter.notifyDataSetChanged() // Now this is the real gem
after invoking this it will make a call to the ViewPagerAdapter function
#Override
public int getItemPosition(Object object) {
return PagerAdapter.POSITION_NONE; // This will get invoke as soon as you call notifyDataSetChanged on viewPagerAdapter.
}
Also the Point is your ViewPagerAdapter should extend FragmentStatePageAdapter. Now the Point is
PagerAdapter.POSITION_NONE
will not cache the fragment and reload a new fragment for that tab position.
Basic idea is we should not make or retutn PagerAdapter.POSITION_NONE everytime on sliding of tab since it destroys the cached element and reload the fragment which affects UI performance.
So finally the basic thing is always check that whether on calling viewPagerAdapter.notifyDataSetChanged() the function getItemPosition() should also gets invoked. Hope it will help somebody. For better perfomance you can make changes according to your requirement.
I got the needed breakthrough and understanding from this post : #Louth Answer
Remove Fragment Page from ViewPager in Android
Just put
viewPager.setCurrentItem(tab.getPosition());
in your onTabSelected method like:
tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
#Override
public void onTabSelected(TabLayout.Tab tab) {
viewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(TabLayout.Tab tab) {
}
#Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
I have two fragments SearchFragment and CreateFragment in a view pager inside a activity called TicketManagementActivity. Now when the user presses the search button in SearchFragment, I want SearchFragment to be replaced with SearchResultFragment. I should then be able to swipe between SeachResultFragment and CreateFragment in the ViewPager. Also when I press back from SearchResultFragment I should go back to SearchFragment.
Right now, when I press the button I get a blank screen instead of the layout of SearchResultFragment. When I press back I get to SearchFragment but now I have to click the button twice for the blank screen to come. Now after the blank screen comes after the double click, whenever I swipe to CreateFragment tab I get a blank screen instead of CreateFragment layout.
I looked at quite a number of questions on SO but none of them seem to be working for me. Most useful seems to be the first two answers in this question, but the first answer doesn't handle the back press, nor am I able to implement it. The second answer seems very implementable but I get errors which I have mentioned below.
My main TicketManagemementActivity:
public class TicketManagementActivity extends FragmentActivity implements
ActionBar.TabListener {
ViewPager viewPager;
TabsPagerAdapter adapter;
ActionBar actionBar;
String[] tabs={"Search", "Create"};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_ticket_management);
viewPager=(ViewPager)findViewById(R.id.pager);
actionBar=getActionBar();
adapter=new TabsPagerAdapter(getSupportFragmentManager());
viewPager.setAdapter(adapter);
actionBar.setHomeButtonEnabled(false);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
for(String tab_name : tabs){
actionBar.addTab(actionBar.newTab().setText(tab_name).setTabListener(this));
}
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageSelected(int position) {
// on changing the page
// make respected tab selected
actionBar.setSelectedNavigationItem(position);
}
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
#Override
public void onPageScrollStateChanged(int arg0) {
}
});
}
//removed methods for menu creation and filling and placeholder fragment for brevity on SO
#Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
viewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
}
#Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}
}
My activity_ticket_management.xml which is layout set in onCreate of ticket management activity, just contains the viewpager
<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent">
</android.support.v4.view.ViewPager>
My TabsPagerAdapter class extending FragmentPagerAdapter:
public class TabsPagerAdapter extends FragmentPagerAdapter {
public TabsPagerAdapter(android.support.v4.app.FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int index) {
switch (index) {
case 0:
// Top Rated fragment activity
return new SearchFragment();
case 1:
// Games fragment activity
return new CreateFragment();
}
return null;
}
#Override
public int getCount() {
// get item count - equal to number of tabs
return 2;
}
}
Relevant part of my SearchFragment:
public class SearchFragment extends Fragment implements View.OnClickListener {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_search, container, false);
.
.//some widget initializations
.
return rootView;
}
#Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.ticket_search_btn: searchSigmaTickets();
break;
}
}
public void searchSigmaTickets(){
.
.
.
.//some operations
.
new SearchAsyncTask().execute();
}
}
private class SearchAsyncTask extends AsyncTask<Void, Void, Void>{
protected Void doInBackground(Void... params){
.
.//some more operation
.
}
protected void onPostExecute(Void param){
Fragment newFragment = new SearchResultFragment();
//Here I use getFragmentManager and not getChildFragmentManager
FragmentTransaction transaction = getFragmentManager().beginTransaction();
//HERE I try to replace the fragment. I'm not sure what id to pass, I pass the id of the main veiwpager in ticketmanagement activity
transaction.replace(R.id.pager, newFragment);
transaction.addToBackStack(null);
transaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
transaction.commit();
}
}
}
If I use getChildFragmentManager instead of getFragmentManager as mentioned in the second answer I get
06-25 06:55:32.045: E/AndroidRuntime(2797): java.lang.IllegalArgumentException: No view found for id 0x7f06003c (com.amberroad.sigmaticket:id/pager) for fragment SearchResultFragment{b2fed358 #0 id=0x7f06003c}
Sorry for the lengthy question, how should I solve this?
Kartik, get ready for a lengthy answer to your lenghty question. Replacing fragments in a viewpager is quite involved but is very possible and can look super slick. First, you need to let the viewpager itself handle the removing and adding of the fragments. What is happening is when you replace the fragment inside of SearchFragment, your viewpager retains its fragment views. So you end up with a blank page because the SearchFragment gets removed when you try to replace it.
The solution is to create a listener inside of your viewpager that will handle changes made outside of it so first add this code to the bottom of your adapter.
public interface nextFragmentListener {
public void fragment0Changed(String newFragmentIdentification);
}
Then you need to create a private class in your viewpager that becomes a listener for when you want to change your fragment. For example you could add something like this. Notice that it implements the interface that was just created. So whenever you call this method, it will run the code inside of the class below.
private final class fragmentChangeListener implements nextFragmentListener {
#Override
public void fragment0Changed(String fragment) {
//I will explain the purpose of fragment0 in a moment
fragment0 = fragment;
manager.beginTransaction().remove(fragAt0).commit();
switch (fragment){
case "searchFragment":
fragAt0 = SearchFragment.newInstance(listener);
break;
case "searchResultFragment":
fragAt0 = Fragment_Table.newInstance(listener);
break;
}
notifyDataSetChanged();
}
There are two main things to point out here: 1)fragAt0 is a "flexible" fragment. It can take on whatever fragment type you give it. This allows it to become your best friend in changing the fragment at position 0 to the fragment you desire. 2) Notice the listeners that are placed in the 'newInstance(listener)constructor. These are how you will callfragment0Changed(String newFragmentIdentification)`. The following code shows how you create the listener inside of your fragment.
static nextFragmentListener listenerSearch;
public static Fragment_Journals newInstance(nextFragmentListener listener){
listenerSearch = listener;
return new Fragment_Journals();
}
You could then call the change inside of your onPostExecute
private class SearchAsyncTask extends AsyncTask<Void, Void, Void>{
protected Void doInBackground(Void... params){
.
.//some more operation
.
}
protected void onPostExecute(Void param){
listenerSearch.fragment0Changed("searchResultFragment");
}
}
This would trigger the code inside of your viewpager to switch your fragment at position zero fragAt0 to become a new searchResultFragment. There are two more small pieces you would need to add to the viewpager before it became functional.
One would be in the getItem override method of the viewpager.
#Override
public Fragment getItem(int index) {
switch (index) {
case 0:
//this is where it will "remember" which fragment you have just selected. the key is to set a static String fragment at the top of your page that will hold the position that you had just selected.
if(fragAt0 == null){
switch(fragment0){
case "searchFragment":
fragAt0 = FragmentSearch.newInstance(listener);
break;
case "searchResultsFragment":
fragAt0 = FragmentSearchResults.newInstance(listener);
break;
}
}
return fragAt0;
case 1:
// Games fragment activity
return new CreateFragment();
}
Now without this final piece you would still get a blank page. Kind of lame, but it is an essential part of the viewPager. You must override the getItemPosition method of the viewpager. Ordinarily this method will return POSITION_UNCHANGED which tells the viewpager to keep everything the same and so getItem will never get called to place the new fragment on the page. Here's an example of something you could do
public int getItemPosition(Object object)
{
//object is the current fragment displayed at position 0.
if(object instanceof SearchFragment && fragAt0 instanceof SearchResultFragment){
return POSITION_NONE;
//this condition is for when you press back
}else if{(object instanceof SearchResultFragment && fragAt0 instanceof SearchFragment){
return POSITION_NONE;
}
return POSITION_UNCHANGED
}
Like I said, the code gets very involved, but you basically have to create a custom adapter for your situation. The things I mentioned will make it possible to change the fragment. It will likely take a long time to soak everything in so I would be patient, but it will all make sense. It is totally worth taking the time because it can make a really slick looking application.
Here's the nugget for handling the back button. You put this inside your MainActivity
public void onBackPressed() {
if(mViewPager.getCurrentItem() == 0) {
if(pagerAdapter.getItem(0) instanceof FragmentSearchResults){
((FragmentSearchResults) pagerAdapter.getItem(0)).backPressed();
}else if (pagerAdapter.getItem(0) instanceof FragmentSearch) {
finish();
}
}
}
You will need to create a method called backPressed() inside of FragmentSearchResults that calls fragment0changed. This in tandem with the code I showed before will handle pressing the back button. Good luck with your code to change the viewpager. It takes a lot of work, and as far as I have found, there aren't any quick adaptations. Like I said, you are basically creating a custom viewpager adapter, and letting it handle all of the necessary changes using listeners
Here is the code all together for the TabsPagerAdapter.
public class TabsPagerAdapter extends FragmentPagerAdapter{
Fragment fragAt0;
fragmentChangeListener listener = new fragmentChangeListener();
FragmentManager manager;
static String fragment0 = "SearchFragment";
//when you declare the viewpager in your adapter, pass it the fragment manager.
public viewPager(FragmentManager fm) {
super(fm);
manager = fm;
}
private final class fragmentChangeListener implements nextFragmentListener {
#Override
public void fragment0Changed(String fragment) {
//I will explain the purpose of fragment0 in a moment
fragment0 = fragment;
manager.beginTransaction().remove(fragAt0).commit();
switch (fragment){
case "searchFragment":
fragAt0 = SearchFragment.newInstance(listener);
break;
case "searchResultFragment":
fragAt0 = Fragment_Table.newInstance(listener);
break;
}
notifyDataSetChanged();
}
}
#Override
public Fragment getItem(int index) {
switch (index) {
case 0:
//this is where it will "remember" which fragment you have just selected. the key is to set a static String fragment at the top of your page that will hold the position that you had just selected.
if(fragAt0 == null){
switch(fragment0){
case "searchFragment":
fragAt0 = FragmentSearch.newInstance(listener);
break;
case "searchResultsFragment":
fragAt0 = FragmentSearchResults.newInstance(listener);
break;
}
}
return fragAt0;
case 1:
// Games fragment activity
return new CreateFragment();
}
#Override
public int getCount() {
// Show 3 total pages.
return 3;
}
#Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
String[] tab = {"Journals", "Charts", "Website"};
switch (position) {
case 0:
return tab[0].toUpperCase(l);
case 1:
return tab[1].toUpperCase(l);
case 2:
return tab[2].toUpperCase(l);
}
return null;
}
public int getItemPosition(Object object)
{
//object is the current fragment displayed at position 0.
if(object instanceof SearchFragment && fragAt0 instanceof SearchResultFragment){
return POSITION_NONE;
//this condition is for when you press back
}else if{(object instanceof SearchResultFragment && fragAt0 instanceof SearchFragment){
return POSITION_NONE;
}
return POSITION_UNCHANGED
}
public interface nextFragmentListener {
public void fragment0Changed(String fragment);
}
The fragments I use in my ViewPager instance are quite resource intensive, so I'd only like to load one at a time. When I try the following:
mViewPager.setOffscreenPageLimit(0);
mViewPager.setAdapter(mPagerAdapter);
My FragmentStatePagerAdapter.getItem(int position) override function is called 3 times, which is what happens when I call mViewPager.setOffscreenPageLimit(1). I would expect it to only be called once, because I specified 0 offscreen pages.
I believe I'm calling everything correctly, because if I call mViewPager.setOffscreenPageLimit(2), FragmentStatePagerAdapter.getItem(int position) is called 5 times as I would expect.
Does ViewPager require a minimum of 1 offscreen pages, or am I doing something wrong here?
The best way that I found was setUserVisibleHint
add this to your fragment
#Override
public void setUserVisibleHint(boolean isVisibleToUser) {
super.setUserVisibleHint(isVisibleToUser);
if (isVisibleToUser) {
// load data here
}else{
// fragment is no longer visible
}
}
Does ViewPager require a minimum of 1 offscreen pages
Yes. If I am reading the source code correctly, you should be getting a warning about this in LogCat, something like:
Requested offscreen page limit 0 too small; defaulting to 1
You can try like this :
public abstract class LazyFragment extends Fragment {
protected boolean isVisible;
/**
* 在这里实现Fragment数据的缓加载.
* #param isVisibleToUser
*/
#Override
public void setUserVisibleHint(boolean isVisibleToUser) {
super.setUserVisibleHint(isVisibleToUser);
if(getUserVisibleHint()) {
isVisible = true;
onVisible();
} else {
isVisible = false;
onInvisible();
}
}
protected void onVisible(){
lazyLoad();
}
protected abstract void lazyLoad();
protected void onInvisible(){}
protected abstract void lazyLoad();
protected void onInvisible(){}
First Add
boolean isFragmentLoaded = false;
than
#Override
public void setUserVisibleHint(boolean isVisibleToUser) {
super.setUserVisibleHint(isVisibleToUser);
if (isVisibleToUser && !isFragmentLoaded) {
//Load Your Data Here like.... new GetContacts().execute();
isFragmentLoaded = true;
}
else{
}
}
this may be old thread but this seems to work for me. Override this function :
#Override
public void setMenuVisibility(boolean menuVisible) {
super.setMenuVisibility(menuVisible);
if ( menuVisible ) {
/**
* Load your stuffs here.
*/
} else {
/**
* Fragment not currently Visible.
*/
}
}
happy codings...
ViewPager is default to load the next page(Fragment) which you can't change by setOffscreenPageLimit(0). But you can do something to hack.
You can implement onPageSelected function in Activity containing the ViewPager. In the next Fragment(which you don't want to load), you write a function let's say showViewContent() where you put in all resource consuming init code and do nothing before onResume() method. Then call showViewContent() function inside onPageSelected. Hope this will help.
in my case i wanted to start some animations in views, but with setUserVisibleHint got some issues ...
my solution is :
1/ addOnPageChangeListener for your adapter :
mViewPager.addOnPageChangeListener(this);
2/ implement OnPageChangeListener :
public class PagesFragment extends Fragment implements ViewPager.OnPageChangeListener
3/ override the 3 methodes :
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels)
{
}
#Override
public void onPageSelected(int position)
{
}
#Override
public void onPageScrollStateChanged(int state)
{
}
4/ declare and initialize this variable on your class
private static int mTabState = 1;
notice : i have three fragments in my adapter, and use mTabState for setCurrentItem and current position of adapter which recognize which fragment is show to user in time ...
5/ in onPageSelected method add this codes :
if (mTabState == 0 || position == 0)
{
Intent intent = new Intent("animation");
intent.putExtra("current_position", position);
LocalBroadcastManager.getInstance(mContext).sendBroadcast(intent);
}
if previous page or current page is page 0(fragment in position 0) then do this stuff
6/ now in your fragment class (fragment in position 0 of adapter), you must create broadcast receiver and register it in onResume method and unregister it onPause methos :
BroadcastReceiver broadcastReceiver = new BroadcastReceiver()
{
#Override
public void onReceive(Context context, Intent intent)
{
if (Objects.equals(intent.getAction(), "animation"))
{
int currentPosition = intent.getIntExtra("current_position", 0);
if (currentPosition == 0)
{
startAnimation();
setViewsVisible();
} else
{
setViewsInvisible();
}
}
}
};
#Override
public void onResume()
{
super.onResume();
LocalBroadcastManager.getInstance(mContext).registerReceiver(broadcastReceiver, new IntentFilter("animation"));
}
#Override
public void onPause()
{
super.onPause();
LocalBroadcastManager.getInstance(mContext).unregisterReceiver(broadcastReceiver);
}
summary : i have Fragment Pager Adapter witch shows Three Fragments in it, I want show some Animations on Views in Fragment in Position 0 of Adapter, For this I use BroadcastReceiver. When Fragment is Picked I start the Animation method and shows the Views to User, When Fragment is not Showing to User I try to Invisible Views...
View Pager With only one Page :
This is February 2021: I have able to add only one page with viewPager. The approach is with ViewPager, FragmentPagerAdapter, Tablayout, and a fragment. In my case, I can populate many Pages with many tabs, or only one Page with one Tab. When one tab and one page, on swipe left or right, I can manage to change the chapter of my document (which I want to show next). And when many pages and many tabs, I can change the entire book of documents.
In main Activity Oncreate: (Here is my working code approach, I have changed nothing here from my working code):
if(getIntent()!=null){
if(getIntent().getStringExtra("ONLY_TAFHEEM")!=null)
sectionsPagerAdapter = new SectionsPagerAdapter(this, getSupportFragmentManager(), suraName, suraId, ayatId, true);
else
sectionsPagerAdapter = new SectionsPagerAdapter(this, getSupportFragmentManager(), suraName, suraId, ayatId, false);
}else {
sectionsPagerAdapter = new SectionsPagerAdapter(this, getSupportFragmentManager(), suraName, suraId, ayatId, false);
}
final ViewPager viewPager = findViewById(R.id.view_pager);
viewPager.setAdapter(sectionsPagerAdapter);
tabsLayout = findViewById(R.id.tabs);
tabsLayout.animate();
tabsLayout.setupWithViewPager(viewPager);
In Adapter :
#NonNull
#Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a PlaceholderFragment (defined as a static inner class below).
return PlaceholderFragment.sendData(mContext, postion, suraName, suraId, ayahId, ARABIC_AYAH, BENGALI_AYAH, actualDbNames[position], tafsirDisplayNames[position]);
}
#Nullable
#Override
public CharSequence getPageTitle(int position) {
return tafsirDisplayNames[position];
}
#Override
public int getCount() {
// this is the tricky part // Show pages according to array length. // this may only one // this is the tricky part :
return tafsirDisplayNames.length;
}
And at last the fragments public constructor :
public static PlaceholderFragment sendData(Context mContext, int tabIndex, String suraName, String suraId, String ayahNumber, String arabicAyah, String bengaliAyah, String actualDbName, String displayDbName) {
Log.i("PlaceHolder", "Tafhim sendData: " + bengaliAyah);
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle bundle = new Bundle();
mContext_ = mContext;
BENGALI_AYAH = bengaliAyah;
_DISPLAY_DB_NAME = displayDbName;
bundle.putInt(ARG_SECTION_NUMBER, tabIndex);
bundle.putString(SURA_NAME, suraName);
bundle.putString(SURA_ID, suraId);
bundle.putString(AYAH_NUMBER, ayahNumber);
bundle.putString(ARABIC_AYAH, arabicAyah);
bundle.putString(ACTUAL_DB_NAME, actualDbName);
bundle.putString(DISPLAY_DB_NAME, displayDbName);
fragment.setArguments(bundle);
return fragment;
}
That's all, just passing the array (of Tab Labels) to the adapter, (it may only one element, in case, for one page), with my need, I can populate one page or more page, and according to this it populate one tab or many tabs : in the above code the array is: tafsirDisplayNames. I can also create the array manually in adapter, when the adapter first called, Or, recreate the array with +-elements, on recreate the MainActivity.
Please Try This Code for resolve issue of refreshing view in Viewpager....
/* DO NOT FORGET! The ViewPager requires at least “1” minimum OffscreenPageLimit */
int limit = (mAdapter.getCount() > 1 ? mAdapter.getCount() - 1 : 1);
mViewPager.setOffscreenPageLimit(limit);
for the "instantiateItem" function, just prepare the fragment, but don't load the heavy content.
Use "onPageChangeListener" , so that each time you go to a specific page, you load its heavy content and show it.
I kind of have the same problem. I found some useful code on this site and transform it.
The min int for mViewPager.setOffscreenPageLimit(...); is 1, so even if you change it to 0 you will still have 2 pages loaded.
First thing to do is to create a static int we will call maxPageCount and override FragmentStatePagerAdapter method getCount() to return maxPageCount:
#Override
public int getCount() {
return maxPageCount;
}
Create then a static method accessible from any where in the program that will allow you to change this maxCount:
public static void addPage(){
maxPageCount++; //or maxPageCount = fragmentPosition+2
mFragmentStatePagerAdapter.notifyDataSetChanged(); //notifyDataSetChanged is important here.
}
Now initialize maxPageCount to 1. When ever you want you can add another page.
In my case when I needed the user to treat the current page first before generated the other. He do it and then, without problem can swipe to the next page.
Hope it help someone.
Use This
// create boolean for fetching data
private boolean isViewShown = false;
#Override
public void setUserVisibleHint(boolean isVisibleToUser) {
super.setUserVisibleHint(isVisibleToUser);
if (getView() != null) {
isViewShown = true;
// fetchdata() contains logic to show data when page is selected mostly asynctask to fill the data
fetchData();
} else {
isViewShown = false;
}
}
// step 1: add BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT FragmentPagerAdapter contractor
public class BottomTabViewPager extends FragmentPagerAdapter {
private final List<Fragment> mFragmentList = new ArrayList<>();
private final List<String> mFragmentTitleList = new ArrayList<>();
public BottomTabViewPager(FragmentManager manager) {
super(manager, BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT);
}
#Override
public Fragment getItem(int position) {
return mFragmentList.get(position);
}
#Override
public int getCount() {
return mFragmentList.size();
}
public void addFragment(Fragment fragment, String title) {
mFragmentList.add(fragment);
mFragmentTitleList.add(title);
}
public void addTabs(String title) {
mFragmentTitleList.add(title);
}
#Override
public CharSequence getPageTitle(int position) {
return mFragmentTitleList.get(position);
// return null;
}
}
// step 2: You can try like this :
public class MyFragment extends Fragment {
public MyFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_ui, container, false);
return view;
}
#Override
public void onResume() {
super.onResume();
/**
* Load your stuffs here.
*/
}
}