Using ViewPager with Custom ViewGroups - android

I'm creating an Android app and I have several custom ViewGroups I've created and wanted to add a ViewPager to my MainActivity so that I can swipe the screen to go back and forth between the Views. However it looks like items added to a ViewPager have to be a Fragment. Do I need to create a separate Fragment for each custom ViewGroup or is there someway to directly add them instead?

No, you dont need it.
In your FragmenAdapter set a desired id layout for each Fragment, based on the current Position.
//FragmentStatePagerAdapter
public class DynamicViewsFragmentAdapter extends FragmentStatePagerAdapter {
public DynamicViewsFragmentAdapter(FragmentActivity activity) {
super(activity.getSupportFragmentManager());
}
#Override
public Fragment getItem(int position) {
DynamicViewsFragment fragment = new DynamicViewsFragment();
int idLayout = getIdLayoutBasedOnPosition(position);
fragment.setIdLayout(idLayout);
return fragment;
}
#Override
public int getCount() {
return 3;
}
private int getIdLayoutBasedOnPosition(int position) {
if(position == 0) return R.layout.one;
else if (position == 1) return R.layout.one;
else return R.layout.three;
}
}
//Fragment
public class DynamicViewsFragment extends Fragment {
private int _idLayout;
public void setIdLayout(int idLayout) {
_idLayout = idLayout;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
View rootView = inflater.inflate(_idLayout, container, false);
return rootView;
}
}

Thank you both for your help. I started out using valbertos solution but my app crashed because I tried to access _idLayout before it was set. I ended up finding this solution
http://architects.dzone.com/articles/android-tutorial-using
and modified it to fit my needs and it worked great! Thank you both for your suggestions;

Related

moving from one fragment to another using viewpager

So currently my code can move between objects from the same fragment, but I want to move between different fragments that have different layouts.What code do I need to add to viewpager to make it work? Do I need to make use of a FragentManager? Can anyone guide me on how to go about it? Thanks.
Below if my code:
ScreenSlidePagerActivity.java
public class ScreenSlidePagerActivity extends FragmentActivity {
private static final int NUM_PAGES = 5;
private ViewPager mPager;
private PagerAdapter pagerAdapter;
/**
* The pager adapter, which provides the pages to the view pager widget.
*/
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.slide_screen_viewpager);
//declare viewpager and pageradapter
mPager = findViewById(R.id.ViewPageSlide);
pagerAdapter = new ScreenSlidePagerAdapter(getSupportFragmentManager());
mPager.setAdapter(pagerAdapter);
}
#Override
public void onBackPressed() {
if (mPager.getCurrentItem() == 0){
// If the user is currently looking at the first step, allow the system to handle the
// Back button. This calls finish() on this activity and pops the back stack.
super.onBackPressed();
}
else {
mPager.setCurrentItem(mPager.getCurrentItem() -1 );
}
}
private class ScreenSlidePagerAdapter extends FragmentStatePagerAdapter {
public ScreenSlidePagerAdapter(FragmentManager fm)
{
super(fm);
}
#Override
public Fragment getItem(int position) {
return new ScreenSlidePageFragment();
}
#Override
public int getCount() {
return NUM_PAGES;
}
}
}
ScreenSlidePageFragment.java
public class ScreenSlidePageFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
ViewGroup rootView = (ViewGroup) inflater.inflate(
R.layout.slide_content_page, container, false
);
return rootView;
}
}
You have only one class i.e.,ScreenSlidePageFragment that extends fragments. If you want different layouts for that, its better if you create different classes that inflates different layouts. eg: if you want two layouts, create two classes and both classes should inflate different layouts. The changes need to be done are :
//inside ScreenSlidePagerAdapter
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return new ScreenSlidePageFragment();
case 1:
return new NewClass();
//and so on
}
}
You have to create the new Class similar to ScreenSlidePageFragment. The only change is inflate a different layout.
public class NewClass extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
ViewGroup rootView = (ViewGroup) inflater.inflate(
R.layout.new_layout, container, false
);
return rootView;
}
}
You can create a new_layout similar to slide_content_page and customize it as you want. You can also increase the no of fragment objects and layout as you wish.
But a new way of doing this things has come. Its better if you extend FragmentStateAdapter instead of FragmentStatePagerAdapter. This is more easy and efficient. You have to override createFragment in this case instead of getItem. Ignore of you are okay with it.
Hope this is the question you have asked and this helps. Thankyou.

notifyDataSetChanged Method Takes Away Smooth Scrolling From Tabs

I am currently using Material Design in an Android app that I am making. In this app, I am using the Material Design tab layout to display some information that I am receiving. However when I tap the tabs, the animation is not smooth, and it is very abrupt. Sliding to go to the other tab, however is very smooth.
mTabLayout = (TabLayout) findViewById(R.id.chem_tab_layout);
mGenericAdapter = new GenericPagerAdapter(getSupportFragmentManager());
mPager = (ViewPager) findViewById(R.id.view_pager);
mPager.setAdapter(mGenericAdapter);
//Notice how the Tab Layout links with the Pager Adapter
mTabLayout.setTabsFromPagerAdapter(mGenericAdapter);
//Notice how The Tab Layout and View Pager object are linked
mTabLayout.setupWithViewPager(mPager);
mPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(mTabLayout){
#Override
public void onPageSelected(int position) {
mGenericAdapter.notifyDataSetChanged();
}
});
That is my code for setting the adapter, etc.
This is my custom adapter code for the tabs:
class GenericPagerAdapter extends FragmentStatePagerAdapter {
public GenericPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
ChemGridActivity.MyFragment myFragment = new ChemGridActivity.MyFragment();
return myFragment;
}
#Override
public int getCount() {
return 3; //returns number of tabs that need to be created
}
#Override
public CharSequence getPageTitle(int position) {
if (position == 0) return "Chemistry";
if (position == 1) return "Mathematics";
if (position == 2) return "Physics";
else return null;
}
#Override
public int getItemPosition(Object object) {
return POSITION_NONE;
}
I feel that the choppy transition between tabs is caused by the overriden method onPageSelected method when I add onPageChangeListener. What do I add to this method to make tapping on tabs a smoother animation?
Without knowing much about the internals of your classes, I imagine the problem is not that you have a listener, but what you are doing inside that listener.
In the case of most adapters notifyDataSetChanged() will cause it to re-render the entire view again (including all pages).
Seeing as you haven't specified what the intent here with the notification is, it's hard to tell you how you can do this in an alternative way, but you do need to do something less intensive if you want the animation to remain smooth.
I suspect you just want to change which fragment is shown, in which case just use the FragmentManager where necessary, remembering to reuse fragments which have already been seen once.
EDIT Based on additional info in comments
#Override
public Fragment getItem(int position) {
//POSITION_SOMETHINHG would be one of a set of constants to indicate hwa to display
return ChemGridActivity.MyFragment.newInstance(ChemGridActivity.MyFragment.POSITION_SOMETHINHG);
}
public class ChemGridActivity.MyFragment ... {
private static final String KEY_DISPLAY_TYPE = "KEY_DISPLAY_TYPE";
public static final int POSITION_SOMETHINHG = 11111;
public static MyFragment newInstance(int display) {
MyFragment f = new MyFragment();
Bundle bund = new Bundle();
bund.putInt(KEY_DISPLAY_TYPE, display);
f.setArguments(bund);
return f;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Bundle args = getArguments();
if (args != null) {
mDisplay = args.getInt(KEY_DISPLAY_TYPE, 0);
}
}
#Override
public View onCreateView(final LayoutInflater inflater, final ViewGroup container, final Bundle savedInstanceState) {
final View view = inflater.inflate(R.layout.my_layout, container, false);
//TODO: change something based on mDisplay
return view;
}

Change Fragment with ViewPager

I am using PagerSlidingTab Library for ViewPager. And I want to change Fragment while scrolling of tabs. It is working fine. Check out my code.
I am using AsynTask() on each Fragment.
When the App opens with the MainActivity, First Fragment is attached to the activity, But It shows two AsynTask() dialog message, one from First and another from Second Fragment. And When I scroll to second tab, It shows dialog message of Third Fragment.
So, If I scroll from left to right in tabs, the Fragment right to the current fragment is displayed and if i scroll from right to left, the Fragment left to the current Fragment is displayed.
Please help me to solve the problem.
My Code:
public class PageSlidingTabStripFragment extends Fragment {
public static final String TAG = PageSlidingTabStripFragment.class
.getSimpleName();
public static PageSlidingTabStripFragment newInstance() {
return new PageSlidingTabStripFragment();
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setRetainInstance(true);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.pager, container, false);
}
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
PagerSlidingTabStrip tabs = (PagerSlidingTabStrip) view
.findViewById(R.id.tabs);
ViewPager pager = (ViewPager) view.findViewById(R.id.pager);
MyPagerAdapter adapter = new MyPagerAdapter(getChildFragmentManager());
pager.setAdapter(adapter);
tabs.setViewPager(pager);
}
public class MyPagerAdapter extends FragmentPagerAdapter {
public MyPagerAdapter(android.support.v4.app.FragmentManager fm) {
super(fm);
}
private final String[] TITLES = { "Instant Opportunity", "Events",
"Experts" };
#Override
public CharSequence getPageTitle(int position) {
return TITLES[position];
}
#Override
public int getCount() {
return TITLES.length;
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return new InstantOpportunity();
case 1:
return new Events();
case 2:
return new Experts();
default:
break;
}
return null;
}
}
}
Explanation:
It turns out there is an easier implementation for scrollable tabs which doesn't involve another library. You can easily implement tabs into your app using normal Android code straight from the default SDK.
The Code
Main Class:
public class PageSlidingTabStripFragment extends Fragment {
//Variables
private ViewPager viewPager;
private PagerTitleStrip pagerTitleStrip;
public PageSlidingTabStripFragment() {
// Required empty public constructor
}
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
//Find your pager declared in XML
viewPager = (ViewPager) getView().findViewById(R.id.pager);
//Set the viewPager to a new adapter (see below)
viewPager.setAdapter(new MyAdapter(getFragmentManager()));
//If your doing scrollable tabs as opposed to fix tabs,
//you need to find a pagerTitleStrip that is declared in XML
//just like the pager
pagerTitleStrip = (PagerTitleStrip)
getView().findViewById(R.id.pager_title_strip);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.[your layout name here], container, false);
}
}
Adapter:
//Note: this can go below all of the previous code. Just make sure it's
//below the last curly bracket in your file!
class MyAdapter extends FragmentStatePagerAdapter {
public MyAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int arg0) {
Fragment fragment = null;
if (arg0 == 0) {
fragment = new InstantOpportunity();
}
if (arg0 == 1) {
fragment = new Events();
}
if (arg0 == 2) {
fragment = new Experts();
}
return fragment;
}
#Override
public int getCount() {
return 3;
}
#Override
public CharSequence getPageTitle(int position) {
if (position == 0) {
return "Instant Opportunity";
}
if (position == 1) {
return "Events";
}
if (position == 2) {
return "Experts";
}
return null;
}
}
Conclusion:
I hope this helps you understand another way to make scrollable tabs! I have examples on my Github Page about how to make each type (That being Fixed or Scrollable).
Links:
Fixed Tabs Example - Click Here
Scrollable Tabs Example - Click Here
Hope this helps!
Edit:
When asked what to import, make sure you select the V4 support fragments.
please use this example..its very easy.i already implement that.
reference link
hope its useful to you.its best example of pager-sliding-tabstrip.
Use
framelayout compulsory:
FrameLayout fl = new FrameLayout(getActivity());
fl.addView(urFragementView);
and then set your fragement view in this framelayout.

Setting Data in ViewPagerIndicatorin different layouts

I have 3 different layouts on my ViewPagerIndicator - https://github.com/JakeWharton/Android-ViewPagerIndicator
My project is to load data from the website and set the data accordingly into the 3 different layout of the ViewPager.
How do I go about achieving it?
In my TestFragment, I have
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
Log.i("mContent", mContent);
View view = null;
if (mContent.equalsIgnoreCase("title1")) {
view = inflater.inflate(R.layout.one, container, false);
} else if (mContent.equalsIgnoreCase("title2")) {
view = inflater.inflate(R.layout.two, container, false);
} else if (mContent.equalsIgnoreCase("title3")) {
view = inflater.inflate(R.layout.three, container, false);
//Textview data = (TextView)view.findViewById(id)
}
return view;
}
I know this is for setting layout according to the fling'd titles.
I know how to findViewById to get the id of the widgets and set data. However, the data is set statically in the code itself.
For me, I have to grab data from the internet and put the data in accordingly. How do I achieved that?
Thanks in advance.
I almost know what you want.Here is my answers,and it works well.
You can according to the following steps.
1.Create three different Fragment class ,such as LoadImageFragment1,LoadImageFragment2,LoadImageFragment3, and all of them extends Fragment.
Follow is my example.
public class LoadImageFragment1 extends Fragment {
ListView listView;
LayoutInflater mInflater;
LoadImageAdapter adapter;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
mInflater = inflater;
View view = inflater.inflate(R.layout.loadimage_layout, null);
listView = (ListView) view.findViewById(R.id.listview);
adapter = new LoadImageAdapter();
adapter.initList();
listView.setAdapter(adapter);
return view;
}
private class LoadImageAdapter extends BaseAdapter{
ArrayList<String> list = new ArrayList<String>();
public void initList(){
for(int i = 0 ; i < 30;i ++){
list.add("" + i);
}
}
#Override
public int getCount() {
return list.size();
}
#Override
public Object getItem(int position) {
return position;
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
if(convertView == null){
convertView = mInflater.inflate(R.layout.loadimage_item, null);
}
return convertView;
}
}
2.Then modify your SampleTabsDefault class.
class GoogleMusicAdapter extends FragmentPagerAdapter {
public GoogleMusicAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
// return TestFragment.newInstance(CONTENT[position % CONTENT.length]);
switch(position){
case 0:
return new LoadImageFragment1();
case 1:
return new LoadImageFragment2();
case 2:
return new LoadImageFragment3();
}
}
#Override
public CharSequence getPageTitle(int position) {
return CONTENT[position % CONTENT.length].toUpperCase();
}
#Override
public int getCount() {
return CONTENT.length;
}
}
And I just use the class of SampleTabsDefault as a sample.You can do this in other classes.
Here I just use a ListView as a sample , you can load your images and texts from internt, and you also can do other things in your LoadImageAdapter 's getView() method.
Hope this can help you.
I have 3 different layouts on my ViewPagerIndicator
ViewPagerIndicator is just an indicator
I thought your meaning is your viewadapter have three views to show.
Use FragmentPagerAdapter to handle different view.
you should read the ViewPagerIndicator samples
Before starting, copy the samples from ViewPagerIndicator
https://github.com/JakeWharton/Android-ViewPagerIndicator/tree/master/sample/src/com/viewpagerindicator/sample
The steps to be done are,
Create an custom FragmentPagerAdapter (ex: https://github.com/JakeWharton/Android-ViewPagerIndicator/blob/master/sample/src/com/viewpagerindicator/sample/TestFragmentAdapter.java)
Create custom Fragment for each each layout (in your case 3)
https://github.com/JakeWharton/Android-ViewPagerIndicator/blob/master/sample/src/com/viewpagerindicator/sample/TestFragment.java
Override onActivityCreated in the fragment class
In the onActivityCreated method, u can access the UI components as in onCreate method
So that u can make a web service call, bind it to ur UI components in this segment.
Cheers
Create and implement a Loader (AsyncTaskLoader) to load data from the internet.
Have your TestFragment implement LoaderCallbacks, so that it gets notified when the Loader (AsyncTaskLoader) has finished loading data from the internet.
In your implementation of your TestFragment's onActivityCreated, initialize or restart the loader:
getLoaderManager().initLoader(0, null, this);
In your TestFragment's implementation of onLoadFinished, assign the data to the widgets.
https://developer.android.com/reference/android/content/AsyncTaskLoader.html
https://developer.android.com/reference/android/app/LoaderManager.html
https://developer.android.com/reference/android/app/LoaderManager.LoaderCallbacks.html

Circular ViewPager which uses FragmentPagerAdapter

I would like to implement a ViewPager which uses Fragments and can be swiped in a curcular motion e.g. Page (A<-->B<-->C<-->A).
I have read a couple of posts on how this is done, e.g. returning a fake count of how many elements there are and setting the position at the start in the middle.
how to create circular viewpager?
These all seem to be based of a PagerAdapter. When I try to do a similar thing while extending FragmentPagerAdapter, as soon as I return a fakeCount of pages I get an exception when I Swipe through my Fragments, I only have 2 Fragments.
Exception: java.lang.IllegalStateException: Can't change tag of fragment.
I think this is caused as the FragmentManager thinks I am in position 2 but position 2 points to the fragment at position 0. Does anyone know how I can avoid this? I am thinking I should experiment with extending Fragmentmanager. Any examples or help with this would be greatly appreciated.
I know it is a bit late but this is how it worked for me:
I needed a circular swipe between 3 fragments, so I made those 3 and two more virtual to help me implement the page looping:
public static class FirstViewFragment extends Fragment {
// Empty Constructor
public FirstViewFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_landing_1, container, false);
}
}
public static class SecondViewFragment extends Fragment {
// Empty Constructor
public SecondViewFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_landing_2, container, false);
}
}
public static class ThirdViewFragment extends Fragment {
// Empty Constructor
public ThirdViewFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_landing_3, container, false);
}
}
And two more virtual fragments that enabled me to swipe left from the first and right from the last. The first virtual inflates the same layout as the last actual and the last virtual the same layout as the first actual:
public static class StartVirtualFragment extends Fragment {
public StartVirtualFragment() {}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_landing_3, container, false);
}
}
public static class EndVirtualFragment extends Fragment {
public EndVirtualFragment() {}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_landing_1, container, false);
}
}
My Adapter:
private class ViewPagerAdapter extends FragmentPagerAdapter {
public ViewPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int i) {
switch (i) {
case 0:
return new StartVirtualFragment();
case 1:
if (firstViewFragment == null) {
firstViewFragment = new FirstViewFragment();
}
return firstViewFragment;
case 2:
if (secondViewFragment == null) {
secondViewFragment = new SecondViewFragment();
}
return secondViewFragment;
case 3:
if (thirdViewFragment == null) {
thirdViewFragment = new ThirdViewFragment();
}
return thirdViewFragment;
case 4:
return new EndVirtualFragment();
}
return null;
}
#Override
public int getCount() {
return 5;
}
}
And my page listener I used the onPageScrollStateChanged to set the correct page and implement the loop:
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
}
#Override
public void onPageScrollStateChanged(int state) {
if (state == ViewPager.SCROLL_STATE_DRAGGING) {
int pageCount = viewPager.getChildCount();
int currentItem = viewPager.getCurrentItem();
if (currentItem == 0) {
viewPager.setCurrentItem(pageCount - 2, false);
} else if (currentItem == pageCount - 1) {
viewPager.setCurrentItem(1, false);
}
}
}
});
And in the end:
viewPager.setCurrentItem(1);
Hope I helped
I have a project in the GitHub with some widgets I've created. Here it its:
https://github.com/CyberEagle/AndroidWidgets
In the following package, there are the adapters to be used with the CircularViewPager:
https://github.com/CyberEagle/AndroidWidgets/tree/master/src/main/java/br/com/cybereagle/androidwidgets/adapter
First, you will use CircularViewPager instead of ViewPager in your layout. The CircularViewPager is here: https://github.com/CyberEagle/AndroidWidgets/blob/master/src/main/java/br/com/cybereagle/androidwidgets/view/CircularViewPager.java
This ViewPager expects a WrapperCircularPagerAdapter, instead of a PagerAdapter. This wrapper is used to trick the ViewPager, making it to think there are a lot of items in the ViewPager, but it actually repeat your items to make the circular effect. So, instead of implementing either PagerAdapter, FragmentPagerAdapter or FragmentStatePagerAdapter, you will implement either CircularFragmentPagerAdapter, CircularFragmentStatePagerAdapter or CircularPagerAdapter. Then, you will wrap your adapter with the WrapperCircularPagerAdapter and set the wrapper in the CircularViewPager, instead of your adapter. Also, when it's time to notify dataset changed, you will call the notifyDatasetChanged() in the wrapper.
When implementing one of the circular adapter, you will notice that instead of implementing instantiateItem, you will have to implement instantiateVirtualItem. For the fragment's pager adapter, you will implement getVirtualItem instead of getItem. That is because I've created the concept of virtual items.
To make it clear, imagine a view pager with 4 items, giving that each item represents a music. When you go all the way to left, you will see the 4th item in the left of the first. Actually, it's a whole new item, but it's linked to the virtual item that represents the 4th music.
Another example: imagine there's only one music now. You will see the same music on the left and on the right. There're 3 items at a time, but only one virtual item.
So, as explained, the Wrapper is tricking the ViewPager, making it think that there are a lot of items. To make it more difficult for the user to reach one of the ends of the ViewPager (it'd take a long time anyway), everytime a change happens to the dataset, the ViewPager goes to the same virtual item, but to one of the real items near the middle.
One more important thing is that the CircularViewPager has the method setCurrentVirtualItem. This method calculates which real item is the nearest desired virtual item and then it uses the setCurrentItem to set it. You have also the option to use the getCurrentVirtualItem, that will return the index of the current virtual item. Notice that if you use getCurrentItem, you'll get a large index.
Well, this is it. I'm sorry for the lack of documentation of the project. I'm planning document it soon. I'm also planning to remove the need for the wrapper. Feel free to copy the code (respecting the Apache 2.0 license), to fork or even contribute to it.
**If you want to make 3 views visible at same time and make it circular**
public abstract class CircularPagerAdapter extends PagerAdapter{
private int count;
int[] pagePositionArray;
public static final int EXTRA_ITEM_EACH_SIDE = 2;
private ViewPager.OnPageChangeListener pageChangeListener;
private ViewPager viewPager;
public CircularPagerAdapter(final ViewPager pager, int originalCount ) {
super();
this.viewPager = pager;
count = originalCount + 2*EXTRA_ITEM_EACH_SIDE;
pager.setOffscreenPageLimit(count-2);
pagePositionArray = new int[count];
for (int i = 0; i < originalCount; i++) {
pagePositionArray[i + EXTRA_ITEM_EACH_SIDE] = i;
}
pagePositionArray[0] = originalCount - 2;
pagePositionArray[1] = originalCount -1;
pagePositionArray[count - 2] = 0;
pagePositionArray[count - 1] = 1;
pager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
public void onPageSelected(final int position) {
if(pageChangeListener != null)
{
pageChangeListener.onPageSelected(pagePositionArray[position]);
}
pager.post(new Runnable() {
#Override
public void run() {
if (position == 1){
pager.setCurrentItem(count-3,false);
} else if (position == count-2){
pager.setCurrentItem(2,false);
}
}
});
}
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
if(pageChangeListener != null)
{
pageChangeListener.onPageScrolled(pagePositionArray[position],positionOffset,positionOffsetPixels);
}
}
public void onPageScrollStateChanged(int state) {
if(pageChangeListener != null)
{
pageChangeListener.onPageScrollStateChanged(state);
}
}
});
}
#Override
public int getCount() {
return count;
}
#Override
public boolean isViewFromObject(View view, Object object) {
return false;
}
public abstract Object customInstantiateItem(ViewGroup container, int position);
public void setPageChangeListener(ViewPager.OnPageChangeListener pageChangeListener)
{
this.pageChangeListener = pageChangeListener;
}
#Override
public Object instantiateItem(ViewGroup container, int position) {
int pageId = pagePositionArray[position];
return customInstantiateItem(container,pageId);
}
#Override
public void destroyItem(View container, int position, Object object) {
((ViewPager) container).removeView((View) object);
}
public void setFirstItem()
{
viewPager.setCurrentItem(EXTRA_ITEM_EACH_SIDE - 1);
}
}

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