Develop Reference

How to save dynamically added pages in viewpager Android

With the help of Vivek Pratap Singh and astuetz codes from following questions(Remove Fragment Page from ViewPager in Android and Android saving dynamically added viewpager's fragment while coming back from another activity and reopening app),
In my previous question in stack overflow I used inbuild method onDestroy, as it looks like it will save all the dynamically added fragments in viewpager.
But it's not happening, I am able to see only one intial static page(i.e. fragment) when I restart my app or navigate to another activity and come back to my activity containing the viewpager with fragments.Could any one please help me on this question.
Here is my source code for your reference:
public class MainActivity extends FragmentActivity implements TextProvider {
private Button mAdd;
private Button mRemove;
private ViewPager mPager;
int position;
private MyPagerAdapter mAdapter;
private ArrayList<String> mEntries = new ArrayList<String>();
#Override
public void onSaveInstanceState(Bundle bundle) {
super.onSaveInstanceState(bundle);
bundle.putInt("currenItem", mPager.getCurrentItem());
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mPager = (ViewPager) findViewById(R.id.pager);
if (savedInstanceState != null) {
mPager.setCurrentItem(savedInstanceState.getInt("currentItem", 0));
}
mEntries.add("page 1");
mAdd = (Button) findViewById(R.id.add);
mRemove = (Button) findViewById(R.id.remove);
mAdd.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View view) {
addNewItem();
}
});
mRemove.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View view) {
removeCurrentItem();
}
});
mAdapter = new MyPagerAdapter(this.getSupportFragmentManager(), this);
mPager.setAdapter(mAdapter);
mPager.setOffscreenPageLimit(3);
}
private void addNewItem() {
// int position = mPager.getCurrentItem();
mEntries.add("page ");
mAdapter.notifyDataSetChanged();
}
private void removeCurrentItem() {
int position = mPager.getCurrentItem();
if(position != 0){
mEntries.remove(position);
}else{
Toast.makeText(getApplicationContext(), "Sorry", Toast.LENGTH_LONG).show();
}
mAdapter.notifyDataSetChanged();
}
#Override
public String getTextForPosition(int position) {
return mEntries.get(position);
}
#Override
public int getCount() {
return mEntries.size();
}
private class MyPagerAdapter extends FragmentPagerAdapter {
private TextProvider mProvider;
private long baseId = 0;
public MyPagerAdapter(FragmentManager fm, TextProvider provider) {
super(fm);
this.mProvider = provider;
}
#Override
public Fragment getItem(int position) {
switch(position) {
case 0:
return FragmentOne.newInstance(mProvider.getTextForPosition(position));
case 1:
return FragmentTwo.newInstance(mProvider.getTextForPosition(position));
case 2:
return FragmentThree.newInstance(mProvider.getTextForPosition(position));
default: return FragmentOne.newInstance(mProvider.getTextForPosition(position));
}
}
#Override
public int getCount() {
return mProvider.getCount();
}
//this is called when notifyDataSetChanged() is called
#Override
public int getItemPosition(Object object) {
// refresh all fragments when data set changed
return PagerAdapter.POSITION_NONE;
}
#Override
public long getItemId(int position) {
// give an ID different from position when position has been changed
return baseId + position;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
}
/**
* Notify that the position of a fragment has been changed.
* Create a new ID for each position to force recreation of the fragment
* #param n number of items which have been changed
*/
public void notifyChangeInPosition(int n) {
// shift the ID returned by getItemId outside the range of all previous fragments
baseId += getCount() + n;
}
}
}

How to get the selected page index of ViewPager in fragment

I'm making use of ViewPagerIndicator, and I have my adapter defined like this:
public class MyPagerAdapter extends FragmentPagerAdapter implements
IconPagerAdapter {
private final static String TAB_ITEMS[] = { "Tab 1", "Tab 2", "Tab 3", "Tab 4"};
private int count = TAB_ITEMS.length;
public MyPagerAdapter (FragmentManager fm) {
super(fm);
}
#Override
public int getIconResId(int index) {
// TODO Auto-generated method stub
return 0;
}
#Override
public Fragment getItem(int position) {
Fragment fragment = new BaseFragment();
return fragment;
}
#Override
public int getCount() {
return count;
}
And this is my activity that will contain my fragments:
public class MyActivity extends FragmentActivity implements
OnPageChangeListener {
private int tabPosition;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ViewPager pager = (ViewPager) findViewById(R.id.pager);
MyPagerAdapter adapter = new MyPagerAdapter (
getSupportFragmentManager());
pager.setAdapter(adapter);
UnderlinePageIndicator indicator = (UnderlinePageIndicator) findViewById(R.id.indicator);
indicator.setFades(false);
indicator.setViewPager(pager);
indicator.setOnPageChangeListener(this);
}
#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 position) {
// TODO Auto-generated method stub
setTabPosition(position);
Toast.makeText(MyActivity.this,
"Changed to page: " + position, Toast.LENGTH_SHORT).show();
}
public void setTabPosition(int position) {
this.tabPosition = position;
}
public int getTabPosition() {
return this.tabPosition;
}
}
Finally the definition of BaseFragment:
public class BaseFragment extends Fragment implements OnItemClickListener {
private final static String TAG = "BaseFragment";
private int tabPosition;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_base, container,
false);
return view;
}
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onActivityCreated(savedInstanceState);
tabPosition = ((MyActivity) getActivity()).getTabPosition();
Toast.makeText(getActivity(), "page " + tabPosition, Toast.LENGTH_SHORT)
.show();
}
Now , this is my problem:
The toast in onPageSelected of the activity always shows the correct page when a new page is selected or swiped to.
However, the toast in my fragment only shows the correct page when you swipe to either page 1 or page 2. The only time it toasts page 0 is anytime the app is launched. After that, when the user swipes to page 0 or page 4, no toast is shown at all, not even an empty toast.
I wrote the getTabPosition() and setTabPosition() methods with the intention of getting the current selected tab position in the fragment, but it obviously doesn't work correctly hence I dont get toasts on pages 0 and 4.
My question is: how do I get the selected page position in my BaseFragment, since I need that position to load the appropriate data?
Hope I was clear enough?

Each Fragment will display a different set of data, then maybe it is a good idea to have one fragment for each. Here is what I did to display different Fragments for different data in the FragmentPagerAdapter:
#Override
public Fragment getItem(int index) {
Fragment fragment = null;
// Define the page for each index
switch(index){
case 0:
fragment = new Fragment1();
break;
case 1:
fragment = new Fragment2();
break;
case 2:
fragment = new Fragment3();
break;
}
This may not be the best approach but in your activity that holds reference to ViewPager try this:
public class TabbedViewActivity extends FragmentActivity {
ViewPager viewPager;
public static int tabIndex = 0;
#Override
protected void onCreate(Bundle bundle) {
......
viewPager = (ViewPager)findViewById(R.id.pager);
TabbedViewActivity.tabIndex = 0; // in the start index is always 0 unless coded otherwise
viewPager.setOnPageChangeListener(
new ViewPager.SimpleOnPageChangeListener() {
#Override
public void onPageSelected(int position) {
TabbedViewActivity.tabIndex = position;
}
});
}
Then you can always access this variable statically like this in your Fragment TabbedViewActivity.tabIndex

pager.getCurrentItem();
it return current fragment index

Android endless FragmentPagerAdapter using new adapter on swipe

I am trying to create an endless FragmentPagerAdapter , on swipe to replace the adapter with a new one, and depending on which side you swipe, a global variable to increase or decrease, so you can know on what position you are. So I have tried this
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setOffscreenPageLimit(0);
mViewPager.setAdapter(mSectionsPagerAdapter);
mViewPager.setCurrentItem(1);
mViewPager.setOnPageChangeListener(new OnPageChangeListener() {
#Override
public void onPageSelected(int arg0) {
}
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
if (mViewPager.getCurrentItem() == 0) {
// left
mViewPager.setAdapter(null);
mViewPager.setAdapter(new SectionsPagerAdapter(getSupportFragmentManager()));
mViewPager.setCurrentItem(1);
MyVar.INST.position--;
} else if (mViewPager.getCurrentItem() == 2) {
// right
mViewPager.setAdapter(null);
mViewPager.setAdapter(new SectionsPagerAdapter(getSupportFragmentManager()));
mViewPager.setCurrentItem(1);
MyVar.INST.position++;
}
}
#Override
public void onPageScrollStateChanged(int arg0) {
}
});
}
the problem is, even though I have set the offscreenPageLimit to 0, Android still caches the 3 fragment in the memory by default, so when I scroll to the right, the method inside OnPageChangeListener is not being called, therefore the global variable is not being incremented properly....
Any idea how can I fix that?
EDIT: Here is the adapter
private class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
return Fragment1.newInstance(MyVar.INST.position + position);
}
#Override
public int getCount() {
return 3;
}
}

So I managed to do it like this, works good
private void setAdapter() {
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
mViewPager.setAdapter(mSectionsPagerAdapter);
mViewPager.setCurrentItem(1);
mViewPager.setOnPageChangeListener(new OnPageChangeListener() {
#Override
public void onPageSelected(int arg0) {
if (mViewPager.getCurrentItem() == 0) {
// left
mViewPager.removeAllViews();
//globalVariable--;
setAdapter();
} else if (mViewPager.getCurrentItem() == 2) {
// right
mViewPager.removeAllViews();
//globalVariable++;
setAdapter();
}
}
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
#Override
public void onPageScrollStateChanged(int arg0) {
}
});
}
And the adapter stays the same
private class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
return Fragment1.newInstance(MyVar.INST.position + position);
}
#Override
public int getCount() {
return 3;
}
The main thing that makes it work is the mViewPager.removeAllViews(); which removes the previous fragments, so it doesnt mess up.
Use the globalVariable defined in some other class, singleton for example, to know on which position you are from the start

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
}
}

how to create circular viewpager? [duplicate]

This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
ViewPager as a circular queue / wrapping
I have three fragment classes in my code.
FirstActivity,SecondActivity,ThirdActivity i want to swipe these three activities.. these three are extend from Fragment class
public class ViewPagerFragmentActivity extends FragmentActivity {
private PagerAdapter mPagerAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
requestWindowFeature(Window.FEATURE_NO_TITLE);
super.onCreate(savedInstanceState);
super.setContentView(R.layout.viewpager_layout);
initialisePaging();
}
/**
* Initialize the fragments to be paged
*/
List<Fragment> fragments = new Vector<Fragment>();
ViewPager pager;
private void initialisePaging() {
fragments.add(Fragment.instantiate(this, FirstActivity.class.getName()));
fragments.add(Fragment.instantiate(this, SecondActivity.class.getName()));
fragments.add(Fragment.instantiate(this, ThirdActivity.class.getName()));
this.mPagerAdapter = new MyPagerAdapter(super.getSupportFragmentManager(), fragments);
pager = (ViewPager) super.findViewById(R.id.viewpager);
pager.setAdapter(this.mPagerAdapter);
}
}
and here is my FragmentPageAdapter class
public class MyPagerAdapter extends FragmentPagerAdapter {
private final List<Fragment> fragments;
public MyPagerAdapter(FragmentManager fm, List<Fragment> fragments) {
super(fm);
this.fragments = fragments;
}
#Override
public Fragment getItem(int position) {
System.out.println("position"+position);
return this.fragments.get(position);
}
#Override
public int getCount() {
return this.fragments.size();
}
}
my code is working in this way A<->B<->c
but my requirement is to run like this wayC<->A<->B<->C<-A->
that is in circular fragments are swipable...

Circular ViewPager is possible.
With the help of ViewPager as a circular queue / wrapping this link have coded like this. Hope it helps what you needed.
The CircluarPagerAdapter class:
>
public class CircularPagerAdapter extends PagerAdapter{
private int[] pageIDsArray;
private int count;
public CircularPagerAdapter(final ViewPager pager, int... pageIDs) {
super();
int actualNoOfIDs = pageIDs.length;
count = actualNoOfIDs + 2;
pageIDsArray = new int[count];
for (int i = 0; i < actualNoOfIDs; i++) {
pageIDsArray[i + 1] = pageIDs[i];
}
pageIDsArray[0] = pageIDs[actualNoOfIDs - 1];
pageIDsArray[count - 1] = pageIDs[0];
pager.setOnPageChangeListener(new OnPageChangeListener() {
public void onPageSelected(int position) {
int pageCount = getCount();
if (position == 0){
pager.setCurrentItem(pageCount-2,false);
} else if (position == pageCount-1){
pager.setCurrentItem(1,false);
}
}
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
// TODO Auto-generated method stub
}
public void onPageScrollStateChanged(int state) {
// TODO Auto-generated method stub
}
});
}
public int getCount() {
return count;
}
public Object instantiateItem(View container, int position) {
LayoutInflater inflater = (LayoutInflater) container.getContext()
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
int pageId = pageIDsArray[position];
View view = inflater.inflate(pageId, null);
((ViewPager) container).addView(view, 0);
return view;
}
#Override
public void destroyItem(View container, int position, Object object) {
((ViewPager) container).removeView((View) object);
}
#Override
public void finishUpdate(View container) {
// TODO Auto-generated method stub
}
#Override
public boolean isViewFromObject(View view, Object object) {
return view == ((View) object);
}
#Override
public void restoreState(Parcelable state, ClassLoader loader) {
// TODO Auto-generated method stub
}
#Override
public Parcelable saveState() {
// TODO Auto-generated method stub
return null;
}
#Override
public void startUpdate(View container) {
// TODO Auto-generated method stub
}
}
and this is your main class:
>
public class MainActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ViewPager myPager = (ViewPager) findViewById(R.id.conpageslider);
PagerAdapter adapter = new CircularPagerAdapter(myPager, new int[]{R.layout.first_activity, R.layout.second_activity, R.layout.third_activity});
myPager.setAdapter(adapter);
myPager.setCurrentItem(3);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
}

You can try something like this :
1) Make getCount() return a huge value ( a number of swipe way higher than what your user might use )
2) Make getItem return something like this.fragments.get(position % fragments.size())
3) Make your pager start somewhere in the middle of the range defined by getCount() ( To allow swiping from A to C at the beginning ), make sure to choose a value which will give you the first fragment % 3
I'm aware this solution seems a bit dirty but I cant find a better one at the moment