Develop Reference

Refresh current fragment in tabbed layout viewpager

I am trying to refresh the current fragment in the tabbed layout of my viewpager. I have one fragment (UserProgressFragment) that creates the ViewPager and sets the adapter (UserProgressAdapter) along with creating tabbed layout.
In my UserProgressAdapter, in the getItem() method I am returning two other fragments, (UserWeightTrackerFragment and UserCalorieCounterFragment) based on which tab i am on.
My issue is how do i refresh the fragment and update its content/view from the UserCalorieCounterFragment on a button click, because access to the viewpager and adapter are set in the UserProgressFragment? I have considered notifyDataChange for the adapter but i dont know how to call this from this class as it is set up on the UserProgressFragment class. The purpose of wanting to refresh this page is to update a specific view which is a chart, if context is needed.
I have attached the code below:
UserProgressFragment
public class UserProgressFragment extends Fragment{
public static UserProgressFragment newInstance() {
return new UserProgressFragment();
}
public UserProgressFragment() {
// 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_user_progress, container, false);
ViewPager viewPager = view.findViewById(R.id.progress_viewpager);
viewPager.setAdapter(new UserProgressTabsAdapter(getChildFragmentManager()));
TabLayout tabLayout = view.findViewById(R.id.progress_sliding_tabs);
tabLayout.setupWithViewPager(viewPager, true);
return view;
}
}
UserProgressTabsAdapter
public class UserProgressTabsAdapter extends FragmentStatePagerAdapter {
private static final int PAGE_COUNT = 2;
private String tabTitles[] = new String[]{"Weight Tracker", "Calorie Counter"};
public UserProgressTabsAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return UserWeightTrackerFragment.newInstance(position);
case 1:
return UserCalorieCounterFragment.newInstance(position + 1);
}
return null;
}
#Override
public int getCount() {
return PAGE_COUNT;
}
#Override
public CharSequence getPageTitle(int position) {
// Generate title based on item position
return tabTitles[position];
}
UserCalorieCounterFragment (need to refresh this one)
public class UserCalorieCounterFragment extends Fragment implements View.OnClickListener, AdapterView.OnItemSelectedListener {
public static final String ARG_PAGE = "ARG_PAGE";
public static UserCalorieCounterFragment newInstance(int page) {
Bundle args = new Bundle();
args.putInt(ARG_PAGE, page);
UserCalorieCounterFragment fragment = new UserCalorieCounterFragment();
fragment.setArguments(args);
return fragment;
}
public UserCalorieCounterFragment() {
// Required empty public constructor
}
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
int mPage = getArguments().getInt(ARG_PAGE);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_user_calorie_counter, container, false);
Button mAddCalories = view.findViewById(R.id.btn_add_calorie);
mAddCalories.setOnClickListener(this);
return view;
}
#Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.btn_add_calorie:
//REFRESH/UPDATE HERE
break;
}
}

You can create a public method in your fragment which contains the view pager which will contain the notifyDataSetChanged() function. And in the view pager fragment/item, you can call getParentFragment() and type cast it to your parent/first fragment and access that public method to notifyDataSetChanged().

Android Fragment in the wrong place

I have a weird problem.
In the main activity I use this code:
public class MyPagerAdapter extends FragmentPagerAdapter {
private final String[] TITLES = {"Laatste Nieuws", "Uitrukken", "Voertuigen", "Contact", "Top Grossing"};
public MyPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public CharSequence getPageTitle(int position) {
return TITLES[position];
}
#Override
public int getCount() {
return TITLES.length;
}
#Override
public Fragment getItem(int position) {
Fragment fragment = null;
switch (position) {
case 0:
fragment = NaviContentFragment.newInstance(position);
break;
case 1:
fragment = NaviContentFragmentTwo.newInstance(position);
break;
case 2:
fragment = NaviContentFragment.newInstance(position);
break;
case 3:
fragment = NaviContentFragment.newInstance(position);
break;
case 4:
fragment = NaviContentFragment.newInstance(position);
break;
default:
break;
}
return fragment;
}
}
So when I open a tab it will open a new fragment. And when I open tab 1 labeled "Uitrukken" it should open a other fragment than the other ones. This fragment:
public class NaviContentFragmentTwo extends Fragment {
private static final String ARG_POSITION = "position";
public static NaviContentFragment newInstance(int position) {
NaviContentFragment fragment = new NaviContentFragment();
Bundle b = new Bundle();
b.putInt(ARG_POSITION, position);
fragment.setArguments(b);
return fragment;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = rootView = inflater.inflate(R.layout.navi_content_two, container, false);
TextView textViewNaviConTwo = (TextView) rootView.findViewById(R.id.textViewNaviConTwo);
textViewNaviConTwo.setText("HALLLOOOTJES :)");
return rootView;
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
}
}
With the Text "HALLLOOOTJES :)". And only in that fragment. But the other way around happens. This text is show on all the tabs except for tab number 1.
I'm certainly missing something.
Screenshots:
It should say "HALLLOOOTJES :)"

In your NaviContentFragmentTwo class, you are returning a NaviContentFragment from your newInstance method.
My guess is you should be returning a NaviContentFragmentTwo instance.
So it should be something like..
public class NaviContentFragmentTwo extends Fragment {
private static final String ARG_POSITION = "position";
public static NaviContentFragmentTwo newInstance(int position) {
NaviContentFragmentTwo fragment = new NaviContentFragmentTwo ();
Bundle b = new Bundle();
b.putInt(ARG_POSITION, position);
fragment.setArguments(b);
return fragment;
}

This code could be the possible cause:
public static NaviContentFragment newInstance(int position) {
NaviContentFragment fragment = new NaviContentFragment();
Bundle b = new Bundle();
b.putInt(ARG_POSITION, position);
fragment.setArguments(b);
return fragment;
}
Try replacing NaviContentFragment to NaviContentFragmentTwo.

How to capture the active section or tab of the swipeable tabs in android?

I'm using swipeable tabs as part of an activity with a total of 3 sections. I'm providing the right and left arrows to navigate to the other sections of the swipe-view.
I want my left arrow to disappear when I'm at the leftmost section and my right-arrow to disappear when I'm at the rightmost section.
Here's what I'm trying rightnow, but not getting the desired result:
public class MainActivity extends AppCompatActivity {
private SectionsPagerAdapter mSectionsPagerAdapter;
static Button rightButton;
static Button leftButton;
private ViewPager mViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
rightButton = (Button)findViewById(R.id.buttonRight);
leftButton = (Button)findViewById(R.id.buttonLeft);
// Create the adapter that will return a fragment for each of the three
// primary sections of the activity.
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.container);
mViewPager.setAdapter(mSectionsPagerAdapter);
}
/**
* A {#link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#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.newInstance(position + 1);
}
#Override
public int getCount() {
// Show 3 total pages.
return 3;
}
#Override
public CharSequence getPageTitle(int position) {
switch (position) {
case 0:
return "SECTION 1";
case 1:
return "SECTION 2";
case 2:
return "SECTION 3";
}
return null;
}
}
public static class PlaceholderFragment extends Fragment {
private static final String ARG_SECTION_NUMBER = "section_number";
// Returns a new instance of this fragment for the given section number.
public static PlaceholderFragment newInstance(int sectionNumber) {
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle args = new Bundle();
args.putInt(ARG_SECTION_NUMBER, sectionNumber);
fragment.setArguments(args);
return fragment;
}
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
TextView textView = (TextView) rootView.findViewById(R.id.section_label);
int sectionNumber = getArguments().getInt(ARG_SECTION_NUMBER);
String text = instructions(sectionNumber);
textView.setText(text);
return rootView;
}
private String instructions(int sectionNumber) {
if (sectionNumber == 1) {
leftButton.setVisibility(View.INVISIBLE);
rightButton.setVisibility(View.VISIBLE);
Log.i("Welcome"," to section 1");
return "All questions are mandatory. Each question carries 1 mark. There is no negative marking";
}
else if(sectionNumber == 2) {
leftButton.setVisibility(View.VISIBLE);
rightButton.setVisibility(View.VISIBLE);
Log.i("Welcome", " to section 2");
return "Color the bubble besides the option you think is best for the answer.";
}
else {
leftButton.setVisibility(View.VISIBLE);
rightButton.setVisibility(View.INVISIBLE);
Log.i("Welcome", " to section 3");
return "Click on the skip button above to start the test. Timer will start as soon as you'll click that button!";
}
}
}
}
As you can see in the method instructions, I tried using logs to see what's happening only to find that I never get the "Welcome to section 2" part even after swiping through the tabs multiple times. Although, the texts related to a given section are returned correctly. What am I missing here?

The problem is that you returned a new fragment in getItem
Do it like this:
public class SectionsPagerAdapter extends FragmentPagerAdapter {
private final List<Fragment> mFragments = new ArrayList<Fragment>();
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
mFragments.add(PlaceholderFragment.newInstance(1));
mFragments.add(PlaceholderFragment.newInstance(2));
mFragments.add(PlaceholderFragment.newInstance(3));
}
#Override
public Fragment getItem(int position) {
return mFragments.get(position);
}
}
Also change the Buttons to the fragment_main layout "not" in activity_main and use it like this.
public static class PlaceholderFragment extends Fragment {
private static final String ARG_SECTION_NUMBER = "section_number";
private Button rightButton;
private Button leftButton;
// Returns a new instance of this fragment for the given section number.
public static PlaceholderFragment newInstance(int sectionNumber) {
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle args = new Bundle();
args.putInt(ARG_SECTION_NUMBER, sectionNumber);
fragment.setArguments(args);
return fragment;
}
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
TextView textView = (TextView) rootView.findViewById(R.id.section_label);
rightButton = (Button)rootView.findViewById(R.id.buttonRight);
leftButton = (Button)rootView.findViewById(R.id.buttonLeft);
int sectionNumber = getArguments().getInt(ARG_SECTION_NUMBER);
String text = instructions(sectionNumber);
textView.setText(text);
return rootView;
}
EDIT if you want to know the cuurent page you have to implement this.
mViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
Log.i("Welcome", "page "+ position+1);
}
#Override
public void onPageScrollStateChanged(int state) {
}
});
Also add the following line so that the system will create your fragment only once:
mViewPager.setOffscreenPageLimit(3);
The issue you had is that you're getting the position that the system created now not the current page.

When to update information for ViewPager?

If I ave an activity with a viewPAger on it and two sets of data that I want to display, is it best to have one fragment and load information into textViews based on position passed from activity or better to create more than one fragment and load the one needed?
Any help is greatly appreciated.
public class testFragment extends Fragment {
private static final String ARG_PAGE = "pageNumber";
private static final int DEFAULT_INT = 0;
TextView header, sd1;
int h1, page = 0;
public testFragment (){
}
public testFragment newInstance(int pageNumber) {
testFragment fragment = new testFragment ();
Bundle args = new Bundle();
args.putInt(ARG_PAGE, pageNumber);
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
page = getArguments().getInt(ARG_PAGE);
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
ViewGroup rootView = (ViewGroup) inflater.inflate(R.layout.fragment_high_scores_page, container, false);
return rootView;
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
header = (TextView) getActivity().findViewById(R.id.modes_header);
sd1 = (TextView) getActivity().findViewById(R.id.stat_det_1);
switch (page) {
case 1:
header.setText(R.string.easy_mode);
h1 = DEFAULT_INT;
sh1 = DEFAULT_INT;
sd1.setText(String.valueOf(h1));
break;
case 2:
header.setText(R.string.medium_mode);
h1 = DEFAULT_INT + 1;
sh1 = DEFAULT_INT + 1;
sd1.setText(String.valueOf(h1));
break;
default:
header.setText(R.string.action_restart);
h1 = DEFAULT_INT;
sh1 = DEFAULT_INT;
sd1.setText(String.valueOf(h1));
break;
}
}
public void setTextViewInfo(){
sd1.setText(String.valueOf(h1));
}
}
Or would it be better to send the information from my activity and load one or multiple fragments instead?
public class testActivity extends FragmentActivity {
private static final int NUM_PAGES = 8;
private ViewPager mPager;
private PagerAdapter mPagerAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.testActivity);
// Instantiate a ViewPager and a PagerAdapter.
mPager = (ViewPager) findViewById(R.id.high_scores_pager);
mPagerAdapter = new testActivity (getSupportFragmentManager());
mPager.setAdapter(mPagerAdapter);
}
#Override
public void onBackPressed() {
if (mPager.getCurrentItem() == 0) {
super.onBackPressed();
} else {
mPager.setCurrentItem(mPager.getCurrentItem() - 1);
}
}
private class testActivityAdapter extends FragmentStatePagerAdapter {
public testActivityAdapter (FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
testFragment tf1 = new testFragment ();
notifyDataSetChanged();
return easy.newInstance(position);
case 1:
testFragment2 tf2 = new testFragment ();
notifyDataSetChanged();
return medium.newInstance(position);
default:
testFragment d = new testFragment ();
return d.newInstance();
}
}
#Override
public int getItemPosition(Object object) {
return super.getItemPosition(object);
}
#Override
public int getCount() {
return NUM_PAGES;
}
}
}
edit:
In my adapter, I just tried
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return HighScoresEasyFragment.newInstance(position);
case 1:
return HighScoresMediumFragment.newInstance(position);
case 2:
return HighScoresExpertFragment.newInstance(position);
case 3:
return HighScoresBrainFartFragment.newInstance(position);
case 4:
return HighScoresClassicFragment.newInstance(position);
case 5:
return HighScoresPuzzleFragment.newInstance(position);
case 6:
return HighScoresPerfectFragment.newInstance(position);
case 7:
return HighScoresPowerFragment.newInstance(position);
default:
return HighScoresEasyFragment.newInstance(position);
}
ugh, but it didn't load anything... my constructor is now...:
public static HighScoresEasyFragment newInstance(int pageNumber) {
HighScoresEasyFragment fragment = new HighScoresEasyFragment();
Bundle args = new Bundle();
args.putInt(ARG_PAGE, pageNumber);
fragment.setArguments(args);
return fragment;
}
It loaded the first page's header but no data and it didn't load anything for second to 8th fragments...

You should call notifyDataChanged() from your activity using your adapter reference. Basically notifyDataChanged just tells all your fragments in your adapter that data has changed and they should refresh themselves. Remove notifyDataChanged from your getItem() method and put it when you change data in your activity.

How to Use ViewPager to switch to other layout?

public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int i) {
Fragment fragment = new DummySectionFragment();
Bundle args = new Bundle();
args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, i + 1);
fragment.setArguments(args);
return fragment;
}
#Override
public int getCount() {
return 3;
}
#Override
public CharSequence getPageTitle(int position) {
switch (position) {
case 0: return getString(R.string.title_section1).toUpperCase();
case 1: return getString(R.string.title_section2).toUpperCase();
case 2: return getString(R.string.title_section3).toUpperCase();
}
return null;
}
}
/**
* A dummy fragment representing a section of the app, but that simply displays dummy text.
*/
public static class DummySectionFragment extends Fragment {
public DummySectionFragment() {
}
public static final String ARG_SECTION_NUMBER = "section_number";
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
TextView textView = new TextView(getActivity());
textView.setGravity(Gravity.CENTER);
Bundle args = getArguments();
textView.setText(Integer.toString(args.getInt(ARG_SECTION_NUMBER)));
return inflater.inflate(R.layout.fragment_content1, container, false);
}
}
}
The code above is the template from the SDK for ViewPager, it only put text 1 to 3 when I swipe from one page to one page. The question is how can I replace that text and put my own layout xml when I swipe it, and is it possible to use WebView with this feature. For example: when the activity loads it goes to google.com then when i swipe to other page it change the url of the WebView each time I swipe? Hope someone can help me...

You have to create classes that extend from android.support.v4.app.Fragment just like the class DummySectionFragment. Then, into the method getItem(int i) you should instantiate each class you want for each index and the method getCount() must return the number of Fragments you are instantiating.

viewpager.setCurrentItem(index) where index is the desired fragment index.