Basically all i have is tablayout with each tab containing a webview. From the settings menu I enable the user to add or remove tabs. when this is done I need to call pageradapter.notifydatasetchanged(); however doing this all the webview starts to refresh . My question is, Is there a way to avoid this ? I just want the tab to be added or deleted without affecting other tabs.
case "Yahoo":
if (!fragmentList.contains(fragYahoo)) {
if (tabYahoo == null) {
tabYahoo = tabLayout.newTab().setText("Yahoo").setTag("Yahoo");
}
tabLayout.addTab(tabYahoo);
fragYahoo = NewsFragment.newInstance("http://www.Yahoo.com/");
fragmentList.add(fragYahoo);
navigationView.getMenu().findItem(R.id.Yahoo).setVisible(true);
}
break;
case "stackoverflow":
if (!fragmentList.contains(fragstackoverflow)) {
if (tabstackoverflow == null) {
tabstackoverflow = tabLayout.newTab().setText("stackoverflow").setTag("stackoverflow");
}
tabLayout.addTab(tabstackoverflow);
fragstackoverflow = NewsFragment.newInstance("http://www.stackoverflow.com/");
fragmentList.add(fragstackoverflow);
navigationView.getMenu().findItem(R.id.stackoverflow).setVisible(true);
}
pagerAdapter.notifyDataSetChanged();
pageradapter initialization
public List<Fragment> fragmentList = new ArrayList<>();
mViewPager = (ViewPager) findViewById(R.id.pager);
pagerAdapter = new TabPagerAdapter(getSupportFragmentManager(), fragmentList);
mViewPager.setAdapter(pagerAdapter);
mViewPager.setOffscreenPageLimit(pagerAdapter.getCount()-1);
I did not test, but you can use TabLayout#setupWithViewPager(viewPager, false);.
The second parameter is autoRefresh:
* #param autoRefresh whether this layout should refresh its contents if the given ViewPager's
* content changes
Related
I want to access Views that are in Fragment's children that are put in ViewPager. The idea is to toggle (disable/enable) spinners when button is pressed. Spinners are placed in separate fragments that are displayed in ViewPager controlled by TabLayout:
// Snippet of code from Fragment A
final TabLayout tabLayout = (TabLayout) view.findViewById(R.id.tabLayout);
final ViewPager viewPager = (ViewPager) view.findViewById(R.id.viewPager);
Fragment childFragment = new Fragment();
FragmentTransaction transaction = getChildFragmentManager().beginTransaction();
transaction.replace(R.id.viewPager, childFragment).commit();
ViewPagerAdapter adapter = new ViewPagerAdapter(childFragment.getFragmentManager());
adapter.AddFragment(new fragment_unositelj(), "FragmentB");
adapter.AddFragment(new fragment_voditelj(), "FragmentC");
adapter.AddFragment(new fragment_pratitelj(), "FragmentD");
viewPager.setAdapter(adapter);
tabLayout.setupWithViewPager(viewPager);
FragmentB = viewPager.findViewById(R.id.FragmentB);
FragmentC = viewPager.findViewById(R.id.FragmentC);
FragmentD = viewPager.findViewById(R.id.FragmentD);
I don't know how to achieve to set Spinner disabled / enabled in all fragment children's spinner. I tried to set public variable in MainActivity and to control Spinners attribute based on that, but I am not sure in which lifecycle part to place it because fragment B is inflated initialy, and others are when TabItem clicked. I hope I could describe my problem properly. If anything more is needed please let me know. Thanks!
I found workaround for this problem, I am not sure if it is correct way, but for now it works for me. In FragmentB,FragmentC,FragmentD i added
#Nullable
#Override
public View getView() {
if (((MainActivity) getActivity()).getStatus() == 1) {
mySpinner.setEnabled( true );
} else
mySpinner.setEnabled( false );
return super.getView();
}
//(MainActivity) getActivity()).getStatus() - method that returns state if it shold be enabled
I already have a viewpager that works but I have a small bug. The user can add or delete the pages himself. In these pages I have an edittext (in fact I have more but it is the same case for all) which is the name of the page. If the user creates a page that it calls "page 1", deletes it and creates another page immediately after it, which it calls "page 2", the fragment will display the data on page 1 ". Why ? I call notifyDataSetChanged (); After creating and deleting a page so why the fragment is not refreshed? If I leave the activity and I restart it the "page 2" that the user created will display the data of "page 2". What more do I need to do to properly refresh the fragment?
I use this library : link
My onCreate method
viewPager = (ViewPager) findViewById(R.id.viewpager);
viewPagerTab = (SmartTabLayout) findViewById(R.id.viewpagertab);
pages = new FragmentPagerItems(this);
int i = 0;
for (Points points : Pref.getList_points()) {
pages.add(FragmentPagerItem.of(points.getName(), FragmentConfigurationPoints.class, new Bundler().putInt("param1", i).get()));
i++;
}
adapter = new FragmentPagerItemAdapter(getSupportFragmentManager(), pages){
#Override
public int getItemPosition(Object object) {
return PagerAdapter.POSITION_NONE;
}
};
viewPager.setAdapter(adapter);
viewPagerTab.setViewPager(viewPager);
My methods to add a page
pages.add(FragmentPagerItem.of(
Pref.getList_points().get(Pref.get_size() - 1).getName(),
FragmentConfigurationPoints.class,
new Bundler().putInt("param1", Pref.get_size() - 1).get()
));
adapter.notifyDataSetChanged();
viewPagerTab.setViewPager(viewPager);
viewPager.setCurrentItem(Pref.get_size() - 1, true);
Reset adapter with new Data should force to load new data.
viewPager.setAdapter(adapter);
notifyDataSetChanged() won't properly do what you need.
this method refresh data inside adapter not Adapter itself.
check out the reference
void notifyDataSetChanged ()
/*Notifies the attached observers that the underlying data has been changed and any View reflecting the data set should refresh itself.*/
I'm populating view pager through fragments likes this
pagerAdapter = new PagerAdapter(getSupportFragmentManager());
mViewPager = (ViewPager) findViewById(R.id.container);
for (int i = 0; i < 10; i++) {
newfragment fragobj = new newfragment();
fragobj.setArguments(bundle);
pagerAdapter.addFragment(fragobj, "Category");
}
mViewPager.setAdapter(pagerAdapter);
mViewPager.setCurrentItem(page);
I want to clear all fragments and add new fragments after clearing. If I add new fragments now it ads on with old fragments.
I tried many stack overflow answers but none of them worked for me.
the fragment was already getting removed and destroyed. the issue was of viewpages.
Only this worked for me
myViewPager.setSaveFromParentEnabled(false);
Cheers !
Add this method in ViewPagerAdapter and call it when you want to clear fragments from viewPager
public void clear() {
FragmentTransaction transaction = manager.beginTransaction();
for (Fragment fragment : mFragmentList) {
transaction.remove(fragment);
}
mFragmentList.clear();
transaction.commitAllowingStateLoss();
}
mViewPager : is the view you are using to set you Fragment
mViewPager = (YourViewPager) findViewById(R.id.myPager);
TABLE : is just a Integer list of the position of all my Fragments
public void destroyAllItem() {
int mPosition = mViewPager.getCurrentItem();
int mPositionMax = mViewPager.getCurrentItem()+1;
if (TABLE.size() > 0 && mPosition < TABLE.size()) {
if (mPosition > 0) {
mPosition--;
}
for (int i = mPosition; i < mPositionMax; i++) {
try {
Object objectobject = this.instantiateItem(mViewPager, TABLE.get(i).intValue());
if (objectobject != null)
destroyItem(mViewPager, TABLE.get(i).intValue(), objectobject);
} catch (Exception e) {
Log.i(TAG, "no more Fragment in FragmentPagerAdapter");
}
}
}
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
super.destroyItem(container, position, object);
if (position <= getCount()) {
FragmentManager manager = ((Fragment) object).getFragmentManager();
FragmentTransaction trans = manager.beginTransaction();
trans.remove((Fragment) object);
trans.commit();
}
}
With ViewPager2 (1.0.0) and FragmentStateAdapter I also found the current view not to be recreated after updating the data set using notifyDataSetChanged, even when the data corresponding to the current view is changed. Apparently, notifyDataSetChanged doesn't perform a very thorough investigation of what has been changed and assumes the current view to be still correct.
The workaround I found was to simply set the same adapter that I had already set for the previous data set again:
viewPager2.setAdapter(myFragmentStateAdapter);
Apparently, setting an adapter makes it flush the cached views, which makes very good sense of course. Luckily, it doesn't check whether it's the same adapter.
I use navController fragment and in one fragment I also had viewPager with few slides set in a "parent fragment, which was part of the nav tree".
Sadly after the parent fragment was destoryed, the frags created within it for view pager were not getting cleared and they were restored while resuming the app, even tho they couldn't be shown!!
I've set adapter to null in parent's fragment onDestroy()-. and it clears all frags used inside viewPager.
If you have similiar problem, this wokrs 100%.
I have created 30 scrollable tabs using tablayout.
So first three tabs are visible on screen and rest of them are invisible which can be scroll using swipe gesture.
The problem is when I am selecting last tab programmatically but it is not get visible (tab layout not get scrolled to last tab).
How can I make tablayout to scroll to last tab?
I found the solution.
First I had found the width of tablayout and scroll it's x position to width and than called the select() method of last tab.
And it works fine.
Below is the code.
mTabLayout.setScrollX(mTabLayout.getWidth());
mTabLayout.getTabAt(lastTabIndex).select();
Updated:
If above is not working you can use the below code as well, it is also working fine.
new Handler().postDelayed(
new Runnable() {
#Override public void run() {
mTabLayout.getTabAt(TAB_NUMBER).select();
}
}, 100);
write this method in your custom tablayout (Your own layout which extends tablayout). So, in future you can use this method whenever you need instad of code duplication
public void selectTabAt(int tabIndex) {
if (tabIndex >= 0 && tabIndex < getTabCount() && getSelectedTabPosition() != tabIndex) {
final Tab currentTab = getTabAt(tabIndex);
if (currentTab != null) {
this.post(new Runnable() {
#Override
public void run() {
currentTab.select();
}
});
}
}
}
If you don't want yo use CustomLayout. you can just do this
final Tab currentTab = mTabLayout.getTabAt(tabIndex);
if(currentTab != null){
mTabLayout.post(new Runnable() {
#Override
public void run() {
currentTab.select();
}
});
}
I found this solution for me:
TabLayout tabLayout = activity.getTabLayout();
tabLayout.setSmoothScrollingEnabled(true);
tabLayout.setScrollPosition(targetChannelPosition, 0f, true);
Also, if you receive this error: "Only the original thread that created a view hierarchy can touch its views.", you can use this code, in order to run on Ui thread:
// find a way to get the activity containing the tab layout
TabLayout tabLayout = activity.getTabLayout();
activity.runOnUiThread(new Runnable()
{
#Override
public void run()
{
TabLayout.Tab tab = tabLayout.getTabAt(targetChannelPosition);
tab.select();
}
});
Are you calling tab.select() before the TabLayout and its children have actually been measured and drawn? If so, your TabLayout won't animate to the selection with tab.select() (or Kayvan N's suggestion of scrollTo()). Using a Handler will probably work, but that's not an ideal solution.
Provided the layout hasn't been laid out yet, a ViewTreeObserver will allow you to move to your selected tab after the layout process is finished.
private void scrollToTabAfterLayout(final int tabIndex) {
if (getView() != null) {
final ViewTreeObserver observer = mTabLayout.getViewTreeObserver();
if (observer.isAlive()) {
observer.dispatchOnGlobalLayout(); // In case a previous call is waiting when this call is made
observer.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
observer.removeOnGlobalLayoutListener(this);
} else {
//noinspection deprecation
observer.removeGlobalOnLayoutListener(this);
}
mTabLayout.getTabAt(tabIndex).select();
}
});
}
}
}
Please comment if you have any suggestions.
The above answer wouldn't work because first As agirardello mentioned you should not use mTabLayout.getWidth() since it doesn't return what we need (which is the position of the child you want to scroll to) and the updated solution doesn't always work because of a bug in TabLayout (reported here) but a work around is simple.
The tabs on the tabLayout are not direct children of the TabLayout so we need to go one level deeper using
((ViewGroup) mTabLayout.getChildAt(0)).getChildAt(YOUR_DESIRED_TAB_INDEX).getRight()
the only child of tabLayout is a TabLayout.SlidingTabStrip which is also a ViewGroup and getRight() will give us the right most position of our desired tab view. Thus scrolling to that position will give us what we desire. Here is a complete code:
int right = ((ViewGroup) mTabLayout.getChildAt(0)).getChildAt(4).getRight();
mTabLayout.scrollTo(right,0);
mTabLayout.getTabAt(4).select();
NOTE: Make sure you are calling these methods after the layout has been drown (like onResume and not onCreate)
Hope this helps.
new Handler().postDelayed(
new Runnable() {
#Override public void run() {
mTabLayout.getTabAt(TAB_NUMBER).select();
}
}, 100);
The code snippet below works for me
class TriggerOnceListener(private val v: View, private val block: () -> Unit) : ViewTreeObserver.OnPreDrawListener {
override fun onPreDraw(): Boolean {
block()
v.viewTreeObserver.removeOnPreDrawListener(this)
return true
}
}
fun onCreate() {
val position = ***The tab position you want to scroll to, 29 for your case here***
tabLayout.let { it.viewTreeObserver.addOnPreDrawListener(TriggerOnceListener(it)
{ it.setScrollPosition(position, 0f, true) } ) }
}
I dived into Tab.select(), and found Android uses Tablayout.setScrollPosition() to do this scrolling. And in onCreate() the widgets have not been measured, you need to postpone the call until layout is complete.
To select the last tab, use
tabLayout.getTabAt(X).select(); where X is the last tab index
If your TabLayout is used in conjunction with a ViewPager, which is common, simply add the following in the onCreate() method in your Activity:
tabLayout.addOnTabSelectedListener(new TabLayout.ViewPagerOnTabSelectedListener(viewPager);
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout);
That some of your tabs are not being shown indicates the tabMode attribute is set to app:tabMode="scrollable".
viewpager.setItem(position) should also set the position of the tab
This solution worked for me. My situation is a little bit different though; in my case, I am using the TabLayout with a ViewPager and adding more views and calling notifyDataSetChange().
The solution is to set a callback on the observer of TabLayout and scroll when the children are actually added to the TabLayout. Here is my example:
/**
Keep in mind this is how I set my TabLayout up...
PagerAdapter pagerAdapter = new PagerAdapter(...);
ViewPager pager = (ViewPager)findViewById(...);
pager.setAdapter(pagerAdapter);
TabLayout tabLayout = (TabLayout)findViewById(...);
tabLayout.setupWithViewPager(pager);
*/
public void loadTabs(String[] topics) {
animateTabsOpen(); // Irrelevant to solution
// Removes fragments from ViewPager
pagerAdapter.clear();
// Adds new fragments to ViewPager
for (String t : topics)
pagerAdapter.append(t, new TestFragment());
// Since we need observer callback to still animate tabs when we
// scroll, it is essential to keep track of the state. Declare this
// as a global variable
scrollToFirst = true;
// Alerts ViewPager data has been changed
pagerAdapter.notifyOnDataSetChanged();
// Scroll to the beginning (or any position you need) in TabLayout
// using its observer callbacks
tabs.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
/**
We use onGlobalLayout() callback because anytime a tab
is added or removed the TabLayout triggers this; therefore,
we use it to scroll to the desired position we want. In my
case I wanted to scroll to the beginning position, but this
can easily be modified to scroll to any position.
*/
if (scrollToFirst) {
tabs.getTabAt(0).select();
tabs.scrollTo(0, 0);
scrollToFirst = false;
}
}
});
}
Here is my code for the PagerAdapter if you need it too lol:
public class PagerAdapter extends FragmentStatePagerAdapter {
private List<Fragment> fragments;
private List<String> titles;
public PagerAdapter(FragmentManager fm) {
super(fm);
this.fragments = new ArrayList<>();
this.titles = new ArrayList<>();
}
/**
* Adds an adapter item (title and fragment) and
* doesn't notify that data has changed.
*
* NOTE: Remember to call notifyDataSetChanged()!
* #param title Fragment title
* #param frag Fragment
* #return This
*/
public PagerAdapter append(String title, Fragment frag) {
this.titles.add(title);
this.fragments.add(frag);
return this;
}
/**
* Clears all adapter items and doesn't notify that data
* has changed.
*
* NOTE: Rememeber to call notifyDataSetChanged()!
* #return This
*/
public PagerAdapter clear() {
this.titles.clear();
this.fragments.clear();
return this;
}
#Override
public Fragment getItem(int position) {
return fragments.get(position);
}
#Override
public CharSequence getPageTitle(int position) {
return titles.get(position);
}
#Override
public int getCount() {
return fragments.size();
}
#Override
public int getItemPosition(Object object) {
int position = fragments.indexOf(object);
return (position >= 0) ? position : POSITION_NONE;
}
}
I wonder if this is answer will be relevant since its coming very late. i actually achieved it in C# using Xamarin.
tabs.GetChildAt(0).Selected = true;
viewPager.SetCurrentItem(0, true);
tab = tabLayout.getSelectedTabPosition();
tab++;
TabLayout.Tab tabs = tabLayout.getTabAt(tab);
if (tabs != null) {
tabs.select();
}
else {
tabLayout.getTabAt(0).select();
}
if you want next tab on click event then use this code its work perfactly
I have a ViewPager, defined in an Activity, and many Fragments sequentially shown in the ViewPager. In these fragments there are dynamically constructed checkboxes and radiobuttons, which the user is supposed to manipulate. On the very moment that the user swipes to the next page I need the user data to be retrieved and stored in the Application object. I can't figure out what the standard way of doing this is. Since there are many Fragments I opted for using the FragmentStatePagerAdapter. Any help would be welcome, thanks in advance!
Update-1:
I do have this:
pageAdapter = new MyPageAdapter(getSupportFragmentManager());
pager = (ViewPager) findViewById(R.id.viewpager);
pager.setAdapter(pageAdapter);
// detects viewpager page change
pager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
#Override
public void onPageSelected(int position) {
Log.i("TAG", "onPageSelected");
int index = pager.getCurrentItem();
MyPageAdapter adapter = ((MyPageAdapter) pager.getAdapter());
QuestionFragment fragment = (QuestionFragment) adapter.getItem(position);
if (fragment.rdbtn != null) {
for (int i = 0; i < fragment.rdbtn.length; i++) {
if (fragment.rdbtn[i].isChecked())
Log.i("TAG", "checked");
else
Log.i("TAG", "not checked");
}
}
// fragment.refresh();
}
});
When checking the debugger, after starting up, the ViewPager instantiates Fragments 0 and 1 (standard behavior). When the user manipulates fragment-0 and swipes, the handler is indeed called but with position=1, not 0. And the public elements I want to read are null!
UPDATE-2
I notice in the debugger that the data I need is stored in adapter.mCurrentPrimaryItem.
How to retrieve CurrentPrimaryItem in the code?!
You can implement a pageChangeListener in your activity and set this to the viewPager.
Then you can have a class abstract BaseFragment extends Fragment and declare an abstract method, say, getData() that every fragment in the ViewPager extends and overrides the method.
And in onPageSelected() of the activity you can access those data.