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.
Related
so i'm using ViewPager to make my app much faster , instead of using an activity for each layout.
the problem is , in activity you can write your code inside onCreate
and it will only starts when you start the activity , right?
but when you go with fragments and fragmentPagerAdapter and use ViewPager for them.
all your fragments going to start their (onCreateView) together even if your ViewPager only showing the First Fragment!
if you are you playing a sound or animation on the start of a fragment , it will starts in the background !
here's my fragmentPagerAdapter class:
public class PagerAdapter extends FragmentStatePagerAdapter {
private final List<Fragment> mFragmentList = new ArrayList<>();
private final List<String> mFragmentTitle = new ArrayList<>();
public PagerAdapter(FragmentManager fm) {
super(fm);
}
#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);
mFragmentTitle.add(title);
}
}
and i have this (second Fragment) that i don't want it to starts without being seleceted!
public class GameFragment extends Fragment{
private View gameLayout
private Animation showBtn;
private Button button;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
gameLayout = inflater.inflate(R.layout.game_layout, container, false);
button = gameLayout .findViewById(R.id.button);
// loading my anim xml file
showBtn = AnimationUtils.loadAnimation(getContext(),R.anim.btn_show);
button.startAnimation(showBtn);
loadLevel();
return gameLayout
}
finally this is my Activity that have ViewPager :
public class ControllerActivity extends AppCompatActivity {
public CustomPager viewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_controller);
viewPager = findViewById(R.id.viewPager);
PagerAdapter adapter = new PagerAdapter(getSupportFragmentManager());
adapter.addFragment(new HomeFragment(),"Home");
adapter.addFragment(new GameFragment(),"Game");
viewPager.setAdapter(adapter);
viewPager.setCurrentItem(0);
}
i need your help to show me my mistakes here and what is the correct way
Using an OnPageChangeListener in your View Pager, you can detect which fragment is currently shown in the View Pager. You'll then need to check which fragment is shown and then call a method on that fragment's class to start any sounds for example that you don't want to start until the fragment is the fragment in view.
You should use an interface for this.
Here you can find an example of using an OnPageChangeListener.
Here you can find an example of Activity to Fragment communication using interfaces. This example has a lot of code that won't be relevant to your use case, but demonstrates the use of interfaces.
One way to do it "Might" be to just initialize the view of the fragment in onCreateView :
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
view = inflater.inflate(R.layout.fragment_media_viewer, container, false);
return view;
}
Then in the override the setUserVisibleHint() function and do the rest of the initialization there. This function is called when ever the fragment is in view.
#Override
public void setUserVisibleHint(boolean isVisibleToUser) {
super.setUserVisibleHint(isVisibleToUser);
// do the rest of the code here.
}
I haven't used setuserVisibleHint for this purpose yet. But you can try it. Let me know too.
I have a fragment, fragment A, which holds a ViewPager. The ViewPager loads different fragments which the user can swipe through "indefinitely" (I use a really high number of pages/loops to emulate this). When a user clicks on the current ViewPager fragment, then fragment A with the ViewPager is replaced by fragment B in the fragment manager. When the user returns from fragment B, the backstack is popped using popBackStackImmediate(). If the user repeats this action several times, the heap begins to fill up by about 100kb at a time until the app starts to become sloppy and malfunction as the memory fills up. I'm unsure what exactly is causing this, can anyone help?
My fragment A with the ViewPager:
public class MainFragment extends Fragment {
private MainWearActivity mMainWearActivity;
View view;
private int currentPage;
private ViewPager pager;
private ViewPagerAdapter adapter;
private LinearLayout helpIcons;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mMainWearActivity = (MainWearActivity) getActivity();
adapter = new ViewPagerAdapter(this.getChildFragmentManager());
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
view = inflater.inflate(R.layout.fragment_main, container, false);
// Scrolling menu
pager = (ViewPager) view.findViewById(R.id.watchNavPager);
pager.setAdapter(adapter);
pager.addOnPageChangeListener(adapter);
// Set current item to the middle page
pager.setCurrentItem(Consts.FIRST_PAGE);
currentPage = Consts.FIRST_PAGE;
// Set number of pages
pager.setOffscreenPageLimit(4);
// Set no margin so other pages are hidden
pager.setPageMargin(0);
return view;
}
#Override
public void onDestroyView() {
pager = null;
super.onDestroyView();
}
}
My adapter class:
public class ViewPagerAdapter extends FragmentPagerAdapter implements
ViewPager.OnPageChangeListener {
public ViewPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position)
{
position = position % Consts.PAGES;
switch(position){
case Consts.AUDIO_POS:
return new AdapterAudioFragment();
case Consts.VOICE_POS:
return new AdapterVoiceFragment();
case Consts.MAIL_POS:
return new AdapterMailFragment();
case Consts.INFO_POS:
return new AdapterInfoFragment();
default:
return null;
}
}
#Override
public int getCount()
{
return Consts.PAGES * Consts.LOOPS; // (4 * 1000)
}
#Override
public void onPageScrolled(int position, float positionOffset,
int positionOffsetPixels) {}
#Override
public void onPageSelected(int position) {}
#Override
public void onPageScrollStateChanged(int state) {}
}
One of my fragments that the adapter loads (they are all pretty much the same):
public class AdapterAudioFragment extends Fragment {
private ImageView menuImg;
private TextView menuText;
private LinearLayout rootView;
private MainWearActivity mMainWearActivity;
private View.OnClickListener imgClickListener;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mMainWearActivity = (MainWearActivity) getActivity();
imgClickListener = new View.OnClickListener() {
#Override
public void onClick(View v) {
mMainWearActivity.replaceFragment(mMainWearActivity.getFragment(Consts.FRAG_AUDIO), Consts.FRAG_AUDIO);
}
};
}
#Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
// Get root view of the fragment layout
rootView = (LinearLayout) inflater.inflate(
R.layout.fragment_nav_object, container, false);
// Set the current menu image and text
menuImg = (ImageView) rootView.findViewById(R.id.fragment_image);
menuImg.setImageResource(R.mipmap.ic_audio);
menuImg.setOnClickListener(imgClickListener);
menuText = (TextView) rootView.findViewById(R.id.menuTxt);
menuText.setText(Consts.MENU_HEADER_AUDIO);
// Set the current menu selection
mMainWearActivity.setCurrentSelection(Consts.AUDIO_POS);
return rootView;
}
}
I have a feeling that the adapter's fragments are all being created but never destroyed and piling up in the heap but I can't figure out how to resolve this. Do I need to call destroyItem in the adapter and manually destroy them? Any help would be most appreciated, thanks.
Adding this to Fragment stopped leaks for me:
#Override
public void onDestroyView() {
super.onDestroyView();
viewPager.setAdapter(null);
}
Looking at the source code, the problem seems to be that when calling ViewPager#setAdapter the view will register itself as observer for the adapter. So each time onViewCreated is called your pager adapter instance will have reference of the newly created view.
There is a specific PagerAdapter for your needs - FragmentStatePagerAdapter
This version of the pager is more useful when there are a large number of pages, working more like a list view. When pages are not visible to the user, their entire fragment may be destroyed, only keeping the saved state of that fragment. This allows the pager to hold on to much less memory associated with each visited page as compared to FragmentPagerAdapter at the cost of potentially more overhead when switching between pages.
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;
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.
I want to create a screen with 4 tabs. But initially only first tab have to be seen.
Based on an action in the content ( which is a fragment) I need to create a new tab with different layout. Consider this an application as a form form applying to something. So tabs represents Steps 1,2,3,4. So once I complete the Step 1 I will click on a button which creates a new tab Step2.
I don't want to implement it by launching activities because I need to maintain previous tabs. So how do I catch a button click in a fragment and add a tab at runtime?
create a new tab with different layout
See this Example
How do you set Android ViewPager to encompass only one View or Layout?
The question is not related to you but Example is Valid and related to One part of your question
EDITED
This is how you can link fragments with your tabs.
class TestFragmentAdapter extends FragmentPagerAdapter {
private int mCount = TABS.length;
public TestFragmentAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
MainSummary f1 = new MainSummary();
MainActivity f2 = new MainActivity();
if(TABS[position].equals("Summary")){
return f1;
}else if(TABS[position].equals("Activity")){
return f2;
}else{
return null;
}
}
#Override
public int getCount() {
return mCount;
}
#Override
public CharSequence getPageTitle(int position) {
return TABS[position];
}
}
And for each fragment you can have separate class and layout (R.layout.main_summary) like this
public final class MainSummary extends ListFragment{
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
View view = inflater.inflate(R.layout.main_summary, container, false);
return view;
}
}
There are some useful sample projects here https://github.com/github/android
You can find all answers of your question if you study these samples