How do I update a ListView in a Fragment? - java

I´m trying to udate a ListView in a Fragment the only way it actually will work is if I instanciate the fragment new. adpter.notifyDataSetChanged() is not working? Whay not? Here the Code an Activity and the Fragment:
public class TimerList extends Activity{
private DataSource datasource;
TimerListFragment timerfragment;
IntervalListFragment intervalfragment;
public List<TimerObject> values;
public String name;
public String intervals;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.interval_fragment_container);
datasource = new DataSource(this);
datasource.open();
values = datasource.getAllComments();
if (savedInstanceState == null) {
Toast.makeText(getApplicationContext(), "MADE NEW FRAGMENTS", Toast.LENGTH_SHORT).show();
timerfragment = new TimerListFragment();
intervalfragment = new IntervalListFragment();
}
}
public void delete(Long position){
TimerObject timerobject = datasource.getTimerObject(position);
datasource.deleteComment(timerobject);
values = datasource.getAllComments();
}
#Override
protected void onStart() {
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.add(R.id.fragment_container, timerfragment);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
super.onStart();
}
And my Fragment :
public class TimerListFragment extends ListFragment {
List<TimerObject> values ;
Activity a;
ArrayAdapter<TimerObject> adapter;
ListView lv;
#Override
public void onCreate(Bundle savedInstanceState) {
setHasOptionsMenu(true);
values = ((TimerList)getActivity()).getValues();
setBar();
adapter = new ArrayAdapter<TimerObject>(getActivity(), android.R.layout.simple_list_item_1, values);
setListAdapter(adapter);
super.onCreate(savedInstanceState);
}
#Override
public void onListItemClick(ListView l, View v, int position, long id) {
((TimerList)getActivity()).play(Long.valueOf(position));
super.onListItemClick(l, v, position, id);
}
public void setBar(){
ActionBar actionbar = getActivity().getActionBar();
actionbar.setTitle("Timer List");
}
public void update(){
setBar();
Toast.makeText(getActivity(), "UPDATE", Toast.LENGTH_LONG).show();
values = ((TimerList)getActivity()).getValues();
adapter.notifyDataSetChanged();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.interval_timer_list,
container, false);
return view;
}
#Override
public void onStart() {
update();
lv = getListView();
lv.setOnItemLongClickListener(new OnItemLongClickListener() {
public boolean onItemLongClick(AdapterView parent, View view, int position, long id) {
final TimerObject selected = adapter.getItem(position);
final Dialog d = new Dialog(getActivity());
d.setContentView(R.layout.interval_deletetimer_dialog);
d.setTitle("Delete " + selected.getComment() + "?" );
ImageButton delete = (ImageButton) d.findViewById(R.id.delete);
delete.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
((TimerList)getActivity()).delete(Long.valueOf(selected.getId()));
update();
}
});
d.show();
return true;
}
});
super.onStart();
}

I tried to do something similar, and I solved this problem by simply redoing the fragment transaction.
In your case, you could accomplish this within your onListItemClick() method.
you could copy this:
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.add(R.id.fragment_container, timerfragment);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
into your onListItemClick() method in your fragment
This resets the fragment. Unfortunately, this would also set your list to null. A way around this would be to make the values list a private static variable of the TimerListFragment class. That way, any changes made to the list will remain 'saved', and when you reload your fragment, it will be populated with the newly updated list.
hope this helps

Related

Update WebView in Fragment from RecyclerView Item

I'm trying to update my WebView in a Fragment when RecyclerView Item is clicked. In the debug console it's printing my hard-coded URL, but it's not updating the View - it is staying on "Google" webpage without any changes, but seems like onClickListener is working.
MainActivity.java
public class MainActivity extends AppCompatActivity {
private RecyclerView mRecyclerView;
private RecyclerView.Adapter mAdapter;
private RecyclerView.LayoutManager mLayoutManager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Add Websites
ArrayList<Website> websitesList = new ArrayList<>();
websitesList.add(new Website(R.drawable.ic_launcher_background, "Line 1", "https://google.com/"));
websitesList.add(new Website(R.drawable.ic_launcher_background, "Line 2", "https://yahoo.com/"));
websitesList.add(new Website(R.drawable.ic_launcher_background, "Line 3", "https://abv.bg/"));
mRecyclerView = findViewById(R.id.recyclerView);
mLayoutManager = new LinearLayoutManager(this);
mAdapter = new WebsiteAdapter(websitesList);
mRecyclerView.setLayoutManager(mLayoutManager);
mRecyclerView.setAdapter(mAdapter);
}
public void switchContent(int id, Fragment fragment) {
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.add(id, fragment);
ft.commit();
}
}
RecyclerView Adapter
#Override
public void onBindViewHolder(#NonNull ExampleViewHolder holder, int position) {
final Website currentItem = mWebsiteList.get(position);
holder.mImageView.setImageResource(currentItem.getImage());
holder.mTitle.setText(currentItem.getTitle());
holder.mTitle.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
fragmentJump(currentItem);
}
});
}
#Override
public int getItemCount() {
return mWebsiteList.size();
}
private void fragmentJump(Website mItemSelected) {
Fragment mFragment = new WebsiteView();
Bundle mBundle = new Bundle();
mBundle.putString("url", "http://facebook.com/");
mFragment.setArguments(mBundle);
switchContent(R.id.fragment, mFragment);
}
public void switchContent(int id, Fragment fragment) {
if (mContext == null)
return;
if (mContext instanceof MainActivity) {
MainActivity mainActivity = (MainActivity) mContext;
mainActivity.switchContent(id, fragment);
}
}
WebView Fragment
private WebView webView;
String mUrl;
public WebsiteView() {}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_website_view, container, false);
try {
mUrl = getArguments().getString("url");
} catch(Exception ex) {
System.out.println(ex.toString());
mUrl = "http://google.com/";
}
System.out.println(mUrl);
webView = v.findViewById(R.id.webView);
webView.setWebViewClient(new WebViewClient());
webView.loadUrl(mUrl);
return v;
}
Okay, it appeared that I'm actually trying to update the Fragment data, and when I replace another fragment with my desired one it works. Any ideas how to update the WebView in the fragment?

Listen DialogFragment dismiss event from ViewPager Fragment

There are lot of (duplicate) questions and answers are available, I went through almost all of them and failed. On reference of this question, I made some changes recently.
Brief : In my app, MainActivity holds Fragment View Pager and FrangmentA,B and C. FrangmentA Shows a DialogFragment CDialog onClik. After dismissing CDialog I need to Call FragmentA's doReload() which is not happening here.
MainActivity
protected void onCreate(Bundle savedInstanceState){
...
mSectionsPageAdapter = new FragmentAdapter(getSupportFragmentManager());
mViewPager = (ViewPager) findViewById(R.id.container);
setupViewPager(mViewPager);
TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(mViewPager);
int defaultValue = 0;
int page = getIntent().getIntExtra("One", defaultValue);
mViewPager.setCurrentItem(page);
}
private void setupViewPager(ViewPager viewPager)
{
FragmentAdapter adapter = new
FragmentAdapter(getSupportFragmentManager());
adapter.addFragment(new FragmentA(), "FragA");
adapter.addFragment(new FragmentB(), "FragB");
adapter.addFragment(new FragmentC(), "FragC");
viewPager.setAdapter(adapter);
}
FragmentA
public class FragmentA extends Fragment implements CDialog.Dismissed{
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
...
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
FragmentManager fm = getActivity().getFragmentManager();
DialogFragment f = new CDialog();
f.show(fm, "CDialog");
}
});
#Override
public void dialogDismissed() {
Log.e(DFD_1, "dialogDismiss Called" );// <-- This is not working*
doReload();
}
}
And CDialogue
public class CDialog extends DialogFragment{
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
....
return v;
}
#Override
public void onViewCreated(View view, #Nullable Bundle savedInstanceState) {
...
dfd_1.setOnClickListener(
new View.OnClickListener() {
public void onClick(View v) {
getDialog().dismiss(); //<--when this happens*
}
});
}
#Override
public void onDismiss(DialogInterface dialog) {
if (getActivity() != null && getActivity() instanceof Dismissed) {
((Dismissed) getActivity()).dialogDismissed();
}
super.onDismiss(dialog);
}
public interface Dismissed {
public void dialogDismissed(); //<-- FragmentA implements this
}
}
You can always have direct callback to your Fragment itself.
First step, is to set targetFragment using setTargetFragment():
DialogFragment#setTargetFragment(Fragment fragment, int requestCode);
I do it this way:
public void showDialogFragment(Fragment targetFragment, AppCompatDialogFragment appCompatDialogFragment, int requestCode) {
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.setCustomAnimations(android.R.anim.fade_in, android.R.anim.fade_out);
appCompatDialogFragment.setTargetFragment(targetFragment, requestCode);
fragmentTransaction.add(appCompatDialogFragment, appCompatDialogFragment.getClass().getSimpleName());
fragmentTransaction.commitAllowingStateLoss();
}
and then call to this method to open dialog fragment as:
public static final int RC_CDIALOG = 111;
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
showDialogFragment(FragmentA.this, new CDialog(), RC_CDIALOG);
}
});
Then, in your DialogFragment's onDismissListener(), have some code like below:
#Override
public void onDismiss(DialogInterface dialog) {
super.onDismiss(dialog);
if (getTargetFragment() instanceof FragmentA)
((FragmentA) getTargetFragment()).doReload();
}
What you did this way is:
Show Dialog Fragment "CDialog" along with telling it that your target fragment is "FragmentA" whose reference you can use incase you have something to do with it. In your case you had to call doReload();

NULL in Adapter in Fragment (FragmentPagerAdapter) after screen rotation

I was looking answer in similar topics but nothing works for me. I have Activity which has a fragment. This fragment has adapter. Everything is fine even if I rotate screen, but when I rotate screen and try to update adapter (for example by sort items in adapter - method sort) I get NULL on adapter.
When Activity starts first time this is happening:
ON CREATE (ACTIVITY)
SETUP VIEW PAGER (ACTIVITY)
CONSTRUCTOR (FRAGMENT)
SET DATA IN ADAPTER (ACTIVITY)
ON CREATE (FRAGMENT)
CREATE ADAPTER (FRAGMENT)
ON CREATE VIEW (FRAGMENT)
UPDATE ADAPTER (FRAGMENT)
ON ACTIVITY CREATED (FRAGMENT)
In the second time when I rotate screen:
ON CREATE (ACTIVITY)
CONSTRUCTOR (FRAGMENT)
ON CREATE (FRAGMENT)
CREATE ADAPTER (FRAGMENT)
SETUP VIEW PAGER (ACTIVITY)
CONSTRUCTOR (FRAGMENT)
SET DATA IN ADAPTER (ACTIVITY)
ON CREATE VIEW (FRAGMENT)
UPDATE ADAPTER (FRAGMENT)
ON ACTIVITY CREATED (FRAGMENT)
So the problem is that in activity method super.onCreate(savedInstanceState) the fragment is recreated istelf. I was trying pass NULL for super.onCreate(null) and also checking if savedInstance is NULL, changing FragmentPagerAdapter for FragmentStatePagerAdapter, and many others things. What I want to do is save and get fragment, adapter in proper way or just make activity start everytime like in the first time.
PART OF MAIN ACTIVITY
public class MainActivity extends AppCompatActivity {
private TabLayout tabLayout;
private ViewPager viewPager;
SongsFragment songsFragment;
TabAdapter tabAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(null);
setContentView(R.layout.activity_main);
//init work
tabAdapter = new TabAdapter(getSupportFragmentManager());
songsFragment = new SongsFragment();
songsFragment.setData(database.getSongs(readOption(), readOrder()));
tabAdapter.addFragment(songsFragment, "TAB");
viewPager.setAdapter(tabAdapter);
tabLayout.setupWithViewPager(viewPager);
}
public void sort() {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setItems(R.array.sorts, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
if(which == 0) writeSort("number", "ASC");
else if(which == 1) writeSort("number", "DESC");
else if(which == 2) writeSort("title", "ASC");
else if(which == 3) writeSort("title", "DESC");
songsFragment.setData(database.getSongs(readOption(), readOrder()));
songsFragment.updateAdapter();
}
}).show();
}
}
FRAGMENT
public class SongsFragment extends Fragment {
private RecyclerView recyclerView;
List<Song> songs = new ArrayList<>();
SongsAdapter adapter;
public SongsFragment() {
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.v("TAG", "onCr");
if(!(savedInstanceState == null || !savedInstanceState.containsKey("list"))) {
songs = (List<Song>) savedInstanceState.getSerializable("list");
}
createAdapter();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
Log.v("TAG", "onCrV");
View view = inflater.inflate(R.layout.fragment_songs, container, false);
recyclerView = (RecyclerView) view.findViewById(R.id.fragment_songs_SongsList);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
recyclerView.setAdapter(adapter);
updateAdapter();
return view;
}
#Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putSerializable("list", (Serializable) songs);
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
}
public void setData(List<Song> songs) {
this.songs = songs;
}
public void createAdapter() {
adapter = new SongsAdapter(getContext(), songs);
}
public void updateAdapter() {
adapter.clear();
adapter.addAll(songs);
adapter.notifyDataSetChanged();
}
}
FRAGMENT PAGER ADAPTER
public class TabAdapter extends FragmentStatePagerAdapter {
List<Fragment> fragments = new ArrayList<>();
List<String> titles = new ArrayList<>();
public TabAdapter(FragmentManager manager) {
super(manager);
}
#Override
public Fragment getItem(int position) {
return fragments.get(position);
}
#Override
public int getCount() {
return fragments.size();
}
#Override
public CharSequence getPageTitle(int position) {
return titles.get(position);
}
public void addFragment(Fragment fragment, String title) {
fragments.add(fragment);
titles.add(title);
}
}

Unable to access a ListFragment

I have a MainActivity like this
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
} }
and this
public class MyListFragment extends ListFragment implements OnItemClickListener {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.list_fragment, container, false);
return view;
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(getActivity(), R.array.Planets, android.R.layout.simple_list_item_1);
setListAdapter(adapter);
getListView().setOnItemClickListener(this);
int count = getListView().getCount();
getListView().setSelection(getListView().getCount() - 1);
test();
}
public void test(){
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(getActivity(), R.array.Planets, android.R.layout.simple_list_item_1);
setListAdapter(adapter);
getListView().setOnItemClickListener(this);
int count = getListView().getCount();
getListView().setSelection(getListView().getCount() - 1);
Toast.makeText(getActivity(), "ccc"+count, Toast.LENGTH_SHORT)
.show();
}
#Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
Toast.makeText(getActivity(), "Item: " + position, Toast.LENGTH_SHORT)
.show();
} }
The activity_main.xml has a
fragment
android:layout_width="match_parent"
android:layout_height="match_parent"
android:name="com.example.mike.mqtt.MyListFragment"
android:id="#+id/fragment_content" />
When the application starts I get the fragment_content filled up with some rows.
How can I access the ListFragment(MyListFragment.java) from inside the MainActivity.java in the onCreate.
When I press a button the get the ListFragment content count, and to set focus at the end of the list.
I have no idea.Thank you.
MyListFragment fragment = (MyListFragment) getFragmentManager().findFragmentById(R.id.fragment_content)
I avoid using fragments in XML as it alows me to replace them on-the-fly. I usually use something like this:
private MyListFragment mListFragment;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// the usual business
FragmentManager fm = getSupportFragmentManager();
if (savedInstanceState == null) {
// the activity opened for the first time, we create and commit fragment
mListFragment = new MyListFragment();
fm.beginTransaction().replace(android.R.id.content, f).commit);
} else {
// activity is recreating so it's safe to find already added fragments
mListFragment = fm.findFragmentById(android.R.id.content);
}
}

Tabs with Fragment life cycle

in my app i have a Tabs with fragment classes. i trying to refresh listView in "fragment a" with the new data i insert.
In "fragment b" i have EditText and Button ,that inserting text to the database.
in "fragment a" i have the ListView with the dataBase rows. when "fragment a" is "OnCreateView" i just put the dataBase on a "ArrayList" and past it to my baseAdapter.
but "onCreateView" not refreshing my new data every time i get into the "fragment a" else i goes to "fragment c" and "onDestroy" call on "fragment a".
so my result it was to call : "setUserVisibleHint" override method, and check if it is visible and refreshing the list.
but i dont think it is the good practice .
what should i do?
Class a
public class ListFragment extends Fragment{
basAdapterCustom adapter;
ListView lv;
ArrayList<Clock> list;
private DbHandler hand;
Context context;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.list_fragment, container, false);
context = getActivity();
Log.d(TAG, "onCreateView");
hand = new DbHandler(context);
list = new ArrayList<Clock>();
lv = (ListView) v.findViewById(R.id.listOfShifts);
adapter = new basAdapterCustom(list, getActivity());
lv.setAdapter(adapter);
refreshList();
return v;
}
//like on "resume":
#Override
public void setUserVisibleHint(boolean isVisibleToUser) {
super.setUserVisibleHint(isVisibleToUser);
// Make sure that we are currently visible
if (this.isVisible()) {
refreshList();
if (!isVisibleToUser) {
// TODO stop
}
}
}
private void refreshList() {
list = hand.getByWorkName();
adapter = new basAdapterCustom(list,getActivity());
lv.setAdapter(adapter);
}
class b:
public class ClockFragment extends Fragment{
DbHandler hand;
Context context;
#Override
public View onCreateView(LayoutInflater inflater,
#Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.clock, container,false);
context = getActivity();
hand = new DbHandler(context);
return v;
}
// ADD to .Db
public void addToDb(View v){
hand.add(new Clock(0, dateDay));
}
}
class mainActivity:
public class MainActivity extends FragmentActivity implements ActionBar.TabListener, OnPageChangeListener{
public static final String TAG = "myClock";
String[] tabMenu = {"FRAG A","FRAG B","FRAG C"};
private ViewPager viewPager;
private TabPagerAdapter mAdapter;
private ActionBar actionBar;
#SuppressLint("NewApi")
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Log.d(MainActivity.TAG, "OnCreate = MainActivity (Pager");
viewPager = (ViewPager) findViewById(R.id.pager );
actionBar = getActionBar();
mAdapter = new TabPagerAdapter(getSupportFragmentManager());
viewPager.setAdapter(mAdapter);
actionBar.setHomeButtonEnabled(false);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
for (String tabsNames : tabMenu) {
actionBar.addTab(actionBar.newTab().setText(tabsNames).setTabListener(this));
}
viewPager.setOnPageChangeListener(this);
}
// public void transDialog(){
// Dialog mDialog = new Dialog(this, android.R.style.Theme_Translucent_NoTitleBar_Fullscreen);
// }
#Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
viewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
// TODO Auto-generated method stub
}
#Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}
#Override
public void onPageScrollStateChanged(int arg0) {
}
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
#Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
}
PagetAdapter.class
public class TabPagerAdapter extends FragmentPagerAdapter {
private static final String TAG = "myClock";
public TabPagerAdapter(FragmentManager fm) {
super(fm);
// TODO Auto-generated constructor stub
}
#Override
public Fragment getItem(int index) {
Log.d(TAG, " CLASS : TabPagerAdapter");
switch (index) {
case 0:
return new ListFragment();
case 1:
return new ClockFragment();
case 2:
return new SettingFragment();
default:
break;
}
Log.d(TAG, " CLASS : TabPagerAdapter = "+index);
return null;
}
#Override
public int getCount() {
return 3;
}
}
Please help me i hope you are understand my problem...
You want to update listView in fragment A, after insert data in fragment b? Then  you have a few solutions to choose:
1. Implement communications between fragments via activity. Then B insert date, it send message to activity, that data need to be updated. Then fragment A started, it's ask activity to need update data. For details on implementing this communication check link.
2. Use some bus library, EventBus for example. Then fragment B insert data, it post 'data changed' event to bus. Fragment A checks on start if this event occurs.
3. Use Loaders which "monitor the source of their data and deliver new results when the content changes."

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