Let say the target application is built from 3 fragments which are all in the same activity public class MainActivity extends android.support.v4.app.FragmentActivity implements ActionBar.TabListener. Starting fragment is public class ButtonSectionFragment extends Fragment where there is a Button:
public class ButtonSectionFragment extends Fragment {
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final View rootView = inflater.inflate(R.layout.btn, container, false);
Button mybutton = (Button) rootView.findViewById(R.id.mybutton);
mybutton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
????????????????????
}
});
}
There are ?? in the onClick method, I will get to that. And there is another fragment like this:
public static class TextSectionFragment extends Fragment {
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.tv, container, false);
TextView textv = (TextView) rootView.findViewById(R.id.texty);
}
Both of the fragments are using different layouts so this is why rootView is being used right in front of findViewById.
The outcome I would like to achieve is: by Button from 1st fragment click set the TextView from 2nd fragment to Hello. What should I put in the ??? part to make it all work?
You need to use interface as callback to the activity then set the textview in fragment.
Two framgents should never communicate directly.
http://developer.android.com/training/basics/fragments/communicating.html.
Framgent1 -->Activity -->Fragment2.
You can comunicate value from fragment2 to activity first then from activity to fragment2. Then set text in fragment2
You just have to use getActivity().findViewById() instead of getView().findViewById()
final TextView tv = (TextView) getActivity().findViewById(R.id.texty);
if (tv != null)
tv.setText("Hello");
Fragments are just branches inside the common layout tree of activity. All fragment views of a common activity can be accessed through Activity.findViewByXXX(). The only complication is that fragments can be dynamically added, removed, replaced, etc. So you to be sure that the needed fragment is already inflated into the layout hierarchy. You can make initialization of the UI in onViewCreated() of the other fragment. That guarantees you the layout has been loaded already.
Fragment frag1 = new ButtonSectionFragment ();
Fragment frag2 = new TextSectionFragment();
FragmentManager fm = getSupportFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
ft.add(layout, frag1);
ft.add(layout, frag2);
ft.commit();
View frag1RootView = frag1.getView();
View frag2RootView = frag2.getView();
Button btn = (Button)frag1RootView.findViewById(id);
TextView tv = (TextView)frag2RootView.findViewById(id);
untested but... I think that would do it...
EDIT: You should get the root views onActivityCreated(); or it'll throw you a null...
In continuation to Raghunandan's answer, you could check similar implementation in the link.
update TextView in fragment A when clicking button in fragment B
Do not forget to get a reference of the textview of the TextSectionFragment into the MainActivity.
Related
I've incorporated a horizontal slide navigation component (which required making the class extend Fragment). The slide part works fine. Here i have respective onClick() buttons which open a new activity. If I add a button into one of those activities I'm not finding a way to have the displayed activity subsequently refresh. I would think inflating an activity from a button within a fragment would be possible but anything I try stops the emulator.
There's not much to my code so far, so I'm not going to clutter my question with the associated layout part. Any help is certainly appreciated.
Fragment #1’s Java code
public class TasksFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_tasks, container, false);
Button ID = (Button) rootView.findViewById(R.id.button_create_appraisal_rpt);
ID.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
AppraisalReportActivity appraisalRptAct = new AppraisalReportActivity();
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.child_fragment, appraisalRptAct);
fragmentTransaction.setTransition(fragmentTransaction.TRANSIT_FRAGMENT_OPEN);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
}
});
return rootView;
}
}
Fragment #1 (portion), which has the button that should initiate aa refresh of this Fragment #1 with Fragment #2
Fragment #2 that's to supersede/refresh the previous fragment when Fragment #1's button is clicked
I don't really understand what you mean. Do you want to click Button in Fragment to jump to another Activity?
If it is,I think maybe you can try use getActivity() to make Activity are working.
for example:
getActivity().startActivity(new Intent(getActivity(),Activity.class))
I hope my answer will help you
I am trying to add a fragment, then find a view inside said fragment, and add a view into it. However I keep getting a NullPointerException on this statement
FrameLayout container2 = (FrameLayout) fragment.getActivity().findViewById(R.id.content_frame);
Here is my code. Can someone tell me how to fix this please? thanks
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
Fragment fragment = new FragmentNavigationDrawer();
ViewGroup decor = (ViewGroup) getActivity().getWindow().getDecorView();
View child = decor.getChildAt(0);
decor.removeView(child);
fragmentTransaction.add(decor.getId(), fragment);
fragmentTransaction.commit();
FrameLayout container2 = (FrameLayout) fragment.getActivity().findViewById(R.id.content_frame);
container2.addView(child);
Just use a getter. Set a tag on your fragment so you can access it later, then either call getView() on your fragment to return its root view, or use a getter to access a specific View:
public class MainActivity extends AppCompatActivity {
//In onCreate
if (getFragmentManager().findFragmentByTag(FragmentNavigationDrawer.TAG) == null) {
getFragmentManager()
.beginTransaction()
.add(android.R.id.content, new FragmentNavigationDrawer(), FragmentNavigationDrawer.TAG)
.commit();
}
//Later, when you want to add said View:
FragmentNavigationDrawer frag =
(FragmentNavigationDrawer) getFragmentManager().findFragmentByTag(FragmentNavigationDrawer.TAG)
//Return the root view:
View fragRootView = frag.getView();
//Return a specific view:
frag.getUpdatableViewGroup().addView(newViewToAdd):
}
For your Fragment:
public class FragmentNavigationDrawer extends Fragment {
public static final String TAG = FragmentNavigationDrawer.class.getSimpleName();
FrameLayout updatableViewGroup;
//Can do this inside onCreateView() whilst inflating your Fragment's Views
//That's up to you.
#Override
public void onViewCreated (View view, Bundle savedInstanceState) {
updateableViewGroup = view.findViewById(R.id.updateable_view_group);
}
public FrameLayout getUpdatableViewGroup() {
return updateableViewGroup;
}
Be conscious of the Activity and Fragment life cycles however, and be careful not to attempt to access the Fragment's Views until they have finished inflating - onStart() of your Activity and later should be ok.
Please see the javadoc for FragmentTransaction.commit(). It says it will schedule a change to the fragment back stack. It doesn't happen immediately. It looks like you're expecting the fragment and its views to be instantly available.
Also, I'm really confused why you're reaching in a decor view to make changes. Usually you call out a view by id in the host activity's layout and make changes inside it.
First time posting here and also a new developer for Android Apps.
Desire Function of Example App:
1) Activity starts in fullscreen A
2) Fragment B then populates/inflates container of A fullscreen
3) Fragment B has a button, button is press
4) Fragment B is now replaced with Fragment C
5) Fragment C is now full screen and has data that is inputted by users, user then hits button to send to next Fragment
6) Fragment C is replaced with Fragment D and presents data to view which was inputted from Fragment C
Summary Functionality:
I am trying to keep everything on one screen going from
A (Activity) -> B (Fragment replace) -> C (Fragment replace to type data) -> D (Fragment replace and see last fragment data)
Problem/Issue
My code crashes when I try to populate the last screen with data obviously. It seems to throw an error in MainActivity at this specific line when I debug it
CartFragmentCode addCartInfoTextFragment = (CartFragmentCode) getSupportFragmentManager().findFragmentById(R.id.maincontainer);
I am definitely passing the values correctly through the interface I created, but during the debug process, I found out that my current program is trying to populate information into the same container since it seems like it didn't commit yet to replace the fragment to assign the variables to the right UI.
I was checking if I was able to replace the Fragment C with D, and I was able to only if I remove that above line of code.
Code Below
Main
public class MainActivity extends FragmentActivity implements OrderFragmentCode.FragUIListeners{
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Fragment AllMenu = new AllMenuFragmentCode();
FragmentManager fragManager = getSupportFragmentManager(); //getSupportFragmentManager setup
FragmentTransaction ft = fragManager.beginTransaction(); //setup fragmentTranscation = ft
ft.add(R.id.maincontainer, AllMenu);
ft.commit();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public void onCartButtonClicked(String editFood, String editType, String editName){
CartFragmentCode addCartInfoTextFragment = (CartFragmentCode) getSupportFragmentManager().findFragmentById(R.id.maincontainer);
addCartInfoTextFragment.UpdateCartTexts(editFood, editType, editName);
}}
Fragment A
public class AllMenuFragmentCode extends Fragment implements OnClickListener {
private Button Order;
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
View view = inflater.inflate(R.layout.all_menu_fragment, container, false);
Order = (Button) view.findViewById(R.id.orderButton);
Order.setOnClickListener(this);
return view;
}
#Override
public void onClick(View v) {
Fragment OrderFragmentCode = new OrderFragmentCode();
FragmentManager fragManager = getFragmentManager(); //getSupportFragmentManager setup
FragmentTransaction ft = fragManager.beginTransaction(); //setup fragmentTranscation = ft
ft.replace(R.id.maincontainer, OrderFragmentCode);
ft.addToBackStack(null);
ft.commit();
}}
Fragment C
public class OrderFragmentCode extends Fragment implements OnClickListener {
FragUIListeners activityCallback;
public interface FragUIListeners {
public void onCartButtonClicked(String foodText, String typeText, String nameText);
}
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
activityCallback = (FragUIListeners) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement FragUIListeners");
}
}
private EditText editTextFood;
private EditText editTextType;
private EditText editTextName;
private Button AddToCartButton;
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
View view = inflater.inflate(R.layout.order_fragment, container, false);
editTextFood = (EditText) view.findViewById(R.id.editText);
editTextType = (EditText) view.findViewById(R.id.editText2);
editTextName = (EditText) view.findViewById(R.id.editText3);
AddToCartButton = (Button) view.findViewById(R.id.addToCart);
AddToCartButton.setOnClickListener(this);
return view;
}
#Override
public void onClick(View v) {
Fragment Cart = new CartFragmentCode();
FragmentManager fragManager = getFragmentManager();
FragmentTransaction ft = fragManager.beginTransaction();
ft.replace(R.id.maincontainer, Cart);
ft.addToBackStack(null);
ft.commit();
activityCallback.onCartButtonClicked(editTextFood.getText().toString(), editTextType.getText().toString(), editTextName.getText().toString());
}}
Fragment D
public class CartFragmentCode extends Fragment{
private TextView foodView;
private TextView typeView;
private TextView nameView;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.cart_fragment, container, false);
foodView = (TextView) view.findViewById(R.id.foodView);
typeView = (TextView) view.findViewById(R.id.typeView);
nameView = (TextView) view.findViewById(R.id.nameView);
return view;
}
public void UpdateCartTexts(String editfood, String edittype, String editname)
{
foodView.setText(editfood);
typeView.setText(edittype);
nameView.setText(editname);
}}
--Final Say--
Sorry for the long post, this has been bugging me for HOURS and I even tried to use bundles and setting the arguements but I wasnt able to get that working either (I thought if i were able to obtain values correctly I could work around and use this to assign values to my textviews through getArguments on my last Fragment).
Please help!!!! Thanks!!!
In the line CartFragmentCode addCartInfoTextFragment = (CartFragmentCode) getSupportFragmentManager().findFragmentById(R.id.maincontainer);
findFragmentById sholule be passed that you use as 2nd argument in add while adding fragment to container for e.g. ft.add(R.id.maincontainer, AllMenu); if you want to get this fragment then you use findFragmentById(AllMenu) which is the tag that is associated with the fragment. R.id.maincontainer is the container in which that fragment is being displayed.
I guess the problem is you call onCartButtonClicked inside fragment C (where fragment C still exist) so the fragment D isn't created and take C place yet.
Try to call onCartButtonClicked by a Handler in your MainActivity
This is was one of my resource at the time to mimic a solution (he was using two fragments in one activity, while my app is trying to use one activity and replacing the main framelayout): http://www.techotopia.com/index.php/Using_Fragments_in_Android_-_A_Worked_Example
After playing around with example codes and using the available documentations. I cannot use these two lines to transfer the information as suggested in my MainActivity:
CartFragmentCode addCartInfoTextFragment = (CartFragmentCode) getSupportFragmentManager().findFragmentById(R.id.maincontainer);
addCartInfoTextFragment.UpdateCartTexts(editFood, editType, editName);
I think I finally found a workaround or a solution? I am not sure if this is the correct way of passing information to fragments or other classes, but here it is...
I basically Took away those two lines and rework my MainActivity's Click method and changed it to this...
public void onCartButtonClicked(String editFood, String editType, String editName){
CartFragmentCode.passFood = editFood;
CartFragmentCode.passType = editType;
CartFragmentCode.passName = editName;
}
I then went to my last fragment Code which was OrderFragmentCode.java and declared my Strings to retrieve them at the top of the Class and they were...
public static String passFood;
public static String passType;
public static String passName;
I then took the those values and setText them to my textViews. Wallah! It works as intented, however I am not sure if this is the right way to do things... If you guys are able to find a more professional way to handle data across multiple fragments, please let me know!
The issue I'm having is that I don't know how to get a pointer to a layout within a fragment. It's obvious that to get a layout pointer in Java you would do something like this:
LinearLayout llTemp = (LinearLayout) findViewById(R.id.llTemp)
Something along those lines.
Now what I'm doing is grabbing information from a server in the main class and load a fragment within the same class. I would like to populate the fragment with the information loaded from the outer class. Is there any way to do this? I would have just grabbed the layout from within the fragment and do it that way but I cannot make a reference to it as it's in the fragment.
I'm sure this is a common problem but I couldn't find anything on it specifically like this.
Thanks in advance,
Cheers,
Jake
To Answer the comment:
View view = inflater.inflate(R.layout.main_frag, container, false);
mainLayout = (LinearLayout) view.findViewById(R.id.ll_MainFrag);
return view;
This is what is in my onCreateView.
Okay, just to add how I'm instantiating the Fragment:
private int MAIN = 1;
FragmentManager fm = getSupportFragmentManager();
fragments[MAIN] = new MainFragment();
FragmentTransaction transaction = fm.beginTransaction();
transaction.commit();
getSupportFragmentManager().beginTransaction().add(R.id.flMain, fragments[MAIN]).commit();
From here I would like to be able to do something like:
fragments[MAIN].createTextView();
When creating a Fragment, create public methods to set data:
public class MyFragment extends Fragment {
private TextView text1;
private TextView text2;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View layout = LayoutInflater.from(getActivity()).inflate(R.layout.simple_list_item_2,container,false);
text1 = (TextView) layout.findViewById(R.id.text1);
text2 = (TextView) layout.findViewById(R.id.text2);
return super.onCreateView(inflater, container, savedInstanceState);
}
public void setData(String t1, String t2){
text1.setText(t1);
text2.setText(t2);
}
}
When adding a fragment in parent activity, give it a unique tag:
MyFragment f = new MyFragment();
getFragmentManager().beginTransaction().add(f,"my_fragment").commit();
Later, you can search the fragment from parent activity and call some methods on it:
MyFragment frg = (MyFragment) getFragmentManager().findFragmentByTag("my_fragment");
if(frg != null){
frg.setData("abc","def");
}
Also, if fragment was added from a layout, you can find the fragment by its id.
I'm trying to figure out how fragments are working.
I have 3 classes, MainActivity, Fragment1 and Fragment2.
MainActivity extends SherlockFragmentActivity
and
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Fragment1 firstFragment = new Fragment1();
firstFragment.setArguments(getIntent().getExtras());
getSupportFragmentManager().beginTransaction()
.add(R.id.fragment_container1, firstFragment).commit();
Now, I load Fragment1 into my fragment_container, and it displays nice.
(So main_activity.xml has only one )
Ok, Fragment1 extends SherlockFragment, does nothing more then
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment1layout, container, false);
So I just inflate it from my .xml that has one text view and one button.
Where in the world now can I instance Button, and give him code to replace Fragment1 with Fragment2?
What is the code for that, as I'm now "in Fragment1" so I need to somehow communicate with Fragment holder and tell it "replace me with Fragment2".
Fragment2 also extends SherlockFragment, and does nothing, inflates it's empty .xml
You have to call your fragment2 from fragment1 like below
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment1layout, container, false);
Button button = (Button)view.findViewById(R.id.yourButton);
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
//Replace your fragment
}
});
return view;
}
I'm now "in Fragment1" so I need to somehow communicate with Fragment holder and tell it "replace me with Fragment2".
If you want replace Fragment1 to Fragment2 when you click on button which is into Fragment1:
(best practices)
you should create callbacks from fragment1 to MainActivity like it is described here
into MainActivity place logics which will replace fragment1 to fragment2.
(bad practices)
Create method into MainActivity which will replace one fragment to another for example changeFirstFragmentToAnother()
then when you need to change fragment1 to fragment2 you may call this method manually (from fragment1) like this:
((MainActivity)getActivity()).changeFirstFragmentToAnother();