The action of back button is bring back to the previous page.
How to change the action of back button in Android fragment, for example:
if( click back button ) then
Toast.maketext("text");
my code is :
public class Rechercher extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
/* pour creer le fragment */
view = inflater.inflate(R.layout.rechercheavance, container, false);
return view;
}
}
From the Activity, override the onBackPressed() method for custom back press action. Hold an instance of the fragment when you attach it and use a public method in the fragment for doing something from the fragment by calling it from the onBackPressed() method.
Activity
SomeFragment fragment;
#Override
public void onCreate(Bundle savedInstanceState) {
...
//Create the fragment instance
fragment = new SomeFragment();
//Now add the fragment to the layout
}
...
#Override
public void onBackPressed() {
//Called when back pressed
fragment.doSomething();
}
And in the Fragment define the method doSomething
public void doSomething() {
//custom action
}
Related
I've been developing an android app which I included the default Navigation-Drawer from Android Studio and so on. In my home fragment, I've implemented CarViews, and then set those cardview(s) OnClickListener to replace the fragment with traditional procedure.
After the fragment replacement and new page comes, I wanted to change the Actionbar title.
So in the onCreateView(...) method, I tried,
((AppCompatActivity)getActivity()).getSupportActionBar().setTitle("B");
It worked. But after pressing the hardware back button to go back to the stacked fragment, the title remains changed & it doesn't change to "Home" again. I've tried other ways. Here's my following codes. Thanks in advance.
public class HomeFragment extends Fragment implements View.OnClickListener {
public View onCreateView(#NonNull LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
View root = inflater.inflate(R.layout.fragment_home, container, false);
Objects.requireNonNull(((AppCompatActivity) Objects.requireNonNull(getActivity())).getSupportActionBar()).setTitle("Home");
CardView cardView1 = root.findViewById(R.id.doctor_on);
CardView cardView2 = root.findViewById(R.id.ambulance_e);
CardView cardView3 = root.findViewById(R.id.maintainance_s);
cardView1.setOnClickListener(this);
cardView2.setOnClickListener(this);
cardView3.setOnClickListener(this);
return root;
}
#Override
public void onClick(View v) {
int id = v.getId();
switch (id) {
case R.id.doctor_on:
FragmentTransaction fragmentTransaction = Objects.requireNonNull(getActivity()).getSupportFragmentManager().beginTransaction();
Fragment fragment1 = new doctors();
fragmentTransaction.replace(R.id.container1, fragment1).addToBackStack(getString(R.string.menu_home)).commit();
return;
case R.id.ambulance_e:
//Put Actions
FragmentTransaction fragmentTransaction2 = Objects.requireNonNull(getActivity()).getSupportFragmentManager().beginTransaction();
Fragment fragment2 = new ambulance();
fragmentTransaction2.replace(R.id.container1, fragment2).addToBackStack(getString(R.string.menu_home)).commit();
return;
case R.id.maintainance_s:
//Put Actions
FragmentTransaction fragmentTransaction3 = Objects.requireNonNull(getActivity()).getSupportFragmentManager().beginTransaction();
Fragment fragment3 = new maintanance();
fragmentTransaction3.replace(R.id.container1, fragment3).addToBackStack(getString(R.string.menu_home)).commit();
return;
}
}
#Override
public void onResume() {
super.onResume();
((AppCompatActivity) getActivity()).getSupportActionBar().setTitle("Home");
}
}
To the next fragment(where I change the titlebar and pressed back button):
public class doctors extend Fragment{
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
((AppCompatActivity)getActivity()).getSupportActionBar().setTitle("B");
View root = inflater.inflate(R.layout.fragment_doctors, container, false);
return root;
}
}
And in the doctors Fragment... Should fix the title error.
#Override
public void onDestroyView() {
super.onDestroyView();
Objects.requireNonNull(((AppCompatActivity) Objects.requireNonNull(getActivity()))
.getSupportActionBar())
.setTitle(getString(R.string.your_title_here));
}
You have to override the method onBackPressed() and write the code:
#Override
public View onBackPressed(){
//Here goes the code that head back to your main fragment
FragmentTransaction fragmentTransaction3 = Objects.requireNonNull(getActivity()).getSupportFragmentManager().beginTransaction();
Fragment fragment3 = new maintanance();
fragmentTransaction3.replace(R.id.container1, fragment3).addToBackStack(getString(R.string.menu_home)).commit();
}
}`
Add below code in Home Fragment...
#Override
public void onHiddenChanged(Boolean hidden) {
super.onHiddenChanged(hidden);
((AppCompatActivity) getActivity()).getSupportActionBar().setTitle("Home");
}
I need to display a Fragment when the user touches the TextView of another Fragment. Here's what I have:
public class FindPeopleHelpFragment extends Fragment {
public FindPeopleHelpFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_find_people_help, container, false);
((AppCompatActivity)getActivity()).getSupportActionBar().setTitle(R.string.find_people_help);
TextView welcome_home = (TextView) view.findViewById(R.id.find_people_help);
welcome_home.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View view, MotionEvent evt) {
if (evt.getAction() == MotionEvent.ACTION_DOWN) {
EditProfileFragment editProfileFragment = new EditProfileFragment();
FragmentManager manager = getActivity().getSupportFragmentManager();
manager.beginTransaction().replace(R.id.fragment_container, editProfileFragment, editProfileFragment.getTag()).commit();
}
return true;
}
});
// Inflate the layout for this fragment
return view;
}
}
The issue is that onTouch() returns a boolean, but when replacing the Fragment, I need to return a View. Otherwise I get the following.
10-05 15:00:51.057 25152-25152/wegrok.chiaramail.com E/AndroidRuntime: FATAL EXCEPTION: main
Process: wegrok.chiaramail.com, PID: 25152
java.lang.IllegalArgumentException: No view found for id 0x7f0f00b1 (wegrok.chiaramail.com:id/fragment_container) for fragment FindPeopleHelpFragment{c052157 #1 id=0x7f0f00b1}
Anyone know how to deal with this?
You need to make these Fragment transactions from your Activity. The Activity that hosted the Fragment should have a public function for handling the fragment switching so that when the TextView of your Fragment1 is clicked, the public method of the Activity will be called to make the Fragment switch.
So you might consider having an Activity like this.
public class YourActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_layout);
// The Fragment 1 will be loaded by default
switchToFragment1();
}
public void switchToFragment1() {
getSupportFragmentManager().beginTransaction()
.replace(R.id.fragment_container, new Fragment1()).commit();
}
public void switchToFragment2() {
getSupportFragmentManager().beginTransaction()
.replace(R.id.fragment_container, new Fragment2()).commit();
}
}
Now from your Fragment1, you need to implement an onClick listener in to the TextView, so that when the TextView is clicked, Fragment1 switches to Fragment2.
textView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
((YourActivity) getActivity()).switchToFragment2();
}
});)
Hope that helps.
i am just working with fragments for the 1st time, i have a checkbox inside a fragment and a submit button inside my main activity. what i want to do is when i press submit button i want to toast a message whether the checkbox item is checked or not?
MainActivity.java
public class MainActivity extends AppCompatActivity {
private Spinner Dspinner;
private Button Subbtn;
ArrayAdapter adapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Subbtn = (Button)findViewById(R.id.button);
adapter = ArrayAdapter.createFromResource(this, R.array.spinner_options, android.R.layout.simple_spinner_item);
spinnerListner();
}
public void spinnerListner(){
Dspinner = (Spinner)findViewById(R.id.spinner);
Dspinner.setAdapter(adapter);
Dspinner.setOnItemSelectedListener(
new AdapterView.OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
switch (position){
case 0:
getSupportFragmentManager().beginTransaction().replace(R.id.frag, BlankFragment.newInstance()).addToBackStack(null).commit();
break;
case 1:
getSupportFragmentManager().beginTransaction().replace(R.id.frag, BlankFragment2.newInstance()).addToBackStack(null).commit();
break;
}
}
#Override
public void onNothingSelected(AdapterView<?> parent) {
}
}
);
}
}
BlankFragment.java
public class BlankFragment extends Fragment {
public BlankFragment(){
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_blank, container, false);
}
public static Fragment newInstance() {
BlankFragment fragment = new BlankFragment();
return fragment;
}
}
BlankFragment2.java
public class BlankFragment2 extends Fragment {
public BlankFragment2(){
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_blank_2, container, false);
}
public static Fragment newInstance() {
BlankFragment2 fragment = new BlankFragment2();
return fragment;
}
}
You can use interface to communicate back to MainActivity.
Create a interface and implement it on MainActivity.
Pass the implemented interface to fragment and store it in the fragment
Then When your checkbox state change check that the stored interface is null or not if not null then call the implemented method
of the interface, which is actually implemented in MainActivity.
This way you can communicate back to MainActivity. In MainActivity store your checkbox state and do what you want to do in button press.
Interface
public interface OnStateChanged {
public void onChange(int state);
}
Implement it on MainActivity like
MainActivity implements OnStateChanged {
#Override
public void onChange(int state){
// store your data here
}
Create a variable for OnStateChanged interface and function in Fragment that will pass the interface
In Fragment:
OnStateChanged mListener;
public void setOnStateChangeListener(OnStateChanged listener){
mLinstener = listener;
}
When checkbox state change call the interface function
In Fragment:
//...if state change...
if(mListener!= null) {
mListener.onChange(/*your value*/);
}
Pass the implemented interface instance in MainActivity to fragment
In MainActivity:
fragment.setOnStateChangeListener(this);
There are several ways to realize this function. The easiest way is Defining an interface in your Activity, and let the Fragment implements it.(Or you can define a interface individually and let the Activity implements it, it's the similar solution)
For more solutions you can Google "Fragment and Activity Interaction".
I just can offer you some fragmentary code since I cannot find specific variable names.
First, defining a Interface in your Activity like this:
public static class MainActivity extends AppCompatActivity{
...
//Container Activity must implement this interface
public interface CheckBoxStateCallback{
public Boolean getTheState();
}
...
Second, let your fragments implements it:
public class BlankFragment extends Fragment implements CheckBoxStateCallback{
public BlankFragment(){
}
#Override
public Boolean getTheState(){
//return your checkbox state
}
...
Last, you need to add a click listener onto your Button in Activity:
...
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Boolean b = BlankFragment.newInstance().getTheState();
//then you can make a toast
}
});
...
In MainActivity you would implement an interface CheckboxStatusObserver which we define with a method checkBoxChanged.
public class MainActivity extends AppCompatActivity implements CheckboxStatusObserver{
// other methods
void checkBoxChanged(boolean checkedStatus){
Toast.makeText(getContext(), "status " + checkedStatus, Toast.LENGTH_LONG).show();
}
public interface CheckboxStatusObserver{
void checkBoxChanged(boolean checkedStatus);
}
}
In the Fragment, we would get a reference to the CheckboxStatusObserver as the parent Activity. Then while inflating the contents of the Fragment, we can set up a listener to detect the on change of the checkbox(s). Then we would call the observer.checkBoxChanged(checkedStatus); and pass it the checked status of the checkbox.
public class BlankFragment extends Fragment {
private CheckboxStatusObserver observer;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
observer = (CheckboxStatusObserver) getActivity();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_blank, container, false);
// Find the checkbox instace using view.findViewById();
// Setup change listener on checkbox instance and notify the observer
{
observer.checkBoxChanged(checkedStatus);
}
return view;
}
}
Whenever the checkbox status changes, the method in the MainActivity will get invoked.
See below links for more information:
https://stackoverflow.com/a/25392549/592025
https://developer.android.com/training/basics/fragments/communicating.html
To allow a Fragment to communicate up to its Activity, you can define an interface in the Fragment class and implement it within the Activity. The Fragment captures the interface implementation during its onAttach() lifecycle method and can then call the Interface methods in order to communicate with the Activity.
Create an Interface in Your MainActivity and click listeners as below
try {
((OnClick) this).onSubmitClicked();
} catch (ClassCastException cce) {
cce.printStackTrace();
}
public interface OnClick {
public void onSubmitClicked();
}
Now implement listeners in your Fragment thus you will get onSubmitClicked implemented method as below Enjoy!
public class BlankFragment extends Fragment implements MainActivity.OnClick{
#Override
public void onSubmitClicked() {
//do something here
}
}
This is yet another way different from what i commented that day this might meet your need
In Main Activty
Blank1Fragment fragment1 = new Blank1Fragment();
Blank2Fragment fragment2 = new Blank2Fragment();
Subbtn..setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if(position==0)
fragment1.function();
else if(position==1)
fragment2.function();
}
);
in OnitemClick of spinner
switch (position){
case 0:
position=0;
getSupportFragmentManager().beginTransaction().replace(R.id.frag, fragment1).addToBackStack(null).commit();
break;
case 1:
position=1;
getSupportFragmentManager().beginTransaction().replace(R.id.frag, fragment2).addToBackStack(null).commit();
break;
}
}
Each fragment will have
public class Blank1Fragment extends Fragment {
....
public void function(){
//check which checkbox selected and toast;
}
}
public class Blank2Fragment extends Fragment {
....
public void function(){
//check which checkbox selected and toast;
}
}
I have four fragments in an Activity C. they are behaving as tabs. I have to go from a fragment to a new Activity X. Now i want to come back to fragment from Activity X to fragment.
here is my main activity
'public class MainInterface extends ActionBarActivity {
ViewPager pager;
PagerTabStrip tab_strp;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_interface);
MainPagerAdapter mapager = new MainPagerAdapter(getSupportFragmentManager());
pager = (ViewPager) findViewById(R.id.pager);
pager.setAdapter(mapager);
tab_strp = (PagerTabStrip) findViewById(R.id.tab_strip);
//tab_strp.setTextColor(Color.WHITE);
//tab_strp.setTextSize(14,14);
//tab_strp.setTabIndicatorColor(Color.WHITE);
getSupportActionBar().setBackgroundDrawable(new ColorDrawable(Color.parseColor("#2196f3")));
getSupportActionBar().setTitle("Instructor");
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
//getSupportActionBar().setHomeButtonEnabled(true);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
// app icon in action bar clicked; goto parent activity.
this.finish();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
}
'
here is activity
'public class Discussions extends Fragment implements View.OnClickListener {
ImageButton post;
TextView dTitle;
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View view =inflater.inflate(R.layout.discussions,container,false);
post=(ImageButton)view.findViewById(R.id.ibDisc);
post.setOnClickListener(this);
dTitle=(TextView)view.findViewById(R.id.tvDiscTitle);
return view;
}
#Override
public void onClick(View view) {
Intent in=new Intent(getActivity(),PostDiscussion.class);
startActivity(in);
}
}'
Save the name of your fragment in sharedPreferences before navigating to new activity and onBackpressed of that new activity or when you want to come back to same fragment get the name from SharedPreferences and add that particular fragment to the earlier activity
Any time the main Activity is started or restarted (i.e. by pressing the home button on my action bar), all of the buttons (which reside in a fragment in this main activity) work correctly. However, if I press one of the buttons, then press the back button, the home fragment and its buttons reappears but none of the button callbacks work. The button images continue to change appearance when pressed, as always.
The callbacks are assigned in the onCreateView method of the home fragment, as follows:
public class HomeFragment extends SherlockFragment {
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
Button button = (Button) v.findViewById(R.id.button);
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
Log.d(TAG, "Button!");
mActivity.getSupportFragmentManager().beginTransaction()
.replace(R.id.contFragMain, new SomeFragment())
.addToBackStack(null)
.commit();
}
});
}
Here is the superclass of Fragments I launch with the buttons:
public abstract class RouteListFragment extends SherlockFragment {
private static final String TAG = RouteListFragment.class.getName();
private Activity mActivity; // parent activity
RouteListAdapter mAdapter;
ListView mListViewRouteList;
public RouteListFragment() {
super();
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mActivity = getActivity();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
Bundle bndl = getArguments(); // data passed should contain search term
View v = inflater.inflate(R.layout.fragment_route_list, container, false);
mListViewRouteList = (ListView) v.findViewById(R.id.listViewRouteList);
addRoutesToList(); //Populates the list with data via an async DB call
return v;
}
You shouldn't be stashing the Activity reference; the Activity is probably getting recreated at some point (depends on how your flow is), but you should either reassign the reference in onAttach (Activity activity), or just call getActivity() to get the currently Activity you're attached to.
So mActivity.getSupportFragmentManager()...
should instead be
getActivity().getSupportFragmentManager()...
EDIT: Wait, maybe that's not right. What is v in onCreateView()? You're not creating any UI in this Fragment? You should be using onViewCreated() to get a reference to the views in the created hierarchy.