Develop Reference

Fragment overlapping on click event ? - ANDROID

I don't know why my application behave in 2 different ways when i'm changing fragments. I have a menu drawer and inside a fragment i try to launch a new fragment on the same container using click event.
so when i use the menu to access to that fragment everything work well but when i try to access to the same fragment from another fragment (same container) i got on my screen both fragment overlapping.
Home fragment image
as you can see in this fragment i try to click on the bank icon to change the current fragment with another and that the result
fragment overlapping image
i'm using the fragment class to execute the click event here is the code :
cardView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
FragmentManager fragmentManager = getActivity().getSupportFragmentManager();
FragmentTransaction ft = fragmentManager.beginTransaction();
ft.replace(R.id.nav_host_fragment, new AboutFragment());
ft.commit();
}
});
Please remember that when i access to the 2nd fragment using menu it works.

Fragments stacking on each other

I have a problem with fragments. In my xml file I have a fragment already set there, I want with the click of a button replace it with another fragment. So with my code I can replace the fragment with the one that I want on the click of the button, but the first fragment wont disappear, so I can still see it under my second fragment, the code it's this:
public class MainActivity extends AppCompatActivity {
FragmentManager fragmentManager;
Button button;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.fragment,new BlankFragment2());
fragmentTransaction.addToBackStack(null).commit();
}
});
}
}

Set a background color of the root layout of the second fragment and put clickable and focusable true in xml file. It will make disappear of the first fragment and also disable the clicks of first fragment when showing another fragment.

Remove addToBackStack(null).
That stores the Fragment and keeps it attached so that calling popBackStack() will remove the top Fragment and replace it with the previous.

correctly implementing addToBackStack will help in this case and many other
addToBackStack takes an argument which is called task record TAG , To perform a transaction later on , you can use this tag to remove back stack up to a point
For more understanding read
https://medium.com/#bherbst/managing-the-fragment-back-stack-373e87e4ff62

How to avoid Fragment going back to previous Fragment on pressing device back button?

I am developing an android in which when I pressed device back button I go to previous fragment. What I want to achieve is that when I pressed device back button I don't want to go to previous fragment. How can I achieve that?.

You must be doing calling addtobackstack("name") while adding or replacing the fragment.Remove this function before calling next fragment you wont go back to previous fragment for further desc

Do not add that fragment to backstack of the new fragment you're calling. Look at the below example I've used to explain you how this works.
To make that fragment come again, just add that fragment to backstack which you want to come on back pressed,
Eg:
btnSignIn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Fragment fragment = new LoginFragment();
//replacing the fragment
if (fragment != null) {
FragmentTransaction ft = ((FragmentActivity)getContext()).getSupportFragmentManager().beginTransaction();
ft.replace(R.id.content_frame, fragment);
ft.addToBackStack("SignupFragment");
ft.commit();
}
}
});
In the above case, I m opening a LoginFragment when signIn button is pressed, right now am in SignupFragment. So if I call addToBackStack(TAG), TAG = "SignupFragment", then when back button is pressed in LoginFragment, we come to SignUpFragment.
Happy Coding!

Show/Hide two fragments in a single Layout [Both fragments have a Google map each]

I have an activity with a relative layout; And have two different fragments. I show one fragment and switch to the next fragment on a button click vice verse.
// When button menu is clicked
OnClickListener btnClick = new OnClickListener() {
#Override
public void onClick(View arg0) {
if(currentType==0){
InitThisFragment(1);
}else{
InitThisFragment(0);
}
}
};
public void InitThisFragment(int type){
Fragment newFragment;
if(type==0){
newFragment=new MainFragment();
}else{
newFragment=new JourneyFragment();
}
currentType=type;
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.abs_fragment_container, newFragment);
transaction.addToBackStack(null);
transaction.commit();
}
R.id.abs_fragment_container is a Relative Layout
BOTH THE FRAGMENT CONTAIN GOOGLE MAPS INSIDE THEM;
But it is not working as expected.
By default i add the first fragment [which works fine].
Then after an onClick event the 2nd fragment comes[which also works
fine]
But on my next click the app crashes;
Please help I am new to Google Maps and Fragments;

yeah of course your app crashes because the fragment with the map already exists look at this thread it helped me a lot: Duplicate ID, tag null, or parent id with another fragment for com.google.android.gms.maps.MapFragment
Especially the second answer with 41 ups is easy to understand
And yes I would have posted this one in a comment if I would have enough reputation for it!

Create custom BackKey to navigate through framents

I got the next FragmentActivity. This FragmentActivity inflates a layout with a LinearLayout(a menu where some buttons are defined to call other fragments) and a FrameLayout (a black space where the other fragments are loaded depending the button I select).
public class MenuViewActivity extends FragmentActivity {
....
I load the selected Fragment using onClickListener:
protected void onCreate(Bundle savedInstanceState) {
....
final OnClickListener fragment_1 = new OnClickListener() {
#Override
public void onClick(View v) {
fragment_1 Fragment = new fragment_1();
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.fragment_container, Fragment);
transaction.addToBackStack(null);
transaction.commit();
}
};
I do this for about 5 buttons. This menu also contains a custom back key. The functionality of this back button should be like:
[fragment_1][fragmen_2][fragment_3][fragment_4][fragment_5]
The app starts always showing fragment_1. I con go from fragment_1 to any of the other fragments. So I could go for example from [fragment_1] to [fragment_4]. When pressing the back key I should go back to [fragment_1].
To detail a little bit more the functionality, I could do: [fragment_1]->[fragment_2]->[fragment_3] and when pressing back, should go back to [fragment_1].
I've got a onClickListener for the back key, but I don't know how to implement this functionality.

you're looking for this
getSupportFragmentManager().popBackStack();
also if you're unaware that's the default functionality for the actual android back button, so unless you've overrode it that will do the same thing.

You just need to pop all fragments from your backstack, unless you reach the one you want. It is probably simplest to use FragmentManager's popBackStack():
public abstract void popBackStack (int id, int flags)
Pop all back stack states up to the one with the given identifier