I have two fragments in an activity.
When i go from fragment A to fragment B, custom animation have been added. So that the view of fragment B slides in from the right on entry and then slides back out from right on exit.
But the fragment B can been seen to be entering from behind the view of fragment A. So when Fragment A is replaced by Fragment B, the view of Fragment B animates from right to left but it comes in from behind the view of Fragment A and not
in front of Fragment A.
I am able to notice this since half of Fragment A is transparent and Fragment B sliding in can be seen only from that transparent half indicating that it is sliding in from behind Fragment A and not from the front.
Not entirely sure why this is happening. The respective code has been provided below.
Could someone please help?
private void navigateToFragment(#NonNull Fragment fragment, boolean addToBackStack, int enterAnim, int exitAnim, int popEnterAnim, int popExitAnim) {
FragmentManager fragmentManager = getSupportFragmentManager();
final FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.setCustomAnimations(enterAnim, exitAnim, popEnterAnim, popExitAnim);
transaction.replace(R.id.member_address_root, fragment, fragment.getClass().getSimpleName());
if (addToBackStack){
transaction.addToBackStack(fragment.getTag());
}
fragmentManager.executePendingTransactions();
transaction.commit();
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_member_address);
if (savedInstanceState == null){
if (getIntent() != null){
Fragment fragment = FragmentA.newInstance();
navigateToFragment(fragment, false, R.anim.no_animation, R.anim.no_animation, R.anim.no_animation, R.anim.no_animation);
}
}
}
#Override
public void onFragmentBRequested() {
FragmentB fragment = new FragmentB();
navigateToFragment(fragment, true, R.anim.enter_from_right, R.anim.no_animation, R.anim.no_animation, R.anim.exit_from_right);
}
onFragmentBRequested() is called from FragmentA based on a button click.
Ok, So I experimented a bit with what you are trying to do. Basically you want that current fragment shouldn't move/animate from it's place & the new fragment should animate only. I couldn't achieve with transaction.replace() with 'R.anim.no_animation' as the entry animation happens behind the current fragment.
so instead of replacing new fragment, adding it seems more practical.
so using transaction.add() instead of transaction.replace() works as expected.
Related
Problem 1
I have a Navigation Drawer and most of my fragment transactions happens from here.
So say I have 4 Items in my drawer and I am doing the transaction from all of them. So if I am at the fragment [A] and now I click on the fragment [B], I need to come back to the previous fragment i.e. [A]. But if I keep clicking on the Item B of the navigation drawer that opens the fragment [B], I keep adding it to the backstack and when I press the back button, I am still at the same fragment.
Problem 2
How do I achieve the Clear Top behavior that is used for the intents for the fragments. As intents have the power to clear the activities from the stack from the top only, I want to achieve the same behavior.
Problem 1 & 2 solution Idea:
Create an Interface say FragmentInstanceHandler
public interface FragmentInstanceHandler {
public void openFragment(Fragment fragment, String fragmentTag);
}
Create a BaseFragment like below and extend this to all your Fragment classes:
public BaseFragment extends Fragment {
public FragmentInstanceHandler fragmentInstanceHandler;
public void setFragmentInstanceHandler(FragmentInstanceHandler fragmentInstanceHandler) {
this.fragmentInstanceHandler = fragmentInstanceHandler;
}
}
Implement the FragmentInstanceHandler interface to the Activity in which you are going to open all the Fragments. Let's say Activity is MainActivity:
public MainActivity extends Activity implements FragmentInstanceHandler {
private BaseFragment currentFragment;
#Override
public void openFragment(BaseFragment fragment, String fragmentTag) {
FragmentManager fragmentManager = getSupportFragmentManager();
Fragment oldFragmentInstance = fragmentManager .findFragmentByTag(fragmentTag);
boolean fragmentPopped = fragmentManager.popBackStackImmediate (fragmentTag, 0);
if (!fragmentPopped && oldFragmentInstance == null) {
fragment.setFragmentInstanceHandler(this);
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.add(R.id.container, fragment, fragmentTag);
fragmentTransaction.addToBackStack(fragmentTag);
fragmentTransaction.commit();
currentFragment = fragment;
} else if(fragmentPopped ){
currentFragment = oldFragmentInstance;
}
if(mDrawerLayout!= null)
mDrawerLayout.closeDrawers();
}
}
Now whenever you want to open a new Fragment even from any other Fragment you can call method like below, It is advised to provide new tag if you want to have new instance of same Fragment:
fragmentInstanceHandler.openFragment(new MyFragment(), "FragmentNewInstance");
You can tweak FragmentInstanceHandlerto add your own method to replace the current Fragment instead of adding. Above solution just gives you an idea how you can acheive your solution by putting and mananging all your code from one place.
I am testing situation where a user goes into my app after the system has terminated the app process due to low RAM. I am seeing unexpected behavior and hoping to get some help.
In my app, I have an activity, lets call it ActivityA, that immediately creates a fragment, Fragment A, and does a fragment replacement. FragmentA displays a ListView with two items in it. If the user clicks the first item, a second fragment, Fragment B is created and replaces FragmentA. Otherwise, another FragmentA is created and replaces the original FragmentA. I'm trying to create a file directory tree. FragmentA is for directories, and FragmentB is for files.
Lets say the user clicks on a file. This is the stage in the test where the user switches to another app, and the system terminates my app's process due to low memory. Then, the user goes back into my app expecting everything to be left the way it was. However, what actually happens is Fragment A (The parent directory) is being displayed instead of Fragment B (the file). When the user clicks the back button, Fragment B (the file) is then displayed. What am I doing wrong that is causing the system to restore the backstack in this way?
Here is an example program to further show what my app is doing:
// ActivityA.java
public class ActivityA extends AppCompatActivity implements onItemClickListener
{
#Override
public void onCreate(Bundle savedInstanceState)
{
FragmentA fragA = new FragmentA();
FragmentTransaction fragmentTransaction =
getSupportFragmentManager().beginTransaction();
fragmentTransation.replace(R.id.basic_frame, fragA);
fragmentTransaction.commit();
}
#Override
public void onItemClick(AdapterView<?> aView, View v, int position, long id)
{
if (position == 0)
{
FragmentB fragB = new FragmentB();
FragmentTransaction fragmentTransaction =
getSupportFragmentManager().beginTransaction();
fragmentTransation.replace(R.id.basic_frame, fragB);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
}
else
{
FragmentB fragA = new FragmentA();
FragmentTransaction fragmentTransaction =
getSupportFragmentManager().beginTransaction();
fragmentTransation.replace(R.id.basic_frame, fragA);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
}
}
}
When you call super.onCreate(), Fragments automatically restore their current state when savedInstanceState is not null.
Therefore if you're expecting to do one time set up by adding your intial Fragment, you should always surround it with an if (savedInstanceState == null) check:
#Override
public void onCreate(Bundle savedInstanceState)
{
// I assume you accidentally left out these lines
super.onCreate(savedInstanceState);
setContentView(R.id.your_content_view);
if (savedInstanceState == null) {
FragmentA fragA = new FragmentA();
FragmentTransaction fragmentTransaction =
getSupportFragmentManager().beginTransaction();
fragmentTransation.replace(R.id.basic_frame, fragA);
fragmentTransaction.commit();
}
}
I have these methods for fragment manipulation:
public void replaceFragment(Fragment fragment) {
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.main_frame, fragment);
fragmentTransaction.commit();
fragmentManager.executePendingTransactions();
}
public void addFragment(Fragment fragment, boolean addToBackStack) {
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.main_frame, fragment);
if (addToBackStack) {
fragmentTransaction.addToBackStack(fragment.getClass().getName());
}
fragmentTransaction.commit();
fragmentManager.executePendingTransactions();
}
public void clearFragments() {
if (fragmentManager.getBackStackEntryCount() > 0) {
FragmentManager.BackStackEntry first = fragmentManager.getBackStackEntryAt(0);
fragmentManager.popBackStack(first.getId(), FragmentManager.POP_BACK_STACK_INCLUSIVE);
}
}
Scenario:
I start with fragment A, when activity is created. addFragment(new A, false);
Then I add fragment B. replaceFragment(new B);
I add another fragment C. addFragment(new C);
In C fragment I want to reset application to A fragment. I call clearFragments(); addFragment(new A, false);
The problem is that B fragment onCreateView is called after pressing button on C fragment that clears fragments and adds A fragment. I don't see the fragment, but it starts background thread that crashes my app. I need to clear all fragments without calling their onCreateView() methods.
Is this expected behaviour, or am I doing something wrong?
Actually in such a scenario you will always return to the fragment B.
Step by step:
Adding A.
Replacing A with B <- after this step you don't have A within your activity.
Adding C. Here you are adding another fragment and telling FragmentManager to preserve current state of fragments to the back stack. Your current state at this point is fragment B. Then fragment C is added.
When you call clearFragments, FragmentManager returns to the first saved state - and this state is fragment B.
Maybe you forgot to mention something? I tried to put several entries in a back stack and then reset to the first state - onCreateView is called once, only for the first fragment.
I'm working with Fragments for the first time and running into a weird behavior. I have an activity with a Fragment covering the entire view. It contains a ListView. When I tap on an item in the ListView, I want to show a details fragment which contains information about that item.
This is how I'm presenting the new fragment view:
FragmentManager fragmentManager = this.getActivity().getSupportFragmentManager();
FragmentTransaction transaction = fragmentManager.beginTransaction();
DetailsFragment fragment = new DetailsFragment();
transaction.add(R.id.viewRoot, fragment).setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN)
.addToBackStack("Details").commit();
R.id.viewRoot is the id of the root layout in the first Fragment's layout xml, so the new Fragment fills the entire screen.
My Problem: When the new fragment is visible and covering the entire screen, any clicks or taps which land on the background (i.e. not hitting a button or textfield on the new fragment) appear to be going through the view and landing on the first fragment. So, I tap on a ListView item, which causes the DetailsFragment to get added to the screen. Then when I tap on the background of the DetailsFragment, that tap falls through and lands on the ListView causing another DetailsFragment to be added for whatever item I happened to hit behind the scenes.
Am I adding my new fragment incorrectly? Why are my clicks/taps falling through?
EDIT for caiuspb:
public class BaseFragment extends Fragment {
public void pushNewFragment(Fragment fragment, String description) {
FragmentManager fragmentManager = getActivity().getSupportFragmentManager();
FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.remove(this);
transaction.add(R.id.viewRoot, fragment).setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN)
.addToBackStack(description).commit();
}
}
All of my fragments extend my BaseFragment class.
I experimented with the suggestions I received, but none of them worked. In the end, my solution was to add an OnTouchListener to the root view of my subfragments which discarded all touches.
View view = inflater.inflate(R.layout.mylayout, container, false);
view.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
return true;
}
});
There is another post here on StackOverflow about that strange Fragment behaviour. Try to remove your Fragment before you add it because the replace Method seems to be buggy
edit:
Move the Fragment logic into your Activity because your activity contains your Fragments. Today I tried to use the FragmentActivity and Fragments from the Android Support Library. Now I can use the replace method withouht any bugs. This is my approach and this works:
public class DashActivity extends FragmentActivity{
...
private void changeRightFragment(Fragment fragment) {
Log.i(TAG, "Loading Fragment into container: " + fragment.getClass().toString());
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.replace(R.id.rightfrag, fragment);
// Add a transition effect
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
// Add the Fragment to the BackStack so it can be restored by
// pressing the Back button
ft.addToBackStack(null);
ft.commit();
}
...
public void setUserFragment(User user) {
UserFragment fragment = new UserFragment(user);
changeRightFragment(fragment);
}
So if you want to invoke a changeFragment method from inside your Fragment use a callback mechanism to the Activity
I have a 3 fragments in an activity when the a tablet is held in portrait. However I only have 2 of these fragments when in landscape. The problem I am having is when going from portrait to landscape the activity is creating the 3rd fragment. I receive and error as this fragment cannot be created.
I have worked out that this fragment is being created because it is in the back stack.
I have tried to remove the fragment in the onDestroy method by using
FragmentTransaction f = fragmentManager.beginTransaction();
f.remove(mf);
f.commit();
However the I get an error saying that I cannot use this function after the onSaveInstanceState
What would be the correct way of taking this fragment out of the back stack?
Update
I should probably add that the fragment I am having problems with is a mapFragment from this libary
https://github.com/petedoyle/android-support-v4-googlemaps
The way I use it is like so
mf = MapFragment.newInstance(1, true);
ft = fragmentManager.beginTransaction();
ft.replace(R.id.mapContainer, mf);
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
ft.addToBackStack("map");
ft.commit();
You add to the back state from the FragmentTransaction and remove from the backstack using FragmentManager pop methods:
FragmentManager manager = getActivity().getSupportFragmentManager();
FragmentTransaction trans = manager.beginTransaction();
trans.remove(myFrag);
trans.commit();
manager.popBackStack();
I created a code to jump to the desired back stack index, it worked fine to my purpose.
ie. I have Fragment1, Fragment2 and Fragment3, I want to jump from Fragment3 to Fragment1
I created a method called onBackPressed in Fragment3 that jumps to Fragment1
Fragment3:
public void onBackPressed() {
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.popBackStack(fragmentManager.getBackStackEntryAt(fragmentManager.getBackStackEntryCount()-2).getId(), FragmentManager.POP_BACK_STACK_INCLUSIVE);
}
In the activity, I need to know if my current fragment is the Fragment3, so I call the onBackPressed of my fragment instead calling super
FragmentActivity:
#Override
public void onBackPressed() {
Fragment f = getSupportFragmentManager().findFragmentById(R.id.my_fragment_container);
if (f instanceof Fragment3)
{
((Fragment3)f).onBackPressed();
} else {
super.onBackPressed();
}
}
you show fragment in a container (with id= fragmentcontainer) so you remove fragment with:
Fragment fragment = getSupportFragmentManager().findFragmentById(R.id.fragmentContainer);
fragmentTransaction.remove(fragment);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
In case you ended up here trying to figure out how to remove fragment(s) from backstack and you are using Android Jetpack Navigation component you could just use app:popUpTo and app:popUpToInclusive in action node of navigation graph xml to specify fragments that you want to pop out of back stack.
https://developer.android.com/guide/navigation/navigation-navigate#pop
Check this too
https://stackoverflow.com/a/51974492/4594986
What happens if the fragment that you want to remove is not on top of the stack?
Then you can use theses functions
popBackStack(int arg0, int arg1);
popBackStack(String arg0, int arg1);