Changing fragment transitions

Question

I have several fragments, all the fragments has entering & exit from left to right. I received a new requirement that several fragments will have different exit transitions while the previous fragment will be static(won`t have transition). Like in the image below:

I started by adding abstract function in my base fragment if it has different transitions:

public abstract boolean hasDifferentTransitions();

after that I modified the function where I am changing the fragments:

 public void replaceFragment(int container, Class<?> fragClass, Bundle b,boolean isSplash)
{

    BaseFragment bf = null;
    try
    {
        bf = (BaseFragment) fragClass.newInstance();
    }
    catch (Exception e)
    {
        e.printStackTrace();
    }


    String backStateName = bf.getClass().getSimpleName();
    FragmentManager manager = getSupportFragmentManager();
    //checking if I am on the same fragment
    if(_currentFragment!=null)
    {
        String currentFragmentName = _currentFragment.getClass().getSimpleName();
        if(currentFragmentName.equals(backStateName))//not allow same fragment to be twice in backstack one after the other
            return;
    }

    //checking if the "new fragement" is in the backstack if so I will pop out all the fragments till the required one.
    BaseFragment backStackFrag = (BaseFragment) manager.findFragmentByTag(backStateName);
    if(backStackFrag!=null)
    {
        _currentFragment = backStackFrag;
        for(int fIndex=manager.getBackStackEntryCount()-1;fIndex>=0;fIndex--) {
            String currentFragName = manager.getBackStackEntryAt(fIndex).getName();
            if (backStateName.equals(currentFragName)) {
                break;
            }
            manager.popBackStack();
        }
    }
    else {//new fragment - set the transitions by the hasDifferentTransitions returned value
        _currentFragment = bf;
        FragmentTransaction ft = manager.beginTransaction();
        if (isSplash) {
            ft.setTransition(FragmentTransaction.TRANSIT_NONE);
        } else {
            if(bf.hasDifferentTransitions())
            {
                ft.setCustomAnimations(R.anim.enter_from_left, R.anim.exit_to_right,R.anim.enter_from_right,R.anim.exit_to_left);
            }
            else
            {
                ft.setCustomAnimations(R.anim.enter_from_left, R.anim.exit_to_right);
            }
        }
        ft.replace(container, bf, bf.getClass().getSimpleName());
        ft.addToBackStack(bf.getClass().getSimpleName());
        ft.commitAllowingStateLoss();
    }
}

Unfortunately it`s not working as needed when I am on the "special fragment" and then open "regular fragment" they both moved from right to left, also sometimes when I am entering to "special fragment" it opens without any transitions

score 0 · Accepted Answer · answered Nov 27 '15 at 16:52

After many attempts I managed to implement this requirement. In my baseActivity I added this a variable to know when the user changes to "special fragment"

private boolean        _openedSingleFragment;
public boolean openedSingleFragment()
{
    return _openedSingleFragment;
}

public void setOpenedSingleFragment(boolean state)
{
    _openedSingleFragment = state;
}

then on each regular fragment I override onCreateAnimation as follows:

 @Override
public Animation onCreateAnimation(int transit, boolean enter, int nextAnim) {
    Animation anim = super.onCreateAnimation(transit, enter, nextAnim);
    if(enter && ((BaseActivity)getActivity()).openedSingleFragment())
    {
        anim = new Animation() {};
        anim.setDuration(0);

    }
    return anim;
}

with this code I am just removing the entering transition/animation when the user is on special fragment and open a regular one.

I also override onCreateAnimation in special fragment

 @Override
public Animation onCreateAnimation(int transit, boolean enter, int nextAnim) {
    Animation anim = super.onCreateAnimation(transit, enter, nextAnim);

    if(enter)
    {
        ((BaseActivity)getActivity()).setOpenedSingleFragment(false);
    }
    else
    {
        if (anim == null && nextAnim != 0) {
            anim = AnimationUtils.loadAnimation(getActivity(), R.anim.exit_to_left);
        }
    }

return anim; }

I am only resetting the boolean when starting the transition of the special fragment and when I am opening other fragments I am loading the specified animation.

Changing fragment transitions

1 Answers1