Android Fragment Translate Animation on show, hide

Question

I have 4+ Fragments ( android.support.v4.app.Fragment ).

Fragment f1, f2, f3, f4;
int F1 = 1; int F2 = 2; int F3 = 3; int F4 = 4;

protected void onCreate(Bundle savedInstanceState)
{
  //...
  f1 = new Fragment();
  f2 = new Fragment();
  f3 = new Fragment();
  f4 = new Fragment();

  getSupportFragmentManager().beginTransaction()
            .add(R.id.fl_root, f1)
            .add(R.id.fl_root, f2)
            .add(R.id.fl_root, f3)
            .add(R.id.fl_root, f4)
            .commit();

  setFragment(F1);
}

---

public void setFragment(int fragment)
{
  switch (fragment)
    {
        case F1:
            if (!f1.isVisible()) {
                getSupportFragmentManager().beginTransaction()
                        .setCustomAnimations(R.anim.rtol, R.anim.ltor, 0, 0)
                        .show(f1)
                        .hide(f2)
                        .hide(f3)
                        .hide(f4)
                        .commit();
            }
            break;
       case F2:
            if (!f2.isVisible()) {
                getSupportFragmentManager().beginTransaction()
                        .setCustomAnimations(R.anim.rtol, R.anim.ltor, 0, 0)
                        .show(f2)
                        .hide(f1)
                        .hide(f3)
                        .hide(f4)
                        .commit();
            }
            break;
      case F3:
            if (!f3.isVisible()) {
                getSupportFragmentManager().beginTransaction()
                        .setCustomAnimations(R.anim.rtol, R.anim.ltor, 0, 0)
                        .show(f3)
                        .hide(f1)
                        .hide(f2)
                        .hide(f4)
                        .commit();
            }
            break;
     case F4:
            if (!f1.isVisible()) {
                getSupportFragmentManager().beginTransaction()
                        .setCustomAnimations(R.anim.rtol, R.anim.ltor, 0, 0)
                        .show(f4)
                        .hide(f1)
                        .hide(f2)
                        .hide(f3)
                        .commit();
            }
            break;
}

---

After setFragment to first, second and so on (1->2->3->4) rtol (translate from right to left) animation works, and it's fine.
But after going back, using setFragment (4->3->2->1), there are still rtol animation, instead of correct ltor (translate from left to right).

---

What I'm doing wrong, and what is the solution?

Answer 1

Actually there are 20+ Fragments in Single Activity in my Project.
I solved this animation problem + OutOfMemory (because of 20+ fragments added and hided).
A little bit code:

    FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
    if (!back)
        ft.setCustomAnimations(R.anim.enter_from_right, R.anim.exit_to_left);
    else
        ft.setCustomAnimations(R.anim.enter_from_left, R.anim.exit_to_right);

    switch (fragment)
    {
        case F1:
            ft.replace(R.id.fl_root, new F1(), String.valueOf(F1));
            break;
        //...
    }

---

Slide Animation here

Answer 2

The setCustomAnimations method takes one anim for entering and one for exiting a fragment so even if you go back, you are entering one of these fragments.

So you have to take a look at the fragment you are coming from and switch the animations.

Edit:

Maybe like this untested

int lastFragment;

public void setFragment(int fragment)
{
    FragmentTransaction ft = getSupportFragmentManager.beginTransaction();
    if(fragment > lastFragment) {
        ft.setCustomAnimations(R.anim.rtol, R.anim.ltor, 0, 0);
    } else {
        ft.setCustomAnimations(R.anim.ltor, R.anim.rtol, 0, 0);
    }

  switch (fragment)
    {
        case F1:
            if (!f1.isVisible()) {
                        ft
                        .show(f1)
                        .hide(f2)
                        .hide(f3)
                        .hide(f4)
                        .commit();
            }
            break;
       case F2:
            if (!f2.isVisible()) {
                        ft
                        .show(f2)
                        .hide(f1)
                        .hide(f3)
                        .hide(f4)
                        .commit();
            }
            break;
      case F3:
            if (!f3.isVisible()) {
                        ft
                        .show(f3)
                        .hide(f1)
                        .hide(f2)
                        .hide(f4)
                        .commit();
            }
            break;
     case F4:
            if (!f1.isVisible()) {
                        ft
                        .show(f4)
                        .hide(f1)
                        .hide(f2)
                        .hide(f3)
                        .commit();
            }
            break;

            lastFragment = fragment;
}