RobustDialogFragment: DialogFragment can be robust

DialogFragment works great with Dialog and Fragment.
But DialogFragment is not always working stable. Scenes like:

• Try to show DialogFragment when Activity or Fragment has been destroyed or state-saved, which will throws IllegalStateException, like
  • Can not perform this action after onSaveInstanceState.
  • fragment {xxx} not associated with a fragment manager.
• DialogFragment can't work well with in-layout Fragments, which cause IllegalArgumentException, like
  • Binary XML file line #30: Duplicate id 0x7f080047.
• Sometimes DialogFragment cause memory leaks.

For how official DialogFragment leaks memory, As we know,
official DialogFragment works with Activity/Fragment through FragmentManager.
There is mDialog in DialogFragment which implements DialogInterface.OnDismissListener and mDialog.setOnDismissListener(this) where this is current DialogFragment.
In Dialog#setOnDismissListener(listener), Dialog#mDismissMessage = mListenersHandler.obtainMessage(DISMISS, listener), so Dialog#mDismissMessage#obj is listener, namely current DialogFragment.
So, a Message referred DialogFragment, which referred Activity/Fragment through FragmentManager.
Meantime, in Looper#loop(), there is Message msg = queue.next(), which will block current Thread when no messages in MessageQueue.
When MessageQueue has no messages, queue.next() block current Thread while local variable msg has been allocated.
DialogFragment instance referred by msg won't be gc, and therefore Activity/Fragment won't be gc.
So Memory leaks happen.

So, my solution is: When Dialog#setOnDismissListener(listener), the listener holds DialogFragment instance by WeakReference. So, when MessageQueue blocks, local variable msg won't hold DialogFragment instance. Memory won't leak by MessageQueue#next()#msg or Activity/Fragment.

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