SheetDialogFragment.java

package com.example.dialog;

import android.app.Dialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.design.widget.BottomSheetBehavior;
import android.support.design.widget.BottomSheetDialog;
import android.support.design.widget.BottomSheetDialogFragment;
import android.support.v4.app.DialogFragment;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.EditText;

import com.example.R;


public class SheetDialogFragment extends BottomSheetDialogFragment
{
	private static final String ARGUMENT_EXAMPLE = "example";

	private String mExample;
	private View mRootView;
	private BottomSheetBehavior mBehavior;
	private String mUsername = "";
	private String mPassword = "";
	private SheetDialogListener mListener;


	public interface SheetDialogListener
	{
		void onSheetDialogStateChanged(DialogFragment dialog, int newState, String username, String password);
		void onSheetDialogDismiss(DialogFragment dialog, String username, String password);
	}


	public static SheetDialogFragment newInstance(String example)
	{
		SheetDialogFragment fragment = new SheetDialogFragment();

		// arguments
		Bundle arguments = new Bundle();
		arguments.putString(ARGUMENT_EXAMPLE, example);
		fragment.setArguments(arguments);

		return fragment;
	}


	@Override
	public void onCreate(Bundle savedInstanceState)
	{
		super.onCreate(savedInstanceState);
		setCancelable(true);
		setRetainInstance(true);

		// handle fragment arguments
		Bundle arguments = getArguments();
		if(arguments != null)
		{
			handleArguments(arguments);
		}

		// set callback listener
		try
		{
			mListener = (SheetDialogListener) getTargetFragment();
		}
		catch(ClassCastException e)
		{
			throw new ClassCastException(getTargetFragment().toString() + " must implement " + SheetDialogListener.class.getName());
		}
	}


	@Override
	public void onActivityCreated(Bundle savedInstanceState)
	{
		super.onActivityCreated(savedInstanceState);

		// cancelable on touch outside
		if(getDialog() != null) getDialog().setCanceledOnTouchOutside(true);

		// restore saved state
		handleSavedInstanceState();
	}


	@Override
	public void onDestroyView()
	{
		// http://code.google.com/p/android/issues/detail?id=17423
		if(getDialog() != null && getRetainInstance()) getDialog().setDismissMessage(null);
		super.onDestroyView();
	}


	@Override
	public void onSaveInstanceState(Bundle outState)
	{
		// save current instance state
		super.onSaveInstanceState(outState);

		EditText usernameEditText = (EditText) mRootView.findViewById(R.id.dialog_custom_username);
		EditText passwordEditText = (EditText) mRootView.findViewById(R.id.dialog_custom_password);

		mUsername = usernameEditText.getText().toString();
		mPassword = passwordEditText.getText().toString();
	}


	@Override
	public Dialog onCreateDialog(Bundle savedInstanceState)
	{
		// inflate layout
		LayoutInflater inflater = getActivity().getLayoutInflater();
		mRootView = inflater.inflate(R.layout.dialog_custom, null);

		// create dialog
		final BottomSheetDialog dialog = (BottomSheetDialog) super.onCreateDialog(savedInstanceState);
		dialog.setContentView(mRootView);

		// set arguments
		EditText usernameEditText = (EditText) mRootView.findViewById(R.id.dialog_custom_username);
		usernameEditText.setHint(mExample);

		// setup behavior
		mBehavior = BottomSheetBehavior.from((View) mRootView.getParent());
		mBehavior.setBottomSheetCallback(new BottomSheetBehavior.BottomSheetCallback()
		{
			@Override
			public void onStateChanged(@NonNull View bottomSheet, int newState)
			{
				EditText usernameEditText = (EditText) mRootView.findViewById(R.id.dialog_custom_username);
				EditText passwordEditText = (EditText) mRootView.findViewById(R.id.dialog_custom_password);

				String username = usernameEditText.getText().toString();
				String password = passwordEditText.getText().toString();

				// TODO: data validation

				mListener.onSheetDialogStateChanged(SheetDialogFragment.this, newState, username, password);
				if(newState == BottomSheetBehavior.STATE_HIDDEN) dialog.dismiss();
			}


			@Override
			public void onSlide(@NonNull View bottomSheet, float slideOffset)
			{
				// do nothing
			}
		});

		return dialog;
	}


	@Override
	public void onDismiss(DialogInterface dialog)
	{
		EditText usernameEditText = (EditText) mRootView.findViewById(R.id.dialog_custom_username);
		EditText passwordEditText = (EditText) mRootView.findViewById(R.id.dialog_custom_password);

		String username = usernameEditText.getText().toString();
		String password = passwordEditText.getText().toString();

		// TODO: data validation

		mListener.onSheetDialogDismiss(SheetDialogFragment.this, username, password);

		// destroy dialog fragment
		if(getFragmentManager() != null)
		{
			getFragmentManager().beginTransaction().remove(this).commitAllowingStateLoss();
		}
	}


	private void handleArguments(Bundle arguments)
	{
		if(arguments.containsKey(ARGUMENT_EXAMPLE))
		{
			mExample = (String) arguments.get(ARGUMENT_EXAMPLE);
		}
	}


	private void handleSavedInstanceState()
	{
		EditText usernameEditText = (EditText) mRootView.findViewById(R.id.dialog_custom_username);
		EditText passwordEditText = (EditText) mRootView.findViewById(R.id.dialog_custom_password);

		usernameEditText.setText(mUsername);
		passwordEditText.setText(mPassword);
	}
}