the diff with onCreateView and onCreateDialog in DialogFragment

Question

I had a working DialogFragment that was using an inner class to do a bunch of things on some objects, set menu icons etc. When i went to Android Studio i realised that was incorrect and i've been trying to change the inner class to be static.

In so doing, I am now trying to use onCreateDialog to, as per Google docs, "doPositiveClick" and "doNegativeClick", so that the calling MainActivity can do the work on those objects instead of the fragment doing it.

What is now confusing me however, is how do I set the layout in the fragment - I can enter a title, message and buttons as such:

return new AlertDialog.Builder(getActivity())
                .setTitle(R.string.alert_title)
                .setMessage(R.string.alert_message)

                .setPositiveButton(R.string.set,
                        new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int whichButton) {
                                ((MainActivity)getActivity()).doPositiveClick();
                            }
                        }
                )
                .setNegativeButton(R.string.cancel,
                        new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int whichButton) {
                                ((MainActivity)getActivity()).doNegativeClick();
                            }
                        }
                )

But previously I was doing the layout like:

        final EditText input = new EditText(MainActivity.this);
        LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(20, 20);
        input.setText("5");
        input.setLayoutParams(lp);
        input.setRawInputType(Configuration.KEYBOARD_QWERTY);

Problem is, where does this go in onCreateDialog ? The Google docs shows how to set text on a dialog textView, but that is within onCreateView().

My confusion is that the google doc doesnt do both, ie, it doesnt show how to both, set up custom elements, AND set up the positive/negative click in the calling MainActivity - or if it does, i'm sorry I cant see it right now.

So can anyone make it clearer for me, using the above onCreateDialog, how can I have an editText field, with a default value that takes user input, and then get back that input to the doPositiveClick() to process.

Answer 1

DialogFragment can use in 2 ways: dialog or view.

case1: use DialogFragment as a dialog. you have to implement onCreateDialog() to return a dialog. and then have to show the dialog in the following way. see the example:

public static class MyAlertDialogFragment extends DialogFragment {

public static MyAlertDialogFragment newInstance(int title) {
    MyAlertDialogFragment frag = new MyAlertDialogFragment();
    Bundle args = new Bundle();
    args.putInt("title", title);
    frag.setArguments(args);
    return frag;
}

@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
    int title = getArguments().getInt("title");

    return new AlertDialog.Builder(getActivity())
            .setIcon(R.drawable.alert_dialog_icon)
            .setTitle(title)
            .setPositiveButton(R.string.alert_dialog_ok,
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int whichButton) {
                        ((FragmentAlertDialog)getActivity()).doPositiveClick();
                    }
                }
            )
            .setNegativeButton(R.string.alert_dialog_cancel,
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int whichButton) {
                        ((FragmentAlertDialog)getActivity()).doNegativeClick();
                    }
                }
            )
            .create();
}

}

Create and have to show dialog as the following way. show this way don't care, whether onCreateView() is implemented or not.

    // Create the fragment and show it as a dialog.
DialogFragment newFragment = MyDialogFragment.newInstance();
newFragment.show(getFragmentManager(), "dialog");

case2: use as view (it is not feature of dialog). it is only view. you have to implement onCreateView() and show dialog as the following way:

public static class MyDialogFragment extends DialogFragment {
static MyDialogFragment newInstance() {
    return new MyDialogFragment();
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.hello_world, container, false);
    View tv = v.findViewById(R.id.text);
    ((TextView)tv).setText("This is an instance of MyDialogFragment");
    return v;
}

}

and have to show view as follow. the same as use Fragment class. show this way don't care, whether onCreateDialog() is implemented or not.

FragmentTransaction ft = getFragmentManager().beginTransaction();
DialogFragment newFragment = MyDialogFragment.newInstance();
ft.add(R.id.embedded, newFragment);
ft.commit();

summary: in design, you can implement onCreateView() and onCreateDialog() together and use the same source code with this DialogFragment lifecycle. If the screen is small, use DialogFragment as Dialog. If the screen is big, use DialogFragment as view (the same common Fragment class).

Notice that use the correct way to show DialogFragment to suitable with onCreateView() and onCreateDialog() to prevent exception.

Answer 2

sorry guys I thought I exhausted my searches but just after I posted this I was able to fix it, putting the text field/layout inside the onCreateDialog BEFORE the Builder and then doing setView() to that input as such:

        **LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(20, 20);
        final EditText input = new EditText(getActivity());
        input.setText("5");
        input.setLayoutParams(lp);
        input.setRawInputType(Configuration.KEYBOARD_QWERTY);**

        // Use the Builder class for convenient dialog construction
        return new AlertDialog.Builder(getActivity())
                .setTitle(R.string.alert_title)
                .setMessage(R.string.alert_message)
                **.setView(input)**
                .setPositiveButton(R.string.set,
                        new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int whichButton) {
                                ((MainActivity)getActivity()).doPositiveClick();
                            }
                        }
                )

Only question now is how do I get the value back after the user inputs ?