Catch keyboard 'Done' for NumberPicker

Question

I have an AlertDialog with just some text, a NumberPicker, an OK, and a Cancel.

package org.dyndns.schep.example;
import android.os.Bundler;
import android.view.View;
import android.widget.NumberPicker;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.app.DialogFragment;
import android.content.DialogInterface;

public class FooFragment extends DialogFragment {
    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        mParent = (MainActivity) activity;
    }

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        builder.setPositiveButton(android.R.string.ok,
                new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int id) {
                mParent.setFoo(foo());
            }
        })
        .setNegativeButton(android.R.string.cancel, null);

        View view = getActivity().getLayoutInflater.inflate(
                R.layout.dialog_foo, null);
        mPicker = (NumberPicker) view.findViewById(R.id.numberPicker1);
        mPicker.setValue(mParent.getFoo());
        builder.setView(view);
        return builder.create();
    }

    public int foo() {
        return mPicker.getValue();
    }

    private MainActivity mParent;
    private NumberPicker mPicker;
}

(This dialog doesn't yet do the things it should to preserve state on Pause and Resume, I know.)

I would like the "Done" action on the soft keyboard or other IME to dismiss the dialog as though "OK" were pressed, since there's only the one widget to edit.

It looks like the best way to deal with an IME "Done" is usually to setOnEditorActionListener on a TextView. But I don't have any TextView variable, and NumberPicker doesn't obviously expose any TextView, or similar editor callbacks. (Maybe NumberPicker contains a TextView with a constant ID I could search for using findViewById?)

NumberPicker.setOnValueChangedListener does get triggered on the "Done" action, but it also fires when tapping or flicking the list of numbers, which definitely should not dismiss the dialog.

Based on this question, I tried checking out setOnKeyListener, but that interface didn't trigger at all when using the soft keyboard. Not a total surprise, since the KeyEvent documentation suggests it's meant more for hardware events, and in recent APIs the soft keyboard won't send them at all.

How can I connect the IME "Done" to my dialog's "OK" action?

Edit: From the looks of the source, a NumberPicker layout does contain a EditText, but its id is id/numberpicker_input in package com.android.internal. Using that would not be easy, and is obviously discouraged. But it seems like there might only be hack ways to get the behavior I want.

Answer 1

How can I connect the IME "Done" to my dialog's "OK" action?

The problem is that you can't pass the IME's events if you don't have a listener set on the TextView widget which currently works with the IME. One way to do what you want is to hook our own logic to the NumberPicker's child which works with the IME(like you already talked in the last part of your question). To avoid using certain ids or other layout tricks(which can be problematic) to get a hold of that widget, you could use a greedy tactic, setting the listener to any widget from the NumberPicker which could trigger the desired event(TextViews or any subclass of TextView). Something like this:

    private AlertDialog mCurrentDialog;
    private List<TextView> mTargets = new ArrayList<TextView>();
    private OnEditorActionListener mListener = new OnEditorActionListener() {

        @Override
        public boolean onEditorAction(TextView v, int actionId,
                KeyEvent event) {
            if (actionId == EditorInfo.IME_ACTION_DONE) {
                // if a child of NumberPicker triggers the DONE editor event
                // get a reference to the positive button(which you use in your
                // code) and click it
               mCurrentDialog.getButton(Dialog.BUTTON_POSITIVE).performClick();
            }
            return false;
        }
    };

@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
     // ...
     mPicker = (NumberPicker) view.findViewById(R.id.numberPicker1);
        mPicker.setValue(mParent.getFoo());
        // clear any previous targets
        mTargets.clear();
        // find possible targets in the NumberPicker 
        findTextViews(mPicker);
        // setup those possible targets with our own logic 
        setupEditorListener();          
        builder.setView(view);
        // get a reference to the current showed dialog 
        mCurrentDialog = builder.create();          
        return mCurrentDialog;
    }

Where the methods are:

private void findTextViews(ViewGroup parent) {
        final int count = parent.getChildCount();
        for (int i = 0; i < count; i++) {
            final View child = parent.getChildAt(i);
            if (child instanceof ViewGroup) {
                findTextViews((ViewGroup) child);
            } else if (child instanceof TextView) {
                mTargets.add((TextView) child);
            }
        }
    }

    private void setupEditorListener() {
        final int count = mTargets.size();
        for (int i = 0; i < count; i++) {
            final TextView target = mTargets.get(i);
            target.setOnEditorActionListener(mListener);
        }
    }

The other possible(and reasonable) solution(like Naveen already mentioned in his comment) is to use one of the ports of the NumberPicker class(or modify the one from the SDK) out there and insert your own widget ids(which will make getting a reference to the widget a simple task). This would be easier to implement now but inconvenient to maintain on the long run.

Answer 2

My search and experimentation has also turned out empty handed. That said I wouldn't encourage this kind of behavior as it doesn't make much sense.

If you need a NumberPicker it is because you want the feature of scrolling to the value that you need, not entering it (though it is possible). If you want to enter the value you'd use an EditText and you would be able to implement what you need without problems.

Alternatively you have to copy NumberPicker implementation from the source and then change it according to your needs (fx by adding ime options).