NumberPickerDialog.java

package what.whatandroid.forums;

import android.app.Dialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.support.v4.app.DialogFragment;
import android.support.v7.app.AlertDialog;
import android.view.ContextThemeWrapper;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.NumberPicker;

import what.whatandroid.R;

/**
 * Dialog for showing users a number picker that they can
 * use to select a number. Eg. in the forums/threads we
 * use this to pick page numbers to jump too
 * <p/>
 * The number selected is passed back through the target fragment's
 * onActivityResultCallback which should implement the NumberPickerListener
 */
public class NumberPickerDialog extends DialogFragment {
    /**
     * Interface to receive the picked number
     */
    public interface NumberPickerListener {
        /**
         * Called when a number is picked
         *
         * @param number the chosen number
         */
        public void pickNumber(int number);
    }

    public static final String MIN = "what.whatandroid.numberpickerdialog.MIN",
            MAX = "what.whatandroid.numberpickerdialog.MAX",
            TITLE = "what.whatandroid.numberpickerdialog.TITLE",
            VALUE = "what.whatandroid.numberpickerdialog.VALUE";

    private NumberPickerListener listener;

    /**
     * Create a NumberPickerDialog to pick values in the range [min, max]
     * and with the desired title
     *
     * @param title title for the dialog
     * @param min   min value that should be selectable
     * @param max   max value that should be selectable
     */
    public static NumberPickerDialog newInstance(String title, int min, int max) {
        NumberPickerDialog d = new NumberPickerDialog();
        Bundle args = new Bundle();
        args.putString(TITLE, title);
        args.putInt(MIN, min);
        args.putInt(MAX, max);
        args.putInt(VALUE, 1); // default page is 1
        d.setArguments(args);
        return d;
    }

    /**
     * Create a NumberPickerDialog to pick values in the range [min, max]
     * and with the desired title and initial value
     *
     * @param title title for the dialog
     * @param min   min value that should be selectable
     * @param max   max value that should be selectable
     * @param value initial value of the dialog
     */
    public static NumberPickerDialog newInstance(String title, int min, int max, int value) {
        NumberPickerDialog d = newInstance(title, min, max);
        d.getArguments().putInt(VALUE, value);
        return d;
    }

    public NumberPickerDialog() {
        //Required empty ctor
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        try {
            listener = (NumberPickerListener) getTargetFragment();
        } catch (ClassCastException e) {
            throw new ClassCastException(getTargetFragment().toString() + " must implement NumberPickerListener");
        }
    }

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        LayoutInflater inflater = LayoutInflater.from(getActivity());
        View view = inflater.inflate(R.layout.dialog_number_picker, null);
        final NumberPicker picker = (NumberPicker) view.findViewById(R.id.number_picker);

        Bundle args = getArguments();
        picker.setMinValue(args.getInt(MIN));
        picker.setMaxValue(args.getInt(MAX));
        picker.setValue(args.getInt(VALUE));

        builder.setView(view)
                .setTitle(args.getString(TITLE))
                .setPositiveButton("Select", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        listener.pickNumber(picker.getValue());
                    }
                })
                .setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.cancel();
                    }
                });
        return builder.create();
    }
}