ca.ualberta.slevinsk.gameshow.SpinListener.java Source code

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Here is the source code for ca.ualberta.slevinsk.gameshow.SpinListener.java

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package ca.ualberta.slevinsk.gameshow;

import android.support.v4.util.Pair;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;

import java.util.List;

/**
 * Copyright 2015 John Slevinsky
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * Listens to a spinner, and updates a ListView's ArrayAdapter when the Spinner changes,
 * based on the data generated by Generator.
 */
public class SpinListener implements AdapterView.OnItemSelectedListener, Listener {

    private Spinner spinner;
    private List list;
    private ArrayAdapter adapter;
    private Generator<List, Integer> generateListData;

    public Integer getLastPosition() {
        return lastPosition;
    }

    private Integer lastPosition;

    /**
     *
     * @param spinner A spinner widget
     * @param list A list, that is used in a ListView
     * @param adapter the ListView's ArrayAdapter
     * @param generateListData a Generator that generates list's data.
     */
    SpinListener(Spinner spinner, final List list, final ArrayAdapter adapter,
            Generator<List, Integer> generateListData) {
        this.adapter = adapter;
        this.list = list;
        this.spinner = spinner;
        this.generateListData = generateListData;
        lastPosition = 0;
    }

    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
        update(position);
    }

    @Override
    public void onNothingSelected(AdapterView<?> parent) {
        update();
    }

    public void update() {
        update(getLastPosition());
    }

    public void update(int position) {
        Pair<String, Integer> selected = (Pair<String, Integer>) spinner.getItemAtPosition(position);
        list.clear();
        list.addAll(generateListData.generate(selected.second));
        adapter.notifyDataSetChanged();
        lastPosition = position;
    }
}