MultiChoicePrompt.java

/*******************************************************************************
 * Copyright 2011 The Regents of the University of California
 * 
 * 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.
 ******************************************************************************/
package org.ohmage.prompt.multichoice;

import org.json.JSONArray;
import org.ohmage.OhmageMarkdown;
import org.ohmage.R;
import org.ohmage.Utilities.KVLTriplet;
import org.ohmage.prompt.AbstractPrompt;

import android.content.Context;
import android.text.SpannableStringBuilder;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.CheckedTextView;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.SimpleAdapter.ViewBinder;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

public class MultiChoicePrompt extends AbstractPrompt {
	
	private static final String TAG = "MultiChoicePrompt";
	
	private List<KVLTriplet> mChoices;
	private ArrayList<Integer> mSelectedIndexes;
	
	public MultiChoicePrompt() {
		super();
		mSelectedIndexes = new ArrayList<Integer>();
	}
	
	public void setChoices(List<KVLTriplet> choices) {
		mChoices = choices;
	}
	
	public List<KVLTriplet> getChoices(){
		return mChoices;
	}

	@Override
	protected void clearTypeSpecificResponseData() {
		if (mSelectedIndexes == null) {
			mSelectedIndexes = new ArrayList<Integer>();
		} else {
			mSelectedIndexes.clear();
		}
	}
	
	/**
	 * Always returns true as an number of selected items is valid.
	 */
	@Override
	public boolean isPromptAnswered() {
		return true;
	}

	@Override
	protected Object getTypeSpecificResponseObject() {
		JSONArray jsonArray = new JSONArray();
		for (int index : mSelectedIndexes) {
			if (index >= 0 && index < mChoices.size())
				jsonArray.put(Integer.decode(mChoices.get(index).key));
		}
		return jsonArray;
	}
	
	/**
	 * The text to be displayed to the user if the prompt is considered
	 * unanswered.
	 */
	@Override
	public String getUnansweredPromptText() {
		return("Please choose at least one of the items in the list.");
	}
	
	@Override
	protected Object getTypeSpecificExtrasObject() {
		return null;
	}

	@Override
	public View getView(Context context) {
		LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
		ListView listView = (ListView) inflater.inflate(R.layout.prompt_multi_choice, null);
		
		listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
		
		String [] from = new String [] {"value"};
		int [] to = new int [] {android.R.id.text1};
		
		List<HashMap<String, CharSequence>> data = new ArrayList<HashMap<String, CharSequence>>();
		for (int i = 0; i < mChoices.size(); i++) {
			HashMap<String, CharSequence> map = new HashMap<String, CharSequence>();
			map.put("key", mChoices.get(i).key);
			map.put("value", OhmageMarkdown.parse(mChoices.get(i).label));
			data.add(map);
		}
		
		SimpleAdapter adapter = new SimpleAdapter(context, data, R.layout.multi_choice_list_item, from, to);
		
		adapter.setViewBinder(new ViewBinder() {
			
			@Override
			public boolean setViewValue(View view, Object data, String textRepresentation) {
				((CheckedTextView) view).setText((SpannableStringBuilder)data);
				return true;
			}
		});
		
		listView.setAdapter(adapter);
		
		if (mSelectedIndexes.size() > 0) {
			for (int index : mSelectedIndexes) {
				if (index >= 0 && index < mChoices.size())
					listView.setItemChecked(index, true);
			}
		}
		
		listView.setOnItemClickListener(new OnItemClickListener() {

			@Override
			public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
				
				//SparseBooleanArray checkItemPositions = ((ListView)parent).getCheckedItemPositions();
				if (((ListView)parent).isItemChecked(position)) {
					mSelectedIndexes.add(Integer.valueOf(position));
				} else {
					mSelectedIndexes.remove(Integer.valueOf(position));
				}
			}
		});
		
		return listView;
	}

	@Override
	public void setDefaultValue(String defaultValue) {
		this.mDefaultValue = defaultValue;
		try {
			if(defaultValue != null) {
				String[] values = defaultValue.split(",");
				for(int i=0; i<values.length; i++)
					mSelectedIndexes.add(Integer.valueOf(values[i]));
			}
		} catch(NumberFormatException e) {
			// No number...
		}
	}
}