SelectMultipleImageQuestionFragment.java

package org.adaptlab.chpir.android.survey.QuestionFragments;

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

import org.adaptlab.chpir.android.survey.PictureUtils;
import org.adaptlab.chpir.android.survey.QuestionFragment;
import org.adaptlab.chpir.android.survey.R;
import org.adaptlab.chpir.android.survey.Models.Image;

import android.graphics.Color;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.ColorDrawable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.GridView;
import android.widget.ImageView;

public class SelectMultipleImageQuestionFragment extends QuestionFragment {
	private final int SELECTED = Color.GREEN;
	private final int UNSELECTED = Color.TRANSPARENT;
	private List<Integer> mSelectedViews;
	private GridView mGridView;
	private ArrayList<Image> mImages;
	
	@Override
	protected void createQuestionComponent(ViewGroup questionComponent) {
		LayoutInflater inflater = getActivity().getLayoutInflater();
		View v = inflater.inflate(R.layout.fragment_image, questionComponent, false);
		mImages = (ArrayList<Image>) getQuestion().images();
		mSelectedViews = new ArrayList<Integer>();
		mGridView = (GridView) v.findViewById(R.id.imageGridView);
		setUpAdapter();
		mGridView.setOnItemClickListener(new OnItemClickListener() {
	        public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
	        	toggleImageBackgroundColor((ImageView) v);
	        }
	    });
		questionComponent.addView(mGridView);
	}

	private void setUpAdapter() {
		if (getActivity() == null || mGridView == null) return;
        if (mImages != null) {
            mGridView.setAdapter(new ImageAdapter(mImages));
        } else {
            mGridView.setAdapter(null);
        }
	}
	
	private void toggleImageBackgroundColor(ImageView view) {
		ColorDrawable drawable = (ColorDrawable) view.getBackground();
		if (drawable.getColor() == SELECTED) {
			view.setBackgroundColor(UNSELECTED);
		} else {
			view.setBackgroundColor(SELECTED);
		}
		saveResponse();
	}

	@Override
	protected String serialize() {
		String serialized = "";
		for (int i=0; i < mGridView.getChildCount(); i++) {
			ImageView view = (ImageView) mGridView.getChildAt(i);
			ColorDrawable drawable = (ColorDrawable) view.getBackground();
			if (drawable.getColor() == SELECTED) {
				serialized += i;
				if (i <  mGridView.getChildCount() - 1) serialized += LIST_DELIMITER;
			}
		}
		return serialized;
	}

	@Override
	protected void deserialize(String responseText) {
		if (responseText.equals("")) return;   
        String[] listOfIndices = responseText.split(LIST_DELIMITER);
        for (String index : listOfIndices) {
            if (!index.equals("")) {
                Integer indexInteger = Integer.parseInt(index);
                mSelectedViews.add(indexInteger);
            }
        }		
	}
	
	private class ImageAdapter extends ArrayAdapter<Image> {
		
		public ImageAdapter(ArrayList<Image> images) {
			super(getActivity(), 0, images);
		}
		
		public View getView(int position, View view, ViewGroup parent) {
			if (view == null) {
                view = getActivity().getLayoutInflater().inflate(R.layout.image_item, parent, false);
            }
			Image img = getItem(position);
			ImageView imageView = (ImageView)view.findViewById(R.id.image_item_view);
			String path = getActivity().getFileStreamPath(img.getBitmapPath()).getAbsolutePath();
			BitmapDrawable bitmap = PictureUtils.getScaledDrawable(getActivity(), path);
			imageView.setImageDrawable(bitmap);
			if (mSelectedViews.contains(position)) {
				imageView.setBackgroundColor(SELECTED);
			} else {
				imageView.setBackgroundColor(UNSELECTED);
			}
			return view;	
		}
	}

}