TourAdapter.java

package edu.vanderbilt.vm.guide.ui.adapter;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import edu.vanderbilt.vm.guide.R;
import edu.vanderbilt.vm.guide.db.GuideDBConstants;
import edu.vanderbilt.vm.guide.db.GuideDBOpenHelper;
import edu.vanderbilt.vm.guide.util.DBUtils;

public class TourAdapter extends BaseAdapter {

    public static final int NO_ID = -1;

    private static final Logger logger = LoggerFactory.getLogger("ui.adapter.TourAdapter");

    private Cursor mCursor;

    private GuideDBOpenHelper mHelper;

    private Context mContext;

    public TourAdapter(Context context, Cursor tourCursor, GuideDBOpenHelper helper) {
        mCursor = tourCursor;
        mHelper = helper;
        mContext = context;
    }

    @Override
    public int getCount() {
        return mCursor.getCount();
    }

    @Override
    public Object getItem(int position) {
        if (mCursor.moveToPosition(position)) {
            SQLiteDatabase db = mHelper.getReadableDatabase();
            return DBUtils.getTourFromCursor(mCursor, db);
        } else {
            return null;
        }
    }

    @Override
    public long getItemId(int position) {
        int index = mCursor.getColumnIndex(GuideDBConstants.TourTable.ID_COL);
        if (mCursor.moveToPosition(position) && index != -1) {
            return mCursor.getInt(index);
        } else {
            return NO_ID;
        }
    }

    private static final class ViewHolder {
        ImageView iv;

        TextView tv;

        int imageColIx;

        int nameColIx;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View view;
        ViewHolder holder;

        if (convertView == null) {
            view = LayoutInflater.from(mContext).inflate(R.layout.tour_grid_item, null);
        } else {
            view = convertView;
        }

        if (view.getTag() == null || !(view.getTag() instanceof ViewHolder)) {
            holder = new ViewHolder();
            holder.iv = (ImageView)view.findViewById(R.id.tourGridItemIV);
            holder.tv = (TextView)view.findViewById(R.id.tourGridItemTV);
            holder.imageColIx = mCursor.getColumnIndex(GuideDBConstants.TourTable.ICON_LOC_COL);
            holder.nameColIx = mCursor.getColumnIndex(GuideDBConstants.TourTable.NAME_COL);
            view.setTag(holder);
        } else {
            holder = (ViewHolder)view.getTag();
        }

        if (mCursor.moveToPosition(position)) {
            String imageLoc = null;
            String name = null;
            if (holder.imageColIx != -1) {
                imageLoc = mCursor.getString(holder.imageColIx);
            }
            if (holder.nameColIx != -1) {
                name = mCursor.getString(holder.nameColIx);
            }

            // For now we're not supporting tours with icons that need to be
            // downloaded from the web. We will probably never need this
            // functionality anyway.
            int imageResource;
            if (imageLoc == null) {
                logger.warn("Row {} in tour cursor has a null image location.  "
                        + "Using default icon.", position);
                imageResource = R.drawable.tour_placeholder;
            } else {
                String packageName = mContext.getApplicationContext().getPackageName();
                imageResource = mContext.getResources().getIdentifier(imageLoc, "drawable",
                        packageName);
            }
            holder.iv.setImageResource(imageResource);

            if (name == null) {
                logger.warn("Row {} in tour cursor has a null tour name");
                name = "Unnamed Tour";
            }
            holder.tv.setText(name);

        } else {
            throw new IndexOutOfBoundsException();
        }
        return view;
    }

}