LocationsForCategorySearchCursorAdapter.java

package edu.mit.mitmobile2.facilities;

import edu.mit.mitmobile2.TwoLineActionRow;
import android.content.Context;
import android.database.Cursor;
import android.database.CursorWrapper;
import android.graphics.Color;
import android.text.Spannable;
import android.text.style.ForegroundColorSpan;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CursorAdapter;
import android.widget.FilterQueryProvider;
import android.widget.TextView;

public class LocationsForCategorySearchCursorAdapter extends CursorAdapter implements FilterQueryProvider {
	
	FacilitiesDB mFacilitiesDB;
	private static final String TAG = "LocationsSearchCursorAdapter";
	
	public LocationsForCategorySearchCursorAdapter(Context context, FacilitiesDB facilitiesDB) {
		super(context, facilitiesDB.getLocationCursor());
		mFacilitiesDB = facilitiesDB;
		setFilterQueryProvider(this);
	}

	@Override
	public Cursor runQuery(CharSequence constraint) {
		Log.d(TAG,"constraint = " + constraint);
		String trimmedConstraint = constraint.toString().trim();
		if(trimmedConstraint.length() > 0) {
			Cursor c = mFacilitiesDB.getLocationForCategorySearchCursor(trimmedConstraint);
			return new FilteredCursor(c, trimmedConstraint.toString());
		} else {
			return null;
		}
	}

	@Override
	public void bindView(View view, Context context, Cursor cursor) {
		TwoLineActionRow actionRow = (TwoLineActionRow) view;
		int idIndex = cursor.getColumnIndexOrThrow("_id");
		int displayNameIndex = cursor.getColumnIndexOrThrow("display_name");
		String displayName = cursor.getString(displayNameIndex);
		if(cursor.getLong(idIndex) == -1) {
			actionRow.setTitle(displayName);
			return;
		}
		
		FilteredCursor filteredCursor = (FilteredCursor) cursor;
		String constraint = filteredCursor.getConstraint().toLowerCase();
		String displayNameLower = displayName.toLowerCase();
		if(displayNameLower.indexOf(constraint) < 0) {
			int extraFieldsFirstIndex = cursor.getColumnIndexOrThrow("categoryName");
			int extraFieldsLastIndex = cursor.getColumnIndexOrThrow("altname");
			int fieldIndex = extraFieldsFirstIndex;
			while(fieldIndex <= extraFieldsLastIndex) {
				String matchCandidate = cursor.getString(fieldIndex);
				if(matchCandidate != null) {
					if(matchCandidate.toLowerCase().indexOf(constraint) >= 0) {
						displayName += " (" + matchCandidate +  ")";
						displayNameLower = displayName.toLowerCase();
						break;
					}
				}
				fieldIndex++;
			}
		}	
		Spannable title = Spannable.Factory.getInstance().newSpannable(displayName);		
		
		// find substrings matching constraint
		int currentIndex = 0;
		while(displayNameLower.indexOf(constraint, currentIndex) >= 0) {
			int foundIndex = displayNameLower.indexOf(constraint, currentIndex);
			title.setSpan(new ForegroundColorSpan(Color.RED), foundIndex, foundIndex + constraint.length(), Spannable.SPAN_INCLUSIVE_EXCLUSIVE);
			currentIndex = foundIndex + constraint.length();
		}
		
		actionRow.setTitle(title, TextView.BufferType.SPANNABLE);	
	}

	@Override
	public View newView(Context context, Cursor cursor, ViewGroup parent) {
		return new TwoLineActionRow(context);
	}

	@Override
	public String convertToString(Cursor cursor) {
		return "";
	}
	
	private static class FilteredCursor extends CursorWrapper {

		String mConstraint;
		
		public FilteredCursor(Cursor cursor, String constraint) {
			super(cursor);
			mConstraint = constraint;
		}
		
		public String getConstraint() {
			return mConstraint;
		}
	}

}