/***
	Copyright (c) 2008-2009 CommonsWare, LLC
	Portions (c) 2009 Google, Inc.
	
	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 com.commonsware.cwac.sacklist;

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

import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;

/**
 * Adapter that simply returns row views from a list.
 * 
 * If you supply a size, you must implement newView(), to create a required
 * view. The adapter will then cache these views.
 * 
 * If you supply a list of views in the constructor, that list will be used
 * directly. If any elements in the list are null, then newView() will be called
 * just for those slots.
 * 
 * Subclasses may also wish to override areAllItemsEnabled() (default: false)
 * and isEnabled() (default: false), if some of their rows should be selectable.
 * 
 * It is assumed each view is unique, and therefore will not get recycled.
 * 
 * Note that this adapter is not designed for long lists. It is more for screens
 * that should behave like a list. This is particularly useful if you combine
 * this with other adapters (e.g., SectionedAdapter) that might have an
 * arbitrary number of rows, so it all appears seamless.
 */
public class SackOfViewsAdapter extends BaseAdapter {
	private List<View> views = null;

	/**
	 * Constructor creating an empty list of views, but with a specified count.
	 * Subclasses must override newView().
	 */
	public SackOfViewsAdapter(int count) {
		super();

		views = new ArrayList<View>(count);

		for (int i = 0; i < count; i++) {
			views.add(null);
		}
	}

	/**
	 * Constructor wrapping a supplied list of views. Subclasses must override
	 * newView() if any of the elements in the list are null.
	 */
	public SackOfViewsAdapter(List<View> views) {
		super();

		this.views = views;
	}

	/**
	 * Get the data item associated with the specified position in the data set.
	 * 
	 * @param position
	 *            Position of the item whose data we want
	 */
	@Override
	public Object getItem(int position) {
		return (views.get(position));
	}

	/**
	 * How many items are in the data set represented by this Adapter.
	 */
	@Override
	public int getCount() {
		return (views.size());
	}

	/**
	 * Returns the number of types of Views that will be created by getView().
	 */
	@Override
	public int getViewTypeCount() {
		return (getCount());
	}

	/**
	 * Get the type of View that will be created by getView() for the specified
	 * item.
	 * 
	 * @param position
	 *            Position of the item whose data we want
	 */
	@Override
	public int getItemViewType(int position) {
		return (position);
	}

	/**
	 * Are all items in this ListAdapter enabled? If yes it means all items are
	 * selectable and clickable.
	 */
	@Override
	public boolean areAllItemsEnabled() {
		return (false);
	}

	/**
	 * Returns true if the item at the specified position is not a separator.
	 * 
	 * @param position
	 *            Position of the item whose data we want
	 */
	@Override
	public boolean isEnabled(int position) {
		return (false);
	}

	/**
	 * Get a View that displays the data at the specified position in the data
	 * set.
	 * 
	 * @param position
	 *            Position of the item whose data we want
	 * @param convertView
	 *            View to recycle, if not null
	 * @param parent
	 *            ViewGroup containing the returned View
	 */
	@Override
	public View getView(int position, View convertView, ViewGroup parent) {
		View result = views.get(position);

		if (result == null) {
			result = newView(position, parent);
			views.set(position, result);
		}

		return (result);
	}

	/**
	 * Get the row id associated with the specified position in the list.
	 * 
	 * @param position
	 *            Position of the item whose data we want
	 */
	@Override
	public long getItemId(int position) {
		return (position);
	}

	/**
	 * Create a new View to go into the list at the specified position.
	 * 
	 * @param position
	 *            Position of the item whose data we want
	 * @param parent
	 *            ViewGroup containing the returned View
	 */
	protected View newView(int position, ViewGroup parent) {
		throw new RuntimeException("You must override newView()!");
	}
}