/src/com/bit101/components/List.as

/**

 * List.as

 * Keith Peters

 * version 0.9.9

 * 

 * A scrolling list of selectable items. 

 * 

 * Copyright (c) 2011 Keith Peters

 * 

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 * 

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 * 

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */



package com.bit101.components

{

	import flash.display.DisplayObjectContainer;

	import flash.display.Sprite;

	import flash.events.Event;

	import flash.events.MouseEvent;

	

	[Event(name="select", type="flash.events.Event")]

	public class List extends Component

	{

		protected var _items:Array;

		protected var _itemHolder:Sprite;

		protected var _panel:Panel;

		protected var _listItemHeight:Number = 20;

		protected var _listItemClass:Class =ListItem;

		protected var _scrollbar:VScrollBar;

		protected var _selectedIndex:int = -1;

		protected var _defaultColor:uint = Style.LIST_DEFAULT;

		protected var _alternateColor:uint = Style.LIST_ALTERNATE;

		protected var _selectedColor:uint = Style.LIST_SELECTED;

		protected var _rolloverColor:uint = Style.LIST_ROLLOVER;

		protected var _alternateRows:Boolean = false;

		

		/**

		 * Constructor

		 * @param parent The parent DisplayObjectContainer on which to add this List.

		 * @param xpos The x position to place this component.

		 * @param ypos The y position to place this component.

		 * @param items An array of items to display in the list. Either strings or objects with label property.

		 */

		public function List(parent:DisplayObjectContainer=null, xpos:Number=0, ypos:Number=0, items:Array=null)

		{

			if(items != null)

			{

				_items = items;

			}

			else

			{

				_items = new Array();

			}

			super(parent, xpos, ypos);

		}

		

		/**

		 * Initilizes the component.

		 */

		protected override function init() : void

		{

			super.init();

			setSize(100, 100);

			addEventListener(MouseEvent.MOUSE_WHEEL, onMouseWheel);

            addEventListener(Event.RESIZE, onResize);

            makeListItems();

            fillItems();

		}

		

		/**

		 * Creates and adds the child display objects of this component.

		 */

		protected override function addChildren() : void

		{

			super.addChildren();

			_panel = new Panel(this, 0, 0);

			_panel.color = _defaultColor;

			_itemHolder = new Sprite();

			_panel.content.addChild(_itemHolder);

			_scrollbar = new VScrollBar(this, 0, 0, onScroll);

            _scrollbar.setSliderParams(0, 0, 0);

		}

		

		/**

		 * Creates all the list items based on data.

		 */

		protected function makeListItems():void

		{

			while(_itemHolder.numChildren > 0) _itemHolder.removeChildAt(0);



            var numItems:int = Math.ceil(_height / _listItemHeight);

			for(var i:int = 0; i < numItems; i++)

			{



				var item:ListItem = new _listItemClass(_itemHolder, 0, i * _listItemHeight);

				item.setSize(width, _listItemHeight);

				item.defaultColor = _defaultColor;



				item.selectedColor = _selectedColor;

				item.rolloverColor = _rolloverColor;

				item.addEventListener(MouseEvent.CLICK, onSelect);

			}

		}



        protected function fillItems():void

        {

            var offset:int = _scrollbar.value;

            var numItems:int = Math.ceil(_height / _listItemHeight);

			

            for(var i:int = 0; i < numItems; i++)

            {

                var item:ListItem = _itemHolder.getChildAt(i) as ListItem;

				if(offset + i < _items.length)

				{

	                item.data = _items[offset + i];

				}

				else

				{

					item.data = "";

				}

				if(_alternateRows)

				{

					item.defaultColor = ((offset + i) % 2 == 0) ? _defaultColor : _alternateColor;

				}

				else

				{

					item.defaultColor = _defaultColor;

				}

                if(offset + i == _selectedIndex)

                {

                    item.selected = true;

                }

                else

                {

                    item.selected = false;

                }

            }

        }

		

		/**

		 * If the selected item is not in view, scrolls the list to make the selected item appear in the view.

		 */

		protected function scrollToSelection():void

		{

            var numItems:int = Math.ceil(_height / _listItemHeight);

			if(_selectedIndex != -1)

			{

				if(_scrollbar.value > _selectedIndex)

				{

//                    _scrollbar.value = _selectedIndex;

				}

				else if(_scrollbar.value + numItems < _selectedIndex)

				{

                    _scrollbar.value = _selectedIndex - numItems + 1;

				}

			}

			else

			{

				_scrollbar.value = 0;

			}

            fillItems();

		}

		

		

		

		///////////////////////////////////

		// public methods

		///////////////////////////////////

		

		/**

		 * Draws the visual ui of the component.

		 */

		public override function draw() : void

		{

			super.draw();

			

			_selectedIndex = Math.min(_selectedIndex, _items.length - 1);





			// panel

			_panel.setSize(_width, _height);

			_panel.color = _defaultColor;

			_panel.draw();

			

			// scrollbar

			_scrollbar.x = _width - 10;

			var contentHeight:Number = _items.length * _listItemHeight;

			_scrollbar.setThumbPercent(_height / contentHeight); 

			var pageSize:Number = Math.floor(_height / _listItemHeight);

            _scrollbar.maximum = Math.max(0, _items.length - pageSize);

			_scrollbar.pageSize = pageSize;

			_scrollbar.height = _height;

			_scrollbar.draw();

            scrollToSelection();

		}

		

		/**

		 * Adds an item to the list.

		 * @param item The item to add. Can be a string or an object containing a string property named label.

		 */

		public function addItem(item:Object):void

		{

			_items.push(item);

			invalidate();

            fillItems();

		}

		

		/**

		 * Adds an item to the list at the specified index.

		 * @param item The item to add. Can be a string or an object containing a string property named label.

		 * @param index The index at which to add the item.

		 */

		public function addItemAt(item:Object, index:int):void

		{

			index = Math.max(0, index);

			index = Math.min(_items.length, index);

			_items.splice(index, 0, item);

			invalidate();

            fillItems();

		}

		

		/**

		 * Removes the referenced item from the list.

		 * @param item The item to remove. If a string, must match the item containing that string. If an object, must be a reference to the exact same object.

		 */

		public function removeItem(item:Object):void

		{

			var index:int = _items.indexOf(item);

			removeItemAt(index);

		}

		

		/**

		 * Removes the item from the list at the specified index

		 * @param index The index of the item to remove.

		 */

		public function removeItemAt(index:int):void

		{

			if(index < 0 || index >= _items.length) return;

			_items.splice(index, 1);

			invalidate();

            fillItems();

		}

		

		/**

		 * Removes all items from the list.

		 */

		public function removeAll():void

		{

			_items.length = 0;

			invalidate();

            fillItems();

		}

		

		

		

		

		

		///////////////////////////////////

		// event handlers

		///////////////////////////////////

		

		/**

		 * Called when a user selects an item in the list.

		 */

		protected function onSelect(event:Event):void

		{

			if(! (event.target is ListItem)) return;

			

			var offset:int = _scrollbar.value;

			

			for(var i:int = 0; i < _itemHolder.numChildren; i++)

			{

				if(_itemHolder.getChildAt(i) == event.target) _selectedIndex = i + offset;

				ListItem(_itemHolder.getChildAt(i)).selected = false;

			}

			ListItem(event.target).selected = true;

			dispatchEvent(new Event(Event.SELECT));

		}

		

		/**

		 * Called when the user scrolls the scroll bar.

		 */

		protected function onScroll(event:Event):void

		{

            fillItems();

		}

		

		/**

		 * Called when the mouse wheel is scrolled over the component.

		 */

		protected function onMouseWheel(event:MouseEvent):void

		{

			_scrollbar.value -= event.delta;

            fillItems();

		}



        protected function onResize(event:Event):void

        {

            makeListItems();

            fillItems();

        }

		///////////////////////////////////

		// getter/setters

		///////////////////////////////////

		

		/**

		 * Sets / gets the index of the selected list item.

		 */

		public function set selectedIndex(value:int):void

		{

			if(value >= 0 && value < _items.length)

			{

				_selectedIndex = value;

//				_scrollbar.value = _selectedIndex;

			}

			else

			{

				_selectedIndex = -1;

			}

			invalidate();

			dispatchEvent(new Event(Event.SELECT));

		}

		public function get selectedIndex():int

		{

			return _selectedIndex;

		}

		

		/**

		 * Sets / gets the item in the list, if it exists.

		 */

		public function set selectedItem(item:Object):void

		{

			var index:int = _items.indexOf(item);

//			if(index != -1)

//			{

				selectedIndex = index;

				invalidate();

				dispatchEvent(new Event(Event.SELECT));

//			}

		}

		public function get selectedItem():Object

		{

			if(_selectedIndex >= 0 && _selectedIndex < _items.length)

			{

				return _items[_selectedIndex];

			}

			return null;

		}



		/**

		 * Sets/gets the default background color of list items.

		 */

		public function set defaultColor(value:uint):void

		{

			_defaultColor = value;

			invalidate();

		}

		public function get defaultColor():uint

		{

			return _defaultColor;

		}



		/**

		 * Sets/gets the selected background color of list items.

		 */

		public function set selectedColor(value:uint):void

		{

			_selectedColor = value;

			invalidate();

		}

		public function get selectedColor():uint

		{

			return _selectedColor;

		}



		/**

		 * Sets/gets the rollover background color of list items.

		 */

		public function set rolloverColor(value:uint):void

		{

			_rolloverColor = value;

			invalidate();

		}

		public function get rolloverColor():uint

		{

			return _rolloverColor;

		}



		/**

		 * Sets the height of each list item.

		 */

		public function set listItemHeight(value:Number):void

		{

			_listItemHeight = value;

            makeListItems();

			invalidate();

		}

		public function get listItemHeight():Number

		{

			return _listItemHeight;

		}



		/**

		 * Sets / gets the list of items to be shown.

		 */

		public function set items(value:Array):void

		{

			_items = value;

			invalidate();

		}

		public function get items():Array

		{

			return _items;

		}



		/**

		 * Sets / gets the class used to render list items. Must extend ListItem.

		 */

		public function set listItemClass(value:Class):void

		{

			_listItemClass = value;

			makeListItems();

			invalidate();

		}

		public function get listItemClass():Class

		{

			return _listItemClass;

		}



		/**

		 * Sets / gets the color for alternate rows if alternateRows is set to true.

		 */

		public function set alternateColor(value:uint):void

		{

			_alternateColor = value;

			invalidate();

		}

		public function get alternateColor():uint

		{

			return _alternateColor;

		}

		

		/**

		 * Sets / gets whether or not every other row will be colored with the alternate color.

		 */

		public function set alternateRows(value:Boolean):void

		{

			_alternateRows = value;

			invalidate();

		}

		public function get alternateRows():Boolean

		{

			return _alternateRows;

		}



        /**

         * Sets / gets whether the scrollbar will auto hide when there is nothing to scroll.

         */

        public function set autoHideScrollBar(value:Boolean):void

        {

            _scrollbar.autoHide = value;

        }

        public function get autoHideScrollBar():Boolean

        {

            return _scrollbar.autoHide;

        }



	}

}