/src/com/bit101/components/TextArea.as

  1/**
  2 * TextArea.as
  3 * Keith Peters
  4 * version 0.9.2
  5 * 
  6 * A Text component for displaying multiple lines of text with a scrollbar.
  7 * 
  8 * Copyright (c) 2010 Keith Peters
  9 * 
 10 * Permission is hereby granted, free of charge, to any person obtaining a copy
 11 * of this software and associated documentation files (the "Software"), to deal
 12 * in the Software without restriction, including without limitation the rights
 13 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 14 * copies of the Software, and to permit persons to whom the Software is
 15 * furnished to do so, subject to the following conditions:
 16 * 
 17 * The above copyright notice and this permission notice shall be included in
 18 * all copies or substantial portions of the Software.
 19 * 
 20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 23 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 25 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 26 * THE SOFTWARE.
 27 */
 28
 29package com.bit101.components
 30{
 31	import com.dgrigg.minimalcomps.skins.TextAreaSkin;
 32	import com.dgrigg.utils.Logger;
 33	
 34	import flash.display.DisplayObjectContainer;
 35	import flash.events.Event;
 36	
 37	public class TextArea extends Text
 38	{
 39		protected var _scrollbar:VScrollBar;
 40		private var _dirtyScroller:Boolean = false;
 41		
 42		/**
 43		 * Constructor
 44		 * @param parent The parent DisplayObjectContainer on which to add this Label.
 45		 * @param xpos The x position to place this component.
 46		 * @param ypos The y position to place this component.
 47		 * @param text The initial text to display in this component.
 48		 */
 49		public function TextArea(parent:DisplayObjectContainer=null, xpos:Number=0, ypos:Number=0, text:String="")
 50		{
 51			skinClass = com.dgrigg.minimalcomps.skins.TextAreaSkin;
 52			super(parent, xpos, ypos, text);
 53			
 54		}
 55		
 56		/**
 57		 * Creates and adds the child display objects of this component.
 58		 */
 59		/*
 60		override protected function addChildren():void
 61		{
 62			super.addChildren();
 63			
 64		}
 65		*/
 66		
 67		/**
 68		 * Changes the thumb percent of the scrollbar based on how much text is shown in the text area.
 69		 */
 70		protected function updateScrollbar():void
 71		{
 72			if (_tf)
 73			{
 74				var visibleLines:int = _tf.numLines - _tf.maxScrollV + 1;
 75				var percent:Number = visibleLines / _tf.numLines;
 76				
 77				if (_scrollbar)
 78				{
 79					_scrollbar.setSliderParams(1, _tf.maxScrollV, _tf.scrollV);
 80					_scrollbar.setThumbPercent(percent);
 81					_scrollbar.pageSize = visibleLines;
 82					
 83					_dirtyScroller = true;
 84					invalidate();
 85					
 86				}
 87			}
 88			
 89			
 90			
 91		}
 92		
 93		
 94		override protected function skinPartAdded(part:String, instance:Object):void
 95		{
 96			super.skinPartAdded(part, instance);
 97			
 98			switch (part)
 99			{
100				case "textField":
101					_tf.addEventListener(Event.SCROLL, onTextScroll);
102					_tf.addEventListener(Event.CHANGE, onChange);
103					
104					break;
105				case "scrollBar":
106					_scrollbar = instance as VScrollBar;
107					_scrollbar.addEventListener(Event.CHANGE, onScrollbarScroll);
108					break;
109			}
110		}
111		
112		
113		
114		///////////////////////////////////
115		// public methods
116		///////////////////////////////////
117		
118		/**
119		 * Draws the visual ui of the component.
120		 */
121		override public function draw():void
122		{
123			super.draw();
124			
125			_skin.validate();
126			
127			addEventListener(Event.ENTER_FRAME, onTextScrollDelay);
128			
129		}
130			
131		
132		
133		
134		///////////////////////////////////
135		// event handlers
136		///////////////////////////////////
137		
138		/**
139		 * Waits one more frame before updating scroll bar.
140		 * It seems that numLines and maxScrollV are not valid immediately after changing a TextField's size.
141		 */
142		protected function onTextScrollDelay(event:Event):void
143		{
144			removeEventListener(Event.ENTER_FRAME, onTextScrollDelay);
145			if (_dirtyScroller)
146			{
147				updateScrollbar();
148			}
149			_dirtyScroller = false;
150		}
151		
152		/**
153		 * Called when the text in the text field is manually changed.
154		 */
155		protected override function onChange(event:Event):void
156		{
157			super.onChange(event);
158			updateScrollbar();
159		}
160		
161		/**
162		 * Called when the scroll bar is moved. Scrolls text accordingly.
163		 */
164		protected function onScrollbarScroll(event:Event):void
165		{
166			if (_tf && _scrollbar)
167			{
168				_tf.scrollV = Math.round(_scrollbar.value);
169			}
170		}
171		
172		/**
173		 * Called when the text is scrolled manually. Updates the position of the scroll bar.
174		 */
175		protected function onTextScroll(event:Event):void
176		{
177			if (_tf && _scrollbar)
178			{
179				_scrollbar.value = _tf.scrollV;
180				updateScrollbar();
181			}
182		}
183	}
184}