moeplayer/source/com/adobe/net/URIEncodingBitmap.as

/*
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	Copyright(c) 2005 Adobe Systems Incorporated. All rights reserved.
	
	Please read this Source Code License Agreement carefully before using
	the source code.
	
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package com.adobe.net
{
	import flash.utils.ByteArray;
	
	/**
	 * This class implements an efficient lookup table for URI
	 * character escaping.  This class is only needed if you
	 * create a derived class of URI to handle custom URI
	 * syntax.  This class is used internally by URI.
	 * 
	 * @langversion ActionScript 3.0
	 * @playerversion Flash 9.0* 
	 */
	public class URIEncodingBitmap extends ByteArray
	{
		/**
		 * Constructor.  Creates an encoding bitmap using the given
		 * string of characters as the set of characters that need
		 * to be URI escaped.
		 * 
		 * @langversion ActionScript 3.0
		 * @playerversion Flash 9.0
		 */
		public function URIEncodingBitmap(charsToEscape:String) : void
		{
			var i:int;
			var data:ByteArray = new ByteArray();
			
			// Initialize our 128 bits (16 bytes) to zero
			for (i = 0; i < 16; i++)
				this.writeByte(0);
				
			data.writeUTFBytes(charsToEscape);
			data.position = 0;
			
			while (data.bytesAvailable)
			{
				var c:int = data.readByte();
				
				if (c > 0x7f)
					continue;  // only escape low bytes
					
				var enc:int;
				this.position = (c >> 3);
				enc = this.readByte();
				enc |= 1 << (c & 0x7);
				this.position = (c >> 3);
				this.writeByte(enc);
			}
		}
		
		/**
		 * Based on the data table contained in this object, check
		 * if the given character should be escaped.
		 * 
		 * @param char	the character to be escaped.  Only the first
		 * character in the string is used.  Any other characters
		 * are ignored.
		 * 
		 * @return	the integer value of the raw UTF8 character.  For
		 * example, if '%' is given, the return value is 37 (0x25).
		 * If the character given does not need to be escaped, the
		 * return value is zero.
		 * 
		 * @langversion ActionScript 3.0
		 * @playerversion Flash 9.0 
		 */
		public function ShouldEscape(char:String) : int
		{
			var data:ByteArray = new ByteArray();
			var c:int, mask:int;
			
			// write the character into a ByteArray so
			// we can pull it out as a raw byte value.
			data.writeUTFBytes(char);
			data.position = 0;
			c = data.readByte();
			
			if (c & 0x80)
			{
				// don't escape high byte characters.  It can make international
				// URI's unreadable.  We just want to escape characters that would
				// make URI syntax ambiguous.
				return 0;
			}
			else if ((c < 0x1f) || (c == 0x7f))
			{
				// control characters must be escaped.
				return c;
			}
			
			this.position = (c >> 3);
			mask = this.readByte();
			
			if (mask & (1 << (c & 0x7)))
			{
				// we need to escape this, return the numeric value
				// of the character
				return c;
			}
			else
			{
				return 0;
			}
		}
	}
}