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package
{
import flash.display.Loader;
import flash.net.URLRequest;
import flash.net.URLStream;
import flash.events.IOErrorEvent;
import flash.events.SecurityErrorEvent;
import flash.events.Event;
import flash.utils.ByteArray;
import flash.utils.Endian;
import flash.errors.EOFError;
/**
* Loads a SWF file as version 9 format forcibly even if version is under 9.
*
* Usage:
* <pre>
* var loader:Loader = Loader(addChild(new Loader()));
* var fLoader:ForcibleLoader = new ForcibleLoader(loader);
* fLoader.load(new URLRequest('swf7.swf'));
* </pre>
*
* @author yossy:beinteractive
* @see http://www.be-interactive.org/?itemid=250
* @see http://fladdict.net/blog/2007/05/avm2avm1swf.html
*/
public class ForcibleLoader
{
public function ForcibleLoader(loader:Loader)
{
this.loader = loader;
_stream = new URLStream();
_stream.addEventListener(Event.COMPLETE, completeHandler);
_stream.addEventListener(IOErrorEvent.IO_ERROR, ioErrorHandler);
_stream.addEventListener(SecurityErrorEvent.SECURITY_ERROR, securityErrorHandler);
}
private var _loader:Loader;
private var _stream:URLStream;
public function get loader():Loader
{
return _loader;
}
public function set loader(value:Loader):void
{
_loader = value;
}
public function load(request:URLRequest):void
{
_stream.load(request);
}
private function completeHandler(event:Event):void
{
var inputBytes:ByteArray = new ByteArray();
_stream.readBytes(inputBytes);
_stream.close();
inputBytes.endian = Endian.LITTLE_ENDIAN;
if (isCompressed(inputBytes)) {
uncompress(inputBytes);
}
var version:uint = uint(inputBytes[3]);
if (version < 9) {
updateVersion(inputBytes, 9);
}
if (version > 7) {
flagSWF9Bit(inputBytes);
}
else {
insertFileAttributesTag(inputBytes);
}
loader.loadBytes(inputBytes);
}
private function isCompressed(bytes:ByteArray):Boolean
{
return bytes[0] == 0x43;
}
private function uncompress(bytes:ByteArray):void
{
var cBytes:ByteArray = new ByteArray();
cBytes.writeBytes(bytes, 8);
bytes.length = 8;
bytes.position = 8;
cBytes.uncompress();
bytes.writeBytes(cBytes);
bytes[0] = 0x46;
cBytes.length = 0;
}
private function getBodyPosition(bytes:ByteArray):uint
{
var result:uint = 0;
result += 3; // FWS/CWS
result += 1; // version(byte)
result += 4; // length(32bit-uint)
var rectNBits:uint = bytes[result] >>> 3;
result += (5 + rectNBits * 4) / 8; // stage(rect)
result += 2;
result += 1; // frameRate(byte)
result += 2; // totalFrames(16bit-uint)
return result;
}
private function findFileAttributesPosition(offset:uint, bytes:ByteArray):int
{
bytes.position = offset;
try {
for (;;) {
var byte:uint = bytes.readShort();
var tag:uint = byte >>> 6;
if (tag == 69) {
return bytes.position - 2;
}
var length:uint = byte & 0x3f;
if (length == 0x3f) {
length = bytes.readInt();
}
bytes.position += length;
}
}
catch (e:EOFError) {
}
return -1;
}
private function flagSWF9Bit(bytes:ByteArray):void
{
var pos:int = findFileAttributesPosition(getBodyPosition(bytes), bytes);
if (pos != -1) {
bytes[pos + 2] |= 0x08;
}
else {
insertFileAttributesTag(bytes);
}
}
private function insertFileAttributesTag(bytes:ByteArray):void
{
var pos:uint = getBodyPosition(bytes);
var afterBytes:ByteArray = new ByteArray();
afterBytes.writeBytes(bytes, pos);
bytes.length = pos;
bytes.position = pos;
bytes.writeByte(0x44);
bytes.writeByte(0x11);
bytes.writeByte(0x08);
bytes.writeByte(0x00);
bytes.writeByte(0x00);
bytes.writeByte(0x00);
bytes.writeBytes(afterBytes);
afterBytes.length = 0;
}
private function updateVersion(bytes:ByteArray, version:uint):void
{
bytes[3] = version;
}
private function ioErrorHandler(event:IOErrorEvent):void
{
loader.contentLoaderInfo.dispatchEvent(event.clone());
}
private function securityErrorHandler(event:SecurityErrorEvent):void
{
loader.contentLoaderInfo.dispatchEvent(event.clone());
}
}
}
@kasparsj
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kasparsj commented May 9, 2017

Error #2118: The LoaderInfo class does not implement this method.

Apparently dispatchEvent is private in LoaderInfo.

@nsdevaraj
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Author

nsdevaraj commented Oct 4, 2018

@kasparsj it works only on AIR

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