private static void CheckNetscapeExtension(Stream s, int loopCount)
{
// check netscape extension
ApplicationExtension ae = new ApplicationExtension(s);
Assert.AreEqual(ErrorState.Ok, ae.ConsolidatedState);
NetscapeExtension ne = new NetscapeExtension(ae);
Assert.AreEqual(ErrorState.Ok, ne.ConsolidatedState);
Assert.AreEqual(loopCount, ne.LoopCount);
}
/// <summary>
/// Writes a Netscape application extension defining the repeat count
/// to the supplied output stream, if the repeat count is greater than
/// or equal to zero.
/// </summary>
/// <param name="outputStream">
/// The stream to write to.
/// </param>
private void WriteNetscapeExtension(Stream outputStream)
{
// Repeat count -1 means don't repeat the animation, so don't add
// a Netscape extension.
if (_repeatCount >= 0)
{
outputStream.WriteByte(GifComponent.CodeExtensionIntroducer);
outputStream.WriteByte(GifComponent.CodeApplicationExtensionLabel);
NetscapeExtension ne = new NetscapeExtension(_repeatCount);
ne.WriteToStream(outputStream);
}
}
public void ConstructorIntTest()
{
_ne = new NetscapeExtension(257);
Assert.AreEqual("NETSCAPE", _ne.ApplicationIdentifier);
Assert.AreEqual("2.0", _ne.ApplicationAuthenticationCode);
Assert.AreEqual(2, _ne.ApplicationData.Count);
Assert.AreEqual(3, _ne.ApplicationData[0].Data.Length);
Assert.AreEqual(1, _ne.ApplicationData[0].Data[0]);
Assert.AreEqual(1, _ne.ApplicationData[0].Data[1]);
Assert.AreEqual(1, _ne.ApplicationData[0].Data[2]);
Assert.AreEqual(0, _ne.ApplicationData[1].Data.Length);
Assert.AreEqual(257, _ne.LoopCount);
}
public void ConstructorTest()
{
byte[] idData = new byte[]
{
(byte)'N',
(byte)'E',
(byte)'T',
(byte)'S',
(byte)'C',
(byte)'A',
(byte)'P',
(byte)'E',
(byte)'2',
(byte)'.',
(byte)'0',
};
DataBlock idBlock = new DataBlock(11, idData);
Collection <DataBlock> appData = new Collection <DataBlock>();
// First byte in the data block is always 1 for a netscape extension
// Second and third bytes are the loop count, lsb first
byte[] loopCount = new byte[] { 1, 4, 0 };
appData.Add(new DataBlock(3, loopCount));
// Add the block terminator
appData.Add(new DataBlock(0, new byte[0]));
ApplicationExtension appExt
= new ApplicationExtension(idBlock, appData);
_ne = new NetscapeExtension(appExt);
Assert.AreEqual(4, _ne.LoopCount);
Assert.AreEqual("NETSCAPE", _ne.ApplicationIdentifier);
Assert.AreEqual("2.0", _ne.ApplicationAuthenticationCode);
Assert.AreEqual(ErrorState.Ok, _ne.ConsolidatedState);
}
public void ConstructorTestNot2Point0()
{
byte[] idData = new byte[]
{
(byte)'N',
(byte)'E',
(byte)'T',
(byte)'S',
(byte)'C',
(byte)'A',
(byte)'P',
(byte)'E',
(byte)'3',
(byte)'.',
(byte)'0',
};
DataBlock idBlock = new DataBlock(11, idData);
ApplicationExtension appExt
= new ApplicationExtension(idBlock, new Collection <DataBlock>());
try
{
_ne = new NetscapeExtension(appExt);
}
catch (ArgumentException ex)
{
string message
= "The application authentication code is not '2.0' "
+ "therefore this application extension is not a "
+ "Netscape extension. Application authentication code: 3.0";
StringAssert.Contains(message, ex.Message);
Assert.AreEqual("applicationExtension", ex.ParamName);
throw;
}
}
public void ConstructorTestNotNetscape()
{
byte[] idData = new byte[]
{
(byte)'B',
(byte)'I',
(byte)'G',
(byte)'P',
(byte)'A',
(byte)'N',
(byte)'T',
(byte)'S',
(byte)'2',
(byte)'.',
(byte)'0',
};
DataBlock idBlock = new DataBlock(11, idData);
ApplicationExtension appExt
= new ApplicationExtension(idBlock, new Collection <DataBlock>());
try
{
_ne = new NetscapeExtension(appExt);
}
catch (ArgumentException ex)
{
string message
= "The application identifier is not 'NETSCAPE' "
+ "therefore this application extension is not a "
+ "Netscape extension. Application identifier: BIGPANTS";
StringAssert.Contains(message, ex.Message);
Assert.AreEqual("applicationExtension", ex.ParamName);
throw;
}
}
/// <summary>
/// Main file parser. Reads GIF content blocks.
/// </summary>
/// <param name="inputStream">
/// Input stream from which the GIF data is to be read.
/// </param>
private void ReadContents(Stream inputStream)
{
// read GIF file content blocks
bool done = false;
GraphicControlExtension lastGce = null;
string message; // for error conditions
while (!done && ConsolidatedState == ErrorState.Ok)
{
int code = Read(inputStream);
MyProgressCounters[_readStreamCounterText].Value
= (int)inputStream.Position;
WriteCodeToDebugXml(code);
switch (code)
{
case CodeImageSeparator:
WriteDebugXmlComment("0x2C - image separator");
AddFrame(inputStream, lastGce);
MyProgressCounters[_readStreamCounterText].Value
= (int)inputStream.Position;
break;
case CodeExtensionIntroducer:
WriteDebugXmlComment("0x21 - extension introducer");
code = Read(inputStream);
MyProgressCounters[_readStreamCounterText].Value
= (int)inputStream.Position;
WriteCodeToDebugXml(code);
switch (code)
{
case CodePlaintextLabel:
// FEATURE: handle plain text extension
WriteDebugXmlComment("0x01 - plain text extension");
SkipBlocks(inputStream);
MyProgressCounters[_readStreamCounterText].Value
= (int)inputStream.Position;
break;
case CodeGraphicControlLabel:
WriteDebugXmlComment("0xF9 - graphic control label");
lastGce = new GraphicControlExtension(inputStream,
XmlDebugging);
MyProgressCounters[_readStreamCounterText].Value
= (int)inputStream.Position;
WriteDebugXmlNode(lastGce.DebugXmlReader);
break;
case CodeCommentLabel:
// FEATURE: handle comment extension
WriteDebugXmlComment("0xFE - comment extension");
SkipBlocks(inputStream);
MyProgressCounters[_readStreamCounterText].Value
= (int)inputStream.Position;
break;
case CodeApplicationExtensionLabel:
WriteDebugXmlComment("0xFF - application extension label");
ApplicationExtension ext
= new ApplicationExtension(inputStream,
XmlDebugging);
MyProgressCounters[_readStreamCounterText].Value
= (int)inputStream.Position;
WriteDebugXmlNode(ext.DebugXmlReader);
if (ext.ApplicationIdentifier == "NETSCAPE" &&
ext.ApplicationAuthenticationCode == "2.0")
{
_netscapeExtension = new NetscapeExtension(ext);
}
else
{
// TESTME: ReadContents - non-Netscape application extension
_applicationExtensions.Add(ext);
}
break;
default: // uninteresting extension
// TESTME: ReadContents - uninteresting extension
WriteDebugXmlComment("Ignoring this extension");
SkipBlocks(inputStream);
MyProgressCounters[_readStreamCounterText].Value
= (int)inputStream.Position;
break;
}
break;
case CodeTrailer:
// We've reached an explicit end-of-data marker, so stop
// processing the stream.
WriteDebugXmlComment("0x3B - end of data");
done = true;
break;
case 0x00: // bad byte, but keep going and see what happens
WriteDebugXmlComment("0x00 - unexpected code");
message
= "Unexpected block terminator encountered at "
+ "position " + inputStream.Position
+ " after reading " + _frames.Count + " frames.";
SetStatus(ErrorState.UnexpectedBlockTerminator,
message);
break;
case -1: // reached the end of the input stream
WriteDebugXmlComment("-1 - end of input stream");
message
= "Reached the end of the input stream without "
+ "encountering trailer 0x3b";
SetStatus(ErrorState.EndOfInputStream, message);
break;
default:
WriteDebugXmlComment("Not a recognised code");
message
= "Bad data block introducer: 0x"
+ code.ToString("X", CultureInfo.InvariantCulture).PadLeft(2, '0')
+ " (" + code + ") at position " + inputStream.Position
+ " ("
+ inputStream.Position.ToString("X",
CultureInfo.InvariantCulture)
+ " hex) after reading "
+ _frames.Count + " frames.";
SetStatus(ErrorState.BadDataBlockIntroducer, message);
break;
}
}
}
public void WikipediaExampleTest()
{
ReportStart();
_e = new AnimatedGifEncoder();
GifFrame frame = new GifFrame(WikipediaExample.ExpectedBitmap);
frame.Delay = WikipediaExample.DelayTime;
_e.AddFrame(frame);
// TODO: some way of creating/testing a UseLocal version of WikipediaExample
string fileName = "WikipediaExampleUseGlobal.gif";
_e.WriteToFile(fileName);
Stream s = File.OpenRead(fileName);
int code;
// check GIF header
GifHeader gh = new GifHeader(s);
Assert.AreEqual(ErrorState.Ok, gh.ConsolidatedState);
// check logical screen descriptor
LogicalScreenDescriptor lsd = new LogicalScreenDescriptor(s);
Assert.AreEqual(ErrorState.Ok, lsd.ConsolidatedState);
WikipediaExample.CheckLogicalScreenDescriptor(lsd);
// read global colour table
ColourTable gct
= new ColourTable(s, WikipediaExample.GlobalColourTableSize);
Assert.AreEqual(ErrorState.Ok, gct.ConsolidatedState);
// cannot compare global colour table as different encoders will
// produce difference colour tables.
// WikipediaExample.CheckGlobalColourTable( gct );
// check for extension introducer
code = ExampleComponent.CallRead(s);
Assert.AreEqual(GifComponent.CodeExtensionIntroducer, code);
// check for app extension label
code = ExampleComponent.CallRead(s);
Assert.AreEqual(GifComponent.CodeApplicationExtensionLabel, code);
// check netscape extension
ApplicationExtension ae = new ApplicationExtension(s);
Assert.AreEqual(ErrorState.Ok, ae.ConsolidatedState);
NetscapeExtension ne = new NetscapeExtension(ae);
Assert.AreEqual(ErrorState.Ok, ne.ConsolidatedState);
Assert.AreEqual(0, ne.LoopCount);
// check for extension introducer
code = ExampleComponent.CallRead(s);
Assert.AreEqual(GifComponent.CodeExtensionIntroducer, code);
// check for gce label
code = ExampleComponent.CallRead(s);
Assert.AreEqual(GifComponent.CodeGraphicControlLabel, code);
// check graphic control extension
GraphicControlExtension gce = new GraphicControlExtension(s);
Assert.AreEqual(ErrorState.Ok, gce.ConsolidatedState);
WikipediaExample.CheckGraphicControlExtension(gce);
// check for image separator
code = ExampleComponent.CallRead(s);
Assert.AreEqual(GifComponent.CodeImageSeparator, code);
// check for image descriptor
ImageDescriptor id = new ImageDescriptor(s);
Assert.AreEqual(ErrorState.Ok, id.ConsolidatedState);
WikipediaExample.CheckImageDescriptor(id);
// read, decode and check image data
// Cannot compare encoded LZW data directly as different encoders
// will create different colour tables, so even if the bitmaps are
// identical, the colour indices will be different
int pixelCount = WikipediaExample.FrameSize.Width
* WikipediaExample.FrameSize.Height;
TableBasedImageData tbid = new TableBasedImageData(s, pixelCount);
for (int y = 0; y < WikipediaExample.LogicalScreenSize.Height; y++)
{
for (int x = 0; x < WikipediaExample.LogicalScreenSize.Width; x++)
{
int i = (y * WikipediaExample.LogicalScreenSize.Width) + x;
Assert.AreEqual(WikipediaExample.ExpectedBitmap.GetPixel(x, y),
gct[tbid.Pixels[i]],
"X: " + x + ", Y: " + y);
}
}
// Check for block terminator after image data
code = ExampleComponent.CallRead(s);
Assert.AreEqual(0x00, code);
// check for GIF trailer
code = ExampleComponent.CallRead(s);
Assert.AreEqual(GifComponent.CodeTrailer, code);
// check we're at the end of the stream
code = ExampleComponent.CallRead(s);
Assert.AreEqual(-1, code);
s.Close();
_d = new GifDecoder(fileName);
_d.Decode();
Assert.AreEqual(ErrorState.Ok, _d.ConsolidatedState);
BitmapAssert.AreEqual(WikipediaExample.ExpectedBitmap,
(Bitmap)_d.Frames[0].TheImage,
"");
ReportEnd();
}
