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DataStorage: Store settings type-safe

, 8 Aug 2012 GPL3
Shows how to use the DataStorage classes to generate type-safe settings classes.
DataStorage.zip
DataStorage
Aga.Controls
Aga.Controls.csproj.user
key.snk
Properties
Resources
check.bmp
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Threading
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CommandLineGenerator
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DataGeneration
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Add.png
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PropertyBool.png
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Properties
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Properties
#region Java Info
/**
 * Class GifDecoder - Decodes a GIF file into one or more frames.
 * <br><pre>
 * Example:
 *    GifDecoder d = new GifDecoder();
 *    d.read("sample.gif");
 *    int n = d.getFrameCount();
 *    for (int i = 0; i < n; i++) {
 *       BufferedImage frame = d.getFrame(i);  // frame i
 *       int t = d.getDelay(i);  // display duration of frame in milliseconds
 *       // do something with frame
 *    }
 * </pre>
 * No copyright asserted on the source code of this class.  May be used for
 * any purpose, however, refer to the Unisys LZW patent for any additional
 * restrictions.  Please forward any corrections to kweiner@fmsware.com.
 *
 * @author Kevin Weiner, FM Software; LZW decoder adapted from John Cristy's ImageMagick.
 * @version 1.03 November 2003
 *
 */
#endregion

using System;
using System.Collections;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;

namespace Aga.Controls
{
	public class GifFrame
	{
		private Image _image;
		public Image Image
		{
			get { return _image; }
		}

		private int _delay;
		public int Delay
		{
			get { return _delay; }
		}

		public GifFrame(Image im, int del)
		{
			_image = im;
			_delay = del;
		}
	}

	public class GifDecoder 
	{
		public const int StatusOK = 0;//File read status: No errors.
		public const int StatusFormatError = 1; //File read status: Error decoding file (may be partially decoded)
		public const int StatusOpenError = 2; //Unable to open source.

		private Stream inStream;
		private int status;

		private int width; // full image width
		private int height; // full image height
		private bool gctFlag; // global color table used
		private int gctSize; // size of global color table
		private int loopCount = 1; // iterations; 0 = repeat forever

		private int[] gct; // global color table
		private int[] lct; // local color table
		private int[] act; // active color table

		private int bgIndex; // background color index
		private int bgColor; // background color
		private int lastBgColor; // previous bg color
		private int pixelAspect; // pixel aspect ratio

		private bool lctFlag; // local color table flag
		private bool interlace; // interlace flag
		private int lctSize; // local color table size

		private int ix, iy, iw, ih; // current image rectangle
		private Rectangle lastRect; // last image rect
		private Image image; // current frame
		private Bitmap bitmap;
		private Image lastImage; // previous frame

		private byte[] block = new byte[256]; // current data block
		private int blockSize = 0; // block size

		// last graphic control extension info
		private int dispose = 0;
		// 0=no action; 1=leave in place; 2=restore to bg; 3=restore to prev
		private int lastDispose = 0;
		private bool transparency = false; // use transparent color
		private int delay = 0; // delay in milliseconds
		private int transIndex; // transparent color index

		private const int MaxStackSize = 4096;
		// max decoder pixel stack size

		// LZW decoder working arrays
		private short[] prefix;
		private byte[] suffix;
		private byte[] pixelStack;
		private byte[] pixels;

		private ArrayList frames; // frames read from current file
		private int frameCount;
		private bool _makeTransparent;

		/**
		 * Gets the number of frames read from file.
		 * @return frame count
		 */
		public int FrameCount
		{
			get
			{
				return frameCount;
			}
		}

		/**
		 * Gets the first (or only) image read.
		 *
		 * @return BufferedImage containing first frame, or null if none.
		 */
		public Image Image
		{
			get
			{
				return GetFrame(0).Image;
			}
		}

		/**
		 * Gets the "Netscape" iteration count, if any.
		 * A count of 0 means repeat indefinitiely.
		 *
		 * @return iteration count if one was specified, else 1.
		 */
		public int LoopCount
		{
			get
			{
				return loopCount;
			}
		}

		public GifDecoder(Stream stream, bool makeTransparent)
		{
			_makeTransparent = makeTransparent;
			if (Read(stream) != 0)
				throw new InvalidOperationException();
		}

		/**
		 * Creates new frame image from current data (and previous
		 * frames as specified by their disposition codes).
		 */
		private int[] GetPixels(Bitmap bitmap)
		{
			int [] pixels = new int [ 3 * image.Width * image.Height ];
			int count = 0;
			for (int th = 0; th < image.Height; th++)
			{
				for (int tw = 0; tw < image.Width; tw++)
				{
					Color color = bitmap.GetPixel(tw, th);
					pixels[count] = color.R;
					count++;
					pixels[count] = color.G;
					count++;
					pixels[count] = color.B;
					count++;
				}
			}
			return pixels;
		}

		private void SetPixels(int[] pixels)
		{
			int count = 0;
			for (int th = 0; th < image.Height; th++)
			{
				for (int tw = 0; tw < image.Width; tw++)
				{
					Color color = Color.FromArgb( pixels[count++] );
					bitmap.SetPixel( tw, th, color );
				}
			}
			if (_makeTransparent)
				bitmap.MakeTransparent(bitmap.GetPixel(0, 0));
		}

		private void SetPixels() 
		{
			// expose destination image's pixels as int array
			//		int[] dest =
			//			(( int ) image.getRaster().getDataBuffer()).getData();
			int[] dest = GetPixels( bitmap );

			// fill in starting image contents based on last image's dispose code
			if (lastDispose > 0) 
			{
				if (lastDispose == 3) 
				{
					// use image before last
					int n = frameCount - 2;
					if (n > 0) 
					{
						lastImage = GetFrame(n - 1).Image;
					} 
					else 
					{
						lastImage = null;
					}
				}

				if (lastImage != null) 
				{
					//				int[] prev =
					//					((DataBufferInt) lastImage.getRaster().getDataBuffer()).getData();
					int[] prev = GetPixels( new Bitmap( lastImage ) );
					Array.Copy(prev, 0, dest, 0, width * height);
					// copy pixels

					if (lastDispose == 2) 
					{
						// fill last image rect area with background color
						Graphics g = Graphics.FromImage( image );
						Color c = Color.Empty;
						if (transparency) 
						{
							c = Color.FromArgb( 0, 0, 0, 0 ); 	// assume background is transparent
						} 
						else 
						{
							c = Color.FromArgb( lastBgColor ) ;
							//						c = new Color(lastBgColor); // use given background color
						}
						Brush brush = new SolidBrush( c );
						g.FillRectangle( brush, lastRect );
						brush.Dispose();
						g.Dispose();
					}
				}
			}

			// copy each source line to the appropriate place in the destination
			int pass = 1;
			int inc = 8;
			int iline = 0;
			for (int i = 0; i < ih; i++) 
			{
				int line = i;
				if (interlace) 
				{
					if (iline >= ih) 
					{
						pass++;
						switch (pass) 
						{
							case 2 :
								iline = 4;
								break;
							case 3 :
								iline = 2;
								inc = 4;
								break;
							case 4 :
								iline = 1;
								inc = 2;
								break;
						}
					}
					line = iline;
					iline += inc;
				}
				line += iy;
				if (line < height) 
				{
					int k = line * width;
					int dx = k + ix; // start of line in dest
					int dlim = dx + iw; // end of dest line
					if ((k + width) < dlim) 
					{
						dlim = k + width; // past dest edge
					}
					int sx = i * iw; // start of line in source
					while (dx < dlim) 
					{
						// map color and insert in destination
						int index = ((int) pixels[sx++]) & 0xff;
						int c = act[index];
						if (c != 0) 
						{
							dest[dx] = c;
						}
						dx++;
					}
				}
			}
			SetPixels( dest );
		}

		/**
		 * Gets the image contents of frame n.
		 *
		 * @return BufferedImage representation of frame.
		 */
		public GifFrame GetFrame(int n) 
		{
			if ((n >= 0) && (n < frameCount))
				return (GifFrame)frames[n];
			else
				throw new ArgumentOutOfRangeException();
		}

		/**
		 * Gets image size.
		 *
		 * @return GIF image dimensions
		 */
		public Size FrameSize
		{
			get
			{
				return new Size(width, height);
			}
		}

		/**
		 * Reads GIF image from stream
		 *
		 * @param BufferedInputStream containing GIF file.
		 * @return read status code (0 = no errors)
		 */
		private int Read( Stream inStream ) 
		{
			Init();
			if ( inStream != null) 
			{
				this.inStream = inStream;
				ReadHeader();
				if (!Error()) 
				{
					ReadContents();
					if (frameCount < 0) 
					{
						status = StatusFormatError;
					}
				}
				inStream.Close();
			} 
			else 
			{
				status = StatusOpenError;
			}
			return status;
		}


		/**
		 * Decodes LZW image data into pixel array.
		 * Adapted from John Cristy's ImageMagick.
		 */
		private void DecodeImageData() 
		{
			int NullCode = -1;
			int npix = iw * ih;
			int available, 
				clear,
				code_mask,
				code_size,
				end_of_information,
				in_code,
				old_code,
				bits,
				code,
				count,
				i,
				datum,
				data_size,
				first,
				top,
				bi,
				pi;

			if ((pixels == null) || (pixels.Length < npix)) 
			{
				pixels = new byte[npix]; // allocate new pixel array
			}
			if (prefix == null) prefix = new short[MaxStackSize];
			if (suffix == null) suffix = new byte[MaxStackSize];
			if (pixelStack == null) pixelStack = new byte[MaxStackSize + 1];

			//  Initialize GIF data stream decoder.

			data_size = Read();
			clear = 1 << data_size;
			end_of_information = clear + 1;
			available = clear + 2;
			old_code = NullCode;
			code_size = data_size + 1;
			code_mask = (1 << code_size) - 1;
			for (code = 0; code < clear; code++) 
			{
				prefix[code] = 0;
				suffix[code] = (byte) code;
			}

			//  Decode GIF pixel stream.

			datum = bits = count = first = top = pi = bi = 0;

			for (i = 0; i < npix;) 
			{
				if (top == 0) 
				{
					if (bits < code_size) 
					{
						//  Load bytes until there are enough bits for a code.
						if (count == 0) 
						{
							// Read a new data block.
							count = ReadBlock();
							if (count <= 0)
								break;
							bi = 0;
						}
						datum += (((int) block[bi]) & 0xff) << bits;
						bits += 8;
						bi++;
						count--;
						continue;
					}

					//  Get the next code.

					code = datum & code_mask;
					datum >>= code_size;
					bits -= code_size;

					//  Interpret the code

					if ((code > available) || (code == end_of_information))
						break;
					if (code == clear) 
					{
						//  Reset decoder.
						code_size = data_size + 1;
						code_mask = (1 << code_size) - 1;
						available = clear + 2;
						old_code = NullCode;
						continue;
					}
					if (old_code == NullCode) 
					{
						pixelStack[top++] = suffix[code];
						old_code = code;
						first = code;
						continue;
					}
					in_code = code;
					if (code == available) 
					{
						pixelStack[top++] = (byte) first;
						code = old_code;
					}
					while (code > clear) 
					{
						pixelStack[top++] = suffix[code];
						code = prefix[code];
					}
					first = ((int) suffix[code]) & 0xff;

					//  Add a new string to the string table,

					if (available >= MaxStackSize)
						break;
					pixelStack[top++] = (byte) first;
					prefix[available] = (short) old_code;
					suffix[available] = (byte) first;
					available++;
					if (((available & code_mask) == 0)
						&& (available < MaxStackSize)) 
					{
						code_size++;
						code_mask += available;
					}
					old_code = in_code;
				}

				//  Pop a pixel off the pixel stack.

				top--;
				pixels[pi++] = pixelStack[top];
				i++;
			}

			for (i = pi; i < npix; i++) 
			{
				pixels[i] = 0; // clear missing pixels
			}

		}

		/**
		 * Returns true if an error was encountered during reading/decoding
		 */
		private bool Error() 
		{
			return status != StatusOK;
		}

		/**
		 * Initializes or re-initializes reader
		 */
		private void Init() 
		{
			status = StatusOK;
			frameCount = 0;
			frames = new ArrayList();
			gct = null;
			lct = null;
		}

		/**
		 * Reads a single byte from the input stream.
		 */
		private int Read() 
		{
			int curByte = 0;
			try 
			{
				curByte = inStream.ReadByte();
			} 
			catch (IOException) 
			{
				status = StatusFormatError;
			}
			return curByte;
		}

		/**
		 * Reads next variable length block from input.
		 *
		 * @return number of bytes stored in "buffer"
		 */
		private int ReadBlock() 
		{
			blockSize = Read();
			int n = 0;
			if (blockSize > 0) 
			{
				try 
				{
					int count = 0;
					while (n < blockSize) 
					{
						count = inStream.Read(block, n, blockSize - n);
						if (count == -1) 
							break;
						n += count;
					}
				} 
				catch (IOException) 
				{
				}

				if (n < blockSize) 
				{
					status = StatusFormatError;
				}
			}
			return n;
		}

		/**
		 * Reads color table as 256 RGB integer values
		 *
		 * @param ncolors int number of colors to read
		 * @return int array containing 256 colors (packed ARGB with full alpha)
		 */
		private int[] ReadColorTable(int ncolors) 
		{
			int nbytes = 3 * ncolors;
			int[] tab = null;
			byte[] c = new byte[nbytes];
			int n = 0;
			try 
			{
				n = inStream.Read(c, 0, c.Length );
			} 
			catch (IOException) 
			{
			}
			if (n < nbytes) 
			{
				status = StatusFormatError;
			} 
			else 
			{
				tab = new int[256]; // max size to avoid bounds checks
				int i = 0;
				int j = 0;
				while (i < ncolors) 
				{
					int r = ((int) c[j++]) & 0xff;
					int g = ((int) c[j++]) & 0xff;
					int b = ((int) c[j++]) & 0xff;
					tab[i++] = ( int ) ( 0xff000000 | (r << 16) | (g << 8) | b );
				}
			}
			return tab;
		}

		/**
		 * Main file parser.  Reads GIF content blocks.
		 */
		private void ReadContents() 
		{
			// read GIF file content blocks
			bool done = false;
			while (!(done || Error())) 
			{
				int code = Read();
				switch (code) 
				{

					case 0x2C : // image separator
						ReadImage();
						break;

					case 0x21 : // extension
						code = Read();
					switch (code) 
					{
						case 0xf9 : // graphics control extension
							ReadGraphicControlExt();
							break;

						case 0xff : // application extension
							ReadBlock();
							String app = "";
							for (int i = 0; i < 11; i++) 
							{
								app += (char) block[i];
							}
							if (app.Equals("NETSCAPE2.0")) 
							{
								ReadNetscapeExt();
							}
							else
								Skip(); // don't care
							break;

						default : // uninteresting extension
							Skip();
							break;
					}
						break;

					case 0x3b : // terminator
						done = true;
						break;

					case 0x00 : // bad byte, but keep going and see what happens
						break;

					default :
						status = StatusFormatError;
						break;
				}
			}
		}

		/**
		 * Reads Graphics Control Extension values
		 */
		private void ReadGraphicControlExt() 
		{
			Read(); // block size
			int packed = Read(); // packed fields
			dispose = (packed & 0x1c) >> 2; // disposal method
			if (dispose == 0) 
			{
				dispose = 1; // elect to keep old image if discretionary
			}
			transparency = (packed & 1) != 0;
			delay = ReadShort() * 10; // delay in milliseconds
			transIndex = Read(); // transparent color index
			Read(); // block terminator
		}

		/**
		 * Reads GIF file header information.
		 */
		private void ReadHeader() 
		{
			String id = "";
			for (int i = 0; i < 6; i++) 
			{
				id += (char) Read();
			}
			if (!id.StartsWith("GIF")) 
			{
				status = StatusFormatError;
				return;
			}

			ReadLSD();
			if (gctFlag && !Error()) 
			{
				gct = ReadColorTable(gctSize);
				bgColor = gct[bgIndex];
			}
		}

		/**
		 * Reads next frame image
		 */
		private void ReadImage() 
		{
			ix = ReadShort(); // (sub)image position & size
			iy = ReadShort();
			iw = ReadShort();
			ih = ReadShort();

			int packed = Read();
			lctFlag = (packed & 0x80) != 0; // 1 - local color table flag
			interlace = (packed & 0x40) != 0; // 2 - interlace flag
			// 3 - sort flag
			// 4-5 - reserved
			lctSize = 2 << (packed & 7); // 6-8 - local color table size

			if (lctFlag) 
			{
				lct = ReadColorTable(lctSize); // read table
				act = lct; // make local table active
			} 
			else 
			{
				act = gct; // make global table active
				if (bgIndex == transIndex)
					bgColor = 0;
			}
			int save = 0;
			if (transparency) 
			{
				save = act[transIndex];
				act[transIndex] = 0; // set transparent color if specified
			}

			if (act == null) 
			{
				status = StatusFormatError; // no color table defined
			}

			if (Error()) return;

			DecodeImageData(); // decode pixel data
			Skip();

			if (Error()) return;

			frameCount++;

			// create new image to receive frame data
			//		image =
			//			new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB_PRE);

			bitmap = new Bitmap( width, height );
			image = bitmap;
			SetPixels(); // transfer pixel data to image

			frames.Add(new GifFrame(bitmap, delay)); // add image to frame list

			if (transparency) 
			{
				act[transIndex] = save;
			}
			ResetFrame();

		}

		/**
		 * Reads Logical Screen Descriptor
		 */
		private void ReadLSD() 
		{

			// logical screen size
			width = ReadShort();
			height = ReadShort();

			// packed fields
			int packed = Read();
			gctFlag = (packed & 0x80) != 0; // 1   : global color table flag
			// 2-4 : color resolution
			// 5   : gct sort flag
			gctSize = 2 << (packed & 7); // 6-8 : gct size

			bgIndex = Read(); // background color index
			pixelAspect = Read(); // pixel aspect ratio
		}

		/**
		 * Reads Netscape extenstion to obtain iteration count
		 */
		private void ReadNetscapeExt() 
		{
			do 
			{
				ReadBlock();
				if (block[0] == 1) 
				{
					// loop count sub-block
					int b1 = ((int) block[1]) & 0xff;
					int b2 = ((int) block[2]) & 0xff;
					loopCount = (b2 << 8) | b1;
				}
			} while ((blockSize > 0) && !Error());
		}

		/**
		 * Reads next 16-bit value, LSB first
		 */
		private int ReadShort() 
		{
			// read 16-bit value, LSB first
			return Read() | (Read() << 8);
		}

		/**
		 * Resets frame state for reading next image.
		 */
		private void ResetFrame() 
		{
			lastDispose = dispose;
			lastRect = new Rectangle(ix, iy, iw, ih);
			lastImage = image;
			lastBgColor = bgColor;
			//		int dispose = 0;
			lct = null;
		}

		/**
		 * Skips variable length blocks up to and including
		 * next zero length block.
		 */
		private void Skip() 
		{
			do 
			{
				ReadBlock();
			} while ((blockSize > 0) && !Error());
		}
	}
}

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About the Author

pchinery
pdfforge GbR
Germany Germany
Philip is a Software Architect with severaly years of experience. He studied business IT in the University of Wedel, Germany, and has reached his Masters degree in 2010. Back in 2002, he started his so far best-known software PDFCreator. The second developer joined two years later and since then, both constantly improve this piece of open source software.

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