Mercurial > projects > dwt-win
view dwt/internal/image/PngInputStream.d @ 213:36f5cb12e1a2
Update to SWT 3.4M7
author | Frank Benoit <benoit@tionex.de> |
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date | Sat, 17 May 2008 17:34:28 +0200 |
parents | 57151e2793a2 |
children |
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/******************************************************************************* * Copyright (c) 2000, 2006 IBM Corporation and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * IBM Corporation - initial API and implementation * Port to the D programming language: * Frank Benoit <benoit@tionex.de> *******************************************************************************/ module dwt.internal.image.PngInputStream; import dwt.dwthelper.InputStream; import dwt.dwthelper.System; import dwt.internal.image.PngIdatChunk; import dwt.internal.image.PngChunkReader; import dwt.internal.image.PngChunk; import tango.core.Exception; import Math = tango.math.Math; public class PngInputStream : InputStream { alias InputStream.read read; PngChunkReader reader; PngChunk chunk; int offset, length; final static int DATA_OFFSET = 8; public this(PngIdatChunk chunk, PngChunkReader reader) { this.chunk = chunk; this.reader = reader; length = chunk.getLength(); offset = 0; } private bool checkChunk() { while (offset is length) { chunk = reader.readNextChunk(); if (chunk is null) throw new IOException("no data"); if (chunk.getChunkType() is PngChunk.CHUNK_IEND) return false; if (chunk.getChunkType() !is PngChunk.CHUNK_IDAT) throw new IOException(""); length = chunk.getLength(); offset = 0; } return true; } public override void close() { chunk = null; } public override int read() { if (chunk is null) throw new IOException(""); if (offset is length && !checkChunk()) return -1; int b = chunk.reference[DATA_OFFSET + offset] & 0xFF; offset++; return b; } public override int read(byte[] b, int off, int len) { if (chunk is null) throw new IOException(""); if (offset is length && !checkChunk()) return -1; len = Math.min(len, length - offset); System.arraycopy(chunk.reference, DATA_OFFSET + offset, b, off, len); offset += len; return len; } }