1 files changed, 64 insertions, 0 deletions
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/internal/image/PngChunkReader.java b/bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/internal/image/PngChunkReader.java
new file mode 100755
index 0000000000..f93b716697
--- /dev/null
+++ b/bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/internal/image/PngChunkReader.java
@@ -0,0 +1,64 @@
+package org.eclipse.swt.internal.image;
+
+import org.eclipse.swt.*;
+
+/*
+ * Licensed Materials - Property of IBM,
+ * (c) Copyright IBM Corp. 1998, 2000  All Rights Reserved
+ */
+
+public class PngChunkReader {
+	LEDataInputStream inputStream;
+	PngFileReadState readState;
+	PngIhdrChunk headerChunk;
+	PngPlteChunk paletteChunk;
+	
+PngChunkReader(LEDataInputStream inputStream) {
+	this.inputStream = inputStream;
+	readState = new PngFileReadState();
+	headerChunk = null;
+}
+
+PngIhdrChunk getIhdrChunk() {
+	if (headerChunk == null) {
+		try { 
+			PngChunk chunk = PngChunk.readNextFromStream(inputStream);
+			headerChunk = (PngIhdrChunk) chunk;
+			headerChunk.validate(readState, null);
+		} catch (ClassCastException e) {
+			SWT.error(SWT.ERROR_INVALID_IMAGE);
+		}
+	}
+	return headerChunk;
+}
+
+PngChunk readNextChunk() {
+	if (headerChunk == null) return getIhdrChunk();
+	
+	PngChunk chunk = PngChunk.readNextFromStream(inputStream);
+	switch (chunk.getChunkType()) {
+		case PngChunk.CHUNK_tRNS:
+			((PngTrnsChunk) chunk).validate(readState, headerChunk, paletteChunk);
+			break;
+		case PngChunk.CHUNK_PLTE:
+			chunk.validate(readState, headerChunk);
+			paletteChunk = (PngPlteChunk) chunk;
+			break;
+		default:
+			chunk.validate(readState, headerChunk);
+	}
+	if (readState.readIDAT && !(chunk.getChunkType() == PngChunk.CHUNK_IDAT)) {
+		readState.readPixelData = true;
+	}
+	return chunk;
+}
+
+boolean readPixelData() {
+	return readState.readPixelData;
+}
+
+boolean hasMoreChunks() {
+	return !readState.readIEND;
+}
+
+}
+\ No newline at end of file