/**
* Process a content stream.
*
* @param contentStream the content stream
* @throws IOException if there is an exception while processing the stream
*/
private void processStream(PDContentStream contentStream) throws IOException {
PDResources parent = pushResources(contentStream);
Stack<PDGraphicsState> savedStack = saveGraphicsStack();
Matrix parentMatrix = initialMatrix;
// transform the CTM using the stream's matrix
getGraphicsState().getCurrentTransformationMatrix().concatenate(contentStream.getMatrix());
// the stream's initial matrix includes the parent CTM, e.g. this allows a scaled form
initialMatrix = getGraphicsState().getCurrentTransformationMatrix().clone();
// clip to bounding box
PDRectangle bbox = contentStream.getBBox();
clipToRect(bbox);
// processStreamOperators(contentStream);
initialMatrix = parentMatrix;
restoreGraphicsStack(savedStack);
popResources(parent);
}
/** Pushes the given stream's resources, returning the previous resources. */
private PDResources pushResources(PDContentStream contentStream) {
// resource lookup: first look for stream resources, then fallback to the current page
PDResources parentResources = resources;
PDResources streamResources = contentStream.getResources();
if (streamResources != null) {
resources = streamResources;
} else if (resources != null) {
// inherit directly from parent stream, this is not in the PDF spec, but the file from
// PDFBOX-1359 does this and works in Acrobat
} else {
resources = currentPage.getResources();
}
// resources are required in PDF
if (resources == null) {
resources = new PDResources();
}
return parentResources;
}
