I have build such kind of application using approximatively the same approach except :
- I cache the generated image on the disk and always generate two to three images in advance in a separate thread.
- I don't overlay with a
UIImage but instead draw the image in the layer when zooming is 1. Those tiles will be released automatically when memory warnings are issued.
Whenever the user start zooming, I acquire the CGPDFPage and render it using the appropriate CTM. The code in - (void)drawLayer: (CALayer*)layer inContext: (CGContextRef) context is like :
CGAffineTransform currentCTM = CGContextGetCTM(context);
if (currentCTM.a == 1.0 && baseImage) {
//Calculate ideal scale
CGFloat scaleForWidth = baseImage.size.width/self.bounds.size.width;
CGFloat scaleForHeight = baseImage.size.height/self.bounds.size.height;
CGFloat imageScaleFactor = MAX(scaleForWidth, scaleForHeight);
CGSize imageSize = CGSizeMake(baseImage.size.width/imageScaleFactor, baseImage.size.height/imageScaleFactor);
CGRect imageRect = CGRectMake((self.bounds.size.width-imageSize.width)/2, (self.bounds.size.height-imageSize.height)/2, imageSize.width, imageSize.height);
CGContextDrawImage(context, imageRect, [baseImage CGImage]);
} else {
@synchronized(issue) {
CGPDFPageRef pdfPage = CGPDFDocumentGetPage(issue.pdfDoc, pageIndex+1);
pdfToPageTransform = CGPDFPageGetDrawingTransform(pdfPage, kCGPDFMediaBox, layer.bounds, 0, true);
CGContextConcatCTM(context, pdfToPageTransform);
CGContextDrawPDFPage(context, pdfPage);
}
}
issue is the object containg the CGPDFDocumentRef. I synchronize the part where I access the pdfDoc property because I release it and recreate it when receiving memoryWarnings. It seems that the CGPDFDocumentRef object do some internal caching that I did not find how to get rid of.
Best Answer
You have to fiddle with the "Content-Disposition" of the response header.
This SO post will be a better guide rather than me copy and paste everything.
Content-Disposition:What are the differences between “inline” and “attachment”?
UPDATE:
After reading your post again, I think I haven't address your question fully.
For the PDF to be displayed in a new tab/window, the hyperlink that links to the aspx that generates the PDF needs to target to a "_blank" or another target name. E.g.
You will the have to work on the response header as mentioned above.