Iphone sdk custom pdf viewer in uiscrollview

Question

just like in the subject, I am struggling to get pdf view in uiscrollview.
now, first of all - I know I can do it with UIWebView. I am doing so now, but next version of my app - I need to gain much more control, hence need for doing it like that.
I hope one day, apple will create example of quartz vector graphics inside uiscrollview.
now, to the point.
basicaly got two methods:
- (void)renderZoomToBitmap
int w,h;
NSDate *start;
NSTimeInterval elapsed;
start = [NSDate date];
CGPDFPageRef pageref = CGPDFDocumentGetPage(pdf, _page);
CGRect mediaBox = CGPDFPageGetBoxRect(pageref, kCGPDFMediaBox);
mediaBox.size.width *= zoomf;
mediaBox.size.height *= zoomf;
w = mediaBox.size.width+0.5;
h = mediaBox.size.height+0.5;
CGRect viewBounds=CGRectMake(0,0,w,h);
char *renderBuff = malloc( w * h * 4 );
CGContextRef cgContext = CGBitmapContextCreate(renderBuff, w, h, 8, w * 4, CGColorSpaceCreateDeviceRGB(), kCGBitmapByteOrder32Host | kCGImageAlphaNoneSkipLast);
CGContextSetRGBFillColor(cgContext, 0.1, 0.1, 0.1, 1);
CGContextFillRect( cgContext, viewBounds );
CGContextDrawPDFPage(cgContext, pageref);
CGContextFlush( cgContext );
renderPage = CGBitmapContextCreateImage(cgContext);
free(renderBuff);
CGContextRelease(cgContext);
elapsed = [start timeIntervalSinceNow] * -1.0;
// NSLog(@"view bounds past zoom w:%f h:%f", b.size.width, b.size.height);
self.frame = viewBounds;
NSLog(@" renderZoomToBitmap zoom:%f took %f s", zoomf, elapsed );
and one that draws actual bitmap
- (void)drawRect:(CGRect)rect
CGContextRef context = UIGraphicsGetCurrentContext();
NSLog(@"draw rect %f %f %f %f", rect.origin.x, rect.origin.y, rect.size.width, rect.size.height);
CGContextTranslateCTM(context, 0.0, rect.size.height);
CGContextScaleCTM(context, 1, -1);
CGContextTranslateCTM(context, -_offset.x, _offset.y);
CGContextDrawImage(context, rect, renderPage);
[self setNeedsDisplay];
now everytime
- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(float)scale
is called , I set new zoom scale (zoomf) in above UIView instance, and call first method - to refresh bitmap.
it does work okay when zoomf=1.0, but when user starts zooming in/out, it does funky things.
What is the problem , do any one of you fine folks know ? please help me out with this. I am very new to quartz.
thanks.
Message was edited by: gryzman

Answer 1

anyone please?