public new void ZoomingStarted(UIScrollView scrollView, UIView view)
{
// Remove back tiled view.
oldPdfView.RemoveFromSuperview();
oldPdfView.Dispose();
// Set the current TiledPDFView to be the old view.
oldPdfView = TiledPdfView;
}
public PdfScrollView(CGRect frame)
: base(frame)
{
ShowsVerticalScrollIndicator = false;
ShowsHorizontalScrollIndicator = false;
BouncesZoom = true;
DecelerationRate = UIScrollView.DecelerationRateFast;
BackgroundColor = UIColor.White;
MaximumZoomScale = 5.0f;
MinimumZoomScale = 0.25f;
// open the PDF file (default directory is the bundle path)
pdf = CGPDFDocument.FromFile("Tamarin.pdf");
// select the first page (the only one we'll use)
page = pdf.GetPage(1);
// make the initial view 'fit to width'
CGRect pageRect = page.GetBoxRect(CGPDFBox.Media);
scale = Frame.Width / pageRect.Width;
pageRect.Size = new CGSize(pageRect.Width * scale, pageRect.Height * scale);
// create bitmap version of the PDF page, to be used (scaled)
// when no other (tiled) view are visible
UIGraphics.BeginImageContext(pageRect.Size);
CGContext context = UIGraphics.GetCurrentContext();
// fill with white background
context.SetFillColor(1.0f, 1.0f, 1.0f, 1.0f);
context.FillRect(pageRect);
context.SaveState();
// flip page so we render it as it's meant to be read
context.TranslateCTM(0.0f, pageRect.Height);
context.ScaleCTM(1.0f, -1.0f);
// scale page at the view-zoom level
context.ScaleCTM(scale, scale);
context.DrawPDFPage(page);
context.RestoreState();
UIImage backgroundImage = UIGraphics.GetImageFromCurrentImageContext();
UIGraphics.EndImageContext();
backgroundImageView = new UIImageView(backgroundImage);
backgroundImageView.Frame = pageRect;
backgroundImageView.ContentMode = UIViewContentMode.ScaleAspectFit;
AddSubview(backgroundImageView);
SendSubviewToBack(backgroundImageView);
// Create the TiledPDFView based on the size of the PDF page and scale it to fit the view.
pdfView = new TiledPdfView(pageRect, (float)scale);
pdfView.Page = page;
AddSubview(pdfView);
// no need to have (or set) a UIScrollViewDelegate with MonoTouch
this.ViewForZoomingInScrollView = delegate {
// return the view we'll be using while zooming
return(pdfView);
};
// when zooming starts we remove (from view) and dispose any
// oldPdfView and set pdfView as our 'new' oldPdfView, it will
// stay there until a new view is available (when zooming ends)
this.ZoomingStarted += delegate {
if (oldPdfView != null)
{
oldPdfView.RemoveFromSuperview();
oldPdfView.Dispose();
}
oldPdfView = pdfView;
AddSubview(oldPdfView);
};
// when zooming ends a new TiledPdfView is created (and shown)
// based on the updated 'scale' and 'frame'
ZoomingEnded += delegate(object sender, ZoomingEndedEventArgs e) {
scale *= e.AtScale;
CGRect rect = page.GetBoxRect(CGPDFBox.Media);
rect.Size = new CGSize(rect.Width * scale, rect.Height * scale);
pdfView = new TiledPdfView(rect, (float)scale);
pdfView.Page = page;
AddSubview(pdfView);
};
}
public new void ZoomingStarted(UIScrollView scrollView, UIView view)
{
// Remove back tiled view.
oldPdfView?.RemoveFromSuperview();
oldPdfView = TiledPDFView;
}