Re: force rendering of views off screen
Re: force rendering of views off screen
- Subject: Re: force rendering of views off screen
- From: Martin Glaß <email@hidden>
- Date: Fri, 2 Jul 2010 19:38:01 +0200
hello guys,
thanks for your comments - i just found the right knob to draw the
content of my "invisible" subview in my uiscrollview.
i simply subclassed every subview and implemented -drawRect:
additionally using uigraphicsgetcurrentcontext().
@david
yeah, this was just simple math to picture the scene - but you're
right, it depends...
and could you tell the iOS team i feel great with their APIs, please? thx ;)
here's the (ugly) method code, pdfRef and pageNo are properties of the
enclosing class/instance.
- (void) drawRect:(CGRect)rect {
// get the page reference
CGPDFPageRef page = CGPDFDocumentGetPage(pdfRef, pageNo);
CGContextRef context = UIGraphicsGetCurrentContext();
// white background
CGContextSetRGBFillColor(context, 1.0, 1.0, 1.0, 1.0);
CGContextFillRect(context, CGContextGetClipBoundingBox(context));
// transformation/-lation
CGContextTranslateCTM(context, 0.0, rect.size.height);
CGContextScaleCTM(context, 1.0, -1.0);
CGContextConcatCTM(context, CGPDFPageGetDrawingTransform(page,
kCGPDFCropBox, rect, 0, true));
CGContextDrawPDFPage(context, page);
}
hope this help's someone else.
- bye
2010/6/24 David Duncan <email@hidden>:
> On Jun 24, 2010, at 8:59 AM, Martin Glaß wrote:
>
>> sorry, CATiledLayer actually improves performance. the downside is,
>> the tiles need time to be drawn and are faded in using an animation of
>> 0.25 seconds.
>> so, if there are 6 tiles to be drawn you end up seeing iOS building
>> the "mosaic" in a total of 1.5 seconds.
>
> The fade time is not synchronous with the content generation. If you generate content fast, it could all fade in in 0.25s. If it is taking longer, it is due to the rendering time of that content, but unless your rendering time is 0.25s it is unlikely that you will take exactly 1.5s for all of it to display :).
>
> --
> David Duncan
>
>
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