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POUIView Drawing Best Practices
 

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    <p>My application is able to do some simple figure's drawing (until I get a more stable code, I am sticking with only one figure) and it's also able to re-size them. The code I use to create a <code>UIView</code> is the following :</p> <pre><code>- (void)drawRect:(CGRect)rect { CGContextRef context = UIGraphicsGetCurrentContext(); [self setContextFillColor:context]; [self setContextStrokeColor:context]; [self setLineWidth:context]; CGFloat lineThickness = [self lineWidth] ; CGFloat halfLineThickess = lineThickness / 2.0f; CGContextAddRect(context, CGRectMake(halfLineThickess,halfLineThickess, rect.size.width - lineThickness, rect.size.height - lineThickness)); CGContextDrawPath(context, kCGPathEOFillStroke); } </code></pre> <p>Which gives me, with an input size of (100.0f,100.0f), this:</p> <p><img src="https://i.stack.imgur.com/OELnh.png" alt="enter image description here"></p> <p>This figure is inside a "container" <code>UIView</code> which in turn is inside an <code>UIScrollView</code>. My problem with this is when I am re-sizing my figure and I reach sizes of around 1000*1000 (my "container" is 20,000*20,000), I start receiving memory warnings and the application finally gives up. So my questions are:</p> <p>1) Should I consider putting a maximum size for the <code>UIView</code>?</p> <p>2) How could I use the instruments to track this kind of problems, and see where the problem is coming (or where is the heavy lifting being done).</p> <p>3) Should I use some kind of caching like <a href="https://stackoverflow.com/questions/1798414/drawing-incrementally-in-a-uiview-iphone">this</a>?</p> <p>4) Are there some general <strong>best practices</strong> to consider, when drawing an <code>UIView</code>?</p> <p>5) Should I consider <code>CALayer</code>, although I need to listen to touches? </p> <p>The re-sizing of the <code>UIView</code> is based mostly on <a href="https://github.com/spoletto/SPUserResizableView" rel="nofollow noreferrer">this</a>. </p>
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    1. COHave you considered using QuartzCore and just using your view's layer property to draw a border?
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    2. COThe thing is: this is a simple figure. In the end I will have more complex ones, and I don't think playing around with the `UIView`'s properties would be enough. But thanks for the suggestion.
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    3. COif you need to draw large content (maybe with zoom) you might want to check `CATiledLayer` http://developer.apple.com/library/ios/#documentation/GraphicsImaging/Reference/CATiledLayer_class/Introduction/Introduction.html
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