iOS 5 UIView drawRect override not working on device

Question

I'm preparing my iPhone app to publish on iOS 5 GM and came across a bug with UIView. When I override the drawRect method on a subclass, the Simulator shows the desired result but when I try to test on an actual device, the drawRect override doesn't have any effect at all.

I even placed a logging statement inside a drawRect override and confirmed that it is being called.

Has anyone else noticed this problem?

Here's a override code I'm using:

- (void)drawRect:(CGRect)rect {
DebugLog( @"*** calling drawRect ***" );

CGContextRef context = UIGraphicsGetCurrentContext(); 

// draw the dark gray background
CGContextSetFillColor(context, [SkinManager getWhiteColor]);
CGContextFillRect(context, CGRectMake(0.0, 0.0, rect.size.width, rect.size.height)); 

// draw the text field background in white
CGContextSetFillColor(context, [SkinManager getDarkGray]);
CGContextFillRect(context, CGRectMake(2.0, 2.0, rect.size.width - 4, rect.size.height - 4)); 

}

Here's the code for generating color

    +(const CGFloat*) getDarkGray {
        UIColor *color = [UIColor colorWithRed:51/255.0 green:51/255.0 blue:51/255.0 alpha:1];

        return [self getCGColor:color];
}

+(const CGFloat*) getCGColor: (UIColor*)color {
        CGColorRef colorref = [color CGColor];

        const CGFloat *components = CGColorGetComponents(colorref);

        return components;
}

Again, this code works perfectly in iOS 4.x and in the Simulator for iOS 5. The only place that is broken is iOS 5 Device.

Moonscape

Please post your code, it's more likely there's a problem there than in iOS since it's so very basic that others would have encountered it as well if there really is a bug (our company has several iOS apps and we haven't seen any problems in this area). – Shebeen

Also, iOS 5 is still under NDA so you might want to go to the Dev-Forum. – Gildus

I did post a question in the dev forum but so far no one has any answers. – Moonscape

Answer 1

Use [self setNeedsDisplay];

The drawRect method is called only at init, so it can pass that if your object was inited previously and you need to "refresh" it.

Miamiami

Answer 2

Instead of using rect in your code, try using self.bounds. Rect is the area that needs refreshing, not the entire area of your view.

Dartboard

Are you sure that drawRect is in a subclass and not a category? Overriding within categories doesn't always work on all versions of iOS. – Dartboard

Yes, it's a sub class. It's actually a subclass of a subclass. I'm pretty confident this is a bug since the simulator works correctly. – Moonscape

Possibly, but 99% of the time when you think something is a system/compiler bug it's not. drawRect is obviously used by a lot of classes, so a gaping bug in it is unlikely, although not impossible, especially since iOS 5 isn't shipping yet. The one area where I see a lot of differences between device and the simulator is when accidentally returning uninitialized structures from functions - the simulator tends to zero out values and the device does not, but that doesn't apply here. You aren't calling drawRect directly, are you? – Dartboard

Thinking about what I just said...Show the code for [SkinManager getWhiteColor] and [SkinManager getDarkGray]. I bet you're returning local variable references. – Dartboard

Answer 3

in iOS 5 drawRect: is not on some objects e.g. UINavigationBar. You have to conditionally use the new iOS 5 styling methods under these circumstances.

This question and this question might be useful for you.

Creativity

Not true; it merely says that it won't be called unless you're in a subclass. And the OP is referring to a UIView, not any of the views this applies to. – Drawbar