Multiple error with CGContextRestoreGState

[ldesroziers]

Since I use FXBlurView, I'm getting multiple CGContextRestoreGState errors in the console:

<Error>: CGContextRestoreGState: invalid context 0x0. This is a serious error. This application, or a library it uses, is using an invalid context  and is thereby contributing to an overall degradation of system stability and reliability. This notice is a courtesy: please fix this problem. It will become a fatal error in an upcoming update.

[ldesroziers]

If it helps, seems like -snapshotOfSuperview: is responsible of this bug. But as i'm currently using the SDK 7.0b, it may comes from the SDK itself and the -renderInContext: method...

[nicklockwood]

I think it happens when your view has a size of zero. I thought I'd fixed it, but apparently not.

Try ensuring that your FXBlurView frame is set before you add it to the screen.

[ldesroziers]

I don't think it's the problem (I mean, you clearly have fixed it). This log shows every time I scroll (and thus every time the blurView is updated) and I got only 2 blurView above that scrollView, both have a non-zero size. Once I remove them from screen, no more logs appear.

[nicklockwood]

Hmm. Okay, I'll investigate further. If you can reproduce it with a simple project then that would be a big help.

[ldesroziers]

Gonna try :-)

[ldesroziers]

God dammit, you were right ! I tried to reproduce it on a new project.. First, there were no bug because I instanciated the blurView with a clearly defined frame. And then I tried to instanciate it with CGRectZero, and boom! And forget what I said about the continuous logs while scrolling: logs only appear once.

[nicklockwood]

I've fixed this in 1.3.3.

[ldesroziers]

Nick, I'm still having an issue with zero-sized blurView. In fact, your test seems to only 'work' if both width & height are empty. In my case, the height is never empty (because it's a navbar-like and the height is a static value), but the width depends of the superview (the rootViewController's view of my window), and unfortunately it's 0 when I start my app.

[nicklockwood]

oh, that's odd. OK, I'll try again.

[nicklockwood]

The documentation for CGRectIsEmpty says that it should return YES if the width OR height are zero. Is it possible that something else is going wrong?

[ldesroziers]

Well, I tried to put a MAX() for the width like that: CGRect filtersViewFrame = CGRectMake(0, 0, MAX(CGRectGetWidth([[self view] bounds]),1), [[self filtersView] sizeThatFits:CGSizeZero].height);

And I no longer get warnings. Putting back CGRectGetWidth([[self view] bounds]) brings up warnings again. :/

[nicklockwood]

OK, I can't reproduce this in 1.4. If you're still seeing it, please send me a sample project.

[ldesroziers]

It's OK:) Thank you very much!

[jhollida24]

I'm still seeing this error:

thread #1: tid = 0xe049, 0x000000018506be28 CoreGraphics`CGPostError, queue = 'com.apple.main-thread', stop reason = breakpoint 2.1
frame #0: 0x000000018506be28 CoreGraphics`CGPostError
frame #1: 0x000000018506be1c CoreGraphics`handle_invalid_context + 28
frame #2: 0x0000000187b9a8d8 QuartzCore`-[CALayer renderInContext:] + 380
frame #3: 0x0000000100479848 Brainscape`-[FXBlurView snapshotOfUnderlyingView](self=0x00000001781e1000, _cmd=0x00000001005b0bf8) + 1584 at FXBlurView.m:468
frame #4: 0x000000010047a090 Brainscape`-[FXBlurView updateAsynchronously:completion:](self=0x00000001781e1000, _cmd=0x00000001005b0a0a, async=true, completion=0x000000016fd6c2e8) + 104 at FXBlurView.m:525
frame #5: 0x0000000100477c48 Brainscape`-[FXBlurScheduler updateAsynchronously](self=0x0000000170255630, _cmd=0x00000001005b0961) + 1404 at FXBlurView.m:232
frame #6: 0x0000000100477544 Brainscape`-[FXBlurScheduler addView:](self=0x0000000170255630, _cmd=0x0000000188f92d16, view=0x00000001781e1000) + 244 at FXBlurView.m:198
frame #7: 0x0000000100478ebc Brainscape`-[FXBlurView schedule](self=0x00000001781e1000, _cmd=0x00000001895e21e6) + 252 at FXBlurView.m:400
frame #8: 0x0000000100478db4 Brainscape`-[FXBlurView didMoveToWindow](self=0x00000001781e1000, _cmd=0x0000000188630136) + 92 at FXBlurView.m:393

[isair]

This error happens to me on orientation change and causes my app to crash. I have an FXBlurView inside a UITableViewCell.