UPDATE I’ve posted a Swift version of this answer separately. ORIGINAL This is a fun little problem. First of all, there are lots of ways to draw arrows, with curved or straight sides. Let’s pick a very simple way and label the measurements we’ll need: We want to write a function that takes the start … Read more
I have found a solution for this, we need to create a array of array of DrawingPaths: – (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { // Do the above code, then [m_undoArray addObject:self.currentPath]; } – (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event { [m_parentUndoArray addObject:[NSArray arrayWithArray:m_undoArray]]; } and then stroke the path in DrawRect.
Try to add : CGContextSetInterpolationQuality(g, kCGInterpolationHigh); CGContextSetRenderingIntent(g, kCGRenderingIntentDefault); before : CGContextDrawPDFPage(g, m_page); I had a similar issue and adding the 2 function call above resulted in the rendering using 5x less memory. Might be a bug in the CGContextXXX drawing functions
You can get desired result easily by following 2 concepts of Core Graphics :- i)CGBlendMode ii)OverLap2Layer Blend modes tell a context how to apply new content to itself. They determine how pixel data is digitally blended. class UnionUIBezierPaths : UIView { var firstBeizerPath:UIImage! var secondBeizerPath:UIImage! override func draw(_ rect: CGRect) { super.draw(rect) firstBeizerPath = drawOverLapPath(firstBeizerpath: … Read more
Grab a copy of Apple’s sample app: Son Of Grab. Then build and run it, and you’ll have a very handy interactive app for investigating all the windows known to the window server. The answer to your question is that windows are ordered front to back, but there are far more user interface elements defined … Read more
Oh man, I use this a lot. Have it saved as a snippet: CAGradientLayer *gradient = [CAGradientLayer layer]; gradient.frame = self.textView.superview.bounds; gradient.colors = @[(id)[UIColor clearColor].CGColor, (id)[UIColor blackColor].CGColor, (id)[UIColor blackColor].CGColor, (id)[UIColor clearColor].CGColor]; gradient.locations = @[@0.0, @0.03, @0.97, @1.0]; self.textView.superview.layer.mask = gradient; This solution requires that your text view be embedded in a view of its own. … Read more
From my experimentation, this seems to be due to defining UIViewControllerBasedStatusBarAppearance in Info.plist. It happens on iOS 9 (beta & GM) but not on 8.4.
Details Xcode 11.4 (11E146), swift 5 Tested on iOS 13.1, 12.2, 11.0.1 Solution class UINavigationBarGradientView: UIView { enum Point { case topRight, topLeft case bottomRight, bottomLeft case custom(point: CGPoint) var point: CGPoint { switch self { case .topRight: return CGPoint(x: 1, y: 0) case .topLeft: return CGPoint(x: 0, y: 0) case .bottomRight: return CGPoint(x: 1, … Read more
Edit FWIW: This answer serves its educational purpose by explaining what CGPathAddArcToPoint(…) does for you. I would highly recommend that you read through it as it will help you understand and appreciate the CGPath API. Then you should go ahead and use that, as seen in an0’s answer, instead of this code when you round … Read more
You might be able to modify something like Bin Zhang’s RWBlurPopover to do this. That component uses my GPUImage to apply a Gaussian blur to components underneath it, but you could just as easily use a CIGaussianBlur for the same. GPUImage might be a hair faster though. That component relies on you being able to … Read more