core-graphics

问题 How do I draw an inner shadow on a text in Cocoa for Mac OS X? I am subclassing NSView to create a placeholder control with a gradient background and an inner shadowed text title over it. All current Core Graphics answers on stackoverflow seem to explain drawing text shadows on Cocoa Touch. 回答1: You might think too complicated. If I get your problem right, the only thing you actually want to do is to set the text style. Then do so by simply using: [[object cell] setBackgroundStyle

问题 When programmatically working with display modes in OS X (documentation), I've found that the CGDisplayCopyAllDisplayModes leaves out the rightmost option that is presented in System Preferences. A simple utility that prints the size of the current display mode and all available display mode sizes outputs this current size: 1920x1200 available sizes: 2880x1800 1440x900 2560x1600 2048x1280 1024x768 800x600 640x480 1680x1050 1280x800 1920x1200 is a valid option All of the other options that

问题 I'm attempting the create a clipping path in the shape of a plus sign, so that subsequent paths that I draw into the same context have this portion removed. I create the clipping path using two rectangle paths overlaid on each other. This is what I'd like the final drawing to look like when I subsequently draw a circle: xXX| |XXx XXXX| |XXXX XXXXX| |XXXXX ——— ——— ——— ——— XXXXX| |XXXXX XXXX| |XXXX xXX| |XXx However, it actually looks like this: xXX| |XXx XXXX| |XXXX XXXXX| |XXXXX ——— XX——— ———

问题 I've got a UIView that is set to opaque = NO and it all works nicely. In the drawRect I'm doing custom drawing, and this works CGContextSetFillColor(context, CGColorGetComponents([UIColor blueColor].CGColor)); CGContextFillRect(context, labelOutside); CGContextAddRect(context, labelOutside); but this CGContextSetFillColor(context, CGColorGetComponents([UIColor whiteColor].CGColor)); CGContextFillRect(context, labelOutside); CGContextAddRect(context, labelOutside); results in NO fill being

问题 I want my OSX app to call a function when the user's screen becomes available, ex: their computer wakes from sleep or the user turns on their screen. Basically any time the user goes from having no screen active to having one active, I would like my function to be called. I'm not sure if the best way to do this is to: Check for changes in sleep/wake state or Use CGDisplayReconfigurationCallback or Listen for a NSWorkspaceScreensDidWakeNotification Which of these seems like the best way to do

问题 I'm having trouble performing bitwise operations with CGImageAlphaInfo and CGBitmapInfo in Swift. In particular, I don't know how to port this Objective-C code: bitmapInfo &= ~kCGBitmapAlphaInfoMask; bitmapInfo |= kCGImageAlphaNoneSkipFirst; The following straightforward Swift port produces the somewhat cryptic compiler error 'CGBitmapInfo' is not identical to 'Bool' on the last line: bitmapInfo &= ~CGBitmapInfo.AlphaInfoMask bitmapInfo |= CGImageAlphaInfo.NoneSkipFirst Looking at the source

问题 Background: I am drawing on a UIImageView with Core Graphics. I would like to ultimately draw a text string over the core graphics drawing. This (hackingwithswift.com) method i used to draw the text to an image, set my imageView to that image, and then draw over with core graphics. But I want the text to overlay the core graphics drawing. Now I have moved to this https://stackoverflow.com/a/35574171/6337391 but it still isnt allowing me to write on top of my drawing. class MapViewController:

问题 The article https://www.objc.io/issues/12-animations/animating-custom-layer-properties/ has this to say about doing completely custom animations with Core Animation: Suppose that instead of implementing our clock face using individual layers, we wanted to draw the clock using Core Graphics. (In general this will have inferior performance , but it’s possible to imagine that there are complex drawing operations that we might want to implement that would be hard to replicate using ordinary layer

问题 I would like to draw a circular gradient like in the example picture below. I can manage a radial gradient easily but I am not sure how to do a circular one. I was thinking of drawing a gradient on a line and then transforming it to a circle. Would that be possible? This is how I draw the radial gradient: CGFloat a = MIN(self.frame.size.width, self.frame.size.height) - _lineWidth; //Get current context CGContextRef mainContext = UIGraphicsGetCurrentContext(); CGRect newRect = rect; newRect

问题 I would like to create a UIBezierPath with 10px rounded corners and with gradient fill. How can I acheive this effect? Here's an image of what I want to do: As you can see, this square has: 2px black border 10px rounded corners red to green linear gradient fill How can I do this programatically without using pattern image color ? Here's how I create the path: UIBezierPath *border = [UIBezierPath bezierPathWithRoundedRect:self.bounds cornerRadius:10.0f]; [border setLineWidth:2]; [[UIColor