core-graphics

I am trying to figure out how to get(read only) entire window/view hierarchy of any application. I get list of all open windows using "CGWindowListCopyWindowInfo" . It also returns window number( "kCGWindowNumber" ). It also shows sharing status of root window by "kCGWindowSharingState = 1;" . Now, I want to check that a particular window/view present in hierarchy of that application. I got kCGWindowNumber which is root window of application. This is now possible via the View Debugging features of Xcode. To use this: Start the target app running as you normally would Launch Xcode, and open a

I have the following sample code which works on iPhone. It draws the text "Hello World!" on the screen using Core Text. Dropping this code into a cocoa project in an NSView produces different results. The font size is scaled much bigger and the letters are drawn on top of each other. How do I have the text draw the same in the cocoa app? - (void)drawRect:(CGRect)rect { CGContextRef context = UIGraphicsGetCurrentContext(); CGContextSaveGState(context); CFStringRef font_name = CFStringCreateWithCString(NULL, "Courier", kCFStringEncodingMacRoman); CTFontRef font = CTFontCreateWithName(font_name,

While debugging in instruments using 'ObjectAlloc' I'm noticing 7megs of memory being allocated for the renderInContext call, but it never is released. When I comment out the renderInContext call this doesn't happen, and future renderInContext calls does not continue to increase the memory allotment. UIGraphicsBeginImageContext(contentHolder.bounds.size); [contentHolder.layer renderInContext:UIGraphicsGetCurrentContext()]; UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); Is there a way to force this memory to be released? I found out how to release

So I have a UILabel that is being drawn on top of a gradient image (that is a UIImageView ). It looks sorta like this: I'm trying to change the blendMode of the graphics context in the UILabel 's draw(_ rect: CGRect) function so that it draws the label but blended with the background with a softLight blending mode. Here is what I want it to look like: Here is the code I have in the draw(_ rect: CGRect) function: override func draw(_ rect: CGRect) { // Drawing code if let context = UIGraphicsGetCurrentContext() { context.setBlendMode(.softLight) self.textColor.set() self.drawText(in: rect) } }

How does z-ordering work with sibling NSViews in Cocoa? I'm confused because I'm finding conflicting sources of information in Apple's docs and APIs. (Note: Subviews are obviously rendered on top of its parent view, I am talking explicitly about sibling views here). Hypothesis A : "Yes, you can define the z-order of sibling NSViews " In IB you can place views on top of each other and they will always be composited in the way you'd expect. There's buttons in Xcode under the Editor menu named "Send to Back", "Send Forward" etc. The NSView also has a method named - (void)addSubview:(NSView *

So I have a CGBitmapContext and I get the pixel at a touchlocation using this unsigned char* data = CGBitmapContextGetData (offscreenBuffer); if (data != NULL) { offset = 4*((self.bounds.size.width*round(coord.y))+round(coord.x)); int alpha = data[offset]; int red = data[offset+1]; int green = data[offset+2]; int blue = data[offset+3]; } And then I change the pixel colour like below. data[offset]=255; data[offset+1]=255; data[offset+2]=0; data[offset+3]=0; My question is how do a get a CGImage back from the modified pixels so that I can update my CGBitmapContext ? Any help will be appreciated,