Getting the center point of an NSView

Question

I need to get the center point of a NSView in the form of a CGPoint, how can I achieve this? I am basically looking for the equivalent of the UIKit, UIView.center

score 19 · Answer 1 · edited Apr 10 '15 at 20:21

19

A simple and easy to read way is:

CGPointMake(NSMidX(myView.frame), NSMidY(myView.frame))

I would suggest making this code, a category on NSView with a read only property named center.

edited Apr 10 '15 at 20:21

Kaunteya

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answered Feb 11 '13 at 11:10

lmirosevic

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+1 for NSMidX, wouldn't recommend naming it 'center' though. There already is a -(void)center method on NSWindow so might resolve wrong, and it's a fairly obvious name so Apple might use it as well, but maybe implement it slightly differently and things will break. – uliwitness Feb 28 '15 at 11:18
@uliwitness NSWindow does not inherit from NSView, so that shouldn't be an issue. – aleclarson Mar 02 '19 at 17:27
`NSWindow` doesn't inherit from `NSView`, but nobody's stopping Apple from adding a `-center` method to NSView in the future, and then you get *really* interesting behavior. So when adding categories to Apple classes, it's always a good idea to either use a prefix like `foo_center`, or to at least stay away from the obvious names. – uliwitness Mar 13 '19 at 13:16

score 16 · Accepted Answer · edited Jul 03 '11 at 06:31

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This code will get you that CGPoint:

CGPointMake((myView.frame.origin.x + (myView.frame.size.width / 2)),
            (myView.frame.origin.y + (myView.frame.size.height / 2)))

edited Jul 03 '11 at 06:31

answered Jul 03 '11 at 05:39

Regan

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Thanks. I wish NSView had a center property like UIView. – foobar5512 Jul 03 '11 at 15:12
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@user668518: So make one. It'll be better anyway to use your property/method everywhere you need the center than to copy and paste the coordinate-math code. – Peter Hosey Jul 04 '11 at 03:03
You can use a class extension to do so. – phikes Mar 09 '14 at 14:33
This does not take `CALayer#transform` into account, like `UIView#center` does. – aleclarson Mar 02 '19 at 17:30
But this is correct only when the nsview wasn't rotated. After rotation origin is moved and center point your above calculations are incorrect. – fillky Jun 05 '12 at 09:46

score 1 · Answer 3 · answered Jul 03 '11 at 03:10

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To get an NSPoint of the center, you can just get the x-coordinate of the origin and add (width/2), and get the y-coordinate of the origin and add (height/2). Then you can convert it into a CGPoint.

answered Jul 03 '11 at 03:10

jburns20

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Getting the center point of an NSView

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