Mouse over in a NSView subview - objective-c

Question

i have a subclass of NSView that handles Mouse events, inside that NSView i have a subview (which is another subclass of NSView). How can i handle Mouse Events for both NSViews.
What i want to achieve is the following:
A NSView where i got a character, when i move my mouse around inside that view the character rotate to follow the mouse. inside the same there are some Items, when the mouse hover over an item i want to display some information... how can achieve this?
basically: two classes receive and respond to mouse over.
Best Regards
Kristian

Answer 1

Here is how we did in Swift 5:
class TrackingAreaView: NSView {
private var isMouseOverTheView = false {
didSet {
backgroundColor = isMouseOverTheView ? .red : .green
}
}
private lazy var area = makeTrackingArea()
private var backgroundColor: NSColor? {
didSet {
setNeedsDisplay(bounds)
}
}
init() {
super.init(frame: NSRect()) // Zero frame. Assuming that we are in autolayout environment.
isMouseOverTheView = false
}
required init?(coder: NSCoder) {
fatalError()
}
public override func updateTrackingAreas() {
removeTrackingArea(area)
area = makeTrackingArea()
addTrackingArea(area)
}
public override func mouseEntered(with event: NSEvent) {
isMouseOverTheView = true
}
public override func mouseExited(with event: NSEvent) {
isMouseOverTheView = false
}
private func makeTrackingArea() -> NSTrackingArea {
return NSTrackingArea(rect: bounds, options: [.mouseEnteredAndExited, .activeInKeyWindow], owner: self, userInfo: nil)
}
open override func draw(_ dirtyRect: NSRect) {
if let backgroundColor = backgroundColor {
backgroundColor.setFill()
dirtyRect.fill()
} else {
super.draw(dirtyRect)
}
}
}

Answer 2

i guess, you should play with CreateMouse Region and handle Mouse event like mouseenter , mouse exit on it,
refer following method of NSView
addTrackingRect : provide Rect where you would like to capture mouse event
for that region you would get following event,
mouseDown
mouseUp
mouseEntered
mouseExited
and so on