Treating adjacent tracking areas as one contiguous area

Question

I'm trying to present a UI of a title/less window when a mouse leaves a window's title or contentview, but not when moving from one to the other; in essence have the two tracking areas function as one (I resorted to this as I couldn't figure out how to create a single area when the title view is hidden):

override func mouseEntered(with theEvent: NSEvent) {
    let hideTitle = (doc?.settings.autoHideTitle.value == true)
    if theEvent.modifierFlags.contains(.shift) {
        NSApp.activate(ignoringOtherApps: true)
    }

    switch theEvent.trackingNumber {
    case closeTrackingTag:
        Swift.print("close entered")
        closeButton?.image = closeButtonImage
        break

    default:
        Swift.print(String(format: "%@ entered",
                           (theEvent.trackingNumber == titleTrackingTag
                            ? "title" : "view")))
        let lastMouseOver = mouseOver
        mouseOver = true
        updateTranslucency()

        //  view or title entered
        if hideTitle && (lastMouseOver != mouseOver) {
            updateTitleBar(didChange: !lastMouseOver)
        }
    }
}

override func mouseExited(with theEvent: NSEvent) {
    let hideTitle = (doc?.settings.autoHideTitle.value == true)

    switch theEvent.trackingNumber {
    case closeTrackingTag:
        Swift.print("close exited")
        closeButton?.image = nullImage
        break

    default:
        Swift.print(String(format: "%@ exited",
                           (theEvent.trackingNumber == titleTrackingTag
                            ? "title" : "view")))

        let lastMouseOver = mouseOver
        mouseOver = false
        updateTranslucency()

        if hideTitle && (lastMouseOver != mouseOver) {
            updateTitleBar(didChange: lastMouseOver)
        }
    }
}

Additionally, there's a tracking rect on the close button to appear only when over. Anyway, from my tracer output I see the issue - mouse over window from beneath to over its title:

view entered
updateTitleBar
**view entered**
view exited
updateTitleBar
title entered
updateTitleBar
title exited

Note sure why I'm getting a second view entered event (view entered), but the movement out of the view and onto the adjacent title each triggers an updateTilebar() call which is visually stuttering - not remedied so far with animation:

fileprivate func docIconToggle() {
    let docIconButton = panel.standardWindowButton(.documentIconButton)

    if settings.autoHideTitle.value == false || mouseOver {
        if let doc = self.document {
            docIconButton?.image = (doc as! Document).displayImage
        }
        else
        {
            docIconButton?.image = NSApp.applicationIconImage
        }
        docIconButton?.isHidden = false
        self.synchronizeWindowTitleWithDocumentName()
    }
    else
    {
        docIconButton?.isHidden = true
    }
}

@objc func updateTitleBar(didChange: Bool) {
    if didChange {
        Swift.print("updateTitleBar")
        if settings.autoHideTitle.value == true && !mouseOver {
            NSAnimationContext.runAnimationGroup({ (context) -> Void in
                context.duration = 1.0
                panel.animator().titleVisibility = NSWindowTitleVisibility.hidden
                panel.animator().titlebarAppearsTransparent = true
                panel.animator().styleMask.formUnion(.fullSizeContentView)
            }, completionHandler: {
                self.docIconToggle()
            })
        } else {
            NSAnimationContext.runAnimationGroup({ (context) -> Void in
                context.duration = 1.0
                panel.animator().titleVisibility = NSWindowTitleVisibility.visible
                panel.animator().titlebarAppearsTransparent = false
                panel.animator().styleMask.formSymmetricDifference(.fullSizeContentView)
            }, completionHandler: {
                self.docIconToggle()
            })
        }
    }
}

So my question is about how to defer the actions when areas are adjacent.

They (titlebar & content view) are not siblings of each other so didn't think a hitTest() was doable but basically if I could tell if I was moving into the adjacent tracking area, I'd like it to be a no-op.

Any help with why animation isn't working would be a plus.

Answer 1

Not a true answer, but if you know the adjacent view's rect you can use the event's location to probe whether you'd want to ignore movements among adjacent views:

override func mouseExited(with theEvent: NSEvent) {
    let hideTitle = (doc?.settings.autoHideTitle.value == true)
    let location : NSPoint = theEvent.locationInWindow

    switch theEvent.trackingNumber {
    case closeTrackingTag:
        Swift.print("close exited")
        closeButton?.image = nullImage
        break

    default:
        let vSize = self.window?.contentView?.bounds.size

        //  If we exit to the title bar area we're still "inside"
        //  and visa-versa, leaving title to content view.
        if theEvent.trackingNumber == titleTrackingTag, let tSize = titleView?.bounds.size {
            if location.x >= 0.0 && location.x <= (vSize?.width)! && location.y < ((vSize?.height)! + tSize.height) {
                Swift.print("title -> view")
                return
            }
        }
        else
        if theEvent.trackingNumber == viewTrackingTag {
            if location.x >= 0.0 && location.x <= (vSize?.width)! && location.y > (vSize?.height)! {
                Swift.print("view -> title")
                return
            }
        }

        mouseOver = false
        updateTranslucency()

        if hideTitle {
            updateTitleBar(didChange: true)
        }

        Swift.print(String(format: "%@ exited",
                           (theEvent.trackingNumber == titleTrackingTag
                            ? "title" : "view")))
    }
}