mouseEntered and mouseExited not called in NSImageView SubClass
-
16-06-2021 - |
Question
I created a subclass of NSImageView
to capture mouseEntered
and mouseExited
events.
But only mouseUp
and mouseDown
events are getting called. How to capture the mouseEntered
and mouseExited
events in NSImageView
subclass?
Solution
If You want to use mouseEntered:
and mouseExited:
You need to use NSTrackingArea
. Here is reference NSTrackingArea Class Reference.
Example:
//Add this to Your imageView subclass
-(void)mouseEntered:(NSEvent *)theEvent {
NSLog(@"Mouse entered");
}
-(void)mouseExited:(NSEvent *)theEvent
{
NSLog(@"Mouse exited");
}
-(void)updateTrackingAreas
{
[super updateTrackingAreas];
if(trackingArea != nil) {
[self removeTrackingArea:trackingArea];
[trackingArea release];
}
int opts = (NSTrackingMouseEnteredAndExited | NSTrackingActiveAlways);
trackingArea = [ [NSTrackingArea alloc] initWithRect:[self bounds]
options:opts
owner:self
userInfo:nil];
[self addTrackingArea:trackingArea];
}
OTHER TIPS
Swift 4 version of Justin Boo's answer
override func updateTrackingAreas() {
super.updateTrackingAreas()
for trackingArea in self.trackingAreas {
self.removeTrackingArea(trackingArea)
}
let options: NSTrackingArea.Options = [.mouseEnteredAndExited, .activeAlways]
let trackingArea = NSTrackingArea(rect: self.bounds, options: options, owner: self, userInfo: nil)
self.addTrackingArea(trackingArea)
}
Swift 3 Version of @Justin Boo's answer:
private var trackingArea: NSTrackingArea?
override func updateTrackingAreas() {
super.updateTrackingAreas()
if let trackingArea = self.trackingArea {
self.removeTrackingArea(trackingArea)
}
let options: NSTrackingAreaOptions = [.mouseEnteredAndExited, .activeAlways]
let trackingArea = NSTrackingArea(rect: self.bounds, options: options, owner: self, userInfo: nil)
self.addTrackingArea(trackingArea)
}
C# Xamarin version of Justin Boo's answer
public override void UpdateTrackingAreas ()
{
base.UpdateTrackingAreas ();
foreach (var item in TrackingAreas ()) {
RemoveTrackingArea (item);
}
var options = NSTrackingAreaOptions.MouseEnteredAndExited | NSTrackingAreaOptions.ActiveAlways;
var trackingArea = new NSTrackingArea (this.Bounds, options, this, null);
AddTrackingArea (trackingArea);
}
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