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Back to NSKeyValueObserverMBS class.

NSKeyValueObserverMBS.addObserver(keyPath as string, options as Integer = 5, context as Variant = nil)

Type Topic Plugin Version macOS Windows Linux iOS Targets
method Cocoa MBS MacBase Plugin 13.1 ✅ Yes ❌ No ❌ No ✅ Yes All
Registers observer to receive KVO notifications for the specified key-path relative to the receiver.

keyPath: The key path, relative to the receiver, of the property to observe. This value must not be nil.
options: A combination of the option constants that specifies what is included in observation notifications.
context: Arbitrary data that is passed to anObserver in observeValueForKeyPath.

This class holds a strong references to context and a weak reference to target.
Available in OS X v10.3 and later.

NSKeyValueObserverMBS.Constructor(TargetHandle as Integer)

Type Topic Plugin Version macOS Windows Linux iOS Targets
method Cocoa MBS MacBase Plugin 13.1 ✅ Yes ❌ No ❌ No ✅ Yes All
The constructor.

Please pass the handle of the target Cocoa object.
Like NSWindowMBS.handle or CALayerMBS.

NSKeyValueObserverMBS.Destructor

Type Topic Plugin Version macOS Windows Linux iOS Targets
method Cocoa MBS MacBase Plugin 13.1 ✅ Yes ❌ No ❌ No ✅ Yes All
The destructor.

NSKeyValueObserverMBS.removeObserver(keyPath as string, context as Variant = nil)

Type Topic Plugin Version macOS Windows Linux iOS Targets
method Cocoa MBS MacBase Plugin 13.1 ✅ Yes ❌ No ❌ No ✅ Yes All
Stops a given object from receiving change notifications for the property specified by a given key-path relative to the receiver and a context.

keyPath: A key-path, relative to the receiver, for which observer is registered to receive KVO change notifications.
context: Arbitrary data that more specifically identifies the observer to be removed.

Examining the value in context you are able to determine precisely which addObserver method was used to create the observation relationship. When the same observer is registered for the same key-path multiple times, but with different context pointers, an application can determine specifically which object to stop observing.

The context object is only used in OS X v10.7 and later.

The items on this page are in the following plugins: MBS MacBase Plugin.


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