This method tells an object to broadcast an attribute change to its broadcast list.
Source position: intuition.pas line 2002
const OM_NOTIFY = OM_Dummy + 7; |
This method tells an object to broadcast an attribute change to a set of target objects using OM_UPDATE messages. The return value for this method is not explicitly defined.
The OM_NOTIFY method uses the TopUpdate message structure.
Most dispatchers do not handle the OM_NOTIFY message directly. Normally they inherit this method from a superclass, so they pass the OM_NOTIFY message on to the superclass dispatcher.
Although most dispatchers don't have to process OM_NOTIFY messages, most do have to send them. Whenever an object receives an OM_SET or OM_UPDATE about one of its attributes, it may need to notify other objects of the change. For example, when a prop gadget's PGA_Top value changes, its target object(s) need to hear about it.
If an object needs to notify other objects about a change to one or more of its attributes, it sends itself an OM_NOTIFY message. The OM_NOTIFY message will eventually end up in the hands of a superclass that understands OM_NOTIFY and it will send OM_UPDATE messages to the target objects.
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Perform method on object coerced to superclass. |