DdeClass public instance methods

addCallback:receiver:selector:clientData:

Adds a callback to one of the receiver's callback lists.

Generally speaking, a dde object expecting to interact with an application declares one or more callback lists as resources; the application adds to these callback lists the callbacks that are invoked whenever the predefined callback conditions are met. Callback lists are resources, so that the application can set or change the function that is invoked.

Callbacks are not necessarily invoked in response to any event; a dde object can call the specified routines at any arbitrary point in its code, whenever it wants to provide a "hook" for application interaction. For example, all dde objects provide a terminationCallback resource to enable applications to interpose a routine to be run when the DDE instance is disconnected.

This message adds a new callback to the end of the callback list. A callback is invoked as many times as it occurs in the callback list.

callbackName

The resource name of the callback list to which the callback is to be appended.

receiver

The object to send the callback message to.

selector

The three-parameter message selector to send.

clientData

An object to be passed to the receiver of the callback message as the clientData parameter when the callback is invoked, or nil.

 

connected

Answers a Boolean indicating whether or not the receiver is connected to a remote DDE object.

Return value:

true

Receiver is connected.

false

Receiver is not connected.

 

disconnect

Disconnect the DDE conversation. This causes a DdeNterminationCallback event.

 

removeAllCallbacks:

Deletes all callbacks from a callback list.

This message removes all the dde instance's callback messages identified by callbackName, regardless of the value of the clientData associated with each message. This is in contrast to removeCallback:..., which removes the specified callback only if a specified clientData parameter also matches.

callbackName

The resource name of the callback list to which the callback is to be removed.

 

removeCallback:receiver:selector:clientData:

Deletes a callback from a callback list.

This message removes a callback message identified by callbackName.

The callback is removed only if both the callback object and clientData match a callback/data pair in the list. No warning message is generated if a callback to be removed fails to match a callback or clientData in the list. Use removeAllCallbacks:... if you want to remove a particular callback regardless of the value of its clientData.

callbackName

The resource name of the callback list from which the callback is to be deleted.

receiver

The object to match against the callback receiver in the callback list.

selector

The three-parameter message selector which is to be used to match against the callback in the callback list.

clientData

The object to match with the clientData object in the callback list entry.

 

timeout

Answers an Integer indicating the timeout value in milliseconds.

 

timeout:

Sets the timeout value for this DDE conversation.

numOfMilliseconds

An Integer number of milliseconds.