Events (ActiveX Control)

An ActiveX Control can specify Events, e.g. a button would have a Click event. Events are used to notify the ActiveX Control Container when something important happens in the ActiveX Control, typically when the user interacts with the ActiveX Control.

The ActiveX Control contains the following Events:

AppCommand
CommandAction
DatasetItemEdit
LicenceError
MessageChange
MouseTrack
PromptChange
ScaleChange
SelectionChange
Snap

ActiveX ControlEvents are not sent to the ActiveX Control Container when they occur as a result of actions taken by the ActiveX Control Container, i.e. when the ActiveX Control is inside one of its Methods. Therefore, it may be necessary to act after calling one of the ActiveX ControlMethods, as well as reacting to an Event, e.g. the ScaleChange Event will be called if the user zooms using the keyboard or mousewheel, but not if the ZoomView method is called.

Note: The LicenceError event is an exception to this rule, and will be called immediately any licence error occurs. Care should therefore be taken not to call more Methods from within the LicenceErrorEvent, in order to avoid possible recursion.


AppCommand (comname$)

Called whenever an application command added using AddCommand is selected.

comname$
The command name specified in AddCommand.


CommandAction (comname$, action$)

Called when system command actions take place.

comname$
The command class name.

action$
The command action. One of the following:


DatasetItemEdit (dataset$, edit%, nItems&)

Called when a dataset item is edited.

dataset$
The name of the dataset containing the edited items.

edit%
The edit action. One of the following:

nItems&
Always 0 in this release.


LicenceError ()

Called whenever a runtime licensing error occurs.


MessageChange ()

Called whenever the system message changes.


MouseTrack (x#, y#, z#)

Called whenever the mouse moves in the SIS Control, if the TrackMouse property is set to True. This event can be used in conjuction with the GetCoordString method to mimic the behaviour of the Status Bar in SIS applications.

x#, y#, z#
The mouse position.


PromptChange ()

This event is retained for backwards compatibility only and is never called. The MessageChange event is called instead.


ScaleChange (displayScale#)

Called whenever the display scale changes, e.g. if the view is zoomed or the SIS Control window changes size.


SelectionChange (nEditable&, nHittable&, commonClass$)

Called whenever the selection changes.

nEditable&
The number of editable items currently selected.

nHittable&
The number of hittable items currently selected.

commonClass$
The lowest common denominator class of those selected.


Snap (x#, y#, z#)

Called whenever the user snaps.

x#, y#, z#
The snap position.

The special, system, Named List "*snapped" can be used in this event to query any snapped item.


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