DisplaySetEvent

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Message

DisplaySetEvent <docname> <objectname> <eventclass> <eventmessage>

Originator

Client

Response

SyntaxError: insufficient parameters to DisplaySetEvent

SyntaxError: invalid parameters to DisplaySetEvent

SyntaxError: no such event class

Error: document docname not found by DisplaySetEvent

Error: No object called objectname found on display document docname by DisplaySetEvent

Info: event created for object(s)

Response (immediate socket)

Success

Failure

Details

For every document named docname that contains an object named objectname which has a touch-sensitive region, the server adds an event to that object. The type of event is specified by eventclass, and may be one of the following:

EventClass	Description
MouseDown	The left mouse button is depressed over the object
MouseUp	The left mouse button is released over the object.
MouseDblClick	The object has been double-clicked (see below)
MouseMove	The mouse has moved whilst over the object
TouchDown	The touch stylus is detected over the object (object is touched)
TouchUp	The touch stylus stops being detected over the object
TouchMove	The detected touch stylus is moved whilst over the object

Note: A touch stylus or mouse pointer counts as being 'over' an object if its coordinates fall within the region which would be painted by a solid brush, or by the (clipped or stretched) bitmap contents. Thus purely 'line-based' (Line, Bezier, Arc) objects will never receive touches (events cannot be added to these objects). As of 17 May 2005, or WhiskerServer v2.11, text can be touched (before this, it could not). Also, a mouse or stylus event over an unshaded region of a complex object (e.g. in the centre of a polygon) will not generate an event.

A note about mice: when you double-click the mouse button, Windows processes the first click as 'MouseDown' and the second click as 'MouseDblClick' — a 'MouseDown' event is not generated for the second click. This means that if you are interested in every mouse event, you must request both MouseDown and MouseDblClick events (using the same event message if you do not care about the distinction).

If the server display is double-clicked while the server's input is being used to emulate touches, then double click events are converted to ordinary 'touchdown' events.

Cacheing mode and display events

If cacheing mode is enabled, the client may set or clear events, or change event transparency, for objects not yet displayed (that is, added since DisplayCacheChanges), or for objects which are awaiting deletion (deleted since DisplayCacheChanges). Commands will take effect immediately for any objects currently displayed.

Revision history

Implemented by WhiskerServer version 2.3.