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7 Event handlers

X events are also represented as structured objects with slot names which are directly translated from the C equivalent. The accessor functions are named by <event name>-<slot name>. Some examples:

(event-window event)

This applies to all events

(event-type event)

So does this

(button-event-x event)

Some button event

(button-event-button event)

accessors

At the moment, XClientMessage and XKeyMap events are not supported (they will be in the not too distant future).

Provided conveniences

Since Motif requires the use of font lists for building non-trivial compound strings, there are some Lisp functions to ease the pain of building them:

Function: build-simple-font-list name font-spec ¶

Returns a font list of with the given name associated with the given font. For example,

(build-simple-font-list "MyFont" "8x13")

Function: build-font-list flist-spec ¶

This allows for the construction of font lists with more than one font. An example:

(build-font-list `(("EntryFont" ,entry-font-name)
                   ("HeaderFont" ,header-font-name)
                   ("ItalicFont" ,italic-font-name)))

There are certain callbacks which are of general use, and standard ones are provided for the programmer’s convenience. For all callbacks except QUIT-APPLICATION-CALLBACK, you register some number of widgets with ADD-CALLBACK. These will be the widgets acted upon by the callback:

Function: quit-application-callback ¶

Callback to terminate the current application.

Function: destroy-callback ¶

Destroys all the widgets passed to it.

Function: manage-callabck ¶

Manages all the widgets passed to it.

Function: unmanage-callback ¶

Unmanages all the widgets passed to it.

Function: popup-callback ¶

Calls popup on all widgets passed to it.

Function: popdown-callback ¶

Calls popdown on all widgets passed to it.