Macro

Summary

The define-command macro defines an alias for a mouse or keyboard gesture that can be used in the input model of an output pane.

Package

capi

Signature

define-command name gesture &key translator host

Description

The macro define-command defines an alias for a mouse or keyboard gesture that can then be used in output-pane's input models. The name is the name of the alias and the gesture is one of the gestures accepted by output-pane. The translator is a function that gets passed the arguments that would be passed to the callback, and returns a list of arguments to be passed to the callback along with the output-pane (which will be the first argument). The host indicates which platforms this gesture should apply for (it defaults to all platforms).

For a full description of the gesture syntax, see output-pane.

Example

Firstly, here is an example of defining a command which maps onto a gesture.

(defun gesture-callback (output-pane x y)

  (capi:display-message 

   "Pressed ~S at (~S,~S)"

   output-pane x y))

(capi:define-command :select (:button-1 :press))

(capi:contain (make-instance

               'capi:output-pane

               :input-model '((:select 

                               gesture-callback))))

Here is a more complicated example demonstrating the use of translator to affect the arguments passed to a callback.

(capi:define-command

  :select-object (:button-1 :press)

  :translator #'(lambda (output-pane x y)

                  (let ((object

                        (capi:pinboard-object-at-position

                                        output-pane x y)))

                                  (when object

                                    (list object)))))

(defun object-select-callback (output-pane

                               &optional object)

  (when object (capi:display-message 

                "Pressed on ~S in ~S"

                object output-pane)))

(setq pinboard

      (capi:contain (make-instance

                    'capi:pinboard-layout

                    :input-model '((:select-object

                               object-select-callback)))))

(make-instance 'capi:item-pinboard-object

               :text "Press Me!"

               :parent pinboard

               :x 10 :y 20)

(make-instance 'capi:line-pinboard-object

               :parent pinboard

               :start-x 20 :start-y 50

               :end-x 120 :end-y 150)

There is a further example in the file capi/output-panes/commands.lisp .

See also

output-pane
invoke-command
invoke-untranslated-command