src/cowl-numeric-input.lisp

   1 (in-package #:cowl)
   2
   3 (defclass numeric-input (input)
   4   ((number-type :initarg :number-type :initform 'single-float :accessor number-type :type (or symbol cons)
   5                 :documentation "A typespec of the type to coerce the number into on write."))
   6   (:documentation "Widget for editable numbers.
   7 The writer initarg function will be automatically wrapped in
   8 the initialize-instance so that it is given a number as the first argument."))
   9
  10 (defmethod initialize-instance :after ((numeric-input numeric-input) &key writer)
  11   (when writer
  12     (setf (slot-value numeric-input 'writer)
  13           (lambda (val)
  14             (let ((rval (read-from-string val)))
  15               (when (numberp rval)
  16                 (funcall writer (coerce rval (number-type numeric-input)))))))))
  17
  18 (defmethod accept-char-p ((numeric-input numeric-input) character)
  19   (or (eql #\. character)
  20       (eql #\- character)
  21       (digit-char-p character)))