glgui box dragable

(glgui-box-dragable g x y w h color cb)

glgui-box-dragable is a special version of glgui-box. It plots a dragable filled rectangle (with callback).

Parameter	Description
g	Graphical User Interface (GUI) for this widget
x	Lower left corner along the x-axis in pixels
y	Lower left corner along the y-axis in pixels
w	Width of the element in pixels
h	Height of the element in pixels
c	Color, with which the box is filled
cb	Specifies callback procedure that is executed when box is dragged

Example

Example 1: Make a dragable black square, which when dragged displays the amount in x direction it was moved by. It fills most of the screen width and is approximately half way down an iOS screen.

(set! gui:waves (make-glgui))
(define (wave-canvas-callback g w t x y) (display (glgui-widget-get g w 'offsetx)))
(glgui-box-dragable gui:waves 5 (- (glgui-height-get) 295) (- (glgui-width-get) 10) (+ 295 20) Black wave-canvas-callback)