UIFORM: Fix slider default display and add color customization (#375)

Author: karliwalti

apps/DemoUIForm/VERSION

@@ -1 +1 @@
-1.0
+1.1

apps/DemoUIForm/main.scm

@@ -76,6 +76,9 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    (spacer)
    ;; Button with action callback that returns the page you want to go to
    (button h 75 size header indent 0.05 rounded #t text "Go Back" action ,(lambda () 'main))
+   (spacer)
+    ;; slider 
+   (slider id sliderval number #t min 0 max 100 default 50 labels ("min" "max"))
    (spacer)
    (label text "For more features that you can include in a script see the LNhealth app \"Demo Widgets\". Look at the main.sx file in the sandbox folder which is located at https://github.com/part-cw/LNhealth/tree/master/apps/WidgetDemo" align left size small)
   )

modules/uiform/uiform.scm

@@ -1546,8 +1546,10 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
          (stepnum (fx- max min))
          (stepvalues  (make-list-natural min (+ 1 stepnum)))
          (defaultvalue (glgui:uiform-arg args 'default (/ stepnum 2)))
-         (value (xxget loc id defaultvalue))
-         (boxcolor (glgui:uiform-arg args 'boxcolor (uiget 'color-default))))
+         (value (xxget loc id #f))
+         (boxcolor (glgui:uiform-arg args 'boxcolor (uiget 'color-default)))
+     	 (selcolor (glgui:uiform-arg args 'selcolor (uiget 'color-select)))
+         (numcolor (glgui:uiform-arg args 'numbercolor (uiget 'color-low)))) 
      (uiset idvalues stepvalues)
      (if req
        (uiform-required-set id (abs (- (abs y) (uiget 'offset 0) h))))
@@ -1563,9 +1565,9 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
               (positions (make-list-increment (* w 0.1) (+ 1 stepnum) i)))
 	     (uiset idpositions positions)
          (glgui:draw-box (+ x (* w 0.1)) (+ by (/ bh 4)) sw (/ bh 2) boxcolor) ;; Horizontal bar
-         (glgui:draw-box bx by bw bh (if value White boxcolor))  ;; Slider box
+         (glgui:draw-box bx by bw bh (if value selcolor boxcolor))  ;; Slider box
          (if (and shownumber value)
-           (glgui:draw-text-center bx by bw bh (number->string v) fnt Black))
+           (glgui:draw-text-center bx by bw bh (number->string v) fnt numcolor))
          ;; draw labels if set
 	 (if (fx> (length labels) 1) (begin  
          (glgui:draw-text-left (+ x (* w 0.1)) (+ by (- h fnth)) (- (* w 0.8) bw) fnth (car labels) fnt White)