Write a New Custom Widget

Steps and examples for writing a custom widget using the toolkit.

1. Create a class.
   1. Create XYZentry inheriting from hwtk::interface::HWIWidget

      itcl::class XYZentry {
          inherit hwtk::interface::HWIWidget;
      
          itk_option define -orient orient Orient "horizontal";
      
          constructor {args} {};
          destructor} {};
      
          public method get {args};
      }

2. Writing the constructor:

   itcl::body XYZentry:constructor {args} {
       itk_component add hull {ttk::frame $itk_interior } { }
       itk_component add x {hwtk::label $itk_interior.__x -text "X:"} { }
       itk_component add xe {hwtk::entry $itk_interior.__xe -inputtype double} { }
       itk_component add y {hwtk::label $itk_interior.__y -text "Y:"} { }
       itk_component add ye {hwtk::entry $itk_interior.__ye -inputtype double} { }
       itk_component add z {hwtk::label $itk_interior.__z -text "Z:"
       itk_component add ze {hwtk::entry $itk_interior.__ze -inputtype double
   
   hwtk_setdefaultbindings;
   eval itk_initialize ;
   }

3. Writing the Option Config body:

   itcl::configbody XYZentry::orient {
        switch -glob --itck_option(-orient)
             h* {
                  pack configure $itk_component(x) $itk_component(xe) -side left
                  pack configure $itk_component(y) $itk_component(ye) -side left
                  pack configure $itk_component(z) $itk_component(ze) -side left
             )
             v* {
                  pack configure $itk_component(x) $itk_component(xe) -side top
                  pack configure $itk_component(y) $itk_component(ye) -side top
                  pack configure $itk_component(z) $itk_component(ze) -side top
             )
        }
   }

4. Writing with the Public method (get)

   itcl::body XYZentry::get {args} {
        if {[llength [info level 0]]} {
             return [list [ $itk_component(xe) [$itk_component(ye) [$itk_component(ze) ]
        }
        if {[llength [info level 0]]> 2} {
             return -code error "wrong args # should be $itk_component (hull) get ?X? ?Y? ?Z?"
        }
        switch -- $args{
             X {return [$itk_component(xe) get]}
             Y {return [$itk_component(ye) get]}
             Z {return [$itk_component(ze) get]}
        }
   }

toplevel .t
pack [XYZentry .t.e]

% .t.e get X
12.323
% .t.e get Y
22.333
% .t.e get Z
45.123
% .t.e get
12.323 22.333 45.123