deferred class interface BUTTON

feature(s) from DIALOG_ELEMENT
   --  Parent

   has_dialog_box: BOOLEAN
      --  Does the object has a valid corresponding dialog?


   dialog_box: DIALOG
      --  The object which uses dialog elements.

      require
         has_dialog: has_dialog_box
      ensure
         valid: Result /= Void

feature(s) from DIALOG_ELEMENT
   --  Device independent positioning

   indep_size: RECTANGLE
      --  Size of element using device independent coordinates.

      ensure
         is_copy:  --  can be modified.

   indep_set_size (r: RECTANGLE)
      --  Set element's size in device independent coordinates.

      require
         valid: r /= Void
      ensure
         done: r.is_equal(indep_size)

   indep_set_point (p: POINT)
      --  Set upper-left point of element using device independent units.

      require
         valid_point: p /= Void

   indep_set_width (wi: INTEGER)
      --  Set element's width using device independent units.

      require
         valid: wi >= 0

   indep_set_height (he: INTEGER)
      --  Set element's height using device independent units.

      require
         valid: he >= 0

feature(s) from DIALOG_ELEMENT
   --  Relative positioning

   place_right (other: DIALOG_ELEMENT)
      --  Place the current element to the right of other.

      require
         valid_other: other /= Void

   place_left (other: DIALOG_ELEMENT)
      --  Place the current element to the left of other.

      require
         valid_other: other /= Void

   place_above (other: DIALOG_ELEMENT)
      --  Place the current element above other.

      require
         valid_other: other /= Void

   place_under (other: DIALOG_ELEMENT)
      --  Place the current element under other.

      require
         valid_other: other /= Void

   place_just_under (other: DIALOG_ELEMENT)
      --  Place the current element exactly under 'other'.


   same_width (other: DIALOG_ELEMENT)
      --  Set the current element width to other's.

      require
         valid_other: other /= Void

   same_height (other: DIALOG_ELEMENT)
      --  Set the current element height to be the same as other's.

      require
         valid_other: other /= Void

   align_left (other: DIALOG_ELEMENT)
      --  Align left side of this element with the 
      --  left side of other.

      require
         ok: other /= Void

   align_right (other: DIALOG_ELEMENT)
      --  Align the right side of this element with the right 
      --  side of other.

      require
         ok: other /= Void

   align_top (other: DIALOG_ELEMENT)
      --  Align the top of this element with top of other.

      require
         ok: other /= Void

   align_bottom (other: DIALOG_ELEMENT)
      --  Align the bottom of this element with bottom of other.

      require
         ok: other /= Void

feature(s) from BUTTON
   --  Status

   set_label (label: STRING)
      --  Set the button's displayed label.

      require
         valid: label /= Void

feature(s) from BUTTON
   --  Command

   set_command (gc: GUI_COMMAND)
      --  Set when_executed command.

      require
         nothing:  --  Void means no command
      ensure
         keep_reference: command = gc


end of deferred BUTTON