man(1) Manual page archive


     POPUP(2)                                                 POPUP(2)

     NAME
          Popup: mkbutton, changebutton, event, add - popup list box
          pseudo-widget

     SYNOPSIS
          include "popup.m";
          popup := load Popup Popup->PATH;

          init:         fn();
          mkbutton:     fn(win: ref Tk->Toplevel, name: string,
                           items: array of string, n: int): chan of string;
          changebutton: fn(win: ref Tk->Toplevel, name: string,
                           items: array of string, n: int);
          event:        fn(win: ref Tk->Toplevel, e: string,
                           items: array of string): int;
          add:          fn(items: array of string, s: string):
                           (array of string, int);

     DESCRIPTION
          Popup implements popup list boxes as Tk pseudo-widgets.
          This module has since been superseded by choicebutton(2) in
          Tk itself, but remains for the moment for compatibility.

          Init must be called once to initialise the module.

          Mkbutton creates a new button name, in Tk toplevel win. It
          returns a channel on which it delivers events (see event,
          below).  Once created, name can be packed like any other Tk
          widget.  When the button is pressed with button 1, a menu
          pops up offering a choice from the given items. The value n
          is the index in items of the button's initial value.  The
          current choice is always displayed in the button.  If items
          is nil or an empty array, the string `-----' is displayed
          instead.

          Having created a popup button, the application must receive
          values on the channel returned by mkbutton and pass each
          value it receives to event (as parameter e). (Typically the
          application will receive on the channel in an alt statement
          that watches other channels too.)  Event returns the result
          of a selection, or -1 if no selection was made.  In either
          case, the text of the button name will reflect the currently
          active selection (the application can fetch it using
          `cget -text').  The items parameter must match that given to
          mkbutton (or most recently given to changebutton).

          Changebutton changes the list of items in an existing popup
          button name, and sets its initial selection to the item with
          index n.

     POPUP(2)                                                 POPUP(2)

          Add adds string s to the array items, if it is not already
          there, and in either case returns the resulting new array
          and the index of s therein.  It is useful for calculating a
          list of items dynamically.

     SOURCE
          /appl/lib/popup.b

     SEE ALSO
          tabs(2), tk(2)