Summary

#
  This class provides horizontal and vertical scroll bars.

  There are two ways to use a scroll bar.  The first way is to
  set a total_size (represented by the whole bar), a page_size
  (represented by the draggable button) and an increment_size
  (being the amount added/subtracted when the top/bottom
  button is pressed).  The value will then range from zero to
  (total_size - page_size) inclusive.  An initial value must
  be set with the {set_value()} method.
  @example
  @ vb := ScrollBar()
  @ vb$set_pos("85%", "25%")
  @ vb$set_size(20, "40%")
  @ vb$set_total_size(130)
  @ vb$set_page_size(30)
  @ vb$set_increment_size(1)
  @ vb$set_value(0)
  @ self$add(vb)

  Alternatively, a scroll bar can be used as a slider which
  ranges over a given range of values.  In this case, the
  range is set with {set_range()}.  It is still necessary to set
  the increment size and the initial value, as above, but
  page_size and total_size should not be set.

  Real numbers as opposed to integers can be used for the
  range settings if desired.
  @example
  @ vb := ScrollBar()
  @ vb$set_pos("85%", "25%")
  @ vb$set_size(20, "40%")
  @ vb$set_range(2, 25)
  @ vb$set_value(10)
  @ vb$set_increment_size(1)
  @ self$add(vb)

  An Event is returned whenever the buttons are pressed or the
  bar dragged; the value can be retrieved by get_value().  The
  event code (obtainable by {get_code()}) is 1 if the bar has
  been dragged, and 0 if either button has been pressed or the
  bar released after being dragged.  This fact can be used to
  reduce the number of events which are processed by the
  user's program - just ignore events with code 1.

Superclasses:

Component

Package:

(main)

File:

scrollbar.icn

ScrollBar(argv)

bar_to_win(W)

display(buffer_flag)

#
  Get the page size.

get_total_size()

#
  Return the total size.

get_value()

#
  Get the value.
  @return The value

handle_event(e)

move_value(x)

refresh()

resize()

#
  Set the amount to increase the value by when one of the
  buttons is pressed.
  @param x   The increment size.

set_is_horizontal()

#
  Make the scroll bar horizontal (default is vertical).

set_page_size(x)

#
  Set the size which the bar in the scroll bar area represents.
  @param x   The size.

set_pos_from_value()

set_range(lo, hi)

#
  Set the range of the scroll bar.  The values may
  be integer or real.
  @param lo  The lower bound
  @param hi  The upper bound

set_total_size(x)

#
  Set the total size which the scroll bar area represents.
  @param x   The total size

set_value(x)

#
  Set the value representing the top of the bar in the scroll
  bar.  The value is forced into range if it is not in range already.
  @param x   The value.

set_value_from_pos()