NAME    [Toc]    [Back]

       puff - An X program for sight-impaired users

SYNOPSIS    [Toc]    [Back]

       puff [-toolkit_option] [-option]

OPTIONS    [Toc]    [Back]

       Have  Puff's  false  server  listen at a different display
       number.  By default, Puff listens  to  display  number  1.
       Set  the  magnification factor.  The magnification is constrained
 to be an integer greater than zero.  The  default
       is  6.   Specify  in  milliseconds how often to update the
       Puff window in the absence of pointer of  graphics  activity.
   For example, to update every second, use a value of
       1000.  The default update rate is 500 milliseconds,  or  2
       Hz.   An update value of zero turns off periodic updating.
       Specify the size of the pointer cursor block in  the  Puff
       window.  The actual dimension of the block is '2 * cursorWidth
 * magnification'. The default cursor width is 3. The
       width of the view box outline is `cursorWidth + magnification'.
  Display a short command summary.

DESCRIPTION    [Toc]    [Back]

       Puff (puff) is intended  for  people  who  need  text  and
       graphics  displayed at a high magnification factor.  Typically
 users will want both the  pointer  and  text  to  be
       tracked as they work.

       Puff follows the pointer (also known as the mouse), magnifying
 a part of the screen under the cursor.  In addition,
       Puff can monitor the X11 protocol of X clients and magnify
       the region where graphics were last drawn.  By  monitoring
       a  program  like  xterm,  Puff  can follow the text cursor
       automatically.  Puff switches focus  between  the  pointer
       and graphics, depending on which was last active.

       In  order to track the protocol of X clients, Puff sets up
       a false server on the machine  that  it  is  executed  on.
       This  server  is,  by default, at display number 1.  Any X
       clients connecting with this false server are connected to
       the  same  X  server  that  Puff is connected to.  Puff is
       transparent to X clients.

       Puff draws a box  around  the  location  being  magnified,
       which  makes  it  easier to track the cursor and see where
       Puff is focusing its attention.  The view box  flashes  on
       each update.

INTERFACE    [Toc]    [Back]

       Puff  is  controlled via the keyboard.  The following keys
       have these actions: Change  the  magnification  factor  to
       2-18,  20,  25,  and 30, respectively.  Toggle showing the
       view box.  Quit Puff.   This  will  also  finish  off  any
       clients running through Puff.

       The  following  arrow  key commands make it easier to scan
       text and graphics: Move the magnification window up by 1/4
       the  window height.  Move the magnification window down by
       1/4 the window  height.   Move  the  magnification  window
       right  by  1/4  the  window width.  Move the magnification
       window left by 1/4 the window width.  Return to the  point
       of interest.

ADDITIONAL RESOURCES    [Toc]    [Back]

       The following resources apply to the Puff widget, of class
       puff: Set  the  magnification  factor  in  the  horizontal
       direction.  The resource value must be a positive integer.
       Set the magnification factor in  the  vertical  direction.
       The  resource  value must be a positive integer.  Graphics
       and pointer activity are  accumulated  for  delayMin  milliseconds
  before Puff updates to avoid overwhelming the X
       server.  To decrease  Puff's  impact,  increase  delayMin.
       The  default  value  is 50 milliseconds, or 20 Hz.  If the
       viewBox resource is nonzero, the view box will be drawn.

EXAMPLES    [Toc]    [Back]

       In practice, Puff is used on the top half of  the  screen,
       with  clients  running  on the bottom half.  A sample file
       might read:

       #!/bin/csh xrdb -load  $HOME/.Xdefaults  xclock  -geometry
       -10-10  &  puff -geometry 1280x500+0+0 & xterm -display :1
       -geometry 80x32+5-5 & twm

       For an example of how Puff follows the display, enter  the
       following command after starting Puff:

       xclock -display :1 -u 1

CAVEATS    [Toc]    [Back]

       If  run over a network, Puff can consume a good portion of
       an Ethernet's bandwidth.  To be a good citizen,  run  Puff
       on the same workstation as the X server whenever possible.

       If available, Puff will use the MIT Shared Memory X server
       extension,  which  greatly improves performance.  However,
       if terminated with extreme prejudice (that is,  kill  -9),
       the  program  will not have a chance to release the shared
       memory segments it was using.  The ipcrm  program  can  be
       used to free up Puff's mess.

       Puff  will grab all Ctrl arrow-key events, depriving other
       clients.   This  obnoxious  behavior  should  be  made  an
       option.

AUTHOR    [Toc]    [Back]

       AHPCRC (Army High Performance Computing Research Center)

SEE ALSO    [Toc]    [Back]

       X(1X)



                                                         puff(1X)