/* ---------------------------------------------------------- */
/* GifShow -- an applet that gets a GIF and fits it to window */
/*                                                            */
/* Parameters:                                                */
/*                                                            */
/*   gif    -- name of the gif to load; it is assumed to      */
/*             be in the same directory, or relative to,      */
/*             the document that calls the applet.            */
/*                                                            */
/* Use as:                                                    */
/*                                                            */
/*   <applet code="GifShow.class" width=200 height=150>       */
/*   <param name=gif value="netrexx.gif">                     */
/*   </applet>                                                */
/*                                                            */
/* ---------------------------------------------------------- */
options binary      -- optional; runs a bit faster if set

class GifShow extends Applet
  gif      =String  -- name of the image
  goodimage=Image   -- the Image to draw (null if no good)

 /* init gets the requested image, then uses a MediaTracker to track it
    and wait until it has all arrived.  If it looks good, the goodimage
    property is set so paint(g) can use it. */
 method init
  gif=getParameter('gif')                    -- get gif name from applet tags
  if gif=null then gif='netrexx.gif'         -- use default if none
  newimage=getImage(getDocumentBase(), gif)  -- get the image
  tracker=MediaTracker(this)                 -- 'this' is the "observer"
  tracker.addImage(newimage, 0)              -- track image arrival, ID=0
  do
    tracker.waitForID(0)                     -- wait for image 0 to complete
  catch InterruptedException                 -- something stopped us
    return                                   -- can do no more
  end
  -- Good images have useful dimensions, bad images have -1 or 0 in X or Y
  if newimage.getWidth(this)>0
   then if newimage.getHeight(this)>0
   then goodimage=newimage


 /* paint(g) draws the image to size, if available, or else displays the
    name that it was given. */
 method paint(g=Graphics)
  if goodimage=null
   then g.drawString(gif, 2, 12)             -- Alternative
   else g.drawImage(goodimage, 0, 0, getSize.width, getSize.height, this)