[Mapguide-trac] [mapguide-trac] #2104: Firefox >=14 sometimes does not fully show image on pan on Ajax viewer (redraw issue)

[MapGuide Open Source]

#2104: Firefox >=14 sometimes does not fully show image on pan on Ajax viewer
(redraw issue)
---------------------------+------------------------------------------------
   Reporter:  gabrimonfa   |       Owner:       
       Type:  defect       |      Status:  new  
   Priority:  low          |   Milestone:       
  Component:  AJAX Viewer  |     Version:  2.4.0
   Severity:  trivial      |    Keywords:       
External_id:               |  
---------------------------+------------------------------------------------

Comment(by gabrimonfa):

 I've found a workaround for this problem.

 Let's see function RequestMapImage (in viewerfiles/ajaxmappane.templ).

 On map request, if we are on all browser except safari and chrome the
 innerHtml of div#overlay is modified (on opera a hack is then used to
 force redraw the content).

 On safari and chrome we instead use a sort of double buffering,
 loading images alternatively on two different <img> and toggling their
 visibility.
 This is used because otherwise the browser would show briefly, after a
 pan, the image in the original position and then the moved one, which
 is visually very annoying (it is easy to see that for example if
 chrome is used and the "|| chrome" is removed in the IF clause).

 My workaround is passing Firefox in the list of browser which adopt
 the two images and swaps between them at each image change.

 {{{
 - if(safari || chrome)
 - {
 -    LoadAlternateImage(url, reqId);
 -}

 + if(safari || chrome || firefox)
 + {
 +    LoadAlternateImage(url, reqId);
 +}
 }}}

 This simple update seems to solve the issue, because swapping the
 image force Firefox to redraw map content.

-- 
Ticket URL: <https://trac.osgeo.org/mapguide/ticket/2104#comment:1>
MapGuide Open Source <http://mapguide.osgeo.org/>
MapGuide Open Source Internals