[OpenLayers-Trac] [OpenLayers] #933: Animated transition between views

[OpenLayers]

#933: Animated transition between views
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  Reporter:  openlayers  |       Owner:  pspencer                
      Type:  feature     |      Status:  new                     
  Priority:  minor       |   Milestone:  2.6 Release             
 Component:  general     |     Version:  SVN                     
Resolution:              |    Keywords:  animated transition time
     State:  Review      |  
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Changes (by pspencer):

  * owner:  => pspencer
  * state:  => Review

Comment:

 This patch provides the framework for implementing transition effects when
 zooming (as opposed to panning which is being addressed in #110).  In
 essence, we are create a clone of every tile and use that clone as a
 placeholder while the tile loads.

 The basic framework does not change the existing behaviour if no
 transitionEffect is specified for the layer.

 The code adds a 'resize' effect which immediately resizes the clone tile
 when it is redrawn and the resolution has changed.  The resize puts the
 cloned image in the right place and sizes it correctly to display the old
 geographic extent at the new resolution, effectively stretching or
 shrinking the image.  When the new tiles have loaded, the clones are
 hidden and reset to be ready for the next zoom.

 A nice side effect of this patch is that cloned tile can be used to
 provide visual continuity when panning singleTile layers.  Currently, when
 a singleTile layer is panned to the point where it needs to load a new
 image, the image is hidden and you typically get a flash of the background
 color of the map container while the image loads.  With this patch, the
 cloned version of the image can be 'left behind' while the new singleTile
 is requested.

 Many thanks to Erik for helping me with the original framework.

 Any review/comment/discussion would be appreciated.

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Ticket URL: <http://trac.openlayers.org/ticket/933#comment:1>
OpenLayers <http://openlayers.org/>
A free AJAX map viewer