[OpenLayers-Trac] [OpenLayers] #1018: Remove 'drawn' property from tile altogether

[OpenLayers]

#1018: Remove 'drawn' property from tile altogether
--------------------+-------------------------------------------------------
 Reporter:  euzuro  |       Owner:  euzuro     
     Type:  task    |      Status:  new        
 Priority:  minor   |   Milestone:  2.6 Release
Component:  Tile    |     Version:  2.5 RC3    
 Keywords:          |  
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 The 'drawn' property as we know it is only used in one case:

 the case where you have a gridded layer with buffer set to 0 and where a
 new grid is initialized (initGriddedTiles) and it just so happens that
 there is an extra row/col of tiles to the right or bottom of the displayed
 map. Since the buffer is set to 0 we are instructed to *not* load any
 tiles which are off the grid, so this extra row/col's tiles do not get
 loaded.

 However! in the case where the user then drags the map just a tiny bit up
 or left, that extra row of tiles is brought into view. They then need to
 be drawn, and this is the entire reason for the 'drawn' property and the
 following code snippet, at the end of the moveGriddedTiles() function:

 {{{
         if (this.buffer == 0) {
             for (var r=0, rl=this.grid.length; r<rl; r++) {
                 var row = this.grid[r];
                 for (var c=0, cl=row.length; c<cl; c++) {
                     var tile = row[c];
                     if (!tile.drawn && H
                          tile.bounds.intersectsBounds(bounds, false)) {
                         tile.draw();
                     }
                 }
             }
         }
 }}}

 This border case I believe can be avoided by simply changing one line of
 the tile.draw() function:

 {{{
     var withinMapExtent = (mapExtent &&
                            this.bounds.intersectsBounds(mapExtent,
 false));
 }}}
 to
 {{{
     var withinMapExtent = (mapExtent &&
                            this.bounds.intersectsBounds(mapExtent, true));
 }}}

 which makes the bounds test *inclusive* and therefore yes will draw the
 last col/row of tiles. OK, the user said NO BUFFER, but we're only
 buffering one little tiny row/column and the whole point of OpenLayers in
 the first place is to be slippy and so it doesn't seem unreasonable to
 expect/hope the user to slip around.

 And of course the bonus of this is that by changing that one line, we can
 eliminate a property that results in confusing code that noone can
 understand. To me, this seems like a win.

-- 
Ticket URL: <http://trac.openlayers.org/ticket/1018>
OpenLayers <http://openlayers.org/>
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