Use new drawSeries hook, don't barf on series that don't have images

git-svn-id: https://flot.googlecode.com/svn/trunk@243 1e0a6537-2640-0410-bfb7-f154510ff394

jquery.flot.image.js

@@ -112,10 +112,12 @@ images (like Google Maps).
         });
     }
     
-    function draw(plot, ctx) {
+    function drawSeries(plot, ctx, series) {
         var plotOffset = plot.getPlotOffset();
         
-        $.each(plot.getData(), function (i, series) {
+        if (!series.images || !series.images.show)
+            return;
+        
         var points = series.datapoints.points,
             ps = series.datapoints.pointsize;
         
@@ -206,7 +208,6 @@ images (like Google Maps).
                           x2 - x1, y2 - y1);
             ctx.globalAlpha = tmp;
         }
-        });
     }
 
     function processRawData(plot, series, data, datapoints) {
@@ -225,7 +226,7 @@ images (like Google Maps).
     
     function init(plot) {
         plot.hooks.processRawData.push(processRawData);
-        plot.hooks.draw.push(draw);
+        plot.hooks.drawSeries.push(drawSeries);
     }
     
     $.plot.plugins.push({