X-Git-Url: https://dev.renevier.net/gitweb.cgi?p=syp.git;a=blobdiff_plain;f=js%2Fadmin.js;fp=js%2Fadmin.js;h=71daf2c7cc93ca4ecf6ad97dfa64ed98b9de34a8;hp=abce8a52ef93ee15b24df7ed9f5702e383e852e4;hb=67d307303acfea6e719a51e437833c76408ef703;hpb=5f6e6555d4b0d69a97454f6d6434c7bb6d1fd3e5

diff --git a/js/admin.js b/js/admin.js
index abce8a5..71daf2c 100644
--- a/js/admin.js
+++ b/js/admin.js
@@ -1,6 +1,66 @@
 /* Copyright (c) 2009 Arnaud Renevier, Inc, published under the modified BSD
  * license. */
 
+/*
+ * Fix canvas rendering engine race condition. See js/syp.js for more explanation.
+ */
+OpenLayers.Renderer.Canvas.prototype = OpenLayers.Util.extend({
+    needsRedraw: false,
+    imagesLoading: 0,
+}, OpenLayers.Renderer.Canvas.prototype);
+OpenLayers.Renderer.Canvas.prototype.oldRedraw = OpenLayers.Renderer.Canvas.prototype.redraw;
+OpenLayers.Renderer.Canvas.prototype.redraw = function() {
+    if (this.imagesLoading > 0) {
+        this.needsRedraw = true;
+        return;
+    }
+    OpenLayers.Renderer.Canvas.prototype.oldRedraw.apply(this, arguments);
+}
+OpenLayers.Renderer.Canvas.prototype.drawExternalGraphic = function(pt, style) {
+    var img = new Image();
+    img.src = style.externalGraphic;
+       
+    if(style.graphicTitle) {
+        img.title=style.graphicTitle;           
+    }
+
+    var width = style.graphicWidth || style.graphicHeight;
+    var height = style.graphicHeight || style.graphicWidth;
+    width = width ? width : style.pointRadius*2;
+    height = height ? height : style.pointRadius*2;
+    var xOffset = (style.graphicXOffset != undefined) ?
+        style.graphicXOffset : -(0.5 * width);
+   var yOffset = (style.graphicYOffset != undefined) ?
+       style.graphicYOffset : -(0.5 * height);
+   var opacity = style.graphicOpacity || style.fillOpacity;
+       
+   var context = { img: img, 
+                   x: (pt[0]+xOffset), 
+                   y: (pt[1]+yOffset), 
+                   width: width, 
+                   height: height, 
+                   canvas: this.canvas };
+
+   var self = this;
+   this.imagesLoading++;
+   img.onerror = function() {
+       self.imagesLoading--;
+       if ((self.imagesLoading == 0) && (self.needsRedraw)) {
+           self.needsRedraw = false;
+           self.redraw();
+       }
+   }
+   img.onload = OpenLayers.Function.bind( function() {
+       self.imagesLoading--;
+       if ((self.imagesLoading == 0) && (self.needsRedraw)) {
+           self.needsRedraw = false;
+           self.redraw();
+       } else {
+            this.canvas.drawImage(this.img, this.x, 
+                             this.y, this.width, this.height);
+       }
+   }, context);   
+}
 // drag feature with tolerance
 OpenLayers.Control.SypDragFeature = OpenLayers.Class (OpenLayers.Control.DragFeature, {
     startPixel: null,