From a2131f638052d88255a2696986d5a40f90482df1 Mon Sep 17 00:00:00 2001
From: Robert Kaiser <kairo@kairo.at>
Date: Fri, 14 Dec 2012 14:02:09 +0100
Subject: [PATCH] add a comment about crashing with drawing a blob

---
 js/map.js | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/js/map.js b/js/map.js
index bb2d6bb..04bbc1a 100644
--- a/js/map.js
+++ b/js/map.js
@@ -297,12 +297,16 @@ function drawMap() {
           var iyMin = gPos.y - ht / 2;
           var ixoff = Math.round((aCoords.x * size - ixMin) / gZoomFactor);
           var iyoff = Math.round((aCoords.y * size - iyMin) / gZoomFactor);
+          // Would be nice to draw directly from the blob, but that crashes:
+          // gMapContext.drawImage(aImage, ixoff, iyoff);
           var URL = window.URL;
           var imgURL = URL.createObjectURL(aImage);
           var imgObj = new Image();
           imgObj.src = imgURL;
-          gMapContext.drawImage(imgObj, ixoff, iyoff);
-          URL.revokeObjectURL(imgURL);
+          imgObj.onload = function() {
+            gMapContext.drawImage(imgObj, ixoff, iyoff);
+            URL.revokeObjectURL(imgURL);
+          }
         }
       });
     }
-- 
2.35.3