fixed part of #154 - prevent costumes from being drawn while they are loading

prevents an occasional DOM error saying "an attempt was made to use an
object that is not, or is no longer, usable" when loading a project
that has costumes

1 files changed, 17 insertions, 3 deletions

diff --git a/objects.js b/objects.js
index f0d0e44..9e61d58 100644
--- a/objects.js
+++ b/objects.js
@@ -124,7 +124,7 @@ PrototypeHatBlockMorph*/
 
 // Global stuff ////////////////////////////////////////////////////////
 
-modules.objects = '2013-September-16';
+modules.objects = '2013-September-17';
 
 var SpriteMorph;
 var StageMorph;
@@ -1248,6 +1248,8 @@ SpriteMorph.prototype.drawNew = function () {
         currentCenter = this.center(),
         facing, // actual costume heading based on my rotation style
         isFlipped,
+        isLoadingCostume = this.costume &&
+            typeof this.costume.loaded === 'function',
         pic, // (flipped copy of) actual costume based on my rotation style
         stageScale = this.parent instanceof StageMorph ?
                 this.parent.scale : 1,
@@ -1257,7 +1259,8 @@ SpriteMorph.prototype.drawNew = function () {
         shift,
         corner,
         costumeExtent,
-        ctx;
+        ctx,
+        handle;
 
     if (this.isWarped) {
         this.wantsRedraw = true;
@@ -1271,7 +1274,7 @@ SpriteMorph.prototype.drawNew = function () {
             isFlipped = true;
         }
     }
-    if (this.costume) {
+    if (this.costume && !isLoadingCostume) {
         pic = isFlipped ? this.costume.flipped() : this.costume;
 
         // determine the rotated costume's bounding box
@@ -1328,6 +1331,17 @@ SpriteMorph.prototype.drawNew = function () {
         this.setCenter(currentCenter, true); // just me
         SpriteMorph.uber.drawNew.call(this, facing);
         this.rotationOffset = this.extent().divideBy(2);
+        if (isLoadingCostume) { // retry until costume is done loading
+            handle = setInterval(
+                function () {
+                    myself.changed();
+                    myself.drawNew();
+                    myself.changed();
+                    clearInterval(handle);
+                },
+                100
+            );
+        }
     }
     this.version = Date.now();
 };