From 121bfcb984f08ff2dc8bca2f41d26d93760b4851 Mon Sep 17 00:00:00 2001
From: Winston Chang <winston@stdout.org>
Date: Tue, 7 Aug 2018 14:50:28 -0500
Subject: [PATCH] Import old brush after image has loaded

---
 srcjs/output_binding_image.js | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/srcjs/output_binding_image.js b/srcjs/output_binding_image.js
index d174be040..052e39959 100644
--- a/srcjs/output_binding_image.js
+++ b/srcjs/output_binding_image.js
@@ -998,8 +998,15 @@ imageutils.createBrushHandler = function(inputId, $el, opts, coordmap, outputId)
 
   if (!opts.brushResetOnNew) {
     if ($el.data("mostRecentBrush")) {
-      brush.importOldBrush();
-      brushInfoSender.immediateCall();
+      // Importing an old brush must happen after the image data has loaded
+      // and the <img> DOM element has the updated size. If importOldBrush()
+      // is called before this happens, then the css-img coordinate mappings
+      // will give the wrong result, and the brush will have the wrong
+      // position.
+      $el.find("img").one("load.shiny-image-interaction", function() {
+        brush.importOldBrush();
+        brushInfoSender.immediateCall();
+      });
     }
   }