From 596d0c4f5f37c9c8a499303be740b10380d311da Mon Sep 17 00:00:00 2001
From: Paul Kaplan <pkaplan@media.mit.edu>
Date: Thu, 1 Nov 2018 14:13:07 -0400
Subject: [PATCH] Include the origin blockId of the top block being dragged.

This is required by the GUI in order to take a snapshot of the blocks for the backpack. Only the ID is needed, the rest can be done by the GUI.
---
 src/engine/blocks.js   | 2 +-
 src/engine/runtime.js  | 5 +++--
 src/virtual-machine.js | 4 ++--
 3 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/src/engine/blocks.js b/src/engine/blocks.js
index 28ac3184f..858871f69 100644
--- a/src/engine/blocks.js
+++ b/src/engine/blocks.js
@@ -340,7 +340,7 @@ class Blocks {
                 // Drag blocks onto another sprite
                 if (e.isOutside) {
                     const newBlocks = adapter(e);
-                    optRuntime.emitBlockEndDrag(newBlocks);
+                    optRuntime.emitBlockEndDrag(newBlocks, e.blockId);
                 }
             }
             break;
diff --git a/src/engine/runtime.js b/src/engine/runtime.js
index 95d07aa09..26315a952 100644
--- a/src/engine/runtime.js
+++ b/src/engine/runtime.js
@@ -1857,9 +1857,10 @@ class Runtime extends EventEmitter {
     /**
      * Emit event to indicate that the block drag has ended with the blocks outside the blocks workspace
      * @param {Array.<object>} blocks The set of blocks dragged to the GUI
+     * @param {string} topBlockId The original id of the top block being dragged
      */
-    emitBlockEndDrag (blocks) {
-        this.emit(Runtime.BLOCK_DRAG_END, blocks);
+    emitBlockEndDrag (blocks, topBlockId) {
+        this.emit(Runtime.BLOCK_DRAG_END, blocks, topBlockId);
     }
 
     /**
diff --git a/src/virtual-machine.js b/src/virtual-machine.js
index b7659dd31..1aaae9578 100644
--- a/src/virtual-machine.js
+++ b/src/virtual-machine.js
@@ -96,8 +96,8 @@ class VirtualMachine extends EventEmitter {
         this.runtime.on(Runtime.BLOCK_DRAG_UPDATE, areBlocksOverGui => {
             this.emit(Runtime.BLOCK_DRAG_UPDATE, areBlocksOverGui);
         });
-        this.runtime.on(Runtime.BLOCK_DRAG_END, blocks => {
-            this.emit(Runtime.BLOCK_DRAG_END, blocks);
+        this.runtime.on(Runtime.BLOCK_DRAG_END, (blocks, topBlockId) => {
+            this.emit(Runtime.BLOCK_DRAG_END, blocks, topBlockId);
         });
         this.runtime.on(Runtime.EXTENSION_ADDED, blocksInfo => {
             this.emit(Runtime.EXTENSION_ADDED, blocksInfo);