From fc61f9e547820a92a4346cf7b3cc96f161c21697 Mon Sep 17 00:00:00 2001
From: Paul Kaplan <pkaplan@media.mit.edu>
Date: Tue, 21 Nov 2017 11:45:11 -0500
Subject: [PATCH] Select target after drag end

---
 src/virtual-machine.js       | 23 +++++++++++++++++----
 test/unit/virtual-machine.js | 39 ++++++++++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+), 4 deletions(-)

diff --git a/src/virtual-machine.js b/src/virtual-machine.js
index 994de9860..263248b66 100644
--- a/src/virtual-machine.js
+++ b/src/virtual-machine.js
@@ -36,6 +36,13 @@ class VirtualMachine extends EventEmitter {
          * @type {Target}
          */
         this.editingTarget = null;
+
+        /**
+         * The currently dragging target, for redirecting IO data.
+         * @type {Target}
+         */
+        this._dragTarget = null;
+
         // Runtime emits are passed along as VM emits.
         this.runtime.on(Runtime.SCRIPT_GLOW_ON, glowData => {
             this.emit(Runtime.SCRIPT_GLOW_ON, glowData);
@@ -692,8 +699,8 @@ class VirtualMachine extends EventEmitter {
     startDrag (targetId) {
         const target = this.runtime.getTargetById(targetId);
         if (target) {
+            this._dragTarget = target;
             target.startDrag();
-            this.setEditingTarget(target.id);
         }
     }
 
@@ -703,15 +710,23 @@ class VirtualMachine extends EventEmitter {
      */
     stopDrag (targetId) {
         const target = this.runtime.getTargetById(targetId);
-        if (target) target.stopDrag();
+        if (target) {
+            this._dragTarget = null;
+            target.stopDrag();
+            this.setEditingTarget(target.id);
+        }
     }
 
     /**
-     * Post/edit sprite info for the current editing target.
+     * Post/edit sprite info for the current editing target or the drag target.
      * @param {object} data An object with sprite info data to set.
      */
     postSpriteInfo (data) {
-        this.editingTarget.postSpriteInfo(data);
+        if (this._dragTarget) {
+            this._dragTarget.postSpriteInfo(data);
+        } else {
+            this.editingTarget.postSpriteInfo(data);
+        }
     }
 }
 
diff --git a/test/unit/virtual-machine.js b/test/unit/virtual-machine.js
index f0887039e..40bd6bb54 100644
--- a/test/unit/virtual-machine.js
+++ b/test/unit/virtual-machine.js
@@ -316,3 +316,42 @@ test('emitWorkspaceUpdate', t => {
     t.notEqual(xml.indexOf('blocks'), -1);
     t.end();
 });
+
+test('drag IO redirect', t => {
+    const vm = new VirtualMachine();
+    const sprite1Info = [];
+    const sprite2Info = [];
+    vm.runtime.targets = [
+        {
+            id: 'sprite1',
+            postSpriteInfo: data => sprite1Info.push(data)
+        }, {
+            id: 'sprite2',
+            postSpriteInfo: data => sprite2Info.push(data),
+            startDrag: () => {},
+            stopDrag: () => {}
+        }
+    ];
+    vm.editingTarget = vm.runtime.targets[0];
+    // Stub emitWorkspace/TargetsUpdate, it needs data we don't care about here
+    vm.emitWorkspaceUpdate = () => null;
+    vm.emitTargetsUpdate = () => null;
+
+    // postSpriteInfo should go to the editing target by default``
+    vm.postSpriteInfo('sprite1 info');
+    t.equal(sprite1Info[0], 'sprite1 info');
+
+    // postSprite info goes to the drag target if it exists
+    vm.startDrag('sprite2');
+    vm.postSpriteInfo('sprite2 info');
+    t.equal(sprite2Info[0], 'sprite2 info');
+
+    // stop drag should set the editing target
+    vm.stopDrag('sprite2');
+    t.equal(vm.editingTarget.id, 'sprite2');
+
+    // Then postSpriteInfo should continue posting to the new editing target
+    vm.postSpriteInfo('sprite2 info 2');
+    t.equal(sprite2Info[1], 'sprite2 info 2');
+    t.end();
+});