From f7d80459c7cb693cbc442d99cb38f0e70f6f4ffa Mon Sep 17 00:00:00 2001
From: sjhuang26 <sjhuang26@gmail.com>
Date: Fri, 29 Dec 2017 09:01:30 -0500
Subject: [PATCH] Fixed pen behavior when dragging

---
 src/extensions/scratch3_pen/index.js | 16 ++++++++++------
 src/sprites/rendered-target.js       |  2 +-
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/src/extensions/scratch3_pen/index.js b/src/extensions/scratch3_pen/index.js
index abd46db1..c6540016 100644
--- a/src/extensions/scratch3_pen/index.js
+++ b/src/extensions/scratch3_pen/index.js
@@ -181,14 +181,18 @@ class Scratch3PenBlocks {
      * @param {RenderedTarget} target - the target which has moved.
      * @param {number} oldX - the previous X position.
      * @param {number} oldY - the previous Y position.
+     * @param {boolean} isForce - whether the movement was forced.
      * @private
      */
-    _onTargetMoved (target, oldX, oldY) {
-        const penSkinId = this._getPenLayerID();
-        if (penSkinId >= 0) {
-            const penState = this._getPenState(target);
-            this.runtime.renderer.penLine(penSkinId, penState.penAttributes, oldX, oldY, target.x, target.y);
-            this.runtime.requestRedraw();
+    _onTargetMoved (target, oldX, oldY, isForce) {
+        // Only move the pen if the movement isn't forced (ie. dragged).
+        if (!isForce) {
+            const penSkinId = this._getPenLayerID();
+            if (penSkinId >= 0) {
+                const penState = this._getPenState(target);
+                this.runtime.renderer.penLine(penSkinId, penState.penAttributes, oldX, oldY, target.x, target.y);
+                this.runtime.requestRedraw();
+            }
         }
     }
 
diff --git a/src/sprites/rendered-target.js b/src/sprites/rendered-target.js
index 13f9bd32..fe9ede29 100644
--- a/src/sprites/rendered-target.js
+++ b/src/sprites/rendered-target.js
@@ -203,7 +203,7 @@ class RenderedTarget extends Target {
             this.x = x;
             this.y = y;
         }
-        this.emit(RenderedTarget.EVENT_TARGET_MOVED, this, oldX, oldY);
+        this.emit(RenderedTarget.EVENT_TARGET_MOVED, this, oldX, oldY, force);
         this.runtime.requestTargetsUpdate(this);
     }