From 6ac17bd220455c8efb9426a5103ba93d810d3d93 Mon Sep 17 00:00:00 2001
From: Chad Pilkey <capilkey@gmail.com>
Date: Fri, 20 Jul 2018 14:28:06 -0700
Subject: [PATCH] more assertive annotation and cursor clearing

---
 .../WhiteboardCanvasDisplayModel.as           | 12 ++++++-
 .../whiteboard/views/WhiteboardCanvas.as      | 32 +++++++++++++++++--
 2 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/bigbluebutton-client/src/org/bigbluebutton/modules/whiteboard/WhiteboardCanvasDisplayModel.as b/bigbluebutton-client/src/org/bigbluebutton/modules/whiteboard/WhiteboardCanvasDisplayModel.as
index 585ad25ad7..290df5aabc 100755
--- a/bigbluebutton-client/src/org/bigbluebutton/modules/whiteboard/WhiteboardCanvasDisplayModel.as
+++ b/bigbluebutton-client/src/org/bigbluebutton/modules/whiteboard/WhiteboardCanvasDisplayModel.as
@@ -145,7 +145,12 @@ package org.bigbluebutton.modules.whiteboard
       textUpdateListener.canvasMouseDown();
       
       //LogUtil.debug("**** CanvasDisplay changePage. Clearing page *****");
-      clearBoard();
+      
+      // forcefully clear all annotations and cursors on whiteboard change
+      _annotationsMap = new Object();
+      wbCanvas.removeAllGraphics();
+      
+      clearCursors();
       
       var annotations:Array = whiteboardModel.getAnnotations(wbId);
       //LogUtil.debug("**** CanvasDisplay changePage [" + annotations.length + "] *****");
@@ -154,6 +159,11 @@ package org.bigbluebutton.modules.whiteboard
       }
     }
     
+    public function clearCursors():void {
+      _cursors = new Object();
+      wbCanvas.removeAllCursorChildren();
+    }
+    
 		public function drawCursor(userId:String, xPercent:Number, yPercent:Number):void {
       var showName: Boolean = LiveMeeting.inst().whiteboardModel.multiUser;
       
diff --git a/bigbluebutton-client/src/org/bigbluebutton/modules/whiteboard/views/WhiteboardCanvas.as b/bigbluebutton-client/src/org/bigbluebutton/modules/whiteboard/views/WhiteboardCanvas.as
index 153d0ee738..bd8760e5b8 100755
--- a/bigbluebutton-client/src/org/bigbluebutton/modules/whiteboard/views/WhiteboardCanvas.as
+++ b/bigbluebutton-client/src/org/bigbluebutton/modules/whiteboard/views/WhiteboardCanvas.as
@@ -26,10 +26,15 @@ package org.bigbluebutton.modules.whiteboard.views {
 	import flash.events.MouseEvent;
 	import flash.geom.Point;
 	
+	import melomel.core.UI;
+	
 	import mx.containers.Canvas;
+	import mx.core.IChildList;
 	import mx.managers.CursorManager;
 	
 	import org.bigbluebutton.core.UsersUtil;
+	import org.bigbluebutton.core.model.LiveMeeting;
+	import org.bigbluebutton.core.model.users.User2x;
 	import org.bigbluebutton.main.events.SwitchedPresenterEvent;
 	import org.bigbluebutton.main.events.UserLeftEvent;
 	import org.bigbluebutton.modules.whiteboard.WhiteboardCanvasDisplayModel;
@@ -268,6 +273,13 @@ package org.bigbluebutton.modules.whiteboard.views {
 			else trace("Does not contain");
 		}
 		
+		public function removeAllGraphics():void {
+			var children:IChildList = this.graphicObjectHolder.rawChildren;
+			while (children.numChildren != 0) {
+				children.removeChildAt(children.numChildren - 1);
+			}
+		}
+		
 		public function addGraphic(child:DisplayObject):void {
 			this.graphicObjectHolder.rawChildren.addChild(child);
 		}
@@ -284,6 +296,13 @@ package org.bigbluebutton.modules.whiteboard.views {
 			if (doesContainCursor(cursor)) this.cursorObjectHolder.rawChildren.removeChild(cursor);
 		}
 		
+		public function removeAllCursorChildren():void {
+			var children:IChildList = this.cursorObjectHolder.rawChildren;
+			while (children.numChildren != 0) {
+				children.removeChildAt(children.numChildren - 1);
+			}
+		}
+		
 		public function textToolbarSyncProxy(tobj:TextObject):void {
 			textToolbar.syncPropsWith(tobj);
 		}
@@ -341,11 +360,20 @@ package org.bigbluebutton.modules.whiteboard.views {
 			//if (e.whiteboardId == currentWhiteboardId) {
 			whiteboardToolbar.whiteboardAccessModified(e.multiUser);
 			canvasModel.multiUserChange(e.multiUser);
+			
+			if (!e.multiUser) {
+				canvasDisplayModel.clearCursors();
+			}
 			//}
 		}
 		
 		private function onReceivedCursorPosition(e:WhiteboardCursorEvent):void {
-			canvasDisplayModel.drawCursor(e.userId, e.xPercent, e.yPercent);
+			var user:User2x = UsersUtil.getUser(e.userId);
+			
+			// only draw the cursor if the user exists and it's in multiuser mode or they are the presenter
+			if (user && (LiveMeeting.inst().whiteboardModel.multiUser || user.presenter)) {
+				canvasDisplayModel.drawCursor(e.userId, e.xPercent, e.yPercent);
+			}
 		}
 		
 		private function onEnableWhiteboardEvent(e:WhiteboardButtonEvent):void {
@@ -360,7 +388,7 @@ package org.bigbluebutton.modules.whiteboard.views {
 			
 			stopDrawing();
 			
-			removeCursor()
+			removeCursor();
 			
 			this.whiteboardEnabled = false;
 			setWhiteboardInteractable();