Eliminate spacing memory leak on client (#13315)

Change-Id: I432ae4a04d74826dd1cce108177bd503774a8463

2 files changed, 14 insertions, 8 deletions

diff --git a/client/src/com/vaadin/client/ui/orderedlayout/AbstractOrderedLayoutConnector.java b/client/src/com/vaadin/client/ui/orderedlayout/AbstractOrderedLayoutConnector.java
index ec4307e50b..8ee1921ed7 100644
--- a/client/src/com/vaadin/client/ui/orderedlayout/AbstractOrderedLayoutConnector.java
+++ b/client/src/com/vaadin/client/ui/orderedlayout/AbstractOrderedLayoutConnector.java
@@ -297,9 +297,9 @@ public abstract class AbstractOrderedLayoutConnector extends
 
         // remove spacing as it is exists as separate elements that cannot be
         // removed easily after reordering the contents
-        Profiler.enter("AOLC.onConnectorHierarchyChange addOrMoveSlot temporarily remove spacing");
+        Profiler.enter("AOLC.onConnectorHierarchyChange temporarily remove spacing");
         layout.setSpacing(false);
-        Profiler.leave("AOLC.onConnectorHierarchyChange addOrMoveSlot temporarily remove spacing");
+        Profiler.leave("AOLC.onConnectorHierarchyChange temporarily remove spacing");
 
         for (ComponentConnector child : getChildComponents()) {
             Profiler.enter("AOLC.onConnectorHierarchyChange add children");
@@ -317,12 +317,12 @@ public abstract class AbstractOrderedLayoutConnector extends
         }
 
         // re-add spacing for the elements that should have it
-        Profiler.enter("AOLC.onConnectorHierarchyChange addOrMoveSlot setSpacing");
+        Profiler.enter("AOLC.onConnectorHierarchyChange setSpacing");
         // spacings were removed above
         if (getState().spacing) {
             layout.setSpacing(true);
         }
-        Profiler.leave("AOLC.onConnectorHierarchyChange addOrMoveSlot setSpacing");
+        Profiler.leave("AOLC.onConnectorHierarchyChange setSpacing");
 
         for (ComponentConnector child : previousChildren) {
             Profiler.enter("AOLC.onConnectorHierarchyChange remove children");
@@ -332,9 +332,7 @@ public abstract class AbstractOrderedLayoutConnector extends
                 if (slot.hasCaption()) {
                     slot.setCaptionResizeListener(null);
                 }
-                if (slot.getSpacingElement() != null) {
-                    slot.setSpacingResizeListener(null);
-                }
+                slot.setSpacingResizeListener(null);
                 child.removeStateChangeHandler(childStateChangeHandler);
                 layout.removeWidget(child.getWidget());
             }
diff --git a/client/src/com/vaadin/client/ui/orderedlayout/Slot.java b/client/src/com/vaadin/client/ui/orderedlayout/Slot.java
index efa19895a8..d9037cda3c 100644
--- a/client/src/com/vaadin/client/ui/orderedlayout/Slot.java
+++ b/client/src/com/vaadin/client/ui/orderedlayout/Slot.java
@@ -165,7 +165,7 @@ public final class Slot extends SimplePanel {
     }
 
     /**
-     * Attached resize listeners to the widget, caption and spacing elements
+     * Attaches resize listeners to the widget, caption and spacing elements
      */
     private void attachListeners() {
         if (getWidget() != null && layout.getLayoutManager() != null) {
@@ -204,6 +204,8 @@ public final class Slot extends SimplePanel {
                 lm.removeElementResizeListener(getWidget().getElement(),
                         widgetResizeListener);
             }
+            // in many cases, the listener has already been removed by
+            // setSpacing(false)
             if (getSpacingElement() != null && spacingResizeListener != null) {
                 lm.removeElementResizeListener(getSpacingElement(),
                         spacingResizeListener);
@@ -352,6 +354,12 @@ public final class Slot extends SimplePanel {
              */
             getElement().getParentElement().insertBefore(spacer, getElement());
         } else if (!spacing && spacer != null) {
+            // Remove listener before spacer to avoid memory leak
+            LayoutManager lm = layout.getLayoutManager();
+            if (lm != null && spacingResizeListener != null) {
+                lm.removeElementResizeListener(spacer, spacingResizeListener);
+            }
+
             spacer.removeFromParent();
             spacer = null;
         }