Fix client-side memory leak caused by Grid events (#9103)

Refactors AbstractGridKeyEvent, AbstractGridMouseEvent and their
descendants to follow the pattern used in other GWT DomEvents.

Fixes #7633

6 files changed, 169 insertions, 64 deletions

diff --git a/compatibility-client/src/main/java/com/vaadin/v7/client/widget/grid/events/GridClickEvent.java b/compatibility-client/src/main/java/com/vaadin/v7/client/widget/grid/events/GridClickEvent.java
index 8f2350727f..ec1559b9da 100644
--- a/compatibility-client/src/main/java/com/vaadin/v7/client/widget/grid/events/GridClickEvent.java
+++ b/compatibility-client/src/main/java/com/vaadin/v7/client/widget/grid/events/GridClickEvent.java
@@ -30,8 +30,26 @@ import com.vaadin.v7.shared.ui.grid.GridConstants.Section;
  */
 public class GridClickEvent extends AbstractGridMouseEvent<GridClickHandler> {
 
+    public static final Type<GridClickHandler> TYPE = new Type<GridClickHandler>(
+            BrowserEvents.CLICK, new GridClickEvent());
+
+    /**
+     * @since 7.7.9
+     */
+    public GridClickEvent() {
+    }
+
+    /**
+     * @deprecated This constructor's arguments are no longer used. Use the
+     *             no-args constructor instead.
+     */
+    @Deprecated
     public GridClickEvent(Grid<?> grid, CellReference<?> targetCell) {
-        super(grid, targetCell);
+    }
+
+    @Override
+    public Type<GridClickHandler> getAssociatedType() {
+        return TYPE;
     }
 
     @Override
diff --git a/compatibility-client/src/main/java/com/vaadin/v7/client/widget/grid/events/GridDoubleClickEvent.java b/compatibility-client/src/main/java/com/vaadin/v7/client/widget/grid/events/GridDoubleClickEvent.java
index 711e70f3b4..17231ee3a8 100644
--- a/compatibility-client/src/main/java/com/vaadin/v7/client/widget/grid/events/GridDoubleClickEvent.java
+++ b/compatibility-client/src/main/java/com/vaadin/v7/client/widget/grid/events/GridDoubleClickEvent.java
@@ -31,8 +31,26 @@ import com.vaadin.v7.shared.ui.grid.GridConstants.Section;
 public class GridDoubleClickEvent
         extends AbstractGridMouseEvent<GridDoubleClickHandler> {
 
+    public static final Type<GridDoubleClickHandler> TYPE = new Type<GridDoubleClickHandler>(
+            BrowserEvents.DBLCLICK, new GridDoubleClickEvent());
+
+    /**
+     * @since 7.7.9
+     */
+    public GridDoubleClickEvent() {
+    }
+
+    /**
+     * @deprecated This constructor's arguments are no longer used. Use the
+     *             no-args constructor instead.
+     */
+    @Deprecated
     public GridDoubleClickEvent(Grid<?> grid, CellReference<?> targetCell) {
-        super(grid, targetCell);
+    }
+
+    @Override
+    public Type<GridDoubleClickHandler> getAssociatedType() {
+        return TYPE;
     }
 
     @Override
@@ -51,5 +69,4 @@ public class GridDoubleClickEvent
             handler.onDoubleClick(this);
         }
     }
-
 }
diff --git a/compatibility-client/src/main/java/com/vaadin/v7/client/widget/grid/events/GridKeyDownEvent.java b/compatibility-client/src/main/java/com/vaadin/v7/client/widget/grid/events/GridKeyDownEvent.java
index e4405b69a5..617798cb3c 100644
--- a/compatibility-client/src/main/java/com/vaadin/v7/client/widget/grid/events/GridKeyDownEvent.java
+++ b/compatibility-client/src/main/java/com/vaadin/v7/client/widget/grid/events/GridKeyDownEvent.java
@@ -31,8 +31,26 @@ import com.vaadin.v7.shared.ui.grid.GridConstants.Section;
  */
 public class GridKeyDownEvent extends AbstractGridKeyEvent<GridKeyDownHandler> {
 
+    public static final Type<GridKeyDownHandler> TYPE = new Type<GridKeyDownHandler>(
+            BrowserEvents.KEYDOWN, new GridKeyDownEvent());
+
+    /**
+     * @since 7.7.9
+     */
+    public GridKeyDownEvent() {
+    }
+
+    /**
+     * @deprecated This constructor's arguments are no longer used. Use the
+     *             no-args constructor instead.
+     */
+    @Deprecated
     public GridKeyDownEvent(Grid<?> grid, CellReference<?> targetCell) {
-        super(grid, targetCell);
+    }
+
+    @Override
+    public Type<GridKeyDownHandler> getAssociatedType() {
+        return TYPE;
     }
 
     @Override
diff --git a/compatibility-client/src/main/java/com/vaadin/v7/client/widget/grid/events/GridKeyPressEvent.java b/compatibility-client/src/main/java/com/vaadin/v7/client/widget/grid/events/GridKeyPressEvent.java
index 86a4664df0..1ada27a1f6 100644
--- a/compatibility-client/src/main/java/com/vaadin/v7/client/widget/grid/events/GridKeyPressEvent.java
+++ b/compatibility-client/src/main/java/com/vaadin/v7/client/widget/grid/events/GridKeyPressEvent.java
@@ -31,8 +31,26 @@ import com.vaadin.v7.shared.ui.grid.GridConstants.Section;
 public class GridKeyPressEvent
         extends AbstractGridKeyEvent<GridKeyPressHandler> {
 
+    public static final Type<GridKeyPressHandler> TYPE = new Type<GridKeyPressHandler>(
+            BrowserEvents.KEYPRESS, new GridKeyPressEvent());
+
+    /**
+     * @since 7.7.9
+     */
+    public GridKeyPressEvent() {
+    }
+
+    /**
+     * @deprecated This constructor's arguments are no longer used. Use the
+     *             no-args constructor instead.
+     */
+    @Deprecated
     public GridKeyPressEvent(Grid<?> grid, CellReference<?> targetCell) {
-        super(grid, targetCell);
+    }
+
+    @Override
+    public Type<GridKeyPressHandler> getAssociatedType() {
+        return TYPE;
     }
 
     @Override
diff --git a/compatibility-client/src/main/java/com/vaadin/v7/client/widget/grid/events/GridKeyUpEvent.java b/compatibility-client/src/main/java/com/vaadin/v7/client/widget/grid/events/GridKeyUpEvent.java
index 770f0214f9..ec81e65ea8 100644
--- a/compatibility-client/src/main/java/com/vaadin/v7/client/widget/grid/events/GridKeyUpEvent.java
+++ b/compatibility-client/src/main/java/com/vaadin/v7/client/widget/grid/events/GridKeyUpEvent.java
@@ -31,8 +31,21 @@ import com.vaadin.v7.shared.ui.grid.GridConstants.Section;
  */
 public class GridKeyUpEvent extends AbstractGridKeyEvent<GridKeyUpHandler> {
 
+    public static final Type<GridKeyUpHandler> TYPE = new Type<GridKeyUpHandler>(
+            BrowserEvents.KEYUP, new GridKeyUpEvent());
+
+    /**
+     * @since 7.7.9
+     */
+    public GridKeyUpEvent() {
+    }
+
+    /**
+     * @deprecated This constructor's arguments are no longer used. Use the
+     *             no-args constructor instead.
+     */
+    @Deprecated
     public GridKeyUpEvent(Grid<?> grid, CellReference<?> targetCell) {
-        super(grid, targetCell);
     }
 
     @Override
@@ -47,6 +60,11 @@ public class GridKeyUpEvent extends AbstractGridKeyEvent<GridKeyUpHandler> {
     }
 
     @Override
+    public Type<GridKeyUpHandler> getAssociatedType() {
+        return TYPE;
+    }
+
+    @Override
     protected String getBrowserEventType() {
         return BrowserEvents.KEYUP;
     }
diff --git a/compatibility-client/src/main/java/com/vaadin/v7/client/widgets/Grid.java b/compatibility-client/src/main/java/com/vaadin/v7/client/widgets/Grid.java
index 7ba5c9cc82..3efb253e3a 100644
--- a/compatibility-client/src/main/java/com/vaadin/v7/client/widgets/Grid.java
+++ b/compatibility-client/src/main/java/com/vaadin/v7/client/widgets/Grid.java
@@ -2298,94 +2298,115 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
     public static abstract class AbstractGridKeyEvent<HANDLER extends AbstractGridKeyEventHandler>
             extends KeyEvent<HANDLER> {
 
-        private Grid<?> grid;
-        private final Type<HANDLER> associatedType = new Type<HANDLER>(
-                getBrowserEventType(), this);
-        private final CellReference<?> targetCell;
+        /**
+         * @since 7.7.9
+         */
+        public AbstractGridKeyEvent() {
+        }
 
+        /**
+         * @deprecated This constructor's arguments are no longer used. Use the
+         *             no-args constructor instead.
+         */
+        @Deprecated
         public AbstractGridKeyEvent(Grid<?> grid, CellReference<?> targetCell) {
-            this.grid = grid;
-            this.targetCell = targetCell;
         }
 
         protected abstract String getBrowserEventType();
 
         /**
-         * Gets the Grid instance for this event.
+         * Gets the Grid instance for this event, if it originated from a Grid.
          *
-         * @return grid
+         * @return the grid this event originated from, or {@code null} if this
+         *         event did not originate from a grid
          */
         public Grid<?> getGrid() {
-            return grid;
+            EventTarget target = getNativeEvent().getEventTarget();
+            if (!Element.is(target)) {
+                return null;
+            }
+            return WidgetUtil.findWidget(Element.as(target), Grid.class);
         }
 
         /**
-         * Gets the focused cell for this event.
+         * Gets the reference of target cell for this event, if this event
+         * originated from a Grid.
          *
-         * @return focused cell
+         * @return target cell, or {@code null} if this event did not originate
+         *         from a grid
          */
         public CellReference<?> getFocusedCell() {
-            return targetCell;
+            return getGrid().getEventCell();
         }
 
         @Override
         protected void dispatch(HANDLER handler) {
             EventTarget target = getNativeEvent().getEventTarget();
-            if (Element.is(target)
+            Grid<?> grid = getGrid();
+            if (Element.is(target) && grid != null
                     && !grid.isElementInChildWidget(Element.as(target))) {
 
                 Section section = Section.FOOTER;
                 final RowContainer container = grid.cellFocusHandler.containerWithFocus;
                 if (container == grid.escalator.getHeader()) {
                     section = Section.HEADER;
-                } else if (container == grid.escalator.getBody()) {
+                } else if (container == getGrid().escalator.getBody()) {
                     section = Section.BODY;
                 }
-
                 doDispatch(handler, section);
             }
         }
 
         protected abstract void doDispatch(HANDLER handler, Section section);
-
-        @Override
-        public Type<HANDLER> getAssociatedType() {
-            return associatedType;
-        }
     }
 
     public static abstract class AbstractGridMouseEvent<HANDLER extends AbstractGridMouseEventHandler>
             extends MouseEvent<HANDLER> {
 
-        private Grid<?> grid;
-        private final CellReference<?> targetCell;
-        private final Type<HANDLER> associatedType = new Type<HANDLER>(
-                getBrowserEventType(), this);
+        /**
+         * @since 7.7.9
+         */
+        public AbstractGridMouseEvent() {
+        }
 
+        /**
+         * @deprecated This constructor's arguments are no longer used. Use the
+         *             no-args constructor instead.
+         */
+        @Deprecated
         public AbstractGridMouseEvent(Grid<?> grid,
                 CellReference<?> targetCell) {
-            this.grid = grid;
-            this.targetCell = targetCell;
         }
 
         protected abstract String getBrowserEventType();
 
         /**
-         * Gets the Grid instance for this event.
+         * Gets the Grid instance for this event, if it originated from a Grid.
          *
-         * @return grid
+         * @return the grid this event originated from, or {@code null} if this
+         *         event did not originate from a grid
          */
         public Grid<?> getGrid() {
-            return grid;
+            EventTarget target = getNativeEvent().getEventTarget();
+            if (!Element.is(target)) {
+                return null;
+            }
+            return WidgetUtil.findWidget(Element.as(target), Grid.class);
         }
 
         /**
-         * Gets the reference of target cell for this event.
+         * Gets the reference of target cell for this event, if this event
+         * originated from a Grid.
          *
-         * @return target cell
+         * @return target cell, or {@code null} if this event did not originate
+         *         from a grid
          */
         public CellReference<?> getTargetCell() {
-            return targetCell;
+            Grid<?> grid = getGrid();
+            if (grid == null) {
+                return null;
+            }
+            return grid.getEventCell();
         }
 
         @Override
@@ -2396,6 +2417,12 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
                 return;
             }
 
+            Grid<?> grid = getGrid();
+            if (grid == null) {
+                // Target is not an element of a grid
+                return;
+            }
+
             Element targetElement = Element.as(target);
             if (grid.isElementInChildWidget(targetElement)) {
                 // Target is some widget inside of Grid
@@ -2420,11 +2447,6 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
         }
 
         protected abstract void doDispatch(HANDLER handler, Section section);
-
-        @Override
-        public Type<HANDLER> getAssociatedType() {
-            return associatedType;
-        }
     }
 
     private static final String CUSTOM_STYLE_PROPERTY_NAME = "customStyle";
@@ -2438,12 +2460,6 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
     private static final double DETAILS_ROW_INITIAL_HEIGHT = 50;
 
     private EventCellReference<T> eventCell = new EventCellReference<T>(this);
-    private GridKeyDownEvent keyDown = new GridKeyDownEvent(this, eventCell);
-    private GridKeyUpEvent keyUp = new GridKeyUpEvent(this, eventCell);
-    private GridKeyPressEvent keyPress = new GridKeyPressEvent(this, eventCell);
-    private GridClickEvent clickEvent = new GridClickEvent(this, eventCell);
-    private GridDoubleClickEvent doubleClickEvent = new GridDoubleClickEvent(
-            this, eventCell);
 
     private class CellFocusHandler {
 
@@ -8176,7 +8192,7 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
      */
     public HandlerRegistration addBodyKeyDownHandler(
             BodyKeyDownHandler handler) {
-        return addHandler(handler, keyDown.getAssociatedType());
+        return addHandler(handler, GridKeyDownEvent.TYPE);
     }
 
     /**
@@ -8189,7 +8205,7 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
      * @return the registration for the event
      */
     public HandlerRegistration addBodyKeyUpHandler(BodyKeyUpHandler handler) {
-        return addHandler(handler, keyUp.getAssociatedType());
+        return addHandler(handler, GridKeyUpEvent.TYPE);
     }
 
     /**
@@ -8203,7 +8219,7 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
      */
     public HandlerRegistration addBodyKeyPressHandler(
             BodyKeyPressHandler handler) {
-        return addHandler(handler, keyPress.getAssociatedType());
+        return addHandler(handler, GridKeyPressEvent.TYPE);
     }
 
     /**
@@ -8217,7 +8233,7 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
      */
     public HandlerRegistration addHeaderKeyDownHandler(
             HeaderKeyDownHandler handler) {
-        return addHandler(handler, keyDown.getAssociatedType());
+        return addHandler(handler, GridKeyDownEvent.TYPE);
     }
 
     /**
@@ -8231,7 +8247,7 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
      */
     public HandlerRegistration addHeaderKeyUpHandler(
             HeaderKeyUpHandler handler) {
-        return addHandler(handler, keyUp.getAssociatedType());
+        return addHandler(handler, GridKeyUpEvent.TYPE);
     }
 
     /**
@@ -8245,7 +8261,7 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
      */
     public HandlerRegistration addHeaderKeyPressHandler(
             HeaderKeyPressHandler handler) {
-        return addHandler(handler, keyPress.getAssociatedType());
+        return addHandler(handler, GridKeyPressEvent.TYPE);
     }
 
     /**
@@ -8259,7 +8275,7 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
      */
     public HandlerRegistration addFooterKeyDownHandler(
             FooterKeyDownHandler handler) {
-        return addHandler(handler, keyDown.getAssociatedType());
+        return addHandler(handler, GridKeyDownEvent.TYPE);
     }
 
     /**
@@ -8273,7 +8289,7 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
      */
     public HandlerRegistration addFooterKeyUpHandler(
             FooterKeyUpHandler handler) {
-        return addHandler(handler, keyUp.getAssociatedType());
+        return addHandler(handler, GridKeyUpEvent.TYPE);
     }
 
     /**
@@ -8287,7 +8303,7 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
      */
     public HandlerRegistration addFooterKeyPressHandler(
             FooterKeyPressHandler handler) {
-        return addHandler(handler, keyPress.getAssociatedType());
+        return addHandler(handler, GridKeyPressEvent.TYPE);
     }
 
     /**
@@ -8299,7 +8315,7 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
      * @return the registration for the event
      */
     public HandlerRegistration addBodyClickHandler(BodyClickHandler handler) {
-        return addHandler(handler, clickEvent.getAssociatedType());
+        return addHandler(handler, GridClickEvent.TYPE);
     }
 
     /**
@@ -8312,7 +8328,7 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
      */
     public HandlerRegistration addHeaderClickHandler(
             HeaderClickHandler handler) {
-        return addHandler(handler, clickEvent.getAssociatedType());
+        return addHandler(handler, GridClickEvent.TYPE);
     }
 
     /**
@@ -8325,7 +8341,7 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
      */
     public HandlerRegistration addFooterClickHandler(
             FooterClickHandler handler) {
-        return addHandler(handler, clickEvent.getAssociatedType());
+        return addHandler(handler, GridClickEvent.TYPE);
     }
 
     /**
@@ -8339,7 +8355,7 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
      */
     public HandlerRegistration addBodyDoubleClickHandler(
             BodyDoubleClickHandler handler) {
-        return addHandler(handler, doubleClickEvent.getAssociatedType());
+        return addHandler(handler, GridDoubleClickEvent.TYPE);
     }
 
     /**
@@ -8353,7 +8369,7 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
      */
     public HandlerRegistration addHeaderDoubleClickHandler(
             HeaderDoubleClickHandler handler) {
-        return addHandler(handler, doubleClickEvent.getAssociatedType());
+        return addHandler(handler, GridDoubleClickEvent.TYPE);
     }
 
     /**
@@ -8367,7 +8383,7 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
      */
     public HandlerRegistration addFooterDoubleClickHandler(
             FooterDoubleClickHandler handler) {
-        return addHandler(handler, doubleClickEvent.getAssociatedType());
+        return addHandler(handler, GridDoubleClickEvent.TYPE);
     }
 
     /**