Fixes a bug in MenuBar where the selectedItem was not set to null when an item is removed or clearItems is called. This could result in a JS null pointer exception if garbage collection runs because we try to access an element that no longer has any references to it.
Issue: 2178
Patch by: jlabanca
Review by: bruce
git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@2115 8db76d5a-ed1c-0410-87a9-c151d255dfc7
diff --git a/user/src/com/google/gwt/user/client/ui/MenuBar.java b/user/src/com/google/gwt/user/client/ui/MenuBar.java
index ec97492..be483f7 100644
--- a/user/src/com/google/gwt/user/client/ui/MenuBar.java
+++ b/user/src/com/google/gwt/user/client/ui/MenuBar.java
@@ -227,6 +227,9 @@
* Removes all menu items from this menu bar.
*/
public void clearItems() {
+ // Deselect the current item
+ selectItem(null);
+
Element container = getItemContainerElement();
while (DOM.getChildCount(container) > 0) {
DOM.removeChild(container, DOM.getChild(container, 0));
@@ -347,6 +350,11 @@
* @param item the item to be removed
*/
public void removeItem(MenuItem item) {
+ // Unselect if the item is currently selected
+ if (selectedItem == item) {
+ selectItem(null);
+ }
+
if (removeItemElement(item)) {
setItemColSpan(item, 1);
items.remove(item);
diff --git a/user/test/com/google/gwt/user/client/ui/MenuBarTest.java b/user/test/com/google/gwt/user/client/ui/MenuBarTest.java
index 24925b8..fcfeff0 100644
--- a/user/test/com/google/gwt/user/client/ui/MenuBarTest.java
+++ b/user/test/com/google/gwt/user/client/ui/MenuBarTest.java
@@ -134,4 +134,44 @@
});
delayTestFinish(250);
}
+
+ /**
+ * Test that the selected item points to the correct item.
+ */
+ public void testSelectedItem() {
+ // Create a menu bar
+ MenuBar bar = new MenuBar(true);
+
+ // Create a blank command
+ Command blankCommand = new Command() {
+ public void execute() {
+ }
+ };
+
+ // Add some items
+ MenuItem item0 = bar.addItem("item0", blankCommand);
+ MenuItem item1 = bar.addItem("item1", blankCommand);
+ MenuItem item2 = bar.addItem("item2", blankCommand);
+ MenuItem item3 = bar.addItem("item3", blankCommand);
+ MenuItem item4 = bar.addItem("item4", blankCommand);
+
+ // Test setting the selected item
+ assertNull(bar.getSelectedItem());
+ bar.selectItem(item1);
+ assertEquals(item1, bar.getSelectedItem());
+
+ // Test removing the selected item
+ bar.removeItem(item1);
+ assertNull(bar.getSelectedItem());
+
+ // Test removing an item that is not selected
+ bar.selectItem(item3);
+ assertEquals(item3, bar.getSelectedItem());
+ bar.removeItem(item2);
+ assertEquals(item3, bar.getSelectedItem());
+
+ // Test clearing all items
+ bar.clearItems();
+ assertNull(bar.getSelectedItem());
+ }
}
