Bug 56818 [PropertiesView] Clicking on Advanced Properties toggle when categories are collapsed removes the + next to the category
Clicking on Advanced Properties toggle when categories are collapsed removes the plus sign (+) next to the category and it can no longer be expanded. To reproduce: 1.)Open the Properties view. 2.)Have Show Categories turned on, and Show Advanced Properties turned off. 3.)Collapse all open categories. 4.)Click the Show Advanced Properties button. 5.)Note the plus sign goes away and the categories can no longer be expanded. You need to click the Show Advanced Properties button off to see the plus sign again.
bundles/org.eclipse.ui.views/src/org/eclipse/ui/views/properties/PropertySheetViewer.java
.cellEditorActivated(cellEditor);
		}
	}
	/**
	 * Notifies all registered cell editor activation listeners of a cell editor
	 * deactivation.
	 * 
	 * @param cellEditor
	 *            the deactivated cell editor
	 */
	private void fireCellEditorDeactivated(CellEditor cellEditor) {
		Object[] listeners = activationListeners.getListeners();
		for (int i = 0; i < listeners.length; ++i) {
			((ICellEditorActivationListener) listeners[i])
					.cellEditorDeactivated(cellEditor);
		}
	}
	/**
	 * Returns the active cell editor of this property sheet viewer or
	 * <code>null</code> if no cell editor is active.
	 * 
	 * @return the active cell editor
	 */
	public CellEditor getActiveCellEditor() {
		return cellEditor;
	}
	/**
	 * Returns the children of the given category or entry
	 *
	 * @node a category or entry