Bug 211493 [Markers] [Markers] New Markers view slows down traversal in Package Explorer
I20071127-0800 Traversing over elements in the Package Explorer via Arrow_Down key is slowed down by the new Markers view. Steps: - select org.eclipse.jdt.doc.user (from CVS) - press Arrow_Right - press and hold Arrow_Down => selection moves slowly, gets faster after folders with many files have been passed I quickly profiled this and found that a lot of time is burned in org.eclipse.ui.internal.provisional.views.markers.CachedMarkerBuilder$1.run(IProgressMonitor) This is probably because ExtendedMarkersView.createPartControl(Composite) contains: ISelectionListener listener = getPageSelectionListener(); getSite().getPage().addSelectionListener(listener); listener.selectionChanged(getSite().getPage().getActivePart(), getSite().getPage().getSelection()); 1. => should not leak the listener when the view is disposed 2. => should not update when the Markers view is not visible 3. => should not use addSelectionListener() but addPostSelectionListener()
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/provisional/views/markers/ExtendedMarkersView.java
/*
			 * (non-Javadoc)
			 * 
			 * @see org.eclipse.jface.viewers.ITreeContentProvider#getChildren(java.lang.Object)
			 */
			public Object[] getChildren(Object parentElement) {
				MarkerItem[] children = ((MarkerItem) parentElement)
						.getChildren();
				return getLimitedChildren(children);
			}
			/**
			 * Get the children limited by the marker limits.
			 * 
			 * @param children
			 * @return Object[]
			 */
			private Object[] getLimitedChildren(Object[] children) {
				int newLength = MarkerSupportInternalUtilities.getMarkerLimit();
				if (newLength > 0 && newLength < children.length) {
					Object[] newChildren = new Object[newLength];