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
public boolean hasChildren(Object element) {
				return ((MarkerItem) element).getChildren().length > 0;
			}
			/*
			 * (non-Javadoc)
			 * 
			 * @see org.eclipse.jface.viewers.IContentProvider#inputChanged(org.eclipse.jface.viewers.Viewer,
			 *      java.lang.Object, java.lang.Object)
			 */
			public void inputChanged(Viewer viewer, Object oldInput,
					Object newInput) {
			}
		};
	}
	/**
	 * Return the listener that updates sort values on selection.
	 * 
	 * @return SelectionListener
	 */
	private SelectionListener getHeaderListener() {
		return new SelectionAdapter() {
			/**
			 * Handles the case of user selecting the header area.
			 */
			public void widgetSelected(SelectionEvent e) {
				final TreeColumn column = (TreeColumn) e.widget;
				final MarkerField field = (MarkerField) column
						.getData(MARKER_FIELD);
				setPrimarySortField(field, column);
			}