Bug 28269 type hierarchy makes work much slower even though it's invisible
20021210 i had a big type hierarchy open but put in the background - behind the package explorer i added 1 type to the workspace boom - tyhe whole thing froze for 2 minutes because the type hierarchy was doing a lot of work that i did not ask for and no busy cursor it makes it quite impossible to work if you have a type hierarchy open anywhere
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/typehierarchy/TypeHierarchyViewPart.java
import org.eclipse.swt.custom.SashForm;
import org.eclipse.swt.custom.ViewForm;
import org.eclipse.swt.dnd.DND;
import org.eclipse.swt.dnd.DragSource;
import org.eclipse.swt.dnd.DropTarget;
import org.eclipse.swt.dnd.Transfer;
import org.eclipse.swt.events.KeyAdapter;
import org.eclipse.swt.events.KeyEvent;
import org.eclipse.swt.events.KeyListener;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.ScrollBar;
import org.eclipse.swt.widgets.ToolBar;
import org.eclipse.jface.action.IMenuListener;
import org.eclipse.jface.action.IMenuManager;
import org.eclipse.jface.action.IStatusLineManager;
import org.eclipse.jface.action.IToolBarManager;
import org.eclipse.jface.action.MenuManager;
import org.eclipse.jface.action.Separator;
import org.eclipse.jface.action.ToolBarManager;
import org.eclipse.jface.dialogs.IDialogSettings;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.util.Assert;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;
import org.eclipse.jface.viewers.AbstractTreeViewer;
import org.eclipse.jface.viewers.IBasicPropertyConstants;
import org.eclipse.jface.viewers.ISelection;