Bug 36672 call hierarchy: Should show a progress bar
The Call Hierarchy view should show a progress bar when searching for callers/callees, allowing the user to abort the search.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/callhierarchy/CallHierarchyViewPart.java
private static final String GROUP_FOCUS = "group.focus"; 
    private static final int PAGE_EMPTY = 0;
    private static final int PAGE_VIEWER = 1;
    private Label fNoHierarchyShownLabel;
    private PageBook fPagebook;
    private IDialogSettings fDialogSettings;
    private int fCurrentOrientation;
    private int fCurrentCallMode;
    private int fCurrentImplementorsMode;
    private MethodWrapper fCalleeRoot;
    private MethodWrapper fCallerRoot;
    private IMemento fMemento;
    private IMethod fShownMethod;
    private SelectionProviderMediator fSelectionProviderMediator;
    private List fMethodHistory;
    private TableViewer fLocationViewer;
    private Menu fLocationContextMenu;
    private SashForm fHierarchyLocationSplitter;
    private Clipboard fClipboard;
    private SearchScopeActionGroup fSearchScopeActions;
    private ToggleOrientationAction[] fToggleOrientationActions;
    private ToggleCallModeAction[] fToggleCallModeActions;
    private ToggleImplementorsAction[] fToggleImplementorsActions;
    private CallHierarchyFiltersActionGroup fFiltersActionGroup;
    private HistoryDropDownAction fHistoryDropDownAction;
    private RefreshAction fRefreshAction;
    private OpenLocationAction fOpenLocationAction;
    private FocusOnSelectionAction fFocusOnSelectionAction;
    private CopyCallHierarchyAction fCopyAction;
    private CompositeActionGroup fActionGroups;