view.showHistory(resource);
view.showHistory(resource, false);
	public boolean performDrop(Object data) {		if (data == null) return false;		IResource[] sources = (IResource[])data;		if (sources.length == 0) return false;		IResource resource = sources[0];		if (!(resource instanceof IFile)) return false;		view.showHistory(resource);		return true;	}