Bug 11770 java browsing: multi-selection disabled in 2 of 4 views
multi selection is disabled in the package and type views but it's enabled in project and member views
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/browsing/JavaBrowsingPart.java
Object currentInput= (IJavaElement)getViewer().getInput();
		if (newInput != null && newInput.equals(currentInput)) {
			IJavaElement elementToSelect= findElementToSelect(getElementFromSingleSelection(selection));
			if (elementToSelect != null && getTypeComparator().compare(newInput, elementToSelect) < 0)
				setSelection(new StructuredSelection(elementToSelect), true);
			fPreviousSelectionProvider= part;
			return;
		}
		
		if (part != fPreviousSelectionProvider && newInput != null && !newInput.equals(currentInput) && isInputResetBy(newInput, currentInput, part)) {
			if (!isAncestorOf(newInput, currentInput))
				setInput(null);
			fPreviousSelectionProvider= part;
			return;
		} else if (newInput == null && part == fPreviousSelectionProvider) {
			setInput(null);
			fPreviousSelectionProvider= part;
			return;
		}
		fPreviousSelectionProvider= part;
		
		
		if (newInput instanceof IJavaElement)
			adjustInputAndSetSelection((IJavaElement)newInput);
		else
			setSelection(StructuredSelection.EMPTY, true);
	}
	protected void setInput(Object input) {
		if (input == null)
			setTitleImage(fOriginalTitleImage);