Bug 75711 AstProvider should not create AST if requested by SelectionListenerWithASTManager
3.1 M2 If SelectionListenerWithASTManager waits for an AST and the editor closes we should not create an AST for that one but return null instead.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java
}
	
	/*
	 * @see org.eclipse.ui.texteditor.AbstractDecoratedTextEditor#createChangeHover()
	 */
	protected LineChangeHover createChangeHover() {
		return new JavaChangeHover(IJavaPartitions.JAVA_PARTITIONING);
	}
	protected boolean isPrefQuickDiffAlwaysOn() {
		return false; 
	}
	/*
	 * @see org.eclipse.ui.texteditor.AbstractTextEditor#createNavigationActions()
	 */
	protected void createNavigationActions() {
		super.createNavigationActions();
		final StyledText textWidget= getSourceViewer().getTextWidget();
		IAction action= new SmartLineStartAction(textWidget, false);
		action.setActionDefinitionId(ITextEditorActionDefinitionIds.LINE_START);
		setAction(ITextEditorActionDefinitionIds.LINE_START, action);
		action= new SmartLineStartAction(textWidget, true);
		action.setActionDefinitionId(ITextEditorActionDefinitionIds.SELECT_LINE_START);
		setAction(ITextEditorActionDefinitionIds.SELECT_LINE_START, action);
		action= new NavigatePreviousSubWordAction();
		action.setActionDefinitionId(ITextEditorActionDefinitionIds.WORD_PREVIOUS);
		setAction(ITextEditorActionDefinitionIds.WORD_PREVIOUS, action);
		textWidget.setKeyBinding(SWT.CTRL | SWT.ARROW_LEFT, SWT.NULL);
		action= new NavigateNextSubWordAction();
		action.setActionDefinitionId(ITextEditorActionDefinitionIds.WORD_NEXT);
		setAction(ITextEditorActionDefinitionIds.WORD_NEXT, action);