7

Please follow those steps:

CurrentValue[EvaluationNotebook[], ScreenStyleEnvironment] = "SlideShow"

SetOptions[
   EvaluationNotebook[],
   StyleDefinitions -> Notebook[{
     Cell[StyleData["Notebook"], 
       DockedCells -> {Inherited, Inherited, Cell[TextData["TEST"]]}]
    },
   StyleDefinitions -> "Reference.nb"
]]

enter image description here

As you can see, those double slideshow toolbars are inherited from somewhere even though there is no reference to Core/Default in StyleDefinitions.

Where are they from?

Kuba
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    it comes from the style environment definition: Cell[StyleData[All, "SlideShow", StyleDefinitions -> StyleData[All, "Presentation"]], PageWidth->WindowWidth, DockedCells->FEPrivate`FrontEndResource["FEExpressions", "SlideshowToolbar"], ScrollingOptions->{"PagewiseDisplay"->True, "VerticalScrollRange"->Fit}, ShowGroupOpener->False, MenuSortingValue->1300] – Mike Honeychurch Jun 29 '15 at 23:58
  • @MikeHoneychurch Well, that's what it is but where does it come from? – Kuba Jun 30 '15 at 06:17
  • don't understand your follow up question. This is defined in the default stylesheet. Whenever you switch to slideshow screen environment the docked cell appears as per stylesheet specification. local settings override global settings. you have made specific local settings for the notebook with use the inherited (global) value (i.e. FEPrivateFrontEndResource["FEExpressions", "SlideshowToolbar"]) for slideshows. So for me this does what is expected. – Mike Honeychurch Jun 30 '15 at 07:39
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    @MikeHoneychurch When you edit private stylesheet for a notebook there is a reference to Default.nb at the top (which contains toolbar information). I've set StyleDefinitions without any further references. And this is my question, why something else is inherited at all. – Kuba Jun 30 '15 at 07:49
  • ok i see what you mean. there is always a default stylesheet. For example if you open a new notebook then edit the stylesheet and delete the reference to default.nb that doesn't mean you have no underlying styles. You will have default style definitions which you can find in the option inspector. For me my default is my own custom stylesheet so when I start with a default notebook (white) and then delete the ref to default stylesheet the notebook immediately changes to a yellowish background (my personal default). – Mike Honeychurch Jun 30 '15 at 08:50
  • ...So the lack of reference to default in your example means nothing because there is still the default setting in your options inspector – Mike Honeychurch Jun 30 '15 at 08:50
  • @MikeHoneychurch sounds plausible. But why is there a reference to Default at the beginning at all. And by "default" from OptionsInspector you mean something in $FrontEnd really? So it depends of it and will look differently on someone else machine? This is crazy, why there is no clear description in docs. – Kuba Jun 30 '15 at 09:03

1 Answers1

7

The FE always opens the stylesheet named in the DefaultStyleDefinitions option at the global level. In certain failsafe cases, it will fall back to this stylesheet if style definitions can't be found anywhere else. The one case I know for certain(*) where this happens is if the FE followed a stylesheet chain all the way to the end looking for stylename, and that end was not "Core.nb". There might be other cases, too, but if so, they're probably much less interesting for your purposes.

(*) To clarify, this means that I reminded myself by looking at the source code...I've not tried to run confirmational experiments, and if you find something slightly different, it's possible there's something I'm overlooking.

John Fultz
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