Pressing Esc on empty tree morph raises MNU

> Hi Jakob,
>
> does the change in Morphic-mt.1441 work for you?
>
> Best,
> Marcel
>
> Am 21.04.2018 13:56:35 schrieb Jakob Reschke <[hidden email]>:
>
> Hi all,
>
> I wanted to open the yellow button menu on an empty PluggableTreeMorph
> (the SqueakMap catalog's package list to be precise, but I assume it
> does not matter) and wanted to do so by pressing the escape key and
> got the stack trace below.
>
> The scroller of the PluggableTreeMorph is a TransformMorph, but it has
> no submorphs if the tree is empty. Thus, in
> numberOfItemsPotentiallyInView the localSubmorphBounds are nil, and
> even if they were not, the next error would be a division by zero. The
> TransformMorph does not expect to have no submorphs.
>
> However, the real problem might be (or might not be) that a
> PluggableTreeMorph behaves differently from a PluggableListMorph in
> response to pressing Esc. The latter opens the yellow button menu,
> while the tree morph does not treat Esc specially at all. It uses it
> for list filtering instead, like any typed character. So effectively,
> the Esc key in a tree morph is currently the "expand this node and
> select the first child" key. I like the menu behavior from list morphs
> better... What is your opinion?
>
> Kind regards,
> Jakob
>
>
> UndefinedObject(Object)>>doesNotUnderstand: #height
> TransformMorph>>numberOfItemsPotentiallyInView
> PluggableTreeMorph(ScrollPane)>>numSelectionsInView
> PluggableTreeMorph(SimpleHierarchicalListMorph)>>arrowKey:
> PluggableTreeMorph(SimpleHierarchicalListMorph)>>specialKeyPressed:
> PluggableTreeMorph>>specialKeyPressed:
> PluggableTreeMorph(SimpleHierarchicalListMorph)>>keyStroke:
> PluggableTreeMorph>>keyStroke:
> PluggableTreeMorph(Morph)>>handleKeystroke:
> KeyboardEvent>>sentTo:
> PluggableTreeMorph(Morph)>>handleEvent:
> PluggableTreeMorph(Morph)>>handleFocusEvent:
> MorphicEventDispatcher>>doHandlingForFocusEvent:with:
> MorphicEventDispatcher>>dispatchFocusEvent:with:
> PluggableTreeMorph(Morph)>>processFocusEvent:using:
> PluggableTreeMorph(Morph)>>processFocusEvent:
> [] in [] in [] in HandMorph>>sendFocusEvent:to:clear:
> BlockClosure>>ensure:
> KeyboardEvent(MorphicEvent)>>becomeActiveDuring:
> [] in [] in HandMorph>>sendFocusEvent:to:clear:
>
>
>
>