Selection bug when checkbox in list

[Nyan11]

The labels do not displayed correctly when toggle buttons are in list.

Reproduce

group := ToCheckableGroup new.
moveListElement := ToListElement new.
moveListElement selectionMode selectOnMouseDown: false.
moveListElement nodeBuilder: [ :node :move :holder |
    | moveElement moveNumberLabel whiteMoveLabel moveButtons blackMoveLabel |
    moveButtons := OrderedCollection new.
    moveElement := BlElement new.
    moveElement layout: BlLinearLayout horizontal.
    moveElement margin: (BlInsets all: 5).
    moveElement constraintsDo: [ :c |
        c vertical fitContent.
        c horizontal fitContent ].

    moveNumberLabel := BlTextElement new.
    moveNumberLabel text: move first asString asRopedText.
    moveNumberLabel constraintsDo: [ :c | 
        c linear vertical alignCenter.
        c horizontal exact: 30 ].

    whiteMoveLabel := ToToggleButton new.
    whiteMoveLabel size: 30 @ 20.
    whiteMoveLabel labelText: move second asString asRopedText.
    moveButtons add: whiteMoveLabel.

    blackMoveLabel := ToToggleButton new.
    blackMoveLabel size: 30 @ 20.
    blackMoveLabel labelText: move third asString asRopedText.
    moveButtons add: blackMoveLabel.
    blackMoveLabel addStamp: #link.

    moveElement addChild: moveNumberLabel.
    moveElement addChild: whiteMoveLabel.
    moveElement addChild: blackMoveLabel.

    moveNumberLabel constraintsDo: [ :c | c ignored vertical alignCenter ].

    moveButtons do: [ :e | group register: e ].
    node addChild: moveElement
].
moveListElement size: 800 @ 600.
moveListElement dataAccessor addAll: { { 1. 'e4' . 'e5'} . {2. nil . nil} }.

space := BlSpace new.
space root addChild: moveListElement.
space pulse.
space resizable: true.
space show

Execute the code in playground. Click on all toggle buttons and select a line in the list.

[Nyan11]

In Toplo, the space assigned states to each elements. The state determine if a skin need to be installed, when an element is hover or pressed, or when an element is selected or unselected. Then each element can see if it has a new state and if so, the element can changed its look (visual properties) based on its skin.

The bug is trigger because the ToLabel element of the toggle button receive a ToSelectionState caused by the ToListElement. So when the label apply a "selection state" it's color change.

To debug it you can place two debug points

• In the method ToSkinStateGenerator >> #generateSelectionStateFromEvent: | it will stop before the ToSelectionState is apply to all selected elements of the list.
• In the method ToLabelSkin >> #selectedSkinEvent: | where the state is "applied" and the labels changes. (Be careful it can open a lot of debugger).

It is a Toplo bug.

• To fix it, the skin of the label would need to know if it is a simple label present in a list or if it a label present in a button + all other strange cases you could encounter.

OR

• We could change the method #generateSelectionStateFromEvent: to not affect all elements of the list but only the first ones. (all elements are affected because the #withAllChildrenBreadthFirstDo: )