Splitter's collapsed pane should expand after the panes in the component are resized

[PekoPPT]

This Dojo has 3 panes which width is defined on the component's initialization and the right pane is collapsed by default. On Splitter's initialization, the right pane can be expanded/collapsed as expected. If after initialization we move the horizontal line between the left and central panes the widths of the panes are reset. This is expected behavior as after a Splitter pane is resized, the assumption is that the user wants the size to be exactly as specified and the panes no longer resize proportionately.

The described design feature reflects on the functionality of the collapsed pane(the one on right in our example). If after moving the line between the "left" and "central" panes one tries to expand the right pane, it is expanded to "0px".

Although the behavior of the collapsed pane is expected behavior, we can think about how a pane expanding in a scenario like the described above can result in a visible of the user "expand".

Steps to reproduce the described above:

Scenario without pane resize

1. Open the Dojo
2. Try to expand the right pane
   Result: The pane is expanded/collapsed correctly

Scenario with pane resize

1. Open the Dojo
2. Move the vertical line between the left and central panes
3. Try to expand the right pane
   Result: The pane is not expanded on the first try.

[pepinho24]

The Resizable panes should have one pane with fluid size (the middle one for example), in order to act as a buffer. With 2024.4.1112, the splitter has a better behavior in regards to expanding the collapsed pane.