Draft window splitter design pattern

[mcking65]

The window splitter design pattern is at:
http://w3c.github.io/aria-practices/#windowsplitter

This pattern is largely complete. However, there are changes to the separator role for ARIA 1.1 that need to be addressed.

Changes that need to be made for the window splitter pattern:

• More detailed description.
• Describe how to label and set control values.
• aria-expanded is no longer supported in aria 1.1.
• aria-valuemin, max, and now are required by aria 1.1.

[lifeiscontent]

@mcking65 any updates on this?

[mcking65]

Nop ... we need to get #130 done, which is in current plan but standing still. The editorial work on the pattern itself is complete; we just need to make sure it holds up in practice.

[lifeiscontent]

@mcking65 for the F6 shortcut how does one cycle through windows? is each pane focusable? if so, how does the focus order work with the separator included?

[lifeiscontent]

@mcking65 how would you use this pattern to manage 3 windows? if the separator is the thing that controls the window and I have 3 windows horizontally, how would that work?

[mcking65]

@lifeiscontent

You would have 2 splitters, one between pane1 and pane2 and one between pane2 and pane3.

One approach is to have the left splitter named pane1 and the right splitter named pane3 so that when pane1 splitter is at min and pane3 splitter is at min, pane2 is max size.

Of course, in real life, pane1, pane2, and pane3 would be actual names that reflect the titles of the panes themselves, such as "Table of Contents", "Chapter 1 - Intro to ARIA", and "Comments".

[ZoeBijl]

@mcking65 I think that would cause issues if you get to four or five panes. At what point would you switch to the primary pane being at the end rather than the start in that scenario?

For example: if we have a table with resizable columns.

[lifeiscontent]

given @mcking65 example:

Of course, in real life, pane1, pane2, and pane3 would be actual names that reflect the titles of the panes themselves, such as "Table of Contents", "Chapter 1 - Intro to ARIA", and "Comments".

the idea of a primary pane doesn't make sense in some contexts, for example VSCode has Window Splitting for files that are open, all windows are primary, so how would you handle that case?

I would assume the best way to handle it is by saying a separator controls a pair of elements, but I'm not sure if thats currently possible.