Update multi-thumb slider design pattern

[mcking65]

The multi-thumb slider design pattern
is largely complete. However, some open issues remain.

On December 13, 2016, I made revisions to improve consistency with the APG editorial guidelines, and noticed the following potential deficiencies in the pattern.

• The description does not adequately describe the purpose of the widget. Consider adding an example use case.
• Issues related to the relationships and dependencies between thumbs are not addressed. For example, dynamically adjusting the range of one thumb due to a change in the position of the other.

Final Review Requested October 22, 2017

All required changes and editorial cleanup are complete. The task force has previously discussed changes. Need only double-check of final editorial revisions.

• Review by Ann (@annabbott)

[mcking65]

Per discussion in teleconference on Jan 23, 2017, removed suggestion to implement aria-controls. It is not clear how assistive technologies would be able to exploit aria-controls in order to enhance the accessibility of a multi-thumb slider.

[jnurthen]

The description does not adequately describe the purpose of the widget. Consider adding an example use case.

Group thinks this is a good idea - perhaps a filter for max min required price.

Issues related to the relationships and dependencies between thumbs are not addressed. For example, dynamically adjusting the range of one thumb due to a change in the position of the other.

Yes this needs to be done.