TimeTextBox: filtering not working when drop down opened after typing

[bill]

If you type into a TimeTextBox while the drop down is closed, and then open the drop down afterwards, it isn't filtered by what you typed, like it would be if the drop down was open while you were typing.

I'd like it to work like ComboBox, where the drop down initially shows all the values, but as soon as the user starts modifying the widget's value (either by typing, or by backspacing), then the drop down list is filtered by what's in the <input> box.

Probably the drop down should also open automatically when the user starts typing?

[bill]

(In [22580]) Various [stop gap] fixes to TimeTextBox, although still wondering about full rewrite as per #7631, or replacing custom scrolling with native scrollbar like ComboBox has. Fixes include:

• limit drop down to 10 entries so that (in the majority of cases) it won't overlap the <input> box (fixes #8387)
• same as ComboBox, make typing automatically open the dropdown, and once the user has started typing or backspacing the dropdown list is filtered by what's in the <input> (fixes #11486)
• fix recently introduced problem (with _HasDropDown conversion of _DateTimeTextBox, refs #6416) where drop down becomes detached from <input> when it appears above the input and then user types text to further filter the values shown
• add more tests for TimeTextBox; they previous tests were very sparse; tests include check of current filtering sort order (refs #11485)

!strict as usual.

[Douglas Hays]

After [22580], TimeTextBox?'s popup no longer stays closed after pressing the Escape key.

[bill]

(In [22819]) fix typo from [22580] (thanks Doug) and add missing test case, fixes #11486 !strict.