Clear the filter text when switching element types in Element List

[dkager]

Fixes #5511.

[jcsteh]

Thanks! Unfortunately, this won't work. The filter method has a newElementType argument (defaulting to False) and it must be True when initialising for a new element type. Otherwise, the correct position in the tree is lost.

STR:

1. Go to www.nvaccess.org.
2. Press control+home.
3. Press 2 to move to the "Home of the free NVDA screen reader" heading.
4. Press NVDA+f7.
5. Press alt+h.
6. Press tab.
   • Expected: You should be on the "Home of the free NVDA screen reader" heading.
   • Actual: You're on the "NV Access" heading.

[dkager]

Tis what you get for not reading docs. Fixed.

[dkager]

Hmm, one more optimization could be to not perform the whole filtering algorithm, i.e. transforming all element names into lowercase, if the filter text is empty. Should give a slight performance boost unless Python is already clever enough to always mark "" in blah as true without evaluating blah.

[jcsteh]

Nice catch. Done. I also cleaned up some variable assignment that wasn't needed.