Auto-expand nodes when filtering

[simshaun]

Using ext-filter in hide mode:

Given the following tree:

[-] Homepage
   [+] Events
           Event
   [+] News
           Article

When I filter for "Ar", if News is not expanded already, it should be expanded.

I think that should be done by default, but it could also be enabled via an option in the filter extension as well.

[mar10]

Summarizing the discussion from PR #395

If we have a large tree, and slowly type a common character this may be equivalent to expand all, with no way back. So we should make it optional, or even have a separate function like expandMatches(flag) - for example using an option dict.

We should make it easy to support different use cases:

• while typing in a text box the filter is applied. Either ( Depending on a checkbox?)
  • the matches are made visible (expanded), or
  • folders with matching folders are highlighted (not expanded), or even
  • only counters (badge with count of matching child nodes) are displayed
• when backspace is clicked or the search text is modified the counters and expansion state should adjust
• ESC should reset the filter and restore the original expansion state (?)
• all this should be possible with filterBranches and filterNodes
• later we might extend this to support lazy trees with Ajax requests

Not everything is required in a first implementation, but it should be possible later without breaking the API.
Adding {expand: true} as second parameter might be a good start

[FroggDev]

hi,
maybe the match could trigger the expand if more than (x) letters are typed and if no matching node found then collapse expanded nodes ?