Provide code completion inside editor

[lmihalkovic]

The IDE currently does not provide any form of CTRL-SPACE code completion. The feature is sorely missing, especially for newbies like me. The feature should cover the following

• basic completion based on KWxxx and LITyyy available in the sketch libraries
• specific completion for different file types (keywords.txt, dependencies.txt, library.properties)
• a clean framework for future file types, ....

extended feature would cover more 'smartness' inside c/c++/h/hpp files, WITHOUT writing a full-blown parser

[lmihalkovic]

Framework + initial implementation working for keywords.properties

At the moment I am not sure what LITERALXXX are for so the name strings are all wrong. The implementation is also missing the typical explanation window that opens when a keyword has been selected.

[lmihalkovic]

Current completion for library's library.properties. "*" indicates a mandatory field.

ps: missing backtracking to eliminate already entered properties (should be caught be validator instead???)

[ffissore]

Duplicate of #849 and #3484
@lmihalkovic it seems like you have running code already. Mind to show it? The smaller the PR, the easier it gets merged

[lmihalkovic]

I seem to have missed an episode :( ... where can I find a keywords.txt for the core platform code?

I think I just realized only LIT1 exists, right?!

ps: the code requires only one line of code added to editor.java so risk of collisions is next to nil

[lmihalkovic]

@ffissore I read #3484... quite the PR. IMHO integrating it into the core code as it is basicaly equates giving up on a lot things that are currently easy to do and signing up for a lot of maintenance headaches. The fact that I think it is does not make it so, but the fact that this PR requires so many changes to editor and textarea should itself be a smell of poor API design.

I just find truly unfortunate that a lot of good existing design might be sacrificed.

[lmihalkovic]

Interestingly enough, the weird highlighting in the screenshots was caused by some of the issues I was alluding to in my last comment (code in the wrong place).