Autocomplete usernames on typing based on existing ones

[MuehlburgPhoenix]

Fixes #3126

Autocompletion of usernames.

Type of change

• ✅ New feature (non-breaking change which adds functionality)

Description and Context

Each time the EditEntryWidget opens, a set of existing usernames in the database is retrieved. If the user begins to enter a username, suggestions based on this set are made.

In case of a really large database, the current implementation would lead to a longer loading time of the EditEntryWidget. In this case, the user can disable autocompletion in the settings. Autocompletion in a database with 1000 entries had no noticeable effect on loading time.

Screenshots

Testing strategy

1. Created a new test in TestGroup which tests a new method for retrieving the set of usernames in the database
2. Extended the existing testAddEntry test to make use of the autocompletion
3. Created a database with 1000 entries to check if the "New Entry" widget needs more time to load (not noticeable)

Checklist:

• ✅ I have read the CONTRIBUTING document. [REQUIRED]
• ✅ My code follows the code style of this project. [REQUIRED]
• ✅ All new and existing tests passed. [REQUIRED]
• ✅ I have compiled and verified my code with -DWITH_ASAN=ON. [REQUIRED]
• ✅ I have added tests to cover my changes.

Annotations

The retrieving of existing usernames could be done in a different thread if large databases are a common use case.

If I set UsernameAutocompletion to false in testAddEntry from TestGui, the test still runs successfully. Normally, the test should fail now because of the missing autocompletion. The changed option seems to be ignored. Am I doing it wrong? The option seems to work as intended when tested manually.

(I also removed a duplicate m_defaults.insert("UseGroupIconOnEntryCreation", false); in Config.cpp.)

[droidmonkey]

I would much rather the list of usernames be enumerated once on database load and not every time the entry edit widget is displayed. We also do not want to show every single username, but sort them based of frequency of occurance and only show the top 10. Then remove the setting to disable the suggestions.

[MuehlburgPhoenix]

Thanks for your annotations so far. Current status:

[droidmonkey]

Nice!

[jbtrystram]

This is awesome !