Improving the text editor

[Bios-Marcel]

Currently the editor is only implemented halfway and doesn't solve all the problems we have. As seen in:

• Generalizing the text input component #59
• Improve message input component #38
• A general Autocomplete for the editor #65

What we need is an editor that can be used for both the commandline input and the message input. Looking at it from a general perspective, there are some core features we need:

Proper text editing capabilities

The following functions are needed for the text editing:

• MoveCursorLeft
• MoveCursorRight
• MoveCursorWordRight (Move to the end of the word to the right)
• MoveCursorWordLeft (Move to the beginning of the word to the left)
• MoveCursorToStartOfLine
• MoveCursorToEndOfLine
• MoveCursorToStartOfText
• MoveCursorToEndOfText
• MoveLineUp (Keep cursor on same X position if possible) (Dropped for now)
• MoveLineDown (Keep cursor on same X position if possible) (Dropped for now)
• SelectionToLeft (Extended selection to left or decrease selection if previously selected to right)
• SelectionToRight (Extended selection to right or decrease selection if previously selected to left)
• SelectionWordToLeft (Same rules as for SelectionToLeft but with words instead of characters)
• SelectionWordToRight (Same rules as for SelectionToRight but with words instead of characters)
• SelectToStartOfLine
• SelectToEndOfLine
• SelectToEndOfText
• SelectToEndOfText
• DeleteLeft (delete character left to the cursor or the current selection)
• DeleteRight (delete character the cursor is on or the current selection)

The Cursor always needs to be visible and selection also has to be visible immediately. Selection of empty lines has to be possible and visible as well. The editor needs to be usable for multiline editing and be able to grow as needed.

Tab-Autocomplete

Similar to how bash auto-completes commands and possible parameters, cordless should do the same. The message input most likely won't be needing this though, as it's mainly useful for stuff like commands.

*Will be moved into separate issue

Autocomplete with live suggestions

This feature is necessary for emojis, mentions and maybe more at some point. Since this feature is required for more than one thing, it needs to have some generic API that allows to easily register a new type of live suggestions for a certain pattern.

• Done