Magic top-left key to implement complex characters

lud commented 7 months ago

Context

I don't see if this is possible at the moment, but I think no.

Describe your suggested feature

In messageease, on the top-left square of the 9-grid, there is a © character that will enable combinations of letters.

So for instance cc© becomes ç, <<© becomes «, etc..

There are a lot, for instance I could do the "lambda" symbol for maths, but I can't remember the invocation. I cannot find the list of all possible combinations.

Would you consider implementing this feature?

Other details

No response

Acknowledgements

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slashdevslashurandom commented 7 months ago

This feature would be reminiscent of the "Compose key" that is available on Linux systems.

Here is a list of X11 dead key and compose key combinations (in this situation we are looking for those that include Multi_key).

The only difference is that, when using the Compose key, one is supposed to input it first and then type in the keys for the character, so Compose o c makes the copyright symbol, Compose a e makes æ, Compose ^ j makes ĵ, etc.

nightkr commented 7 months ago

Yeah, I'd like to support this, I'm just not sure we're the correct place to maintain that kind of mapping table. Maybe if we can yoink something from CLDR or X11...

slashdevslashurandom commented 7 months ago

For comparison, this is how the developers of Unexpected Keyboard do character composing -- seems like they just have a list of predefined characters for specific accents, and if that's unavailable, either plug in a composing character codepoint or return failure.

As for the X11 database, it's usually taken from the libX11 source codes. In the libX11 source code file, the /libX11-1.8/nls/en_US.UTF-8/Compose.pre file contains most of the compose key definitions (including ones for non-Latin languages).

nightkr commented 7 months ago

Note to self: https://www.unicode.org/versions/Unicode15.1.0/ch03.pdf#G30602

nightkr commented 7 months ago

Online link to the Xlib compose definition: https://gitlab.freedesktop.org/xorg/lib/libx11/-/blob/041b5291f0956c5cda5054be2981c0d02b009a4c/nls/iso8859-1/Compose.pre

Phidica commented 7 months ago

I'm not sure if this will be useful, but I thought I'd include it in the discussion for completeness. @lud mentioned not being able to find a table of all the combinations supported in MessagEase, but I found one in the "How To..." section in the app and include it at the bottom of this comment.

While I suppose that some of these (like the accented letters) might be covered by an external library that could be relied upon by Flickboard, I think that others (like the maths symbols, punctuation, and Greek letters) are custom to MessagEase. For instance to complete @lud's example, typing a capital lambda is done with L and A.

I don't particularly mind if the required combination changes, but I think it would be nifty to be able to type some of these symbols with Flickboard.

MessagEase table of special characters

lverweijen commented 7 months ago

I know that vim and emacs use RFC1345 (with their own modifications) for making special characters, which has a lot of symbols.

It does have a few downsides that you may want to think about:

It's no longer updated. It's an old standard.
It doesn't have a euro sign €. This symbol is on the main layout, but other modern symbols might be missing.
Instead of writing e/ to get é it would make more sense to write e´ instead. This is because the rfc assumes ` and ´ are not available on old computer keyboards, so it uses slashes for this. It also uses e: instead of e" for dotted e.

nightkr commented 7 months ago

@lverweijen

Yeah, hm.. that's a pretty big downside. But we can always make the source an option or something, and as you say it doesn't have to be the only way to enter characters.

@Phidica

Thanks for the list! Looking at it, it seems like there are basically two different "patterns" going on: "Character with accent" (a¨ -> ä) and "smash these two regular characters together" (ae -> æ). I think, ideally, the former should hopefully already be solved by dead letters/zalgo mode, so the latter is probably what I'd focus on for this.

nightkr / flickboard