Ignore space cadet key release when caps word is active

[p3l6]

Description

If using BOTH_SHIFTS_TURNS_ON_CAPS_WORD and Space cadet, activating Caps word before the tapping term expires produces either an unwanted 0 or 9, depending on which shift was pressed first. A deeper explanation of the cause can be found in the linked issue below.

In this change, when shift if released, I check to see if caps word is enabled, and then perform the same space cadet code branch as if the tapping term had expired. That is to say, releasing the modifier without typing the parenthesis. This works because caps word is processed first, so when entering caps word mode, the flag will already be set when processing space cadet. In the case that a shift key is tapped to exit caps word, the flag will be disabled before space cadet processes, and the key will be processed normally.

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Keyboard (addition or update)
• Keymap/layout/userspace (addition or update)
• Documentation

Issues Fixed or Closed by This PR

• Fixes [Bug] When turning on Caps Word, my keyboard types a number for some reason #17546

Checklist

• My code follows the code style of this project: C, Python
• I have read the PR Checklist document and have made the appropriate changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).

[getreuer]

@p3l6 thank you for contributing this fix!

My impression is this fix makes sense. It is delicate logic how Caps Word and Space Cadet features interoperate. To avoid regression where some future change breaks this behavior again, it would be a good idea to add a unit test to cover BOTH_SHIFTS_TURNS_ON_CAPS_WORD + Space Cadet.

In case you are new to testing in QMK, here are a few notes. I suggest:

1. Add a test case covering this change in tests/caps_word/test_caps_word.cpp.
2. Test it by running make test:caps_word.

Tests written using the GoogleTest framework. Take a look at the existing tests in the same file examples of how GoogleTest is used in QMK to simulate and test key events.

[sigprof]

This change effectively blocks taps of all Space Cadet keys while Caps Word is active. Because Space Cadet keys are customizable and can be used also with other modifiers than just Shift, this restriction may not be desired.

An alternative way to fix the problem might be:

• Add a function to reset the Space Cadet state (the same thing happens when any other key is pressed while a Space Cadet key is held down):

void reset_space_cadet(void) {
    sc_last = 0;
}

• Call reset_space_cadet() from the Caps Word code when the press of both shifts is detected.

This way only the last tap of Space Cadet Shift which activates Caps Word would be forcibly converted to a hold, and other usage of Space Cadet keys during Caps Word would remain undisturbed.

[p3l6]

Thanks for this additional context and write-up, I've re-worked the change in the way you suggested.

[p3l6]

@getreuer When I went to add a new test case, I noticed that the existing cases already covered this combination, but had an exception to wait for the Tapping term to expire to work around the issue. I think removing tapping term in the existing tests could be sufficient, but let me know if you think an explicitly named case would still be good.

I checked that

• Adjusting the test without the fix does fail due to the extra 0 produced
• Tests pass with the fix

[sigprof]

Another feature which probably won't work together with Space Cadet is CAPS_WORD_INVERT_ON_SHIFT (the code for that feature actually intercepts KC_LSFT, KC_RSFT and the MT() and OSM() keycodes for the same modifiers and handles the modifier change in a special way instead of registering the modifier as usual). Not sure how to fix that properly though without introducing some more assumptions about the space cadet configuration (in theory it is possible to configure QK_SPACE_CADET_LEFT_SHIFT_PARENTHESIS_OPEN and QK_SPACE_CADET_RIGHT_SHIFT_PARENTHESIS_CLOSE to use a completely different modifier, and detecting whether the intended space cadet action is actually a tap or a hold is not possible outside of the space cadet code).

[p3l6]

I am also not familiar enough (or at all) with CAPS_WORD_INVERT_ON_SHIFT to want to attempt any similar fix myself.

[github-actions]

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