feat(web): Custom layer targets for Shift double-tap

[mcdurdin]

Applies proposed feature https://community.software.sil.org/t/testing-caps-on-touch/6849/5:

1. A caps layer must still exist in the keyboard.
2. If there is at least one multitap subkey defined on the Shift key on the active layer, then the nextlayer property of the first multitap subkey for the Shift key will be used instead of the default caps.
3. This does not change the behavior of the Shift key otherwise.

For example, the following defines a valid multitap key on Shift on the rightalt layer to switch to a custom extended rightalt-caps layer.

  {
    "id": "K_SHIFT",
    "text": "*Shift*",
    "width": 150,
    "sp": 1,
    "nextlayer": "rightalt-shift",
    "layer": "default",
    "multitap": [
      {
        "text": "",
        "id": "T_new_694",
        "sp": "1",
        "nextlayer": "rightalt-caps"
      }
    ]
  },

This does not implement any other multitap functionality. It just allows the keyboard developer to specify a target layer for a given double-tap.

This change should be forward-compatible with the multitap gesture support.

@keymanapp-test-bot skip

We'll do some testing on this with @MattGyverLee once this hits beta.

[keymanapp-test-bot]

User Test Results

Test specification and instructions

User tests are not required

Test Artifacts

• Android
  • Keyman for Android apk
  • FirstVoices Keyboards for Android apk
  • KMSample1 apk
  • KMSample2 apk
• Developer
  • Keyman Developer
  • Compiler Regression Tests
  • kmcomp.zip
• iOS
  • Keyman for iOS (simulator image)
  • FirstVoices Keyboards for iOS (simulator image)
  • TestFlight internal PR build version - 16.0.96 (0.7608.7249)
• Keyboards
  • Test Keyboards
• Web
  • KeymanWeb Test Home
• Windows
  • Keyman for Windows
  • FirstVoices Keyboards for Windows

[keyman-server]

Changes in this pull request will be available for download in Keyman version 16.0.96-beta

[MattGyverLee]

@mcdurdin I've just tested the Cameroon Azerty on my fork (Master branch of https://github.com/MattGyverLee/keyboards/tree/master/release/sil/sil_cameroon_azerty) on 16.0.96, and it works completely as expected! So far, I have only tested in the debugger and not on native Android/iOS.

Now I just need to decide what version of Keyman should be stable before I release it on keymanapp/keyman
(https://community.software.sil.org/t/testing-caps-on-touch/6849/11)

Note: It's interesting that your pseudocode above uses rightalt-shift-caps, which actually doesn't exist in my mobile keyboard.
"nextlayer": "rightalt-shift-caps"

• Tapping rightalt > caps > shift on mobile cancels caps and takes you back to rightalt.
  • That case is handled by &CasedKeys on desktop.
• Tapping rightalt > shift > caps on mobile "upgrades" your shift to a caps and goes to rightalt-caps.

[mcdurdin]

It's interesting that your pseudocode above uses rightalt-shift-caps

That's because my pseudocode is dumb. It should be rightalt-caps ... 😆

And ... fixed.