[Bug] Android IME combo keycode commands not passed to certain apps

[Eirakkun]

Device Model

Unihertz Titan 2

Operating System Version

Stock(ish) Android 15

Tiny Computer Version

Latest LXQT + Wine

Is this the latest version?

Yes

If not using the latest version, you must explain the reason for not using the latest version

No response

Steps to reproduce the issue

As the Titan 2 runs with a built-in hardware keyboard, it also comes with IMEs that leverage on key combos to pass special character codes. For example, "ALT+W" passes "1" and "ALT+T" passes "(".

For some reason, these combos are passed correctly in FeatherPad, but almost nowhere else (Firefox, LibreOffice). They are passed as direct ALT+key combos instead, as if bypassing the Android IME layer. This happens with all IMEs that leverage the hardware keyboard (Gboard, Kika Keyboard, Pasteira), but software keyboards seem uneffected (as they pass characters directly I think without requiring a key combo).

Initially I thought that this was an issue with the apps being GTK vs QT, but upon further investigation, other QT apps (WPS) also suffer from the same issue. So I'm stumped now - especially as it works fine in FeatherPad. If it didn't I would readily pass the issue to Tiny (or AVNC) reading the Alt-Key combo directly as is (but it works in FeatherPad so that is not true either).

An alternative is to allow the addition of actual keys inside AVNC's shortcut key toolbar (but that will require a feature request in AVNC instead).

Also, this happens in both AVNC and direct X11 modes (though X11 mode is very buggy on the Titan 2 so I didn't really use it for long) so I'm not sure this is an AVNC issue either.

[Cateners]

I'm also puzzled by your description. However, I modified the key transmission mechanism in AVNC, and I'm not sure if that might be affecting things.

In order to make AVNC support Chinese input, starting from v1.0.25, I detect the KeyEvent's keyCode. If it's KEYCODE_UNKNOWN, I put the text into the clipboard, then send it via shift+insert, and finally restore the container's clipboard content—instead of sending it directly.

You can disable this behavior in the AVNC settings under servers → send string via clipboard

[Eirakkun]

Alright, I'll try that. Will record a video soon to clearly show the issue.

[Eirakkun]

Have tried the settings in AVNC. Did not change anything. That said I'm beginning to think that it's actually needed to bridge the Titan 2's hardware keyboard entry to into Tiny somehow.

Let me try to explain again then.

The Unihertz Titan 2, as you can see from a quick search, comes with a built in hardware QWERTY. As with old Blackberries like the KeyOne, these come with symbols and numbers combined within the main layout due to space constraints, and need key combos (function key + letter key) for numbers and symbols.

These combos are IME dependant, but normally it's bound to Alt + Letter Key - and is consistant across different IMEs due to the Titan 2's layout. So in general, Alt + W sends "1", Alt + E sends "2" and Alt + M sends "?". This is true for Kika Keyboard (the default IME), Gboard (which has limited QWERTY support) and Pasteira (what I'm currently using).

Alright, now with Tiny Computer, these symbol key combos DO work, BUT ONLY in system dialogs and programs (like Featherpad). In every other program (for example, Firefox), it will be treated like a direct Alt+Key combo instead.

Do you have any insight as of why? Maybe it is just the fact that certain apps run QT and others GTK (or whatever else) with different user permissions (and thus access to the incoming keystrokes)? Or maybe it's because Alt is just that important in modern linux that the system is processing it with priority over the IME (but that doesn't explain why it works in Featherpad).

Here's a video as promised. In these I used the "wersdfxcv" keys with and without Alt pressed to show the difference in input between Featherpad and Firefox:

https://streamable.com/e81mgs

The video link will expire in 2 days. I will upload a new link if needed.

In the mean time, I'm actually using FCITX's virtual keyboard to insert numbers and symbols into the non-IME compatible apps (but it's tiny at my DPI settings. EDIT: Found Onboard and have set that up instead for now).

[Cateners]

Thank you for providing such detailed information. However, I am still not entirely clear about the possible cause. I suspect that the Android IME might not be working, and that the original Alt+W key combination is still being sent (though this doesn’t explain the behavior in Featherpad).

You could try running a key test in AVNC settings to check the log of keys sent, both with and without the input method enabled (perhaps you could also check the key information on the Linux side using xkb, though I’m not very familiar with xkb).

If it does turn out that Alt+W is being sent, you might be able to use a tool like autokey-gtk to create mapping rules that convert the received Alt+W into 1.