Implement Caps Lock warning for password input

[phoerious]

Type of change

• ✅ New feature (non-breaking change which adds functionality)

Description and Context

This PR adds a warning to the password edit field if cAPS lOCK is enabled. Related to #3487.

As of now, the functionality works on Linux (X11), macOS, and Windows. Wayland is missing because the API sucks.

The change requires the main application to be linked against Qt5::X11Extras and libX11. This is pretty ugly, but I don't want to make this a separate .so either. That will be solved if we move OSUtils to a separate library in the future.

Resolves #2250

Screenshots

Testing strategy

Manual

Checklist:

• ✅ I have read the CONTRIBUTING document. [REQUIRED]
• ✅ My code follows the code style of this project. [REQUIRED]
• ✅ All new and existing tests passed. [REQUIRED]
• ✅ I have compiled and verified my code with -DWITH_ASAN=ON. [REQUIRED]

[phoerious]

Alright, macOS works now, too and Windows has been tested as well. It's astounding how both Windows and macOS can do that in one line, but good-ol' X11 always makes you run the extra mile. Only thing missing now is a Wayland implementation.

I also changed the polling mechanism from timer-based to overriding the event() method. That way the state doesn't neatly update in near-realtime anymore (only on explicit events like show, focus, hover, keypress, etc.), but I think it's worth it, since it reduces the amount of unnecessary polling significantly.

[droidmonkey]

Are you going to pick this back up?

[phoerious]

This is basically ready, I just hate the Wayland implementation. I already depend on a third-party library (the first point I don't like at all) and it is still 40 LOC instead of one like on other sane platforms. An implementation with the plain Wayland C API would add another 100-300 LOC of boilerplate callback code.

[droidmonkey]

CI is missing some dependencies:

  CMake Error at src/CMakeLists.txt:333 (find_package):
    By not providing "FindKF5Wayland.cmake" in CMAKE_MODULE_PATH this project
    has asked CMake to find a package configuration file provided by
    "KF5Wayland", but CMake did not find one.
  
    Could not find a package configuration file provided by "KF5Wayland" with
    any of the following names:
  
      KF5WaylandConfig.cmake
      kf5wayland-config.cmake
  
    Add the installation prefix of "KF5Wayland" to CMAKE_PREFIX_PATH or set
    "KF5Wayland_DIR" to a directory containing one of the above files.  If
    "KF5Wayland" provides a separate development package or SDK, be sure it has
    been installed.

Also need to run make format

[droidmonkey]

I would like to merge this but NOT add the Wayland support for now (requires a new dependency and the code is ugly as sin). Can you extract the Wayland portion into a separate PR for 2.7.0?

[phoerious]

Yeah, we can do that. I would want to redesign the message a little, but we may do that in another PR as well (the unlock dialogue needs some fresh air anyway). Colours also need to be adjusted to meet contrast requirements.

[wolframroesler]

With those changes I'm getting a build error on Linux:

/home/wolfram/src/keepassxc/src/gui/osutils/nixutils/NixUtils.cpp:25:10: fatal error: qpa/qplatformnativeinterface.h: No such file or directory
   25 | #include <qpa/qplatformnativeinterface.h>
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Any idea what to do against it?

[phoerious]

Install qtbase5-private-dev.

[wolframroesler]

Works, thanks for the quick reply :)

Should be added to https://github.com/keepassxreboot/keepassxc/wiki/Set-up-Build-Environment-on-Linux.

[wolframroesler]

BTW, what do you think about using one of the following icons instead of exclamation-mark-in-triangle to indicate that caps-lock is on?

(apple-keyboard-caps, caps-lock, and keyboard-caps on https://materialdesignicons.com/)

EDIT: Forgot to mention that I love the new feature.

[phoerious]

I tried the keyboard-caps icon before, but it's too thin and hard to see and also hard to interpret. The warning triangle was much clearer.

[droidmonkey]

I noticed the pop-up tool tip obscures the repeat password box. This could annoy people who actually use caps lock instead of shift. They are out there...

[phoerious]

We could place it on top, perhaps. But then it obscures the label.

[droidmonkey]

It's fine