api/cpp/docs/live_preview.md
.slint files are compiled to C++ code when using the slint_target_sources() function.
This is the default and recommended for release builds.
During debugging and development, changes to .slint files requires re-compiling and re-starting the application. To speed up
modifications to the UI while connected to the applications' business logic, you can opt into enabling Live-Preview for C++:
SLINT_FEATURE_LIVE_PREVIEW cmake option.SLINT_LIVE_PREVIEW=1 environment variable..slint files after you've modified them on disk.