t4mer@notebook

// til · qml · 10 august 2026 · 1 min

TIL: QML describes the UI tree. C++ still runs the process.

Designer not editing your screen is often the first clue that you are not in a Widgets project.

QML looks a bit like the web: nested objects, properties, something that reminds you of components. It is not C++. It is not HTML either.

C++ is still there - types, the engine, the parts that need to be fast or close to the system. QML describes the UI tree and how it binds. If you open Qt Designer expecting to drag widgets around a .qml file, you will have a confusing afternoon. Designer is happier with .ui / Widgets. QML has different tools.

That mix-up has its own problem log entry. This TIL is just the sentence I needed earlier: the screen file is not the language I compile.

Found something wrong?

These notes can be incomplete, or wrong in a different environment. Suggest a correction on GitHub or email me at me@t4mer.net.

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TIL: Qt is the toolkit. C++ is the language.

Search results get worse when you ask the toolkit to be a language.

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TIL: aka.ms is actually a Microsoft domain

A tiny explanation of Microsoft's URL-shortening domain.

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TIL: what CMake actually does

CMake does not compile your program. It generates the build that compiles your program.