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Qt

1 min

Overview #

This document is a practical Qt cheatsheet focused on frequently used snippets, flags, and core concepts encountered in real-world applications.

Qt is a cross-platform C++ framework (also available via Python bindings such as PySide and PyQt) following the WOCA principle (Write Once, Compile Anywhere). It is widely used for building desktop applications, GUIs, and embedded systems across Windows, Linux, and macOS.

Check if a QListWidgetItem is checkable #

is_checkable = bool(item.flags() & Qt.ItemIsUserCheckable)

Explanation

  • Qt.ItemIsUserCheckable is a flag, not a property.
  • You must test it using a bitwise AND (&).

QListWidgetItem is not checkable by default. The checkbox will only appear if:

  • the Qt.ItemIsUserCheckable flag is set and
  • a check state is explicitly assigned using setCheckState().

✅ Correct usage reminder:

item.setFlags(item.flags() | Qt.ItemIsUserCheckable)
item.setCheckState(Qt.Unchecked)