How can I create simple container directly usable in QML designer.

Here you can find a small example how to integrate a custom qml plugin into the designer: https://qt.gitorious.org/qt-creator/qt-creator/source/394c9dd5507df610f7d60a56b7bf7e707a59142f:tests/manual/qml/testprojects/plugins This is a manual test case, that we use to test the integration of custom QML items. If you put the QML file next to the file you edit (no import needed) nothing is required to get a basic integration. To get something like a collapsable GroupBox working I would suggest to overload the default property using an lias property, like the GroupBox of the Qt Quick Controls does it. The state of of the GroupBox should be exposed as a boolean property.