qml Property binding
Remarks
An object's property can be assigned a static value which stays constant until it is explicitly assigned a new value. However, to make the fullest use of QML and its built-in support for dynamic object behaviors, most QML objects use property bindings.
Property bindings are a core feature of QML that lets developers specify relationships between different object properties. When a property's dependencies change in value, the property is automatically updated according to the specified relationship.
