16 #ifndef QGSRELATIONREFERENCEWIDGETWRAPPER_H    17 #define QGSRELATIONREFERENCEWIDGETWRAPPER_H    52     bool valid() 
const override;
    56     virtual void setEnabled( 
bool enabled ) 
override;
    59     void foreignKeyChanged( 
QVariant value );
    67 #endif // QGSRELATIONREFERENCEWIDGETWRAPPER_H 
A bar for displaying non-blocking messages to the user. 
 
Map canvas is a class for displaying all GIS data types on a canvas. 
 
Represents a vector layer which manages a vector based data sets.