Details
-
Suggestion
-
Resolution: Unresolved
-
Not Evaluated
-
None
-
4.8.0
-
None
Description
Use case:
Data driven applications do a lot things like updating a given control on the screen,
and put back new values of a control into the data container. Currently this has to be done manually.
Example:
class Data : public QObject { Q_OBJECT Q_PROPERTY( QString text READ text WRITE setText ) public: QString text() const { return _text; } void setText( const QString &text ) { if (text != _text) { _text = text; emit someSignal(); } } private: QString _text; }
Problem: the notification mechanism isn't defined. So people tend to create for each property a own signal,
which causes problems with generic implementation of features.
Feature Request:
Automate the generation of fully functional properties with notification and extend the current property system. Extend the MOC to automatically generate code for this simple properties.
Example solution:
There is a base class for elements which are supporting change notification.
This base class has a signal "propertyChanged( QString )" which is emitted for each property which changes.
Creation of the properties has been simplified with some preprocessor macros.
class Project : public dzui::DocumentElement { Q_OBJECT Q_PROPERTY( QString identifier READ identifier WRITE setIdentifier ); Q_PROPERTY( QString name READ name WRITE setName ); Q_PROPERTY( QString installationPath READ installationPath WRITE setInstallationPath ); Q_PROPERTY( QString directory READ directory WRITE setDirectory ); public: Project( QObject *parent = 0 ); virtual ~Project(); public: DZ_DECL_PROPERTY( QString, identifier, setIdentifier ); DZ_DECL_PROPERTY( QString, name, setName ); DZ_DECL_PROPERTY( QString, installationPath, setInstallationPath ); DZ_DECL_PROPERTY( QString, directory, setDirectory ); private: QString _identifier; QString _name; QString _installationPath; QString _directory; };
The implementation of this class:
Project::Project( QObject *parent )
: DocumentElement( parent )
{
}
Project::~Project()
{
}
DZ_IMPL_PROPERTY( QString, Project, identifier, setIdentifier );
DZ_IMPL_PROPERTY( QString, Project, name, setName );
DZ_IMPL_PROPERTY( QString, Project, installationPath, setInstallationPath );
DZ_IMPL_PROPERTY( QString, Project, directory, setDirectory );
--> The class is a fully functional data container which sends signals on property changes.