QtModeling is a C++/Qt-based implementation of the OMG standards for software modeling that aims to address issues with current Java-based implementations. It allows modeling features to be integrated into QtCreator and KDevelop and supports model-driven development workflows in KDE. QtModeling uses Qt's introspection capabilities and treats modeling languages as plugins to provide a standards-compliant, performant, and language-agnostic modeling framework. The Duse tool demonstrates QtModeling's capabilities for working with models. Future plans include additional releases, implementing QML-based concrete syntax, and integrating modeling further into KDE development tools and processes.

1. QtModeling
bringing metamodeling features
into the KDE world
Sandro Andrade
sandroandrade@kde.org

2. whoami
● Assistant Professor at IFBA – Brazil.
● Using KDE and Qt since 1999.
● Contributing to KDE since 2008.
● I've developed QtModeling as part of
my PhD research at UFBA.

3. What's QtModeling about?
● It's about dealing with software models.

4. Why do we need software models?
● Documentation.
● Source code generation / model-code sync.
● Architectural recovery / compliance verification.
● Model-driven QA and CI (DRY).
● Predicting / simulating quality attributes.
● Domain-Specific Languages (DSLs).
● Models@run.time.

5. Why do we need qtmodeling?
● Issues in scalability, performance, and standards
compliance in current UML/MOF/* JAVA-based
implementations.
● Lack of up to date C++ or Qt-based UML/MOF/*
implementations.
● We could support modeling features in QtCreator /
KDevelop and revamp Umbrello.
● We could have more model-centric processes in KDE
development workflows.

6. The basics about metamodeling
UML::ClassUML::Property UML::Association
MOF::Class
User
model
UML
metamodel
MOF
meta-metamodel

7. Qtmodeling Drivers / Rationale
● D1) It should be 100% compliant to OMG standards.
● D2) It should be metamodel-agnostic.
● D3) It should perform well for large models and
when handling multiples models simultaneously.
● D4) Models should be easily queried/changed via
scripting.

8. Qtmodeling Drivers / Rationale
● D1) It should be 100% compliant to OMG standards.
● D2) It should be metamodel-agnostic.
● D3) It should perform well for large models and
when handling multiples models simultaneously.
● D4) Models should be easily queried/changed via
scripting.
Perl
Template
Toolkit
OMG
spec
XMI
C++/Qt
impl
tmpl's
Qt UML
Impl
UML figures:
● 239 metaclasses
● 91.83% generated
automatically
● 300 KLOC
● A lot of dreaded
diamonds

9. Qtmodeling Drivers / Rationale
● D1) It should be 100% compliant to OMG standards.
● D2) It should be metamodel-agnostic.
● D3) It should perform well for large models and
when handling multiples models simultaneously.
● D4) Models should be easily queried/changed via
scripting.
1) Extensive use of Qt's introspection capabilities.
2) Modeling languages (metamodels) as Qt plugins.
3) Qt meta-object capabilities for properties' metadata
have several limitations regarding that (QTBUG-17301).

10. Qtmodeling Drivers / Rationale
● D1) It should be 100% compliant to OMG standards.
● D2) It should be metamodel-agnostic.
● D3) It should perform well for large models and
when handling multiples models simultaneously.
● D4) Models should be easily queried/changed via
scripting.
Already good enough, but (WIP):
1) Copy-on-Write.
2) Reduce footprint of derived union properties.
3) Shared objects when dealing with multiple models.

11. Qtmodeling Drivers / Rationale
● D1) It should be 100% compliant to OMG standards.
● D2) It should be metamodel-agnostic.
● D3) It should perform well for large models and
when handling multiples models simultaneously.
● D4) Models should be easily queried/changed via
scripting.
Basic QtScript code!

12. QtModeling's Qt5 add-ons
Qt5
QtModeling
QtModelingWidgetsUMLPlugin MOFPlugin...
DuSE tool
DuSE plugins
= run-time dependency
XMI serialization
+
Qt meta-object
extensions
New Qt models
and views for dealing
with QtModeling-based
elements
Languages'
implementation

13. The Duse tooldemo

14. So,What's next?
● We are still trying to do a release! QtModeling first,
then metamodels, then widgets …
● QML-based concrete syntax should be implemented
for most used UML constructs.
● That recurrent boring thing: “We need you!” :)

15. Thanks for your attention!
QtModeling
bringing metamodeling features
into the KDE world
Sandro Andrade
sandroandrade@kde.org