Porting QML Applications to Qt 5 Example | Qt 5.15

- Qt 5.15
- Porting QML Applications to Qt 5 Example
- Qt 5.15.17 Reference Documentation

# Porting QML Applications to Qt 5 Example

The new version of Qt Quick in Qt 5 brings in some changes to the way QML applications are developed. For the complete list of changes that affect existing QML applications, refer to Porting QML Applications to Qt 5.

This topic will walk through the porting process to make the `flickr` Qt 4 QML demo work on Qt 5. If you have the SDK based on Qt 4.8 installed, you can find this demo application under `<install_dir_root>/Examples/4.x/declarative/demos/`.

Follow these step-by-step instructions to port the flickr Qt 4 QML application work to Qt 5:

1. Open the flickr project using Qt Creator.
2. Edit all the `.qml` files and replace the `import QtQuick 1.0` statements with `import QtQuick 2.3`.
3. Add the additional `import QtQuick.XmlListModel 2.0` statement to `qml/common/RssModel.qml`.

   Note: XmlListModel is part of a submodule under `QtQuick` and it must be imported explicitly in order to use it.

4. Make the following changes to `qmlapplicationviewer/qmlapplicationviewer.h`:
   - Replace the `#include <QtDeclarative/QDeclarativeView>` with `#include <QQuickView>`.
   - Replace `QDeclarativeView` with `QQuickView` in the class declaration for `QmlApplicationViewer`.
   - Replace the parameter for `QmlApplicationViewer` constructor from `QWidget` to `QWindow`.
5. Make the following changes to `qmlapplicationviewer/qmlapplicationviewer.cpp`:
   - Replace all the `QtCore` and `QtDeclarative` include statements with these:

          #include <QCoreApplication>
          #include <QDir>
          #include <QFileInfo>
          #include <QQmlComponent>
          #include <QQmlEngine>
          #include <QQmlContext>
          #include <QDebug>

   - Replace all instances of `QWidget` with `QWindow`, and `QDeclarativeView` with `QQuickView`.
   - Remove the code between `#if defined(Q_OS_SYMBIAN)` and `#endif` macros as Symbian platform is not supported in Qt 5.
   - Remove the code between `#if QT_VERSION < 0x040702` and `#else`, and `#endif // QT_VERSION < 0x040702` macros towards the end.
6. Save changes to the project and run the application.

Once you see the application running, check whether it behaves as expected. Here is a snapshot of the application running on Ubuntu v12.04:

## Related Topics

Porting QML Applications to Qt 5