Dear Toradex community,
I am doing my first steps with Qt on a Toradex SOM. I setup a demo QT QML sample project via the Toradex extension for VS Code.
To edit the qml and ui.qml files I am using the Qt Design Studio.
To interact with some business logic I setup a counter.cpp class.
I am able to compile and run the following code on the SOM:
Code
Counter.h
// File Counter.h
#ifndef COUNTER_H
#define COUNTER_H
/* === INCLUDE FILES =============================================================== */
#include <QObject>
#include <qqml.h>
/* === CLASS ======================================================================= */
class Counter : public QObject
{
Q_OBJECT
QML_ELEMENT
public:
explicit Counter(QObject *parent = 0);
Q_INVOKABLE void IncrementCounter();
signals:
public slots:
private:
int m_counter;
};
#endif
Counter.cpp
// File Counter.cpp
#include "Counter.h"
#include <QDebug>
Counter::Counter(QObject *parent) :
QObject(parent), m_counter(0)
{
}
void Counter::IncrementCounter() {
m_counter++;
qDebug() << "value: " << QString().number(m_counter);
}
HelloWorldQml.cpp
#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QDebug>
#include "Counter.h"
int main(int argc, char *argv[])
{
QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
QGuiApplication app(argc, argv);
// Register Counter with version 1.0
qmlRegisterType<Counter>("Counter", 1, 0, "Counter");
QQmlApplicationEngine engine;
const QUrl url(QStringLiteral("qrc:/mainwindow.qml"));
QObject::connect(&engine, &QQmlApplicationEngine::objectCreated,
&app, [url](QObject *obj, const QUrl &objUrl) {
if (!obj && url == objUrl)
QCoreApplication::exit(-1);
}, Qt::QueuedConnection);
engine.load(url);
return app.exec();
}
HelloWorldQml.pro
TEMPLATE = app
TARGET = HelloWorldQtQml
HEADERS = HelloWorldQtQml.h \
Source/Counter.h
SOURCES = HelloWorldQtQml.cpp \
Source/Counter.cpp
# $$PWD refers to folder that contains the .pro file
INCLUDEPATH += $$PWD/Source
DESTDIR = $$(QMAKE_DESTIDIR)
QT+= core quick qml
RESOURCES += qml.qrc
# Specifies the directory where all intermediate objects should be placed
OBJECTS_DIR = ./build
MOC_DIR = ./build
UI_DIR = ./build
So far so good.
Now my Qt Design Studio does not recognise this Counter module:
I assume that I have to register this module.
If I try to continue my .pro file as described here:
Continued project file
TEMPLATE = app
TARGET = HelloWorldQtQml
CONFIG += qmltypes
QML_IMPORT_NAME = counter
QML_IMPORT_MAJOR_VERSION = 1
HEADERS = HelloWorldQtQml.h \
Source/Counter.h
SOURCES = HelloWorldQtQml.cpp \
Source/Counter.cpp
# $$PWD refers to folder that contains the .pro file
INCLUDEPATH += $$PWD/Source
DESTDIR = $$(QMAKE_DESTIDIR)
QT+= core quick qml
RESOURCES += qml.qrc
# Specifies the directory where all intermediate objects should be placed
OBJECTS_DIR = ./build
MOC_DIR = ./build
UI_DIR = ./build
it ends in the following error:
/usr/lib/qt5/bin/moc --collect-json -o helloworldqtqml_metatypes.json build/moc_Counter.cpp.json
Error opening build/moc_Counter.cpp.json for reading
make: *** [Makefile:432: helloworldqtqml_metatypes.json] Error 1
The terminal process "/bin/bash '-c', 'make'" failed to launch (exit code: 2).
What is missing to import and use this counter.cpp module in my qml file?
How do I “link” the counter.cpp module with QML_IMPORT_NAME in the .pro file?
My VS code folder looks like this:
Project directory
.
├── appconfig_0
│ ├── config.yaml
│ ├── id_rsa
│ ├── id_rsa.pub
│ ├── sdkfiles
│ │ ├── core.py
│ │ ├── __init__.py
│ │ └── typeinfo.py
│ └── work
│ ├── debug.tar
│ ├── docker-compose.yml.debug
│ ├── Dockerfile.debug
│ ├── Dockerfile_SDK.debug
│ └── HelloWorldQtQml
│ └── HelloWorldQtQml
├── build
│ ├── Counter.o
│ ├── HelloWorldQtQml.o
│ ├── moc_Counter.cpp
│ ├── moc_Counter.o
│ ├── moc_predefs.h
│ └── qrc_qml.o
├── HelloWorldQtQml.cpp
├── HelloWorldQtQml.h
├── helloworldqtqml_metatypes.json
├── HelloWorldQtQml.pro
├── mainwindow.qml
├── Makefile
├── qml.qrc
├── qrc_qml.cpp
└── Source
├── Counter.cpp
└── Counter.h
I am using:
- QMake version: 3.1
- Using Qt version: 5.9.5 in /usr/lib/x86_64-linux-gnu
- Visual Studio Code: 1.68.1
- Toradex Torizon Support extension (v1.4.0)
- Qt Design Studio 1.6.1
- iMX8M Mini Dual Light
- Verdin carrier board
Thank you in advance and best regards,
Zag
