Calling C++ method from QML

Question

HERE IS Qt PROJECT with minimal skeleton to show what is the problem (check console after you run that project) http://uloz.to/xqxrXpdL/qtproject-zip

I try to call public slot from qml

Component.onCompleted: print(model.activate())

Still getting error:

TypeError: Property 'activate' of object QQmlDMObjectData(0x7fa35dd89eb0) is not a function

If i tried to call the method dynamically from C++, it works:

auto item = new TreeItem<MainMenuItem>(new MainMenuItem("kyklop"));

QMetaObject::invokeMethod(item, "activate");

If i try to access regular property of my TreeItemTemplateBackend class from qml (for instance level), it works, so problem is only if calling method. I am thinking it could be something with that subclass/template class.

Registering to qml:

qmlRegisterType<TreeItemTemplateBackend>("engine.ui", 1, 0, "TreeItemTemplateBackend");
qmlRegisterType<TreeItem<InspectorItem>>("engine.ui", 1, 0, "InspectorTreeItem");
qmlRegisterType<TreeItem<MainMenuItem>>("engine.ui", 1, 0, "MainMenuTreeItem");

TreeItem.h

#ifndef TREEITEM_H
#define TREEITEM_H

#include <QObject>
#include "TreeItemTemplateBackend.h"

template <typename T>
class TreeItem :  public TreeItemTemplateBackend
{

public:
    explicit TreeItem(QObject * parent = NULL);
    explicit TreeItem(T * data, QObject * parent = NULL);
    explicit TreeItem(TreeItem<T> & other);
    void addChild(TreeItem<T> * child);
    ~TreeItem() {}
};

#endif // TREEITEM_H

TreeItemTemplateBackend.h

#ifndef TREEITEMTEMPLATEBACKEND_H
#define TREEITEMTEMPLATEBACKEND_H

#include <QList>
#include <QQmlListProperty>

class TreeItemTemplateBackend : public QObject
{
    Q_OBJECT
    Q_PROPERTY(QObject * data READ data WRITE setData NOTIFY dataChanged)
    Q_PROPERTY(QQmlListProperty<TreeItemTemplateBackend> childs READ childs NOTIFY childsChanged)
    Q_PROPERTY(int level READ level WRITE setLevel NOTIFY levelChanged)
public:
    explicit TreeItemTemplateBackend(QObject * parent = NULL);
    QObject * data() const;
    void setData(QObject * data);
    QQmlListProperty<TreeItemTemplateBackend> childs() const;
    void addChild(TreeItemTemplateBackend * child);
    int level() const;
    void setLevel(int level);
    void dump(QString propertyName) const;
    ~TreeItemTemplateBackend() {}
signals:
    void activated(); 
    void dataChanged();
    void childsChanged();
    void levelChanged();
public slots:
    void activate(); // this is what i am trying to call
protected:
    QObject * m_data;
    QList<TreeItemTemplateBackend *> m_children;
    int m_level;
    static void append_function(QQmlListProperty<TreeItemTemplateBackend> * property, TreeItemTemplateBackend * item);
    static TreeItemTemplateBackend * at_function(QQmlListProperty<TreeItemTemplateBackend> * property, int index);
    static void clear_function(QQmlListProperty<TreeItemTemplateBackend> * property);
    static int count_function(QQmlListProperty<TreeItemTemplateBackend> * property);
};

#endif // TREEITEMTEMPLATEBACKEND_H

@ddriver: yes it is, i modified code to show the registration — Krab
– Krab, Commented Jun 19, 2014 at 12:37
Can you provide a compilable example? For example, a single main.cpp and the QML file? — Mitch
– Mitch, Commented Jun 19, 2014 at 16:56
@Mitch: i will post zip file with project that i created (it contains just the minimal to show the problem) — Krab
– Krab, Commented Jun 19, 2014 at 18:23
I am not sure, but it probably has to do with the template. Why don't your try scrapping the template and using QVariant instead of T * for the data, and register needed types to the meta system. Also take a look at this link: doc.qt.digia.com/qq/qq15-academic.html — dtech
– dtech, Commented Jun 20, 2014 at 13:11

Smar · Accepted Answer · 2015-09-08 05:56:25Z

4

QQmlDMObjectData is a wrapper for the actual object used in delegates. The original object is accessible via the property modelData, so model.modelData.activate() should work.

edited Sep 8, 2015 at 5:56

Smar

8,6723 gold badges38 silver badges49 bronze badges

answered Aug 13, 2014 at 11:08

Foobartender

412 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

folibis · Accepted Answer · 2014-08-13 11:28:18Z

0

If you cal for it "method" and still you are use it as a method so convert it to the method:

...
public:
void Q_INVOKABLE activate();
...

answered Aug 13, 2014 at 11:28

folibis

12.9k7 gold badges71 silver badges116 bronze badges

Collectives™ on Stack Overflow

Calling C++ method from QML

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related