Exposing QAbstractListModel to QML SegFault

[blacky_i]

Hello everyone!

I have strange behavior in Qt 5.2. I'm trying to expose QAbstractListModel to QML, but after adding items to it it shows SegFault.
main.cpp

qmlRegisterType<AttachmentsToSendModel>("VKModels",1,0,"AttachmentsToSendModel");

AttachmentsToSendModel.cpp

#include "attachmentstosendmodel.h"

AttachmentsToSendModel::AttachmentsToSendModel(QObject *parent)
{
    setParent(parent);
    roles=roleNames();
    beginInsertRows(QModelIndex(),rowCount(),rowCount());
    AttachmentToSendItem* itm = new AttachmentToSendItem(this);
    QQmlEngine::setObjectOwnership(itm, QQmlEngine::CppOwnership);
    itm->setSource("file:///home/nemo/Pictures/SK/NwC1iub1wog.jpg");
    itm->setType(static_cast<AttachmentToSendItem::FileType>(0));
    Items.append(itm);
    endInsertRows();

}

AttachmentsToSendModel::~AttachmentsToSendModel()
{
    qDebug()<<"Killed";
}

void AttachmentsToSendModel::addAttachment(QString source, int Type)
{
    qDebug()<<source;
 beginInsertRows(QModelIndex(),rowCount(),rowCount());
 AttachmentToSendItem* itm = new AttachmentToSendItem(this);
 QQmlEngine::setObjectOwnership(itm, QQmlEngine::CppOwnership);
 itm->setSource(source);
 itm->setType(static_cast<AttachmentToSendItem::FileType>(Type));
 Items.append(itm);
 endInsertRows();
}


QModelIndex AttachmentsToSendModel::index(int row, int column, const QModelIndex &parent) const
{
}

int AttachmentsToSendModel::rowCount(const QModelIndex &parent) const
{
    return Items.count();
}

QVariant AttachmentsToSendModel::data(const QModelIndex &index, int role) const
{
    if(!index.isValid())
        return QVariant();
    if(index.row()>=Items.size())
        return QVariant();
    if(role==TYPE)
        return Items.at(index.row())->Type();
    if(role==SOURCE)
    {
        qDebug()<<Items.at(index.row())->Source();
//        return Items.at(index.row())->Source();
    }
    if(role==URL)
        qDebug()<<Items.at(index.row())->Url();
    if(role==STATUS)
        qDebug()<<Items.at(index.row())->Status();
    if(role==PROGRESS)
        qDebug()<<Items.at(index.row())->progress();
    if(role==TOTAL)
        qDebug()<<Items.at(index.row())->total();
 //   const RecursingWallItem* Wi = Items.at(index.row());

    return QVariant();

}

//bool AttachmentsToSendModel::insertRows(int row, int count, const QModelIndex &parent)
//{
//}

//bool AttachmentsToSendModel::removeRows(int row, int count, const QModelIndex &parent)
//{
//    beginRemoveRows(QModelIndex(),row,count);
//    for(int i=0;i<count;i++)
//    {
//        Items.at(row+i)->deleteLater();
//        Items.removeAt(row+i);
//    }
//    qDebug()<<"deleting Attach";
//    endRemoveRows();

//}

QHash<int, QByteArray> AttachmentsToSendModel::roleNames() const
{
    QHash<int, QByteArray> roles;

    roles[TYPE] = "type";
    roles[SOURCE] = "c_source";
    roles[STATUS]="c_status";
    roles[URL] = "url";
    roles[PROGRESS] = "progress";
    roles[TOTAL] = "total";

    return roles;


}

AttachmentsToSendItem.h

#ifndef ATTACHMENTTOSENDITEM_H
#define ATTACHMENTTOSENDITEM_H

#include <QObject>
#include <QDebug>

class AttachmentToSendItem : public QObject
{
    Q_OBJECT

public:
    explicit AttachmentToSendItem(QObject* parent=0);
    AttachmentToSendItem(QString source, int type);
    ~AttachmentToSendItem();
    Q_ENUMS(FileType)
    Q_PROPERTY(QString Url READ Url WRITE setUrl NOTIFY UrlChanged)
    Q_PROPERTY(int progress READ progress WRITE setProgress NOTIFY progressChanged)
    Q_PROPERTY(int total READ total WRITE setTotal NOTIFY totalChanged)
    Q_PROPERTY(QString Source READ Source WRITE setSource NOTIFY SourceChanged)
    Q_PROPERTY(FileType Type READ Type WRITE setType NOTIFY TypeChanged)
    Q_PROPERTY(int Status READ Status WRITE setStatus NOTIFY StatusChanged)
    enum FileType {
        PHOTO,
        VIDEO,
        AUDIO,
        DOC,
        WALL
    };
    QString Url() const;

    int progress() const;

    int total() const;

    QString Source() const;

    FileType Type() const;

    int Status() const;

signals:

    void UrlChanged(QString Url);

    void progressChanged(int progress);

    void totalChanged(int total);

    void SourceChanged(QString Source);

    void TypeChanged(FileType Type);

    void StatusChanged(int Status);

public slots:
    void setUrl(QString Url);
    void setProgress(int progress);

    void setTotal(int total);

    void setSource(QString Source);

    void setType(FileType Type);

    void setStatus(int Status);

private:
    QString m_Url="";
    int m_progress=0;
    int m_total;
    QString m_Source;
    FileType m_Type;
    int m_Status=2;
};

#endif // ATTACHMENTTOSENDITEM_H

AttachmentToSendItem.cpp

#include "attachmenttosenditem.h"


AttachmentToSendItem::AttachmentToSendItem(QObject *parent)
{
    setParent(parent);
}

AttachmentToSendItem::AttachmentToSendItem(QString source,int type)
{
    setSource(source);
    setType(static_cast<FileType>(type));
}

AttachmentToSendItem::~AttachmentToSendItem()
{
    qDebug()<<"Killed";
}

QString AttachmentToSendItem::Url() const
{
    return m_Url;
}

int AttachmentToSendItem::progress() const
{
    return m_progress;
}

int AttachmentToSendItem::total() const
{
    return m_total;
}

QString AttachmentToSendItem::Source() const
{
    return m_Source;
}

AttachmentToSendItem::FileType AttachmentToSendItem::Type() const
{
    return m_Type;
}

int AttachmentToSendItem::Status() const
{
    return m_Status;
}

void AttachmentToSendItem::setUrl(QString Url)
{
    if (m_Url == Url)
        return;
    
    m_Url = Url;
    emit UrlChanged(Url);
}

void AttachmentToSendItem::setProgress(int progress)
{
    if (m_progress == progress)
        return;
    
    m_progress = progress;
    emit progressChanged(progress);
}

void AttachmentToSendItem::setTotal(int total)
{
    if (m_total == total)
        return;
    
    m_total = total;
    emit totalChanged(total);
}

void AttachmentToSendItem::setSource(QString Source)
{
    if (m_Source == Source)
        return;
    
    m_Source = Source;
    emit SourceChanged(Source);
}

void AttachmentToSendItem::setType(AttachmentToSendItem::FileType Type)
{
    if (m_Type == Type)
        return;

    m_Type = Type;
    emit TypeChanged(Type);
}

void AttachmentToSendItem::setStatus(int Status)
{
    if (m_Status == Status)
        return;
    
    m_Status = Status;
    emit StatusChanged(Status);
}

.qml

import QtQuick 2.0
import Sailfish.Silica 1.0
import QtMultimedia 5.0
import VKModels 1.0
import ".."
import "../items"
import QtDocGallery 5.0
import org.nemomobile.thumbnailer 1.0


Page{
    id:page

    property string headertitle;
    property int chat_id;
    property bool isMulti:false
    property string sobesed_photo;
    onStatusChanged: {
        if(status == PageStatus.Active)
            historyModel.isActive = true;
        else if(status == PageStatus.Activating)
            historyModel.isActive = true;

        historyModel.isActive = false;
    }
    Component.onCompleted: {
        historyModel.clear_Messages();
        globalSettings.companionId=chat_id;
        vkapi.messages_getHistory(chat_id,0,20,-1);
    }
    Component.onDestruction:
    {
        globalSettings.companionId=0;
    }

    Drawer{
        id:attachDrawer
        open:false
        dock:Dock.Bottom
        anchors.fill: parent
        PageHeader{
            id:name_info
            title:headertitle
            anchors {
                leftMargin: 10
            }
        }
        SilicaListView {
            id: listView
            model: historyModel
            anchors.bottom: sendArea.top
            verticalLayoutDirection: ListView.BottomToTop

            PullDownMenu {
                id:pulley
                MenuItem {
                    text: "добавить прошлые записи"
                    onClicked:
                    {
                        vkapi.messages_getHistory(chat_id,listView.count,20,-1)
                    }
                }
            }

            width: parent.width
            height: parent.height-name_info.height
            spacing: 30
            anchors {
                top:name_info.bottom
            }
            clip:true
            delegate:MessageItem{
                isOut:out
                author: isMulti?first_name+ " "+last_name:""
                fwdMsg: historyModel.getFwdMessage(id)
                attachWallpost: historyModel.getFwdPost(id)
            }

        }

        Item{
            id:sendArea
            anchors.bottom: parent.bottom
            //            anchors.left:parent.left
            width: parent.width
            height: messageArea.height+attachmentstoSend.height+Theme.paddingSmall
//! If model empty everything ok, but if it has items -> SegFault
            SilicaListView{
                id:attachmentstoSend
                width:parent.width
                height: model.count>0?Theme.itemSizeMedium:0
                anchors.bottom: messageArea.top
                model:c_attachmentsModelToSend
                orientation:Qt.Horizontal
                spacing:5
                delegate: Image{
                    width:Theme.itemSizeMedium
                    height:width
                    sourceSize: Qt.size(width,height)
                    source:"image://nemoThumbnail/"+c_source
                    IconButton{
                    icon.source: "image://theme/icon-s-clear-opaque-cross?"+Theme.highlightColor
                    anchors.centerIn: parent
                    //onClicked: c_attachmentsModelToSend.(index)
                    }
                    Rectangle{
                    color:"black"
                    visible: c_status>0
                    opacity: 0.5
                    }
                   BusyIndicator{
                       size: BusyIndicatorSize.Medium
                               anchors.centerIn: parent
                               running: c_status>0

                   }
                }
            }
            IconButton {
                id:skrepkaWizard
                icon.source: "image://theme/icon-m-attach"
                highlighted: false
                anchors.bottom: messageArea.bottom
                anchors.right:messageArea.left
                anchors.bottomMargin: 25
                onClicked: attachDrawer.open=true
            }
            TextArea {
                id:messageArea

                anchors.bottom: parent.bottom
                anchors.right: sendButton.left

                height:  Math.min(Theme.itemSizeExtraLarge,implicitHeight)//Math.max(page.height/5, Math.min(page.height/3,implicitHeight))
                width:parent.width-sendButton.width- skrepkaWizard.width
            }

            IconButton {
                id:sendButton
                icon.source: "image://theme/icon-m-message"
                highlighted: false
                anchors.bottom: messageArea.bottom
                //                anchors.left:messageArea.right
                anchors.right:parent.right
                anchors.bottomMargin: 25

                onClicked: {
                    console.log(parent.width,sendButton.width,messageArea.width)
                    vkapi.messages_send(chat_id,messageArea.text)
                    messageArea.selectAll()
                    messageArea.text=""
                    highlighted=!highlighted

                    //       historyModel.clear_Messages()
                    //       vkapi.messages_getHistory(chat_id,false,20,0)

                }
            }
        }


        MouseArea {
            enabled: attachDrawer.open
            anchors.fill: listView
            onClicked: attachDrawer.open = false
        }


        background:Loader{
            id:attachLoader
            anchors.fill: parent
            source:"../items/AttachComponent.qml"

        }
    }


    MessageModel{
        id:historyModel
        Component.onCompleted:
        {
            historyModel.DataProvider=c_dataProvider
            historyModel.userId=chat_id
        }
    }
    DocumentGalleryModel {
        id: galleryModel
        rootType: DocumentGallery.Image
        properties: [ "url", "title", "dateTaken" ]
        autoUpdate: true
        sortProperties: ["-dateTaken"]
    }
    ListModel{
        id:attachmentsModelToSend
    }

    Connections {
        target: attachLoader.item
        onS_items: {
            console.log(items)
            var types = ["photo","video","place","audio","doc","photoVK","videoVK"];
            for(var i=0;i<items.length;i++)
            {
                console.log(items[i]);
                var file = galleryModel.get(items[i].id).url;
                console.log(file)
                attachmentsModelToSend.append({"url":"image://nemoThumbnail/"+galleryModel.get(items[i].id).url,"type":types[items[i].type],"status":2})
                c_attachmentsModelToSend.addAttachment(file,types[items[i].type])
            }
        }
    }
}

I understand that issue somehow has problem near ownership of QObject. But I can't find it.
Please help.

[p3c0]

@blacky_i Since you have used qmlRegisterType you need to instantiate the type in QML.

VKModels {
  id: vkModels
}

Is it done already? I found it missing in your code.
http://doc.qt.io/qt-5/qtquick-modelviewsdata-cppmodels.html#exposing-c-data-models-to-qml

[blacky_i]

but VKModels is used as import in the beginning of QML...

AttachmentsToSendModel is creating in here

[p3c0]

@blacky_i import doesnot create it. It just makes aware about the type to the engine.
See the example in the link posted earlier.

[blacky_i]

Oh shoot! i posted wrong qml file! here I am creating AttachmentsToSendModel

import QtQuick 2.0
import Sailfish.Silica 1.0
import QtMultimedia 5.0
import VKModels 1.0
import ".."
import "../items"
import QtDocGallery 5.0
import org.nemomobile.thumbnailer 1.0


Page{
    id:page


    signal addAttach(var src,var type);
    property string headertitle;
    property int chat_id;
    property bool isMulti:false
    property string sobesed_photo;
    onStatusChanged: {
        if(status == PageStatus.Active)
            historyModel.isActive = true;
        else if(status == PageStatus.Activating)
            historyModel.isActive = true;

        historyModel.isActive = false;
    }
    Component.onCompleted: {
        historyModel.clear_Messages();
        globalSettings.companionId=chat_id;
        vkapi.messages_getHistory(chat_id,0,20,-1);
    }
    Component.onDestruction:
    {
        globalSettings.companionId=0;
    }

    Drawer{
        id:attachDrawer
        open:false
        dock:Dock.Bottom
        anchors.fill: parent
        PageHeader{
            id:name_info
            title:headertitle
            anchors {
                leftMargin: 10
            }
        }
        SilicaListView {
            id: listView
            model: historyModel
            anchors.bottom: sendArea.top
            verticalLayoutDirection: ListView.BottomToTop

            PullDownMenu {
                id:pulley
                MenuItem {
                    text: "добавить прошлые записи"
                    onClicked:
                    {
                        vkapi.messages_getHistory(chat_id,listView.count,20,-1)
                    }
                }
            }

            width: parent.width
            height: parent.height-name_info.height
            spacing: 30
            anchors {
                top:name_info.bottom
            }
            clip:true
            delegate:MessageItem{
                isOut:out
                author: isMulti?first_name+ " "+last_name:""
                fwdMsg: historyModel.getFwdMessage(id)
                attachWallpost: historyModel.getFwdPost(id)
            }

        }

        Item{
            id:sendArea
            anchors.bottom: parent.bottom
            //            anchors.left:parent.left
            width: parent.width
            height: messageArea.height+attachmentstoSend.height+Theme.paddingSmall
            SilicaListView{
                id:attachmentstoSend
                width:parent.width
                height: model.count>0?Theme.itemSizeMedium:0
                anchors.bottom: messageArea.top
                model:c_attachmentsModelToSend
                orientation:Qt.Horizontal
                spacing:5
                delegate: Image{
                    width:Theme.itemSizeMedium
                    height:width
                    sourceSize: Qt.size(width,height)
                    source:"image://nemoThumbnail/"+c_source
                    IconButton{
                    icon.source: "image://theme/icon-s-clear-opaque-cross?"+Theme.highlightColor
                    anchors.centerIn: parent
                    //onClicked: c_attachmentsModelToSend.(index)
                    }
                    Rectangle{
                    color:"black"
                    visible: c_status>0
                    opacity: 0.5
                    }
                   BusyIndicator{
                       size: BusyIndicatorSize.Medium
                               anchors.centerIn: parent
                               running: c_status>0

                   }
                }
            }
            IconButton {
                id:skrepkaWizard
                icon.source: "image://theme/icon-m-attach"
                highlighted: false
                anchors.bottom: messageArea.bottom
                anchors.right:messageArea.left
                anchors.bottomMargin: 25
                onClicked: attachDrawer.open=true
            }
            TextArea {
                id:messageArea

                anchors.bottom: parent.bottom
                anchors.right: sendButton.left

                height:  Math.min(Theme.itemSizeExtraLarge,implicitHeight)//Math.max(page.height/5, Math.min(page.height/3,implicitHeight))
                width:parent.width-sendButton.width- skrepkaWizard.width
            }

            IconButton {
                id:sendButton
                icon.source: "image://theme/icon-m-message"
                highlighted: false
                anchors.bottom: messageArea.bottom
                //                anchors.left:messageArea.right
                anchors.right:parent.right
                anchors.bottomMargin: 25

                onClicked: {
                    console.log(parent.width,sendButton.width,messageArea.width)
                    vkapi.messages_send(chat_id,messageArea.text)
                    messageArea.selectAll()
                    messageArea.text=""
                    highlighted=!highlighted

                    //       historyModel.clear_Messages()
                    //       vkapi.messages_getHistory(chat_id,false,20,0)

                }
            }
        }


        MouseArea {
            enabled: attachDrawer.open
            anchors.fill: listView
            onClicked: attachDrawer.open = false
        }


        background:Loader{
            id:attachLoader
            anchors.fill: parent
            source:"../items/AttachComponent.qml"

        }
    }


    MessageModel{
        id:historyModel
        Component.onCompleted:
        {
            historyModel.DataProvider=c_dataProvider
            historyModel.userId=chat_id
        }
    }
    DocumentGalleryModel {
        id: galleryModel
        rootType: DocumentGallery.Image
        properties: [ "url", "title", "dateTaken" ]
        autoUpdate: true
        sortProperties: ["-dateTaken"]
    }
    AttachmentsToSendModel{
    id:c_attachmentsModelToSend
    }



    Connections {
        target: attachLoader.item
        onS_items: {
            console.log(items)
            var types = ["photo","video","place","audio","doc","photoVK","videoVK"];
            for(var i=0;i<items.length;i++)
            {
                console.log(items[i]);
                var file = galleryModel.get(items[i].id).url;
                console.log(file)
                c_attachmentsModelToSend.addAttachment(file,types[items[i].type])
            }
        }
    }
}

error still the same. If Items in model >0, then SegFault
If in AttachmentToSendModel.cpp use List<AttachmentToSendItem> Items instead of List<AttachmentToSendItem*> Items as collection, After adding new item it deletes immediately and calling SegFault.

[blacky_i]

Strange, but SegFault is gone.
I removed realization of QModelIndex AttachmentsToSendModel::index(int row, int column, const QModelIndex &parent) and SegFault is gone.
Any ideas why?

[VRonin]

this

QModelIndex AttachmentsToSendModel::index(int row, int column, const QModelIndex &parent) const
{
}

should not even compile, you need to return something...

[blacky_i]

I understand my stupid errror. Problem solved.