QAbstractItemModel and DalegateModel.qml

[blacky_i]

Hello everyone!
I'm developing telegram app for mobile with qt. Got a problem with list of stickers.
Data structure is this:
stickerSet object 1
| sticker 1
| sticker 2
...
| sticker N
stickerSet 2
| sticker 1
| sticker 2
..
| sticker N

code for sticker model on github here
and qml file is here

Problem: After calling dataChanged for sticker to update its filepath, model doesnt update. (ModelIndex for this item is saved in QMap)

I'm assuming I created wrong qabstractitemmodel, but can't find correct example.
Thanks in advance for any clue.

[raven-worx]

@blacky_i said in QAbstractItemModel and DalegateModel.qml:

Problem: After calling dataChanged for sticker to update its filepath, model doesnt update. (ModelIndex for this item is saved in QMap)

1. when do you can dataChanged()?
2. storing QModelIndexes is always a bad idea

To quickly verify your model implementation you can use ModelTest class (check the console output):

#include <modeltest.h>

MyModel *model = new MyModel(this);
new ModelTest(model, this);

[blacky_i]

@raven-worx said in QAbstractItemModel and DalegateModel.qml:

when do you can dataChanged()?

After visualising image in qml. If image do not exists on device, data function emits signal to downloadFile from Telegram and stores its QmodelIndex for future update. MEssage from Telegram returns, it updates item in list and calls dataChanged(). But refresing item do not happening.

[raven-worx]

@blacky_i
the problem with storing model indexes is that they are not meant to be stored, since they are only valid until the next model change.
Try changing the QMap to use QPersistentModelIndexes instead (just changing the QMap declaration in the header should be enough) and check if works.

Otherwise you will need to show a bit more code.

[blacky_i]

@raven-worx Oh, ok. I added links to github in first post, but I will duplicate as message.

StickerModel.cpp

#include "StickerModel.hpp"
#include <QDebug>
#include "tdlibQt/TdlibJsonWrapper.hpp"
#include "tdlibQt/ParseObject.hpp"
namespace tdlibQt {

StickerModel::StickerModel(QObject *parent) : QAbstractItemModel(parent),
    m_client(TdlibJsonWrapper::instance())
{
    connect(m_client, &TdlibJsonWrapper::stickerSetReceived,
            this, &StickerModel::addStickerSet);
    //BUG? Lambda functions requires disconnection before dectruction?. Even disconnection doesnt help
    connect(m_client, &TdlibJsonWrapper::stickerSetsReceived,
            this, &StickerModel::stickersSetsReceived);
    connect(m_client, &TdlibJsonWrapper::stickersReceived,
            this, &StickerModel::stickersReceived);
    connect(m_client, &TdlibJsonWrapper::updateFile,
            this, &StickerModel::updateFile);

    connect(this, &StickerModel::downloadFileStart,
            this, &StickerModel::getFile);

}

StickerModel::~StickerModel()
{
    m_stikerSets.clear();
    m_installedStickerSets.clear();
}

void StickerModel::getAttachedStickerSets(const int file_id)
{
    m_client->getAttachedStickerSets(file_id);
}

void StickerModel::getStickerSet(const qint64 set_id)
{
    m_client->getStickerSet(set_id);
}

void StickerModel::getFavoriteStickers()
{
    m_client->getFavoriteStickers();
}

void StickerModel::getRecentStickers()
{
    m_client->getRecentStickers();
}

void StickerModel::getInstalledStickers(const bool is_masks)
{
    m_client->getInstalledStickerSets(is_masks);
}

void StickerModel::addTrendingStickerSets(const QJsonObject &stickerSetsObject)
{
    auto stickerSetsObj = ParseObject::parseStickerSets(stickerSetsObject);
    for (QSharedPointer<stickerSetInfo> val : stickerSetsObj->sets_)
        m_trendingStickerSets.append(val);
}

QSharedPointer<stickerSet> StickerModel::createStickerSet(const QString &name, const QString &title,
        const std::vector<QSharedPointer<sticker> > &stickers)
{
    if (stickers.size() == 0)
        return QSharedPointer<stickerSet>(nullptr);

    QSharedPointer<stickerSet> resultSet = QSharedPointer<stickerSet>(new stickerSet);
    resultSet->name_ = name.toStdString();
    resultSet->title_ = title.toStdString();
    resultSet->stickers_ = stickers;

    return resultSet;
}

StickerModel::StickerModelState StickerModel::modelState() const
{
    return m_state;
}

QHash<int, QByteArray> StickerModel::roleNames() const
{
    QHash<int, QByteArray>  roles;
    roles[ID] = "id";
    roles[IS_ARCHIVED] = "is_archived";
    roles[IS_INSTALLED] = "is_installed";
    roles[IS_MASKS] = "is_masks";
    roles[IS_OFFICIAL] = "is_official";
    roles[IS_VIEWED] = "is_viewed";
    roles[TITLE] = "title";
    roles[NAME] = "name";
    roles[STICKER] = "sticker";
    roles[EMOJI] = "emoji";
    roles[STICKERS_COUNT] = "stickers_count";
    roles[SET_STICKER_THUMBNAIL] = "set_thumbnail";

    roles[STICKER_FILE_ID] = "sticker_file_id";
    return roles;
}

QVariant StickerModel::data(const QModelIndex &index, int role) const
{
    if (!index.isValid())
        return QVariant();

    if (index.row() < 0)
        return QVariant();

    int rowIndex = index.row();
    int setNumber = index.parent().column() == -1 ? index.parent().row() : rowIndex;//getSetIndex(rowIndex);
    setNumber = setNumber == -1 ? rowIndex : setNumber;
    switch (role) {
    case ID:
        return  QString::number(m_stikerSets[setNumber]->id_);
    case IS_ARCHIVED:
        return    m_stikerSets[setNumber]->is_archived_;
    case IS_INSTALLED:
        return   m_stikerSets[setNumber]->is_installed_;
    case IS_MASKS:
        return    m_stikerSets[setNumber]->is_masks_;
    case IS_OFFICIAL:
        return    m_stikerSets[setNumber]->is_official_;
    case IS_VIEWED:
        return    m_stikerSets[setNumber]->is_viewed_;
    case TITLE:
        return   QString::fromStdString(m_stikerSets[setNumber]->title_);
    case NAME:
        return   QString::fromStdString(m_stikerSets[setNumber]->name_);
    case SET_STICKER_THUMBNAIL:
        return   QString::fromStdString(m_stikerSets[setNumber]->stickers_[0]->sticker_->local_->path_);
    case STICKERS_COUNT:
        return m_stikerSets[setNumber]->stickers_.size();
    case STICKER:
        if (index.parent().row() == -1)
            return QVariant();
        //    m_installedStickerSets[rowIndex]->covers_;
        if (m_stikerSets[setNumber]->stickers_[rowIndex]->sticker_->local_->is_downloading_completed_)
            return   QString::fromStdString(m_stikerSets[setNumber]->stickers_[rowIndex]->sticker_->local_->path_);
        if (m_stikerSets[setNumber]->stickers_[rowIndex]->thumbnail_->photo_->local_->is_downloading_completed_) {
            emit downloadFileStart(m_stikerSets[setNumber]->stickers_[rowIndex]->sticker_->id_, 12, index);
            return   QString::fromStdString(m_stikerSets[setNumber]->stickers_[rowIndex]->thumbnail_->photo_->local_->path_);
        }
        emit downloadFileStart(m_stikerSets[setNumber]->stickers_[rowIndex]->thumbnail_->photo_->id_, 12, index);
        return QVariant();
    case EMOJI: {
        if (index.parent().row() == -1)
            return QVariant();

        QString emojis = "";
        emojis += QString::fromStdString(m_stikerSets[setNumber]->stickers_[rowIndex]->emoji_);
        return emojis;
    }
    break;
    case STICKER_FILE_ID:
        if (index.parent().row() == -1)
            return QVariant();
        return m_stikerSets[setNumber]->stickers_[rowIndex]->sticker_->id_;
        break;
    default:
        return QVariant();
        break;
    }

    //    m_installedStickerSets[rowIndex]->id_;
    //    m_installedStickerSets[rowIndex]->is_archived_;
    //    m_installedStickerSets[rowIndex]->is_installed_;
    //    m_installedStickerSets[rowIndex]->is_masks_;
    //    m_installedStickerSets[rowIndex]->is_official_;
    //    m_installedStickerSets[rowIndex]->is_viewed_;
    //    m_installedStickerSets[rowIndex]->name_;
    //    m_installedStickerSets[rowIndex]->title_;


}


int StickerModel::rowCount(const QModelIndex &parent) const
{
    if (m_state == SendState || m_state == PreviewState) {
        if (parent.column() == 0) {
            return m_stikerSets.at(parent.row())->stickers_.size();
        } else
            return m_stikerSets.size();
    }

    return 0;
}


void StickerModel::addInstalledStickerSets(const QJsonObject &stickerSetsObject)
{
    auto stickerSetsObj = ParseObject::parseStickerSets(stickerSetsObject);
    for (QSharedPointer<stickerSetInfo> val : stickerSetsObj->sets_) {
        m_installedStickerSets.append(val);
        if (m_state == SendState)
            getStickerSet(val->id_);
    }
}

void StickerModel::addStickerSet(const QJsonObject &stickerSetObject)
{
    auto stickerSetObj = ParseObject::parseStickerSet(stickerSetObject);
    if (stickerSetObj.data()) {
        beginInsertRows(QModelIndex(), m_stikerSets.size(), m_stikerSets.size());
        m_stikerSets.append(stickerSetObj);
        endInsertRows();
    }
}

void StickerModel::updateFile(const QJsonObject &fileObject)
{

    if (fileObject["@type"].toString() == "updateFile")
        processFile(fileObject["file"].toObject());
}

void StickerModel::processFile(const QJsonObject &fileObject)
{

    auto file = ParseObject::parseFile(fileObject);
    if (m_stickerUpdateQueue.keys().contains(file->id_)) {
        QVector<int> photoRole;
        QModelIndex viewIndex = m_stickerUpdateQueue[file->id_];
        qDebug() << viewIndex << "Row" << viewIndex.row() << "Column" << viewIndex.column() <<  viewIndex.parent().row();

        int rowIndex = viewIndex.row();
        int setIndex = viewIndex.parent().row();

        if (m_stikerSets[setIndex]->stickers_[rowIndex]->sticker_->id_ == file->id_)
            m_stikerSets[setIndex]->stickers_[rowIndex]->sticker_ = file;
        if (m_stikerSets[setIndex]->stickers_[rowIndex]->thumbnail_->photo_->id_ == file->id_)
            m_stikerSets[setIndex]->stickers_[rowIndex]->thumbnail_->photo_ = file;
        if (file->local_->is_downloading_completed_) {
            photoRole.append(STICKER);
            photoRole.append(SET_STICKER_THUMBNAIL);
            emit refreshSticker();
        }
        emit dataChanged(index(rowIndex, 0, index(setIndex, -1)),
                         index(rowIndex, 0, index(setIndex, -1)), photoRole);
        if (file->local_->is_downloading_completed_)
            m_stickerUpdateQueue.remove(file->id_);
    }

}

void StickerModel::stickersReceived(const QJsonObject &setObject)
{
    if (setObject["@extra"].toString() == "getFavoriteStickers")
        addFavoriteStickers(setObject);
    else
        addRecentStickers(setObject);
}

void StickerModel::stickersSetsReceived(const QJsonObject &setsObject)
{
    if (setsObject["@extra"].toString() == "getTrendingStickerSets")
        addTrendingStickerSets(setsObject);
    else
        addInstalledStickerSets(setsObject);
}

void StickerModel::changeStickerSet(const QString &setId, const bool isInstalled, const bool isArchived)
{
    m_client->changeStickerSet(setId.toLongLong(), isInstalled, isArchived);
}

QVariant StickerModel::getStickerUrl(const int setIndex, const int stickerIndex)
{
    return data(index(stickerIndex, 0, createIndex(setIndex, 0)), DataRoles::STICKER);
}

QVariant StickerModel::getStickerEmoji(const int setIndex, const int stickerIndex)
{
    return data(index(stickerIndex, 0, createIndex(setIndex, 0)), DataRoles::EMOJI);
}

QVariant StickerModel::getStickersCount(const int setIndex)
{
    return data(index(setIndex, 0), DataRoles::STICKERS_COUNT);
}

void StickerModel::setSet_id(QString set_id)
{
    if (m_set_id == set_id)
        return;

    m_set_id = set_id;
    emit set_idChanged(m_set_id);
}

void StickerModel::getFile(const int fileId, const int priority, const QModelIndex indexItem)
{
    m_client->downloadFile(fileId, priority);
    m_stickerUpdateQueue[fileId] = indexItem;

}

int StickerModel::columnCount(const QModelIndex &parent) const
{
    return 1;
}

QModelIndex StickerModel::index(int row, int column, const QModelIndex &parent) const
{
    if (!hasIndex(row, column, parent))
        return QModelIndex();

    if (parent.column() > -1)
        return createIndex(row, column, m_stikerSets.at(parent.row()).data());
    return createIndex(row, column);

}

QModelIndex StickerModel::parent(const QModelIndex &child) const
{
    if (!child.isValid())
        return QModelIndex();

    stickerSet *childItem = static_cast<stickerSet *>(child.internalPointer());
    if (!childItem)
        return QModelIndex();

    if (child.column() == -1)
        return QModelIndex();

    int rowPosition = 0;
    for (int i = 0; i < m_stikerSets.size(); i++)
        if (m_stikerSets.at(i).data() == childItem) {
            rowPosition = i;
            break;
        }
    return createIndex(rowPosition, -1);
}

bool StickerModel::hasChildren(const QModelIndex &parent) const
{
    return parent.column() == -1;
}

QString StickerModel::set_id() const
{
    return m_set_id;
}
void StickerModel::addFavoriteStickers(const QJsonObject &stickersObject)
{
    auto stickersObj = ParseObject::parseStickers(stickersObject);
    auto resultSet = createStickerSet("Favorite", tr("Favorite"), stickersObj->stickers_);
    if (resultSet.data()) {
        beginInsertRows(QModelIndex(), m_stikerSets.size(), m_stikerSets.size());
        m_stikerSets.append(resultSet);
        endInsertRows();
    }
}

void StickerModel::addRecentStickers(const QJsonObject &stickersObjecct)
{
    auto stickersObj = ParseObject::parseStickers(stickersObjecct);
    auto resultSet = createStickerSet("Recent", tr("Recent"), stickersObj->stickers_);

    if (resultSet.data()) {
        beginInsertRows(QModelIndex(), m_stikerSets.size(),  m_stikerSets.size());
        m_stikerSets.append(resultSet);
        endInsertRows();
    }
}

void StickerModel::setModelState(StickerModel::StickerModelState state)
{
    if (m_state == state)
        return;

    m_state = state;
    beginResetModel();
    m_stikerSets.clear();
    m_installedStickerSets.clear();
    endResetModel();
    switch (m_state) {
    case SendState:
        getFavoriteStickers();
        getRecentStickers();
        getInstalledStickers();
        break;
    case PreviewState:
        if (set_id().length() > 0)
            getStickerSet(set_id().toLongLong());
        break;
    case SettingsState:

    case TrendingState:
    default:
        break;
    }
    emit modelStateChanged(m_state);
}
} //tdlibQt

PreviewStickerSetDialog.qml

import QtQuick 2.0
import Sailfish.Silica 1.0
import tdlibQtEnums 1.0
import TelegramModels 1.0
import QtQml.Models 2.3
import org.nemomobile.notifications 1.0
import "../items"
Dialog {
    id:rootPage
    property alias set_id: stickerModel.set_id
    property bool _previewEnabled: false
    property bool _setIsInstalled: false
    canAccept: !_previewEnabled
    states:[
        State {
            name: "general"
            PropertyChanges {
                target: rootPage
                _previewEnabled:false
            }
            PropertyChanges {
                target: rootPage
                backNavigation:true
            }
            PropertyChanges {
                target: previewRect
                visible:false
            }

        },
        State {
            name: "preview"
            PropertyChanges {
                target: rootPage
                _previewEnabled:true
            }
            PropertyChanges {
                target: rootPage
                backNavigation:false
            }
            PropertyChanges {
                target: previewRect
                visible:true
            }
            StateChangeScript {
                name: "showNotification"
                script: notificationPreviewMode.publish()
            }

        }
    ]
    state: "general"
    onAccepted: {
    if(_setIsInstalled)
        stickerModel.changeStickerSet(set_id,false)
    else
        stickerModel.changeStickerSet(set_id,true)
    }
Notification {
    id:notificationPreviewMode
    appName: "Depecher"
    previewBody: qsTr("Sticker preview mode")
}
StickerModel {
    id:stickerModel
    modelState: set_id ==="" ? StickerModel.UknownState : StickerModel.PreviewState
}


MouseArea {
    id:previewArea
    enabled: _previewEnabled
    focus: _previewEnabled
    width: parent.width
    height: parent.height - header.height
    anchors.bottom: parent.bottom
    property var component
    property var previewItem
    preventStealing: true
    onPositionChanged: previewThis(mouseX,mouseY)
    onEnabledChanged: {
        if(enabled)
        {
            component = Qt.createComponent(Qt.resolvedUrl("../items/StickerPreviewComponent.qml"));
            previewItem = component.createObject(rootPage, {"source": undefined});
            previewItem.anchors.centerIn = rootPage
            previewItem.z = listView.z + 2
        }
        else {
            if(component)
                component.destroy()
            if(previewItem)
                previewItem.destroy()
        }
    }

    function previewThis(x,y) {
        //delegateModel do not get item through index
        //Thats why getting sticker url via model slot
        var stikerGridIndex =  listView.indexAt(x,y+listView.contentY)
        var grid =listView.itemAt(x,y+listView.contentY).gridSticker
        if (grid) {
            var previousHeight = 0;
            var indexItem = 0
            var setIndex = stikerGridIndex
            //Get height of all gridView previously
            indexItem = grid.indexAt(x,mapToItem(grid,x,y).y)
            var stickerUrl = listView.model.model.getStickerUrl(setIndex,indexItem);
            if(stickerUrl)
            {
                previewItem.source = "image://depecherDb/"+stickerUrl;
                previewItem.emoji = listView.model.model.getStickerEmoji(setIndex,indexItem);
            }

        }
    }
    onReleased: rootPage.state = "general"
}
Rectangle {
    id:previewRect
    visible: false
    parent: rootPage
    z:listView.z + 1
    anchors.fill: parent
    gradient: Gradient {
        GradientStop { position:  1.0; color: "transparent" }
        GradientStop { position:  0.0; color: Theme.highlightDimmerColor }
    }
}
Column {
    width:parent.width


DialogHeader {
    id:header
    acceptText: rootPage._setIsInstalled ? qsTr("Remove %1 stickers").arg(listView.contentItem.children[0].gridSticker.count) :qsTr("Add %1 stickers").arg(listView.contentItem.children[0].gridSticker.count)
    cancelText: qsTr("Back")
}
        SilicaListView {
            id:listView
            width: parent.width
            height: rootPage.height - header.height
            clip:true
            interactive: !_previewEnabled
            onFlickingChanged: previewTimer.stop()
            model:  DelegateModel {
                id:stickerSetModel
                model: stickerModel
                delegate: Item {
                    width: parent.width
                    height: columnStickers.height
                    property alias itemIndex: stickersGrid
                    property alias gridSticker: stickersGrid
                    property alias stickersCount: stickersGrid.count
                    Column {
                        id:columnStickers
                        width: parent.width
                        height: sectionHeader.height + stickersGrid.height
                        SectionHeader {
                            id:sectionHeader
                            text:title
                        }
                        DelegateModel {
                            id:stickers
                            model: stickerModel
                            rootIndex:listView.model.modelIndex(index)


                            delegate: Image {
                                width: stickersGrid.cellWidth
                                height: width
                                asynchronous: true
                                fillMode: Image.PreserveAspectFit
                                source: "image://depecherDb/" + sticker
                                Connections {
                                    target: stickerModel
                                    onRefreshSticker:{
stickersGrid.forceLayout()
                                    }
                                }
                                MouseArea {
                                    anchors.fill: parent
                                    enabled: !_previewEnabled
                                    onPressed:{
                                        previewTimer.start()
                                    }
                                    onClicked:  {
                                        if( rootPage.state === "general")
                                            sendUrlItems([{"id":sticker_file_id,"type":TdlibState.Sticker,"url":sticker}])

                                    }
                                    onExited: {
                                        if(previewTimer.running)
                                            previewTimer.stop()
                                    }
                                }
                            }
                        }
                        SilicaGridView {
                            id:stickersGrid
                            width: parent.width
                            interactive: !_previewEnabled
                            cellWidth: parent.width/5
                            cellHeight: cellWidth
                            height:Math.ceil(count / 5) * cellHeight
                            model:stickers
                        }
                    }
                Component.onCompleted:{
                    rootPage._setIsInstalled = is_installed
                }
                }
            }


        }
}

        Timer {
            id:previewTimer
            interval: 800
            onTriggered:                 rootPage.state = "preview"
        }
}

[raven-worx]

@blacky_i said in QAbstractItemModel and DalegateModel.qml:

Oh, ok. I added links to github in first post, but I will duplicate as message.

i thought you applied custom changes to the code? I assumed you are using 3rd party code.

[blacky_i]

@raven-worx Many thanks! ModelTest did help. I resloved all Q_ASSERT and model updates fine!) You saved me many nights.

Posting code which works fine:

#include "StickerModel.hpp"
#include <QDebug>
#include "tdlibQt/TdlibJsonWrapper.hpp"
#include "tdlibQt/ParseObject.hpp"
namespace tdlibQt {

StickerModel::StickerModel(QObject *parent) : QAbstractItemModel(parent),
    m_client(TdlibJsonWrapper::instance())
{
    rootSet =     QSharedPointer<stickerSet>(new stickerSet);
    connect(m_client, &TdlibJsonWrapper::stickerSetReceived,
            this, &StickerModel::addStickerSet);
    //BUG? Lambda functions requires disconnection before dectruction?. Even disconnection doesnt help
    connect(m_client, &TdlibJsonWrapper::stickerSetsReceived,
            this, &StickerModel::stickersSetsReceived);
    connect(m_client, &TdlibJsonWrapper::stickersReceived,
            this, &StickerModel::stickersReceived);
    connect(m_client, &TdlibJsonWrapper::updateFile,
            this, &StickerModel::updateFile);

    connect(this, &StickerModel::downloadFileStart,
            this, &StickerModel::getFile);

}

StickerModel::~StickerModel()
{
    m_stikerSets.clear();
    m_installedStickerSets.clear();
}

void StickerModel::getAttachedStickerSets(const int file_id)
{
    m_client->getAttachedStickerSets(file_id);
}

void StickerModel::getStickerSet(const qint64 set_id)
{
    m_client->getStickerSet(set_id);
}

void StickerModel::getFavoriteStickers()
{
    m_client->getFavoriteStickers();
}

void StickerModel::getRecentStickers()
{
    m_client->getRecentStickers();
}

void StickerModel::getInstalledStickers(const bool is_masks)
{
    m_client->getInstalledStickerSets(is_masks);
}

void StickerModel::addTrendingStickerSets(const QJsonObject &stickerSetsObject)
{
    auto stickerSetsObj = ParseObject::parseStickerSets(stickerSetsObject);
    for (QSharedPointer<stickerSetInfo> val : stickerSetsObj->sets_)
        m_trendingStickerSets.append(val);
}

QSharedPointer<stickerSet> StickerModel::createStickerSet(const QString &name, const QString &title,
        const std::vector<QSharedPointer<sticker> > &stickers)
{
    if (stickers.size() == 0)
        return QSharedPointer<stickerSet>(nullptr);

    QSharedPointer<stickerSet> resultSet = QSharedPointer<stickerSet>(new stickerSet);
    resultSet->name_ = name.toStdString();
    resultSet->title_ = title.toStdString();
    resultSet->stickers_ = stickers;

    return resultSet;
}

StickerModel::StickerModelState StickerModel::modelState() const
{
    return m_state;
}

QHash<int, QByteArray> StickerModel::roleNames() const
{
    QHash<int, QByteArray>  roles;
    roles[ID] = "id";
    roles[IS_ARCHIVED] = "is_archived";
    roles[IS_INSTALLED] = "is_installed";
    roles[IS_MASKS] = "is_masks";
    roles[IS_OFFICIAL] = "is_official";
    roles[IS_VIEWED] = "is_viewed";
    roles[TITLE] = "title";
    roles[NAME] = "name";
    roles[STICKER] = "sticker";
    roles[EMOJI] = "emoji";
    roles[STICKERS_COUNT] = "stickers_count";
    roles[SET_STICKER_THUMBNAIL] = "set_thumbnail";

    roles[STICKER_FILE_ID] = "sticker_file_id";
    return roles;
}

QVariant StickerModel::data(const QModelIndex &index, int role) const
{
    if (!index.isValid())
        return QVariant();

    if (index.row() < 0)
        return QVariant();
    stickerSet *childItem = static_cast<stickerSet *>(index.internalPointer());
    if (!childItem)
        return QVariant();

    int rowIndex = index.row();
    int setNumber = 0;//index.parent().column() == 0 ? index.parent().row() : rowIndex;//getSetIndex(rowIndex);
    if (childItem == rootSet.data()) {
        setNumber = index.row();
        rowIndex = index.row();
    } else {
        setNumber = index.parent().row();
        rowIndex = index.row();
    }
    switch (role) {
    case ID:
        return  QString::number(m_stikerSets[setNumber]->id_);
    case IS_ARCHIVED:
        return    m_stikerSets[setNumber]->is_archived_;
    case IS_INSTALLED:
        return   m_stikerSets[setNumber]->is_installed_;
    case IS_MASKS:
        return    m_stikerSets[setNumber]->is_masks_;
    case IS_OFFICIAL:
        return    m_stikerSets[setNumber]->is_official_;
    case IS_VIEWED:
        return    m_stikerSets[setNumber]->is_viewed_;
    case TITLE:
        return   QString::fromStdString(m_stikerSets[setNumber]->title_);
    case NAME:
        return   QString::fromStdString(m_stikerSets[setNumber]->name_);
    case SET_STICKER_THUMBNAIL:
        return   QString::fromStdString(m_stikerSets[setNumber]->stickers_[0]->sticker_->local_->path_);
    case STICKERS_COUNT:
        return m_stikerSets[setNumber]->stickers_.size();
    case STICKER:
        if (index.parent().row() == -1)
            return QVariant();
        //    m_installedStickerSets[rowIndex]->covers_;
        if (m_stikerSets[setNumber]->stickers_[rowIndex]->sticker_->local_->is_downloading_completed_)
            return   QString::fromStdString(m_stikerSets[setNumber]->stickers_[rowIndex]->sticker_->local_->path_);
        if (m_stikerSets[setNumber]->stickers_[rowIndex]->thumbnail_->photo_->local_->is_downloading_completed_) {
            emit downloadFileStart(m_stikerSets[setNumber]->stickers_[rowIndex]->sticker_->id_, 12, index);
            return   QString::fromStdString(m_stikerSets[setNumber]->stickers_[rowIndex]->thumbnail_->photo_->local_->path_);
        }
        emit downloadFileStart(m_stikerSets[setNumber]->stickers_[rowIndex]->thumbnail_->photo_->id_, 12, index);
        return QVariant();
    case EMOJI: {
        if (index.parent().row() == -1)
            return QVariant();

        QString emojis = "";
        emojis += QString::fromStdString(m_stikerSets[setNumber]->stickers_[rowIndex]->emoji_);
        return emojis;
    }
    break;
    case STICKER_FILE_ID:
        if (index.parent().row() == -1)
            return QVariant();
        return m_stikerSets[setNumber]->stickers_[rowIndex]->sticker_->id_;
        break;
    default:
        return QVariant();
        break;
    }

    //    m_installedStickerSets[rowIndex]->id_;
    //    m_installedStickerSets[rowIndex]->is_archived_;
    //    m_installedStickerSets[rowIndex]->is_installed_;
    //    m_installedStickerSets[rowIndex]->is_masks_;
    //    m_installedStickerSets[rowIndex]->is_official_;
    //    m_installedStickerSets[rowIndex]->is_viewed_;
    //    m_installedStickerSets[rowIndex]->name_;
    //    m_installedStickerSets[rowIndex]->title_;


}


int StickerModel::rowCount(const QModelIndex &parent) const
{
    if (m_state == SendState || m_state == PreviewState) {
        stickerSet *childItem = static_cast<stickerSet *>(parent.internalPointer());
        if (parent == QModelIndex())
            return m_stikerSets.size();

        if (childItem == rootSet.data()) {
            return m_stikerSets.at(parent.row())->stickers_.size();
        } else
            return 0;
    }

    return 0;
}


void StickerModel::addInstalledStickerSets(const QJsonObject &stickerSetsObject)
{
    auto stickerSetsObj = ParseObject::parseStickerSets(stickerSetsObject);
    for (QSharedPointer<stickerSetInfo> val : stickerSetsObj->sets_) {
        m_installedStickerSets.append(val);
        if (m_state == SendState)
            getStickerSet(val->id_);
    }
}

void StickerModel::addStickerSet(const QJsonObject &stickerSetObject)
{
    auto stickerSetObj = ParseObject::parseStickerSet(stickerSetObject);
    if (stickerSetObj.data()) {
        beginInsertRows(QModelIndex(), m_stikerSets.size(), m_stikerSets.size());
        m_stikerSets.append(stickerSetObj);
        endInsertRows();
    }
}

void StickerModel::updateFile(const QJsonObject &fileObject)
{

    if (fileObject["@type"].toString() == "updateFile")
        processFile(fileObject["file"].toObject());
}

void StickerModel::processFile(const QJsonObject &fileObject)
{

    auto file = ParseObject::parseFile(fileObject);
    if (m_stickerUpdateQueue.keys().contains(file->id_)) {
        QVector<int> photoRole;
        QPersistentModelIndex viewIndex = m_stickerUpdateQueue[file->id_];
        qDebug() << viewIndex << "Row" << viewIndex.row() << "Column" << viewIndex.column() <<  viewIndex.parent().row();

        int rowIndex = viewIndex.row();
        int setIndex = viewIndex.parent().row();

        if (m_stikerSets[setIndex]->stickers_[rowIndex]->sticker_->id_ == file->id_)
            m_stikerSets[setIndex]->stickers_[rowIndex]->sticker_ = file;
        if (m_stikerSets[setIndex]->stickers_[rowIndex]->thumbnail_->photo_->id_ == file->id_)
            m_stikerSets[setIndex]->stickers_[rowIndex]->thumbnail_->photo_ = file;
        if (file->local_->is_downloading_completed_) {
            photoRole.append(STICKER);
            photoRole.append(SET_STICKER_THUMBNAIL);
        }
        //For child item
        emit dataChanged(viewIndex,
                         viewIndex, photoRole);
        //for thumbnails
        emit dataChanged(viewIndex.parent(),
                         viewIndex.parent(), photoRole);
        if (file->local_->is_downloading_completed_)
            m_stickerUpdateQueue.remove(file->id_);
    }

}

void StickerModel::stickersReceived(const QJsonObject &setObject)
{
    if (setObject["@extra"].toString() == "getFavoriteStickers")
        addFavoriteStickers(setObject);
    else
        addRecentStickers(setObject);
}

void StickerModel::stickersSetsReceived(const QJsonObject &setsObject)
{
    if (setsObject["@extra"].toString() == "getTrendingStickerSets")
        addTrendingStickerSets(setsObject);
    else
        addInstalledStickerSets(setsObject);
}

void StickerModel::changeStickerSet(const QString &setId, const bool isInstalled, const bool isArchived)
{
    m_client->changeStickerSet(setId.toLongLong(), isInstalled, isArchived);
}

QVariant StickerModel::getStickerUrl(const int setIndex, const int stickerIndex)
{
    return data(index(stickerIndex, 0, index(setIndex, 0)), DataRoles::STICKER);
}

QVariant StickerModel::getStickerEmoji(const int setIndex, const int stickerIndex)
{
    return data(index(stickerIndex, 0, index(setIndex, 0)), DataRoles::EMOJI);
}

QVariant StickerModel::getStickersCount(const int setIndex)
{
    return data(index(setIndex, 0), DataRoles::STICKERS_COUNT);
}

void StickerModel::setSet_id(QString set_id)
{
    if (m_set_id == set_id)
        return;

    m_set_id = set_id;
    emit set_idChanged(m_set_id);
}

void StickerModel::getFile(const int fileId, const int priority, const QModelIndex indexItem)
{
    m_client->downloadFile(fileId, priority);
    m_stickerUpdateQueue[fileId] = indexItem;

}

int StickerModel::columnCount(const QModelIndex &parent) const
{
    return 1;
}

QModelIndex StickerModel::index(int row, int column, const QModelIndex &parent) const
{
    if (!hasIndex(row, column, parent))
        return QModelIndex();

    if (parent.column() > -1)
        return createIndex(row, column, m_stikerSets.at(parent.row()).data());
    return createIndex(row, column, rootSet.data());

}

QModelIndex StickerModel::parent(const QModelIndex &child) const
{
    if (!child.isValid())
        return QModelIndex();

    stickerSet *childItem = static_cast<stickerSet *>(child.internalPointer());
    if (!childItem)
        return QModelIndex();

    if (childItem == rootSet.data())
        return QModelIndex();

    if (child.column() == -1)
        return QModelIndex();

    int rowPosition = 0;
    for (int i = 0; i < m_stikerSets.size(); i++)
        if (m_stikerSets.at(i).data() == childItem) {
            rowPosition = i;
            break;
        }
    return createIndex(rowPosition, 0, rootSet.data());
}

bool StickerModel::hasChildren(const QModelIndex &parent) const
{
    if (rowCount(parent) == 0)
        return false;

    return true;
}

QString StickerModel::set_id() const
{
    return m_set_id;
}
void StickerModel::addFavoriteStickers(const QJsonObject &stickersObject)
{
    auto stickersObj = ParseObject::parseStickers(stickersObject);
    auto resultSet = createStickerSet("Favorite", tr("Favorite"), stickersObj->stickers_);
    if (resultSet.data()) {
        beginInsertRows(QModelIndex(), m_stikerSets.size(), m_stikerSets.size());
        m_stikerSets.append(resultSet);
        endInsertRows();
    }
}

void StickerModel::addRecentStickers(const QJsonObject &stickersObjecct)
{
    auto stickersObj = ParseObject::parseStickers(stickersObjecct);
    auto resultSet = createStickerSet("Recent", tr("Recent"), stickersObj->stickers_);

    if (resultSet.data()) {
        beginInsertRows(QModelIndex(), m_stikerSets.size(),  m_stikerSets.size());
        m_stikerSets.append(resultSet);
        endInsertRows();
    }
}

void StickerModel::setModelState(StickerModel::StickerModelState state)
{
    if (m_state == state)
        return;

    m_state = state;
    beginResetModel();
    m_stikerSets.clear();
    m_installedStickerSets.clear();
    endResetModel();
    switch (m_state) {
    case SendState:
        getFavoriteStickers();
        getRecentStickers();
        getInstalledStickers();
        break;
    case PreviewState:
        if (set_id().length() > 0)
            getStickerSet(set_id().toLongLong());
        break;
    case SettingsState:

    case TrendingState:
    default:
        break;
    }
    emit modelStateChanged(m_state);
}
} //tdlibQt

Also, to ensure that ModelTest work, I created rootContext as single model and opened qml page with this model to make ModelTest work. Resolving each seg fault resolved issue