Fetch text from unnamed QGraphicsTextItem

A friend of mine and I are currently trying to make a game in C++ using Qt. Our current problem is that we need to fetch text from a QGraphicsTextItem on a button mousePressEvent. In the game menu it is possible to choose how many players there are, therefore we've placed a QGraphicsTextItem in a for-loop to make it possible for all the users to type in their names. Because of the for-loop, we don't have names for every single text item object so we can store the names. We've managed to store all the memory addresses to the objects using QMap, but we don't know how to get the text of of this. We don't even know if this is the best way to do it.

GameInfo.h

class GameInfo {
public:
    GameInfo();
    int players;

    QStringList names = (QStringList() // Default player names. This array should be overwritten by the custom names
        << "Player 1"
        << "Player 2"
        << "Player 3"
        << "Player 4"
        << "Player 5"
        << "Player 6"
        << "Player 7");

    QMap<int, QGraphicsTextItem**> textBoxMap; // This is where we store all the addresses
};

Game.cpp

    QGraphicsRectItem * overviewBox = new QGraphicsRectItem();
    overviewBox->setRect(0, 0, 782, 686);
    scene->addItem(overviewBox);

    int faceNo = 0;

// Create the player selection section
    for(int i = 1; i <= players; i++) { // "players" is defined another place in the code, and is an integer between 1 and 6
        Container * selContainer = new Container();
        selContainer->Selection(i, faceNo);
        selContainer->setPos(50, 70 + 110 * (i - 1));
        scene->addItem(selContainer);
        Container * ovContainer = new Container(overviewBox);
        ovContainer->Overview(i, faceNo);
        ovContainer->setPos(0, 0 + 110 * (i - 1));

        info->textBoxMap.insert(i, &selContainer->textBox->playerText); // This is where we save the addresses
    }

Selection.cpp

extern Game * game;

Container::Container(QGraphicsItem * parent): QGraphicsRectItem(parent) {

}

void Container::Selection(int nPlayers, int sPiceNo, QGraphicsItem *parent) {

    QString numName = QString::number(nPlayers);

    setRect(0, 0, 672, 110);
    this->setPen(Qt::NoPen); // Removes border

    int posY = this->rect().height() / 2;

    QSignalMapper * signalMapper = new QSignalMapper(this);

    arrowL = new Arrow(0, posY - 32, 0, this);
    piece = new Piece(sPiceNo, 96, posY - 32, 1, 1, this);
    arrowR = new Arrow(192, posY - 32, 1, this);
    textBox = new TextBox(game->info->names[nPlayers - 1], true, this);
    textBox->setPos(288, posY - 32);
    lockBtn = new Button("Lock", 96, 32, this);
    connect(lockBtn, SIGNAL(clicked()), signalMapper, SLOT(map()));
    signalMapper->setMapping(lockBtn, nPlayers);
    connect(signalMapper, SIGNAL(mapped(int)), this, SLOT(lock(int)));
    lockBtn->setPos(640, posY - 16);

}


void Container::Overview(int ovPlayers, int ovPiceNo, QGraphicsItem * parent) {
    // Some code...
}

void Container::lock(int nPlayer) {
    qDebug() << game->info->textBoxMap[nPlayer];
    qDebug() << game->info->names[nPlayer - 1];

    game->info->names[nPlayer - 1] = **game->info->textBoxMap[nPlayer].toPlainText(); // This line causes an error
}

The error that occurs because of the last line looks like this:

error: no match for 'operator=' (operand types are 'QString' and 'QGraphicsTextItem')
 game->info->names[nPlayer - 1] = **game->info->textBoxMap[nPlayer];
                                ^

TextBox.cpp

TextBox::TextBox(QString text, bool editable, QGraphicsItem * parent): QGraphicsRectItem(parent) {
    this->editable = editable;

// Draw the textbox
    setRect(0, 0, 320, 64);
    if(!editable) {
        this->setPen(Qt::NoPen); // Removes border
    }
    else if(editable) {
        QBrush brush;
        brush.setStyle(Qt::SolidPattern);
        brush.setColor(QColor(255, 255, 255, 255));
        setBrush(brush);
    }

// Draw the text
    playerText = new QGraphicsTextItem(text, this);
    int fontId = QFontDatabase::addApplicationFont(":/fonts/built_titling_bd.ttf");

    QString family = QFontDatabase::applicationFontFamilies(fontId).at(0);
    QFont built(family, 25);
    playerText->setFont(built);
    int xPos = 0;
    int yPos = rect().height() / 2 - playerText->boundingRect().height() / 2;
    playerText->setPos(xPos,yPos);
}

My question is how do i fetch the text from the QGraphicsTextItem?