Qt - children set font breaks positioning - c++

Question

Okay, so I've started making a game using Qt so that I can learn both Qt and C++ at the same time :D
However, I'm stuck with an issue at the moment.
I'm trying to make a textbox using a QGraphicsRectItem as a container (parent), and a QGraphicsTextItem as the text itself (child). The problem I'm facing is the child's relative position to the parent. If I set a font on the QGraphicsTextItem, the positioning will be completely wrong, and it will flow outside of the container for that matter.
TextBox.h:
#ifndef TEXTBOX_H
#define TEXTBOX_H
#include <QGraphicsTextItem>
#include <QGraphicsRectItem>
#include <QTextCursor>
#include <QObject>
#include <qDebug>
class TextBox: public QObject, public QGraphicsRectItem {
Q_OBJECT
public:
TextBox(QString text, QGraphicsItem* parent=NULL);
void mousePressEvent(QGraphicsSceneMouseEvent *event);
QString getText();
QGraphicsTextItem* playerText;
};
#endif // TEXTBOX_H
TextBox.cpp
#include "TextBox.h"
TextBox::TextBox(QString text, QGraphicsItem* parent): QGraphicsRectItem(parent) {
// Draw the textbox
setRect(0,0,400,100);
QBrush brush;
brush.setStyle(Qt::SolidPattern);
brush.setColor(QColor(157, 116, 86, 255));
setBrush(brush);
// Draw the text
playerText = new QGraphicsTextItem(text, this);
int xPos = rect().width() / 2 - playerText->boundingRect().width() / 2;
int yPos = rect().height() / 2 - playerText->boundingRect().height() / 2;
playerText->setPos(xPos,yPos);
}
void TextBox::mousePressEvent(QGraphicsSceneMouseEvent *event) {
this->playerText->setTextInteractionFlags(Qt::TextEditorInteraction);
}
Game.cpp (where the code for creating the object and such is located - only included the relevant part):
// Create the playername textbox
for(int i = 0; i < players; i++) {
TextBox* textBox = new TextBox("Player 1");
textBox->playerText->setFont(QFont("Times", 20));
textBox->playerText->setFlags(QGraphicsItem::ItemIgnoresTransformations);
scene->addItem(textBox);
}
Using the default font & size for the QGraphicsTextItem:
Setting a font & size for the QGraphicsTextItem:
The problem, as you may see, is that when I set a font and a size, the text is no longer in the center of the parent element. (Please do not unleash hell on me for bad code, I'm very new to both Qt and C++, and I'm doing this for learning purposes only).

Answer 1

You are calling the boundingRect() method in the constructor, so the position is set before the font is set to it's final value. If you either make a method to set the position and call it after setting the font or set the font before setting the position in the constructor it should work.