Passing QString to PaintEvent

gabor53

Hi,
I have the following code to display a rectangle with a message for 3 seconds:

#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget* parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)

{
    ui->setupUi(this);

}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::paintEvent(QPaintEvent *event)
{
    if(m_showRect)
        {
            QPainter painter(this);

            QFont font = painter.font ();

            font.setFamily ("Arial");
            font.setPixelSize (25);
            painter.setFont (font);
            painter.setPen (Qt::white);

            QRect rect(100, 120, 200, 50);
            painter.setBrush (QColor(65, 163, 255));
            painter.drawRect (rect);

            painter.drawText (rect, Qt::AlignCenter, tr("Record deleted."));
            painter.end();
            QTimer::singleShot(3000,this,&MainWindow::hideRect);
        }
    else
        {
            QWidget::paintEvent(event);
        }
}

void MainWindow::hideRect()
{
    m_showRect = false;
    update();
}

I'd like to rewrite it in a way to be able to pass different messages in a QString so I would be able to use it at several places in the program. I'm thinking of something like this:

painter.drawText(rect,Qt::AlignCenter,tr(msg));

where msg is the QString containing the message.
Please show me the best way to pass msg to drawText. I tried


void MainWindow::paintEvent(QPaintEvent *event, msg)

but that doesn't work. Thank you.

pie62

@gabor53 said in Passing QString to PaintEvent:
You can try look like this.

// mainwindow.h
class MainWindow(QWidget *parent = 0)
{
public:
    .......
    void setMsg(const QString &msg);
    .......
private:
    QString msg;
}

//mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget* parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)

{
    ui->setupUi(this);

}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWondow::setMsg(const QString &msg)
{
    this.msg = msg;
    update();
    QTimer::singleShot(3000,this,&MainWindow::hideRect);
}

void MainWindow::paintEvent(QPaintEvent *event)
{
    if(m_showRect)
        {
            QPainter painter(this);

            QFont font = painter.font ();

            font.setFamily ("Arial");
            font.setPixelSize (25);
            painter.setFont (font);
            painter.setPen (Qt::white);

            QRect rect(100, 120, 200, 50);
            painter.setBrush (QColor(65, 163, 255));
            painter.drawRect (rect);

            painter.drawText (rect, Qt::AlignCenter, msg);
            painter.end();  
        }
    else
        {
            QWidget::paintEvent(event);
        }
}

void MainWindow::hideRect()
{
    //m_showRect = false;
    //update();
    // doing
}

And now you can call MainWindow::setMsg("You text"); for change msg.

gabor53

Hi @pie62 ,
Thank you. It worked perfectly.