Archived:Calculating text width in Qt

Article Metadata

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Tested with

Devices(s): 5800 XpressMusic

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Compatibility

Platform(s): Qt

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Article

Keywords: QFontMetrics, QFont

Created: (26 Mar 2009)

Last edited: tepaa (26 Mar 2009)

Overview

This code snippets shows how to use QFont and QFontMetrics classes to draw string into center of the screen.

Note: In order to use this code, you need to have Qt for S60 installed on your platform.

Preconditions

• Install Qt for S60 Garden release from here: Qt for S60 "Garden" pre-release
• Check this link for installation guide: How to install the package

Source

void QMyWidget::paintEvent(QPaintEvent*)
    {
    QPainter painter(this);
 
    // Create font
    QFont f("Helvetica",6);
    // Set current font
    painter.setFont(f);
    // Set font color
    painter.setPen(Qt::white);
    // Get QFontMetrics reference
    QFontMetrics fm = painter.fontMetrics();
 
    QString text = "helloworld";
 
    // Calculate text center position into the screen using QFontMetrics class
    QPoint center = QPoint((widgetSize.width()-fm.width(text))/2,
                           fm.height());
 
    // QFontMetrics::width() gives calculated text width with current QFont in QPainter
    // QFontMetrics::height() gives text height
 
    painter.drawText(center,text);
    }

Postconditions

Text is screen center.