Archived:Colorize effect with the Qt graphics view framework

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Qt Quick should be used for all UI development on mobile devices. The approach described in this article (based on QWidget) is deprecated.

Article Metadata

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Code Example

Source file: Media:GraphicsEffect-Colorize.zip

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Compatibility

Platform(s): any

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Article

Keywords: QGraphicsColorizeEffect

Created: gnuton (23 Dec 2010)

Last edited: hamishwillee (11 Oct 2012)

Introduction

This article shows how to use the colorize effect using Qt's QGraphicsColorizeEffect. Qt Graphics view framework offers a convenient way to apply graphics effects to Graphics Items.

Code

This is a minimal application which colors a QGraphicsPixmap using the QGraphicsColorizeEffect. The QGraphicsColorizeEffect class provides a colorize effect. The color can be modified using the setColor() function. setStrength() changes the colorize strength property.

#include <QtGui/QApplication>
#include <QGraphicsView>
#include <QGraphicsScene>
#include <QGraphicsPixmapItem>
#include <QGraphicsEffect>
 
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QGraphicsView view;
    view.setScene(new QGraphicsScene);
 
    QGraphicsPixmapItem *p = view.scene()->addPixmap(QPixmap(":/meditate.png"));
 
    QGraphicsColorizeEffect colorize;
    colorize.setColor(QColor(Qt::red)); //Default value is blue
    colorize.setStrength(0.5); //Default value is 1.0
    p->setGraphicsEffect(&colorize);
 
    view.show();
    return a.exec();
}

Source code

• You can download the code from here: Media:GraphicsEffect-Colorize.zip