- Qt 5.5
- Qt Widgets
- Painter Paths Example
- renderarea.cpp Example File
- Qt 5.5.1 Reference Documentation

# renderarea.cpp Example File

painting/painterpaths/renderarea.cpp

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the examples of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:BSD$
    ** You may use this file under the terms of the BSD license as follows:
    **
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    #include "renderarea.h"

    #include <QPainter>

    RenderArea::RenderArea(const QPainterPath &path, QWidget *parent)
        : QWidget(parent), path(path)
    {
        penWidth = 1;
        rotationAngle = 0;
        setBackgroundRole(QPalette::Base);
    }

    QSize RenderArea::minimumSizeHint() const
    {
        return QSize(50, 50);
    }

    QSize RenderArea::sizeHint() const
    {
        return QSize(100, 100);
    }

    void RenderArea::setFillRule(Qt::FillRule rule)
    {
        path.setFillRule(rule);
        update();
    }

    void RenderArea::setFillGradient(const QColor &color1, const QColor &color2)
    {
        fillColor1 = color1;
        fillColor2 = color2;
        update();
    }

    void RenderArea::setPenWidth(int width)
    {
        penWidth = width;
        update();
    }

    void RenderArea::setPenColor(const QColor &color)
    {
        penColor = color;
        update();
    }

    void RenderArea::setRotationAngle(int degrees)
    {
        rotationAngle = degrees;
        update();
    }

    void RenderArea::paintEvent(QPaintEvent *)
    {
        QPainter painter(this);
        painter.setRenderHint(QPainter::Antialiasing);
        painter.scale(width() / 100.0, height() / 100.0);
        painter.translate(50.0, 50.0);
        painter.rotate(-rotationAngle);
        painter.translate(-50.0, -50.0);

        painter.setPen(QPen(penColor, penWidth, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
        QLinearGradient gradient(0, 0, 0, 100);
        gradient.setColorAt(0.0, fillColor1);
        gradient.setColorAt(1.0, fillColor2);
        painter.setBrush(gradient);
        painter.drawPath(path);
    }