Render Area : QWidget « Qt « C++






Render Area

  



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#ifndef RENDERAREA_H
#define RENDERAREA_H

#include <QPainterPath>
#include <QWidget>


class RenderArea : public QWidget
{
    Q_OBJECT

public:
    RenderArea(const QPainterPath &path, QWidget *parent = 0);

    QSize minimumSizeHint() const;
    QSize sizeHint() const;

public slots:
    void setFillRule(Qt::FillRule rule);
    void setFillGradient(const QColor &color1, const QColor &color2);
    void setPenWidth(int width);
    void setPenColor(const QColor &color);
    void setRotationAngle(int degrees);

protected:
    void paintEvent(QPaintEvent *event);



private:
    QPainterPath path;
    QColor fillColor1;
    QColor fillColor2;
    int penWidth;
    QColor penColor;
    int rotationAngle;
};


#endif






#include <QtGui>

#include "renderarea.h"


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);
}






#ifndef WINDOW_H
#define WINDOW_H

#include <QWidget>

QT_BEGIN_NAMESPACE
class QComboBox;
class QLabel;
class QSpinBox;
QT_END_NAMESPACE
class RenderArea;


class Window : public QWidget
{
    Q_OBJECT

public:
    Window();

private slots:
    void fillRuleChanged();
    void fillGradientChanged();
    void penColorChanged();



private:
    void populateWithColors(QComboBox *comboBox);
    QVariant currentItemData(QComboBox *comboBox);



    enum { NumRenderAreas = 9 };

    RenderArea *renderAreas[NumRenderAreas];
    QLabel *fillRuleLabel;
    QLabel *fillGradientLabel;
    QLabel *fillToLabel;
    QLabel *penWidthLabel;
    QLabel *penColorLabel;
    QLabel *rotationAngleLabel;
    QComboBox *fillRuleComboBox;
    QComboBox *fillColor1ComboBox;
    QComboBox *fillColor2ComboBox;
    QSpinBox *penWidthSpinBox;
    QComboBox *penColorComboBox;
    QSpinBox *rotationAngleSpinBox;
};


#endif






#include <QtGui>

#include <math.h>

#include "renderarea.h"
#include "window.h"


const float Pi = 3.14159f;



Window::Window()
{
    QPainterPath rectPath;
    rectPath.moveTo(20.0, 30.0);
    rectPath.lineTo(80.0, 30.0);
    rectPath.lineTo(80.0, 70.0);
    rectPath.lineTo(20.0, 70.0);
    rectPath.closeSubpath();



    QPainterPath roundRectPath;
    roundRectPath.moveTo(80.0, 35.0);
    roundRectPath.arcTo(70.0, 30.0, 10.0, 10.0, 0.0, 90.0);
    roundRectPath.lineTo(25.0, 30.0);
    roundRectPath.arcTo(20.0, 30.0, 10.0, 10.0, 90.0, 90.0);
    roundRectPath.lineTo(20.0, 65.0);
    roundRectPath.arcTo(20.0, 60.0, 10.0, 10.0, 180.0, 90.0);
    roundRectPath.lineTo(75.0, 70.0);
    roundRectPath.arcTo(70.0, 60.0, 10.0, 10.0, 270.0, 90.0);
    roundRectPath.closeSubpath();



    QPainterPath ellipsePath;
    ellipsePath.moveTo(80.0, 50.0);
    ellipsePath.arcTo(20.0, 30.0, 60.0, 40.0, 0.0, 360.0);



    QPainterPath piePath;
    piePath.moveTo(50.0, 50.0);
    piePath.arcTo(20.0, 30.0, 60.0, 40.0, 60.0, 240.0);
    piePath.closeSubpath();



    QPainterPath polygonPath;
    polygonPath.moveTo(10.0, 80.0);
    polygonPath.lineTo(20.0, 10.0);
    polygonPath.lineTo(80.0, 30.0);
    polygonPath.lineTo(90.0, 70.0);
    polygonPath.closeSubpath();



    QPainterPath groupPath;
    groupPath.moveTo(60.0, 40.0);
    groupPath.arcTo(20.0, 20.0, 40.0, 40.0, 0.0, 360.0);
    groupPath.moveTo(40.0, 40.0);
    groupPath.lineTo(40.0, 80.0);
    groupPath.lineTo(80.0, 80.0);
    groupPath.lineTo(80.0, 40.0);
    groupPath.closeSubpath();



    QPainterPath textPath;
    QFont timesFont("Times", 50);
    timesFont.setStyleStrategy(QFont::ForceOutline);
    textPath.addText(10, 70, timesFont, tr("Qt"));



    QPainterPath bezierPath;
    bezierPath.moveTo(20, 30);
    bezierPath.cubicTo(80, 0, 50, 50, 80, 80);



    QPainterPath starPath;
    starPath.moveTo(90, 50);
    for (int i = 1; i < 5; ++i) {
        starPath.lineTo(50 + 40 * cos(0.8 * i * Pi),
                        50 + 40 * sin(0.8 * i * Pi));
    }
    starPath.closeSubpath();



    renderAreas[0] = new RenderArea(rectPath);
    renderAreas[1] = new RenderArea(roundRectPath);
    renderAreas[2] = new RenderArea(ellipsePath);
    renderAreas[3] = new RenderArea(piePath);
    renderAreas[4] = new RenderArea(polygonPath);
    renderAreas[5] = new RenderArea(groupPath);
    renderAreas[6] = new RenderArea(textPath);
    renderAreas[7] = new RenderArea(bezierPath);
    renderAreas[8] = new RenderArea(starPath);
    Q_ASSERT(NumRenderAreas == 9);



    fillRuleComboBox = new QComboBox;
    fillRuleComboBox->addItem(tr("Odd Even"), Qt::OddEvenFill);
    fillRuleComboBox->addItem(tr("Winding"), Qt::WindingFill);

    fillRuleLabel = new QLabel(tr("Fill &Rule:"));
    fillRuleLabel->setBuddy(fillRuleComboBox);



    fillColor1ComboBox = new QComboBox;
    populateWithColors(fillColor1ComboBox);
    fillColor1ComboBox->setCurrentIndex(
            fillColor1ComboBox->findText("mediumslateblue"));

    fillColor2ComboBox = new QComboBox;
    populateWithColors(fillColor2ComboBox);
    fillColor2ComboBox->setCurrentIndex(
            fillColor2ComboBox->findText("cornsilk"));

    fillGradientLabel = new QLabel(tr("&Fill Gradient:"));
    fillGradientLabel->setBuddy(fillColor1ComboBox);

    fillToLabel = new QLabel(tr("to"));
    fillToLabel->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);

    penWidthSpinBox = new QSpinBox;
    penWidthSpinBox->setRange(0, 20);

    penWidthLabel = new QLabel(tr("&Pen Width:"));
    penWidthLabel->setBuddy(penWidthSpinBox);

    penColorComboBox = new QComboBox;
    populateWithColors(penColorComboBox);
    penColorComboBox->setCurrentIndex(
            penColorComboBox->findText("darkslateblue"));

    penColorLabel = new QLabel(tr("Pen &Color:"));
    penColorLabel->setBuddy(penColorComboBox);

    rotationAngleSpinBox = new QSpinBox;
    rotationAngleSpinBox->setRange(0, 359);
    rotationAngleSpinBox->setWrapping(true);
    rotationAngleSpinBox->setSuffix("\xB0");

    rotationAngleLabel = new QLabel(tr("&Rotation Angle:"));
    rotationAngleLabel->setBuddy(rotationAngleSpinBox);



    connect(fillRuleComboBox, SIGNAL(activated(int)),
            this, SLOT(fillRuleChanged()));
    connect(fillColor1ComboBox, SIGNAL(activated(int)),
            this, SLOT(fillGradientChanged()));
    connect(fillColor2ComboBox, SIGNAL(activated(int)),
            this, SLOT(fillGradientChanged()));
    connect(penColorComboBox, SIGNAL(activated(int)),
            this, SLOT(penColorChanged()));

    for (int i = 0; i < NumRenderAreas; ++i) {
        connect(penWidthSpinBox, SIGNAL(valueChanged(int)),
                renderAreas[i], SLOT(setPenWidth(int)));
        connect(rotationAngleSpinBox, SIGNAL(valueChanged(int)),
                renderAreas[i], SLOT(setRotationAngle(int)));
    }

 
    QGridLayout *topLayout = new QGridLayout;
    for (int i = 0; i < NumRenderAreas; ++i)
        topLayout->addWidget(renderAreas[i], i / 3, i % 3);

    QGridLayout *mainLayout = new QGridLayout;
    mainLayout->addLayout(topLayout, 0, 0, 1, 4);
    mainLayout->addWidget(fillRuleLabel, 1, 0);
    mainLayout->addWidget(fillRuleComboBox, 1, 1, 1, 3);
    mainLayout->addWidget(fillGradientLabel, 2, 0);
    mainLayout->addWidget(fillColor1ComboBox, 2, 1);
    mainLayout->addWidget(fillToLabel, 2, 2);
    mainLayout->addWidget(fillColor2ComboBox, 2, 3);
    mainLayout->addWidget(penWidthLabel, 3, 0);
    mainLayout->addWidget(penWidthSpinBox, 3, 1, 1, 3);
    mainLayout->addWidget(penColorLabel, 4, 0);
    mainLayout->addWidget(penColorComboBox, 4, 1, 1, 3);
    mainLayout->addWidget(rotationAngleLabel, 5, 0);
    mainLayout->addWidget(rotationAngleSpinBox, 5, 1, 1, 3);
    setLayout(mainLayout);



    fillRuleChanged();
    fillGradientChanged();
    penColorChanged();
    penWidthSpinBox->setValue(2);

    setWindowTitle(tr("Painter Paths"));
}



void Window::fillRuleChanged()
{
    Qt::FillRule rule = (Qt::FillRule)currentItemData(fillRuleComboBox).toInt();

    for (int i = 0; i < NumRenderAreas; ++i)
        renderAreas[i]->setFillRule(rule);
}



void Window::fillGradientChanged()
{
    QColor color1 = qvariant_cast<QColor>(currentItemData(fillColor1ComboBox));
    QColor color2 = qvariant_cast<QColor>(currentItemData(fillColor2ComboBox));

    for (int i = 0; i < NumRenderAreas; ++i)
        renderAreas[i]->setFillGradient(color1, color2);
}



void Window::penColorChanged()
{
    QColor color = qvariant_cast<QColor>(currentItemData(penColorComboBox));

    for (int i = 0; i < NumRenderAreas; ++i)
        renderAreas[i]->setPenColor(color);
}



void Window::populateWithColors(QComboBox *comboBox)
{
    QStringList colorNames = QColor::colorNames();
    foreach (QString name, colorNames)
        comboBox->addItem(name, QColor(name));
}



QVariant Window::currentItemData(QComboBox *comboBox)
{
    return comboBox->itemData(comboBox->currentIndex());
}







#include <QApplication>

#include "window.h"

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    Window window;
    window.show();
    return app.exec();
}

   
    
  








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