Basic drawing : QBrush « Qt « C++






Basic drawing

  
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**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the examples of the Qt Toolkit.
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** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
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** ensure the GNU Lesser General Public License version 2.1 requirements
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#ifndef RENDERAREA_H
#define RENDERAREA_H

#include <QBrush>
#include <QPen>
#include <QPixmap>
#include <QWidget>


class RenderArea : public QWidget
{
    Q_OBJECT

public:
    enum Shape { Line, Points, Polyline, Polygon, Rect, RoundedRect, Ellipse, Arc,
                 Chord, Pie, Path, Text, Pixmap };

    RenderArea(QWidget *parent = 0);

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

public slots:
    void setShape(Shape shape);
    void setPen(const QPen &pen);
    void setBrush(const QBrush &brush);
    void setAntialiased(bool antialiased);
    void setTransformed(bool transformed);

protected:
    void paintEvent(QPaintEvent *event);

private:
    Shape shape;
    QPen pen;
    QBrush brush;
    bool antialiased;
    bool transformed;
    QPixmap pixmap;
};


#endif





#include <QtGui>

#include "renderarea.h"


RenderArea::RenderArea(QWidget *parent)
    : QWidget(parent)
{
    shape = Polygon;
    antialiased = false;
    transformed = false;
    pixmap.load(":/images/qt-logo.png");

    setBackgroundRole(QPalette::Base);
    setAutoFillBackground(true);
}



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



QSize RenderArea::sizeHint() const
{
    return QSize(400, 200);
}



void RenderArea::setShape(Shape shape)
{
    this->shape = shape;
    update();
}



void RenderArea::setPen(const QPen &pen)
{
    this->pen = pen;
    update();
}



void RenderArea::setBrush(const QBrush &brush)
{
    this->brush = brush;
    update();
}



void RenderArea::setAntialiased(bool antialiased)
{
    this->antialiased = antialiased;
    update();
}



void RenderArea::setTransformed(bool transformed)
{
    this->transformed = transformed;
    update();
}



void RenderArea::paintEvent(QPaintEvent * /* event */)
{
    static const QPoint points[4] = {
        QPoint(10, 80),
        QPoint(20, 10),
        QPoint(80, 30),
        QPoint(90, 70)
    };

    QRect rect(10, 20, 80, 60);

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

    int startAngle = 20 * 16;
    int arcLength = 120 * 16;



    QPainter painter(this);
    painter.setPen(pen);
    painter.setBrush(brush);
    if (antialiased) {
        painter.setRenderHint(QPainter::Antialiasing, true);

        painter.translate(+0.5, +0.5);
    }


    for (int x = 0; x < width(); x += 100) {
        for (int y = 0; y < height(); y += 100) {
            painter.save();
            painter.translate(x, y);
 
            if (transformed) {
                painter.translate(50, 50);
                painter.rotate(60.0);
                painter.scale(0.6, 0.9);
                painter.translate(-50, -50);
            }



            switch (shape) {
            case Line:
                painter.drawLine(rect.bottomLeft(), rect.topRight());
                break;
            case Points:
                painter.drawPoints(points, 4);
                break;
            case Polyline:
                painter.drawPolyline(points, 4);
                break;
            case Polygon:
                painter.drawPolygon(points, 4);
                break;
            case Rect:
                painter.drawRect(rect);
                break;
            case RoundedRect:
                painter.drawRoundedRect(rect, 25, 25, Qt::RelativeSize);
                break;
            case Ellipse:
                painter.drawEllipse(rect);
                break;
            case Arc:
                painter.drawArc(rect, startAngle, arcLength);
                break;
            case Chord:
                painter.drawChord(rect, startAngle, arcLength);
                break;
            case Pie:
                painter.drawPie(rect, startAngle, arcLength);
                break;
            case Path:
                painter.drawPath(path);
                break;
            case Text:
                painter.drawText(rect, Qt::AlignCenter, tr("Qt by\nNokia"));
                break;
            case Pixmap:
                painter.drawPixmap(10, 10, pixmap);
            }
 
            painter.restore();
        }
    }

    painter.setPen(palette().dark().color());
    painter.setBrush(Qt::NoBrush);
    painter.drawRect(QRect(0, 0, width() - 1, height() - 1));
}







#ifndef WINDOW_H
#define WINDOW_H

#include <QWidget>

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


class Window : public QWidget
{
    Q_OBJECT

public:
    Window();

private slots:
    void shapeChanged();
    void penChanged();
    void brushChanged();

private:
    RenderArea *renderArea;
    QLabel *shapeLabel;
    QLabel *penWidthLabel;
    QLabel *penStyleLabel;
    QLabel *penCapLabel;
    QLabel *penJoinLabel;
    QLabel *brushStyleLabel;
    QLabel *otherOptionsLabel;
    QComboBox *shapeComboBox;
    QSpinBox *penWidthSpinBox;
    QComboBox *penStyleComboBox;
    QComboBox *penCapComboBox;
    QComboBox *penJoinComboBox;
    QComboBox *brushStyleComboBox;
    QCheckBox *antialiasingCheckBox;
    QCheckBox *transformationsCheckBox;
};


#endif






#include <QtGui>

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


const int IdRole = Qt::UserRole;



Window::Window()
{
    renderArea = new RenderArea;

    shapeComboBox = new QComboBox;
    shapeComboBox->addItem(tr("Polygon"), RenderArea::Polygon);
    shapeComboBox->addItem(tr("Rectangle"), RenderArea::Rect);
    shapeComboBox->addItem(tr("Rounded Rectangle"), RenderArea::RoundedRect);
    shapeComboBox->addItem(tr("Ellipse"), RenderArea::Ellipse);
    shapeComboBox->addItem(tr("Pie"), RenderArea::Pie);
    shapeComboBox->addItem(tr("Chord"), RenderArea::Chord);
    shapeComboBox->addItem(tr("Path"), RenderArea::Path);
    shapeComboBox->addItem(tr("Line"), RenderArea::Line);
    shapeComboBox->addItem(tr("Polyline"), RenderArea::Polyline);
    shapeComboBox->addItem(tr("Arc"), RenderArea::Arc);
    shapeComboBox->addItem(tr("Points"), RenderArea::Points);
    shapeComboBox->addItem(tr("Text"), RenderArea::Text);
    shapeComboBox->addItem(tr("Pixmap"), RenderArea::Pixmap);

    shapeLabel = new QLabel(tr("&Shape:"));
    shapeLabel->setBuddy(shapeComboBox);



    penWidthSpinBox = new QSpinBox;
    penWidthSpinBox->setRange(0, 20);
    penWidthSpinBox->setSpecialValueText(tr("0 (cosmetic pen)"));

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



    penStyleComboBox = new QComboBox;
    penStyleComboBox->addItem(tr("Solid"), Qt::SolidLine);
    penStyleComboBox->addItem(tr("Dash"), Qt::DashLine);
    penStyleComboBox->addItem(tr("Dot"), Qt::DotLine);
    penStyleComboBox->addItem(tr("Dash Dot"), Qt::DashDotLine);
    penStyleComboBox->addItem(tr("Dash Dot Dot"), Qt::DashDotDotLine);
    penStyleComboBox->addItem(tr("None"), Qt::NoPen);

    penStyleLabel = new QLabel(tr("&Pen Style:"));
    penStyleLabel->setBuddy(penStyleComboBox);

    penCapComboBox = new QComboBox;
    penCapComboBox->addItem(tr("Flat"), Qt::FlatCap);
    penCapComboBox->addItem(tr("Square"), Qt::SquareCap);
    penCapComboBox->addItem(tr("Round"), Qt::RoundCap);

    penCapLabel = new QLabel(tr("Pen &Cap:"));
    penCapLabel->setBuddy(penCapComboBox);

    penJoinComboBox = new QComboBox;
    penJoinComboBox->addItem(tr("Miter"), Qt::MiterJoin);
    penJoinComboBox->addItem(tr("Bevel"), Qt::BevelJoin);
    penJoinComboBox->addItem(tr("Round"), Qt::RoundJoin);

    penJoinLabel = new QLabel(tr("Pen &Join:"));
    penJoinLabel->setBuddy(penJoinComboBox);



    brushStyleComboBox = new QComboBox;
    brushStyleComboBox->addItem(tr("Linear Gradient"),
            Qt::LinearGradientPattern);
    brushStyleComboBox->addItem(tr("Radial Gradient"),
            Qt::RadialGradientPattern);
    brushStyleComboBox->addItem(tr("Conical Gradient"),
            Qt::ConicalGradientPattern);
    brushStyleComboBox->addItem(tr("Texture"), Qt::TexturePattern);
    brushStyleComboBox->addItem(tr("Solid"), Qt::SolidPattern);
    brushStyleComboBox->addItem(tr("Horizontal"), Qt::HorPattern);
    brushStyleComboBox->addItem(tr("Vertical"), Qt::VerPattern);
    brushStyleComboBox->addItem(tr("Cross"), Qt::CrossPattern);
    brushStyleComboBox->addItem(tr("Backward Diagonal"), Qt::BDiagPattern);
    brushStyleComboBox->addItem(tr("Forward Diagonal"), Qt::FDiagPattern);
    brushStyleComboBox->addItem(tr("Diagonal Cross"), Qt::DiagCrossPattern);
    brushStyleComboBox->addItem(tr("Dense 1"), Qt::Dense1Pattern);
    brushStyleComboBox->addItem(tr("Dense 2"), Qt::Dense2Pattern);
    brushStyleComboBox->addItem(tr("Dense 3"), Qt::Dense3Pattern);
    brushStyleComboBox->addItem(tr("Dense 4"), Qt::Dense4Pattern);
    brushStyleComboBox->addItem(tr("Dense 5"), Qt::Dense5Pattern);
    brushStyleComboBox->addItem(tr("Dense 6"), Qt::Dense6Pattern);
    brushStyleComboBox->addItem(tr("Dense 7"), Qt::Dense7Pattern);
    brushStyleComboBox->addItem(tr("None"), Qt::NoBrush);

    brushStyleLabel = new QLabel(tr("&Brush Style:"));
    brushStyleLabel->setBuddy(brushStyleComboBox);



    otherOptionsLabel = new QLabel(tr("Other Options:"));
 
    antialiasingCheckBox = new QCheckBox(tr("&Antialiasing"));
 
    transformationsCheckBox = new QCheckBox(tr("&Transformations"));



    connect(shapeComboBox, SIGNAL(activated(int)),
            this, SLOT(shapeChanged()));
    connect(penWidthSpinBox, SIGNAL(valueChanged(int)),
            this, SLOT(penChanged()));
    connect(penStyleComboBox, SIGNAL(activated(int)),
            this, SLOT(penChanged()));
    connect(penCapComboBox, SIGNAL(activated(int)),
            this, SLOT(penChanged()));
    connect(penJoinComboBox, SIGNAL(activated(int)),
            this, SLOT(penChanged()));
    connect(brushStyleComboBox, SIGNAL(activated(int)),
            this, SLOT(brushChanged()));
    connect(antialiasingCheckBox, SIGNAL(toggled(bool)),
            renderArea, SLOT(setAntialiased(bool)));
    connect(transformationsCheckBox, SIGNAL(toggled(bool)),
            renderArea, SLOT(setTransformed(bool)));



    QGridLayout *mainLayout = new QGridLayout;
 
    mainLayout->setColumnStretch(0, 1);
    mainLayout->setColumnStretch(3, 1);
    mainLayout->addWidget(renderArea, 0, 0, 1, 4);
    mainLayout->setRowMinimumHeight(1, 6);
    mainLayout->addWidget(shapeLabel, 2, 1, Qt::AlignRight);
    mainLayout->addWidget(shapeComboBox, 2, 2);
    mainLayout->addWidget(penWidthLabel, 3, 1, Qt::AlignRight);
    mainLayout->addWidget(penWidthSpinBox, 3, 2);
    mainLayout->addWidget(penStyleLabel, 4, 1, Qt::AlignRight);
    mainLayout->addWidget(penStyleComboBox, 4, 2);
    mainLayout->addWidget(penCapLabel, 5, 1, Qt::AlignRight);
    mainLayout->addWidget(penCapComboBox, 5, 2);
    mainLayout->addWidget(penJoinLabel, 6, 1, Qt::AlignRight);
    mainLayout->addWidget(penJoinComboBox, 6, 2);
    mainLayout->addWidget(brushStyleLabel, 7, 1, Qt::AlignRight);
    mainLayout->addWidget(brushStyleComboBox, 7, 2);
    mainLayout->setRowMinimumHeight(8, 6);
    mainLayout->addWidget(otherOptionsLabel, 9, 1, Qt::AlignRight);
    mainLayout->addWidget(antialiasingCheckBox, 9, 2);
    mainLayout->addWidget(transformationsCheckBox, 10, 2);
    setLayout(mainLayout);

    shapeChanged();
    penChanged();
    brushChanged();
    antialiasingCheckBox->setChecked(true);

    setWindowTitle(tr("Basic Drawing"));
}



void Window::shapeChanged()
{
    RenderArea::Shape shape = RenderArea::Shape(shapeComboBox->itemData(
            shapeComboBox->currentIndex(), IdRole).toInt());
    renderArea->setShape(shape);
}



void Window::penChanged()
{
    int width = penWidthSpinBox->value();
    Qt::PenStyle style = Qt::PenStyle(penStyleComboBox->itemData(
            penStyleComboBox->currentIndex(), IdRole).toInt());
    Qt::PenCapStyle cap = Qt::PenCapStyle(penCapComboBox->itemData(
            penCapComboBox->currentIndex(), IdRole).toInt());
    Qt::PenJoinStyle join = Qt::PenJoinStyle(penJoinComboBox->itemData(
            penJoinComboBox->currentIndex(), IdRole).toInt());

    renderArea->setPen(QPen(Qt::blue, width, style, cap, join));
}



void Window::brushChanged()
{
    Qt::BrushStyle style = Qt::BrushStyle(brushStyleComboBox->itemData(

            brushStyleComboBox->currentIndex(), IdRole).toInt());


    if (style == Qt::LinearGradientPattern) {
        QLinearGradient linearGradient(0, 0, 100, 100);
        linearGradient.setColorAt(0.0, Qt::white);
        linearGradient.setColorAt(0.2, Qt::green);
        linearGradient.setColorAt(1.0, Qt::black);
        renderArea->setBrush(linearGradient);
 
    } else if (style == Qt::RadialGradientPattern) {
        QRadialGradient radialGradient(50, 50, 50, 70, 70);
        radialGradient.setColorAt(0.0, Qt::white);
        radialGradient.setColorAt(0.2, Qt::green);
        radialGradient.setColorAt(1.0, Qt::black);
        renderArea->setBrush(radialGradient);
    } else if (style == Qt::ConicalGradientPattern) {
        QConicalGradient conicalGradient(50, 50, 150);
        conicalGradient.setColorAt(0.0, Qt::white);
        conicalGradient.setColorAt(0.2, Qt::green);
        conicalGradient.setColorAt(1.0, Qt::black);
        renderArea->setBrush(conicalGradient);
 
    } else if (style == Qt::TexturePattern) {
        renderArea->setBrush(QBrush(QPixmap(":/images/brick.png")));
 
    } else {
        renderArea->setBrush(QBrush(Qt::green, style));
    }
}





#include <QApplication>

#include "window.h"

int main(int argc, char *argv[])
{
    Q_INIT_RESOURCE(basicdrawing);

    QApplication app(argc, argv);
    Window window;
    window.show();
    return app.exec();
}

   
    
  








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