- Qt 5.5
- Qt Widgets
- Transformations Example
- window.cpp Example File
- Qt 5.5.1 Reference Documentation

# window.cpp Example File

painting/transformations/window.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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    **     from this software without specific prior written permission.
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    #include "window.h"

    #include <QComboBox>
    #include <QGridLayout>

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

        shapeComboBox = new QComboBox;
        shapeComboBox->addItem(tr("Clock"));
        shapeComboBox->addItem(tr("House"));
        shapeComboBox->addItem(tr("Text"));
        shapeComboBox->addItem(tr("Truck"));

        QGridLayout *layout = new QGridLayout;
        layout->addWidget(originalRenderArea, 0, 0);
        layout->addWidget(shapeComboBox, 1, 0);

        for (int i = 0; i < NumTransformedAreas; ++i) {
            transformedRenderAreas[i] = new RenderArea;

            operationComboBoxes[i] = new QComboBox;
            operationComboBoxes[i]->addItem(tr("No transformation"));
            operationComboBoxes[i]->addItem(tr("Rotate by 60\xC2\xB0"));
            operationComboBoxes[i]->addItem(tr("Scale to 75%"));
            operationComboBoxes[i]->addItem(tr("Translate by (50, 50)"));

            connect(operationComboBoxes[i], SIGNAL(activated(int)),
                    this, SLOT(operationChanged()));

            layout->addWidget(transformedRenderAreas[i], 0, i + 1);
            layout->addWidget(operationComboBoxes[i], 1, i + 1);
        }

        setLayout(layout);
        setupShapes();
        shapeSelected(0);

        setWindowTitle(tr("Transformations"));
    }

    void Window::setupShapes()
    {
        QPainterPath truck;
        truck.setFillRule(Qt::WindingFill);
        truck.moveTo(0.0, 87.0);
        truck.lineTo(0.0, 60.0);
        truck.lineTo(10.0, 60.0);
        truck.lineTo(35.0, 35.0);
        truck.lineTo(100.0, 35.0);
        truck.lineTo(100.0, 87.0);
        truck.lineTo(0.0, 87.0);
        truck.moveTo(17.0, 60.0);
        truck.lineTo(55.0, 60.0);
        truck.lineTo(55.0, 40.0);
        truck.lineTo(37.0, 40.0);
        truck.lineTo(17.0, 60.0);
        truck.addEllipse(17.0, 75.0, 25.0, 25.0);
        truck.addEllipse(63.0, 75.0, 25.0, 25.0);

        QPainterPath clock;
        clock.addEllipse(-50.0, -50.0, 100.0, 100.0);
        clock.addEllipse(-48.0, -48.0, 96.0, 96.0);
        clock.moveTo(0.0, 0.0);
        clock.lineTo(-2.0, -2.0);
        clock.lineTo(0.0, -42.0);
        clock.lineTo(2.0, -2.0);
        clock.lineTo(0.0, 0.0);
        clock.moveTo(0.0, 0.0);
        clock.lineTo(2.732, -0.732);
        clock.lineTo(24.495, 14.142);
        clock.lineTo(0.732, 2.732);
        clock.lineTo(0.0, 0.0);

        QPainterPath house;
        house.moveTo(-45.0, -20.0);
        house.lineTo(0.0, -45.0);
        house.lineTo(45.0, -20.0);
        house.lineTo(45.0, 45.0);
        house.lineTo(-45.0, 45.0);
        house.lineTo(-45.0, -20.0);
        house.addRect(15.0, 5.0, 20.0, 35.0);
        house.addRect(-35.0, -15.0, 25.0, 25.0);

        QPainterPath text;
        QFont font;
        font.setPixelSize(50);
        QRect fontBoundingRect = QFontMetrics(font).boundingRect(tr("Qt"));
        text.addText(-QPointF(fontBoundingRect.center()), font, tr("Qt"));

        shapes.append(clock);
        shapes.append(house);
        shapes.append(text);
        shapes.append(truck);

        connect(shapeComboBox, SIGNAL(activated(int)), this, SLOT(shapeSelected(int)));
    }

    void Window::operationChanged()
    {
        static const Operation operationTable[] = {
            NoTransformation, Rotate, Scale, Translate
        };

        QList<Operation> operations;
        for (int i = 0; i < NumTransformedAreas; ++i) {
            int index = operationComboBoxes[i]->currentIndex();
            operations.append(operationTable[index]);
            transformedRenderAreas[i]->setOperations(operations);
        }
    }

    void Window::shapeSelected(int index)
    {
        QPainterPath shape = shapes[index];
        originalRenderArea->setShape(shape);
        for (int i = 0; i < NumTransformedAreas; ++i)
            transformedRenderAreas[i]->setShape(shape);
    }