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# Code for 2D Painting Example

    /****************************************************************************
    **
    ** Copyright (C) 1992-2008 Trolltech ASA. All rights reserved.
    **
    ** This file is part of Qt Jambi.
    **
    ** ** This file may be used under the terms of the GNU General Public
    ** License version 2.0 as published by the Free Software Foundation
    ** and appearing in the file LICENSE.GPL included in the packaging of
    ** this file.  Please review the following information to ensure GNU
    ** General Public Licensing requirements will be met:
    ** http://www.trolltech.com/products/qt/opensource.html
    **
    ** If you are unsure which license is appropriate for your use, please
    ** review the following information:
    ** http://www.trolltech.com/products/qt/licensing.html or contact the
    ** sales department at sales@trolltech.com.

    **
    ** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
    ** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
    **
    ****************************************************************************/

    package com.trolltech.examples;

    import com.trolltech.qt.core.*;
    import com.trolltech.qt.gui.*;
    import com.trolltech.qt.opengl.*;

    @QtJambiExample(name = "2D Painting")
    public class  Painting2D extends QWidget
    {
        private Helper helper;

        public Painting2D() {
            helper = new Helper();

            Widget widget = new Widget(helper, this);
            GLWidget openGL = new GLWidget(helper, this);
            QLabel nativeLabel = new QLabel(tr("Native"));
            nativeLabel.setAlignment(Qt.AlignmentFlag.AlignHCenter);
            QLabel openGLLabel = new QLabel(tr("OpenGL"));
            openGLLabel.setAlignment(Qt.AlignmentFlag.AlignHCenter);

            QGridLayout layout = new QGridLayout();
            layout.addWidget(widget, 0, 0);
            layout.addWidget(openGL, 0, 1);
            layout.addWidget(nativeLabel, 1, 0);
            layout.addWidget(openGLLabel, 1, 1);
            setLayout(layout);

            QTimer timer = new QTimer(this);
            timer.timeout.connect(openGL, "animate()");
            timer.timeout.connect(widget, "animate()");
            timer.setInterval(1);
            timer.start(50);

            setWindowTitle(tr("2D Painting on Native and OpenGL Widgets"));
            setWindowIcon(new QIcon("classpath:com/trolltech/images/qt-logo.png"));
        }

        class GLWidget extends QGLWidget {
            private Helper helper;
            private int elapsed;

            public GLWidget(Helper helper, QWidget parent) {
                super(new QGLFormat(), parent);

                this.helper = helper;
                setFixedSize(200, 200);
            }

            public void animate() {
                elapsed = (elapsed + ((QTimer) signalSender()).interval()) % 1000;
                repaint();
            }

            @Override
            protected void paintEvent(QPaintEvent event) {
                QPainter painter = new QPainter();
                painter.begin(this);
                painter.setRenderHint(QPainter.RenderHint.Antialiasing);
                helper.paint(painter, event, elapsed);
                painter.end();
            }
        }

        class Widget extends QWidget {
            private int elapsed;
            private Helper helper;

            public Widget(Helper helper, QWidget parent) {
                super(parent);
                this.helper = helper;
                setFixedSize(200, 200);
            }

            public void animate() {
                elapsed = (elapsed + ((QTimer) signalSender()).interval()) % 1000;
                repaint();
            }

            @Override
            public void paintEvent(QPaintEvent event) {
                QPainter painter = new QPainter();
                painter.begin(this);
                painter.setRenderHint(QPainter.RenderHint.Antialiasing);
                helper.paint(painter, event, elapsed);
                painter.end();
            }
        }

        class Helper {
            private QBrush background;
            private QBrush circleBrush;
            private QFont textFont;
            private QPen circlePen;
            private QPen textPen;

            public Helper() {
                QLinearGradient gradient =
                    new QLinearGradient(new QPointF(50, -20), new QPointF(80, 20));
                gradient.setColorAt(0.0, new QColor(Qt.GlobalColor.white));
                gradient.setColorAt(1.0, new QColor(0xa6, 0xce, 0x39));

                background = new QBrush(new QColor(64, 32, 64));
                circleBrush = new QBrush(gradient);
                circlePen = new QPen(new QColor(Qt.GlobalColor.black));
                circlePen.setWidth(1);
                textPen = new QPen(new QColor(Qt.GlobalColor.white));

                textFont = new QFont();
                textFont.setPixelSize(50);
            }

            public void paint(QPainter painter, QPaintEvent event, int elapsed) {
                painter.fillRect(event.rect(), background);
                painter.translate(100, 100);

                painter.save();
                painter.setBrush(circleBrush);
                painter.setPen(circlePen);
                painter.rotate(elapsed * 0.030);

                double r = (elapsed)/1000.0;
                int n = 30;
                for (int i = 0; i < n; ++i) {
                    painter.rotate(30);
                    double radius = 0 + 120.0*((i+r)/n);
                    double circleRadius = 1 + ((i+r)/n)*20;
                    painter.drawEllipse(new QRectF(radius, -circleRadius,
                    circleRadius*2, circleRadius*2));
                }
                painter.restore();

                painter.setPen(textPen);
                painter.setFont(textFont);
                painter.drawText(new QRect(-50, -50, 100, 100), Qt.AlignmentFlag.AlignCenter.value(), "Qt");
            }
        }

        public static void main(String args[]) {
            QApplication.initialize(args);

            Painting2D painting2d = new Painting2D();
            painting2d.show();

            QApplication.exec();
        }
    }