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