1 files changed, 124 insertions, 0 deletions
diff --git a/examples/widgets/painting/concentriccircles/circlewidget.cpp b/examples/widgets/painting/concentriccircles/circlewidget.cpp
new file mode 100644
index 0000000000..2691f20602
--- /dev/null
+++ b/examples/widgets/painting/concentriccircles/circlewidget.cpp
@@ -0,0 +1,124 @@
+/****************************************************************************
+**
+** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/
+**
+** 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:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
+**     the names of its contributors may be used to endorse or promote
+**     products derived from this software without specific prior written
+**     permission.
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtWidgets>
+
+#include "circlewidget.h"
+
+#include <stdlib.h>
+
+//! [0]
+CircleWidget::CircleWidget(QWidget *parent)
+    : QWidget(parent)
+{
+    floatBased = false;
+    antialiased = false;
+    frameNo = 0;
+
+    setBackgroundRole(QPalette::Base);
+    setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
+}
+//! [0]
+
+//! [1]
+void CircleWidget::setFloatBased(bool floatBased)
+{
+    this->floatBased = floatBased;
+    update();
+}
+//! [1]
+
+//! [2]
+void CircleWidget::setAntialiased(bool antialiased)
+{
+    this->antialiased = antialiased;
+    update();
+}
+//! [2]
+
+//! [3]
+QSize CircleWidget::minimumSizeHint() const
+{
+    return QSize(50, 50);
+}
+//! [3]
+
+//! [4]
+QSize CircleWidget::sizeHint() const
+{
+    return QSize(180, 180);
+}
+//! [4]
+
+//! [5]
+void CircleWidget::nextAnimationFrame()
+{
+    ++frameNo;
+    update();
+}
+//! [5]
+
+//! [6]
+void CircleWidget::paintEvent(QPaintEvent *)
+{
+    QPainter painter(this);
+    painter.setRenderHint(QPainter::Antialiasing, antialiased);
+    painter.translate(width() / 2, height() / 2);
+//! [6]
+
+//! [7]
+    for (int diameter = 0; diameter < 256; diameter += 9) {
+        int delta = abs((frameNo % 128) - diameter / 2);
+        int alpha = 255 - (delta * delta) / 4 - diameter;
+//! [7] //! [8]
+        if (alpha > 0) {
+            painter.setPen(QPen(QColor(0, diameter / 2, 127, alpha), 3));
+
+            if (floatBased) {
+                painter.drawEllipse(QRectF(-diameter / 2.0, -diameter / 2.0,
+                                           diameter, diameter));
+            } else {
+                painter.drawEllipse(QRect(-diameter / 2, -diameter / 2,
+                                          diameter, diameter));
+            }
+        }
+    }
+}
+//! [8]