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Diffstat (limited to 'examples/widgets/painting/concentriccircles/circlewidget.cpp')
-rw-r--r-- | examples/widgets/painting/concentriccircles/circlewidget.cpp | 124 |
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] |