| /**************************************************************************** |
| ** |
| ** Copyright (C) 2016 The Qt Company Ltd. |
| ** Contact: https://www.qt.io/licensing/ |
| ** |
| ** This file is part of the documentation of the Qt Toolkit. |
| ** |
| ** $QT_BEGIN_LICENSE:BSD$ |
| ** Commercial License Usage |
| ** Licensees holding valid commercial Qt licenses may use this file in |
| ** accordance with the commercial license agreement provided with the |
| ** Software or, alternatively, in accordance with the terms contained in |
| ** a written agreement between you and The Qt Company. For licensing terms |
| ** and conditions see https://www.qt.io/terms-conditions. For further |
| ** information use the contact form at https://www.qt.io/contact-us. |
| ** |
| ** BSD License Usage |
| ** Alternatively, 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 The Qt Company Ltd 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." |
| ** |
| ** $QT_END_LICENSE$ |
| ** |
| ****************************************************************************/ |
| |
| //! [0] |
| MyGraphicsOpacityEffect::draw(QPainter *painter) |
| { |
| // Fully opaque; draw directly without going through a pixmap. |
| if (qFuzzyCompare(m_opacity, 1)) { |
| drawSource(painter); |
| return; |
| } |
| ... |
| } |
| //! [0] |
| |
| //! [1] |
| MyGraphicsEffect::draw(QPainter *painter) |
| { |
| ... |
| QPoint offset; |
| if (sourceIsPixmap()) { |
| // No point in drawing in device coordinates (pixmap will be scaled anyways). |
| const QPixmap pixmap = sourcePixmap(Qt::LogicalCoordinates, &offset); |
| ... |
| painter->drawPixmap(offset, pixmap); |
| } else { |
| // Draw pixmap in device coordinates to avoid pixmap scaling; |
| const QPixmap pixmap = sourcePixmap(Qt::DeviceCoordinates, &offset); |
| painter->setWorldTransform(QTransform()); |
| ... |
| painter->drawPixmap(offset, pixmap); |
| } |
| ... |
| } |
| //! [1] |
| |
| //! [2] |
| ... |
| QLinearGradient alphaGradient(rect.topLeft(), rect.bottomLeft()); |
| alphaGradient.setColorAt(0.0, Qt::transparent); |
| alphaGradient.setColorAt(0.5, Qt::black); |
| alphaGradient.setColorAt(1.0, Qt::transparent); |
| QGraphicsOpacityEffect *effect = new QGraphicsOpacityEffect; |
| effect->setOpacityMask(alphaGradient); |
| ... |
| //! [2] |