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Diffstat (limited to 'src/gui/effects/qgraphicseffect.cpp')
| -rw-r--r-- | src/gui/effects/qgraphicseffect.cpp | 572 |
1 files changed, 572 insertions, 0 deletions
diff --git a/src/gui/effects/qgraphicseffect.cpp b/src/gui/effects/qgraphicseffect.cpp new file mode 100644 index 0000000..949922a --- /dev/null +++ b/src/gui/effects/qgraphicseffect.cpp @@ -0,0 +1,572 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (qt-info@nokia.com) +** +** This file is part of the QtGui module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain +** additional rights. These rights are described in the Nokia Qt LGPL +** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 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 the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at qt-sales@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! + \class QGraphicsEffect + \brief The QGraphicsEffect class is the base class for all graphics effects. + \since 4.6 + \ingroup multimedia + \ingroup graphicsview-api + + Effects alter the appearance of elements by hooking into the rendering + pipeline and operating between the source (e.g., a QGraphicsPixmapItem), + and the destination device (e.g., QGraphicsView's viewport). Effects can be + disabled by calling setEnabled(); if the effect is disabled, the source is + rendered directly. + + If you want to add a visual effect to a QGraphicsItem, you can either use + one of the standard effects, or create your own effect by making a subclass + of QGraphicsEffect. + + Qt provides several standard effects, including: + + \list + \o QGraphicsGrayScaleEffect - renders the item in shades of gray + \o QGraphicsColorizeEffect - renders the item in shades of any given color + \o QGraphicsPixelizeEffect - pixelizes the item with any pixel size + \o QGraphicsBlurEffect - blurs the item by a given radius + \o QGraphicsDropShadowEffect - renders a dropshadow behind the item + \endlist + + If all you want is to add an effect to an item, you should visit the + documentation for the specific effect to learn more about how each effect + can be used. + + If you want to create your own custom effect, you can start by creating a + subclass of QGraphicsEffect (or any of the existing effects), and + reimplement the virtual function draw(). This function is called whenever + the effect needs to redraw. draw() has two arguments: the painter, and a + pointer to the source (QGraphicsEffectSource). The source provides extra + context information, such as a pointer to the item that is rendering the + effect, any cached pixmap data, and the device rect bounds. See the draw() + documentation for more details. You can also get a pointer to the current + source by calling source(). + + If your effect changes, you can call update() to request a redraw. If your + custom effect changes the bounding rectangle of the source (e.g., a radial + glow effect may need to apply an extra margin), you can reimplement the + virtual boundingRectFor() function, and call updateBoundingRect() to notify + the framework whenever this rectangle changes. The virtual + sourceBoundingRectChanged() function is called to notify the effects that + the source's bounding rectangle has changed (e.g., if the source is a + QGraphicsRectItem, then if the rectangle parameters have changed). + + \sa QGraphicsItem::setGraphicsEffect() +*/ + +#include "qgraphicseffect_p.h" + +#include <QtGui/qimage.h> +#include <QtGui/qpainter.h> +#include <QtCore/qrect.h> +#include <QtCore/qdebug.h> + +QT_BEGIN_NAMESPACE + +QGraphicsEffectSource::QGraphicsEffectSource(QGraphicsEffectSourcePrivate &dd, QObject *parent) + : QObject(dd, parent) +{} + +QGraphicsEffectSource::~QGraphicsEffectSource() +{} + +QRect QGraphicsEffectSource::deviceRect() const +{ + return d_func()->deviceRect(); +} + +QRectF QGraphicsEffectSource::boundingRect(Qt::CoordinateSystem system) const +{ + return d_func()->boundingRect(system); +} + +const QGraphicsItem *QGraphicsEffectSource::graphicsItem() const +{ + return d_func()->graphicsItem(); +} + +const QWidget *QGraphicsEffectSource::widget() const +{ + return d_func()->widget(); +} + +const QStyleOption *QGraphicsEffectSource::styleOption() const +{ + return d_func()->styleOption(); +} + +void QGraphicsEffectSource::draw(QPainter *painter) +{ + d_func()->draw(painter); +} + +void QGraphicsEffectSource::update() +{ + d_func()->update(); +} + +bool QGraphicsEffectSource::isPixmap() const +{ + return d_func()->isPixmap(); +} + +QPixmap QGraphicsEffectSource::pixmap(Qt::CoordinateSystem system, QPoint *offset) const +{ + return d_func()->pixmap(system, offset); +} + +/*! + Constructs a new QGraphicsEffect instance. +*/ +QGraphicsEffect::QGraphicsEffect(QObject *parent) + : QObject(*new QGraphicsEffectPrivate, parent) +{ +} + +/*! + \internal +*/ +QGraphicsEffect::QGraphicsEffect(QGraphicsEffectPrivate &dd, QObject *parent) + : QObject(dd, parent) +{ +} + +/*! + Removes the effect from the source, and destroys the graphics effect. +*/ +QGraphicsEffect::~QGraphicsEffect() +{ + Q_D(QGraphicsEffect); + d->setGraphicsEffectSource(0); +} + +/*! + Returns the bounding rectangle for this effect (i.e., the bounding + rectangle of the source, adjusted by any margins applied by the effect + itself). + + \sa boundingRectFor(), updateBoundingRect() +*/ +QRectF QGraphicsEffect::boundingRect() const +{ + Q_D(const QGraphicsEffect); + if (d->source) + return boundingRectFor(d->source->boundingRect()); + return QRectF(); +} + +/*! + Returns the bounding rectangle for this effect, given the provided source + \a rect. When writing you own custom effect, you must call + updateBoundingRect() whenever any parameters are changed that may cause + this this function to return a different value. + + \sa boundingRect() +*/ +QRectF QGraphicsEffect::boundingRectFor(const QRectF &rect) const +{ + return rect; +} + +/*! + \property QGraphicsEffect::enabled + \brief whether the effect is enabled or not. + + If an effect is disabled, the source will be rendered with as normal, with + no interference from the effect. If the effect is enabled (default), the + source will be rendered with the effect applied. + + This property is provided so that you can disable certain effects on slow + platforms, in order to ensure that the user interface is responsive. +*/ +bool QGraphicsEffect::isEnabled() const +{ + Q_D(const QGraphicsEffect); + return d->isEnabled; +} + +void QGraphicsEffect::setEnabled(bool enable) +{ + Q_D(QGraphicsEffect); + if (d->isEnabled == enable) + return; + + d->isEnabled = enable; + if (d->source) + d->source->update(); + emit enabledChanged(enable); +} + +/*! + Returns a pointer to the source, which provides extra context information + that can be useful for the effect. + + \sa draw() +*/ +QGraphicsEffectSource *QGraphicsEffect::source() const +{ + Q_D(const QGraphicsEffect); + return d->source; +} + +/*! + This function notifies the effect framework that the effect's bounding + rectangle has changed. As a custom effect author, you must call this + function whenever you change any parameters that will cause the virtual + boundingRectFor() function to return a different value. + + \sa boundingRectFor(), boundingRect() +*/ +void QGraphicsEffect::updateBoundingRect() +{ + Q_D(QGraphicsEffect); + if (d->source) + d->source->update(); +} + +/*! + This virtual function is called by QGraphicsEffect to notify the effect + that the source has changed. If the effect applies any cache, then this + cache must be purged in order to reflect the new appearance of the source. + + The \a flags describes what has changed. +*/ +void QGraphicsEffect::sourceChanged(ChangeFlags flags) +{ + Q_UNUSED(flags); +} + +QGraphicsGrayscaleEffect::QGraphicsGrayscaleEffect(QObject *parent) + : QGraphicsEffect(*new QGraphicsGrayscaleEffectPrivate, parent) +{ +} + +QGraphicsGrayscaleEffect::~QGraphicsGrayscaleEffect() +{ +} + +void QGraphicsGrayscaleEffect::draw(QPainter *painter, QGraphicsEffectSource *source) +{ + Q_D(QGraphicsGrayscaleEffect); + QPoint offset; + if (source->isPixmap()) { + // No point in drawing in device coordinates (pixmap will be scaled anyways). + const QPixmap pixmap = source->pixmap(Qt::LogicalCoordinates, &offset); + d->filter->draw(painter, offset, pixmap); + return; + } + + // Draw pixmap in device coordinates to avoid pixmap scaling; + const QPixmap pixmap = source->pixmap(Qt::DeviceCoordinates, &offset); + QTransform restoreTransform = painter->worldTransform(); + painter->setWorldTransform(QTransform()); + d->filter->draw(painter, offset, pixmap); + painter->setWorldTransform(restoreTransform); + +} + +QGraphicsColorizeEffect::QGraphicsColorizeEffect(QObject *parent) + : QGraphicsEffect(*new QGraphicsColorizeEffectPrivate, parent) +{ +} + +QGraphicsColorizeEffect::~QGraphicsColorizeEffect() +{ +} + +QColor QGraphicsColorizeEffect::color() const +{ + Q_D(const QGraphicsColorizeEffect); + return d->filter->color(); +} + +void QGraphicsColorizeEffect::setColor(const QColor &c) +{ + Q_D(QGraphicsColorizeEffect); + if (d->filter->color() == c) + return; + + d->filter->setColor(c); + emit colorChanged(c); +} + +void QGraphicsColorizeEffect::draw(QPainter *painter, QGraphicsEffectSource *source) +{ + Q_D(QGraphicsColorizeEffect); + QPoint offset; + if (source->isPixmap()) { + // No point in drawing in device coordinates (pixmap will be scaled anyways). + const QPixmap pixmap = source->pixmap(Qt::LogicalCoordinates, &offset); + d->filter->draw(painter, offset, pixmap); + return; + } + + // Draw pixmap in deviceCoordinates to avoid pixmap scaling. + const QPixmap pixmap = source->pixmap(Qt::DeviceCoordinates, &offset); + QTransform restoreTransform = painter->worldTransform(); + painter->setWorldTransform(QTransform()); + d->filter->draw(painter, offset, pixmap); + painter->setWorldTransform(restoreTransform); +} + +QGraphicsPixelizeEffect::QGraphicsPixelizeEffect(QObject *parent) + : QGraphicsEffect(*new QGraphicsPixelizeEffectPrivate, parent) +{ +} + +QGraphicsPixelizeEffect::~QGraphicsPixelizeEffect() +{ +} + +int QGraphicsPixelizeEffect::pixelSize() const +{ + Q_D(const QGraphicsPixelizeEffect); + return d->pixelSize; +} + +void QGraphicsPixelizeEffect::setPixelSize(int size) +{ + Q_D(QGraphicsPixelizeEffect); + if (d->pixelSize == size) + return; + + d->pixelSize = size; + emit pixelSizeChanged(size); +} + +static inline void pixelize(QImage *image, int pixelSize) +{ + Q_ASSERT(pixelSize > 0); + Q_ASSERT(image); + int width = image->width(); + int height = image->height(); + for (int y = 0; y < height; y += pixelSize) { + int ys = qMin(height - 1, y + pixelSize / 2); + QRgb *sbuf = reinterpret_cast<QRgb*>(image->scanLine(ys)); + for (int x = 0; x < width; x += pixelSize) { + int xs = qMin(width - 1, x + pixelSize / 2); + QRgb color = sbuf[xs]; + for (int yi = 0; yi < qMin(pixelSize, height - y); ++yi) { + QRgb *buf = reinterpret_cast<QRgb*>(image->scanLine(y + yi)); + for (int xi = 0; xi < qMin(pixelSize, width - x); ++xi) + buf[x + xi] = color; + } + } + } +} + +void QGraphicsPixelizeEffect::draw(QPainter *painter, QGraphicsEffectSource *source) +{ + Q_D(QGraphicsPixelizeEffect); + if (d->pixelSize <= 0) { + source->draw(painter); + return; + } + + QPoint offset; + if (source->isPixmap()) { + const QPixmap pixmap = source->pixmap(Qt::LogicalCoordinates, &offset); + QImage image = pixmap.toImage().convertToFormat(QImage::Format_ARGB32); + pixelize(&image, d->pixelSize); + painter->drawImage(offset, image); + return; + } + + // Draw pixmap in device coordinates to avoid pixmap scaling. + const QPixmap pixmap = source->pixmap(Qt::DeviceCoordinates, &offset); + + // pixelize routine + QImage image = pixmap.toImage().convertToFormat(QImage::Format_ARGB32); + pixelize(&image, d->pixelSize); + + QTransform restoreTransform = painter->worldTransform(); + painter->setWorldTransform(QTransform()); + painter->drawImage(offset, image); + painter->setWorldTransform(restoreTransform); +} + +QGraphicsBlurEffect::QGraphicsBlurEffect(QObject *parent) + : QGraphicsEffect(*new QGraphicsBlurEffectPrivate, parent) +{ +} + +QGraphicsBlurEffect::~QGraphicsBlurEffect() +{ +} + +int QGraphicsBlurEffect::blurRadius() const +{ + Q_D(const QGraphicsBlurEffect); + return d->filter->radius(); +} + +void QGraphicsBlurEffect::setBlurRadius(int radius) +{ + Q_D(QGraphicsBlurEffect); + if (d->filter->radius() == radius) + return; + + d->filter->setRadius(radius); + updateBoundingRect(); + emit blurRadiusChanged(radius); +} + +QRectF QGraphicsBlurEffect::boundingRectFor(const QRectF &rect) const +{ + Q_D(const QGraphicsBlurEffect); + return d->filter->boundingRectFor(rect); +} + +void QGraphicsBlurEffect::draw(QPainter *painter, QGraphicsEffectSource *source) +{ + Q_D(QGraphicsBlurEffect); + if (d->filter->radius() <= 0) { + source->draw(painter); + return; + } + + QPoint offset; + if (source->isPixmap()) { + // No point in drawing in device coordinates (pixmap will be scaled anyways). + const QPixmap pixmap = source->pixmap(Qt::LogicalCoordinates, &offset); + d->filter->draw(painter, offset, pixmap); + return; + } + + // Draw pixmap in device coordinates to avoid pixmap scaling. + const QPixmap pixmap = source->pixmap(Qt::DeviceCoordinates, &offset); + QTransform restoreTransform = painter->worldTransform(); + painter->setWorldTransform(QTransform()); + d->filter->draw(painter, offset, pixmap); + painter->setWorldTransform(restoreTransform); +} + +QGraphicsDropShadowEffect::QGraphicsDropShadowEffect(QObject *parent) + : QGraphicsEffect(*new QGraphicsDropShadowEffectPrivate, parent) +{ +} + +QGraphicsDropShadowEffect::~QGraphicsDropShadowEffect() +{ +} + +QPointF QGraphicsDropShadowEffect::offset() const +{ + Q_D(const QGraphicsDropShadowEffect); + return d->filter->offset(); +} + +void QGraphicsDropShadowEffect::setOffset(const QPointF &ofs) +{ + Q_D(QGraphicsDropShadowEffect); + if (d->filter->offset() == ofs) + return; + + d->filter->setOffset(ofs); + updateBoundingRect(); + emit offsetChanged(ofs); +} + +int QGraphicsDropShadowEffect::blurRadius() const +{ + Q_D(const QGraphicsDropShadowEffect); + return d->filter->blurRadius(); +} + +void QGraphicsDropShadowEffect::setBlurRadius(int blurRadius) +{ + Q_D(QGraphicsDropShadowEffect); + if (d->filter->blurRadius() == blurRadius) + return; + + d->filter->setBlurRadius(blurRadius); + updateBoundingRect(); + emit blurRadiusChanged(blurRadius); +} + +QColor QGraphicsDropShadowEffect::color() const +{ + Q_D(const QGraphicsDropShadowEffect); + return d->filter->color(); +} + +void QGraphicsDropShadowEffect::setColor(const QColor &color) +{ + Q_D(QGraphicsDropShadowEffect); + if (d->filter->color() == color) + return; + + d->filter->setColor(color); + emit colorChanged(color); +} + +QRectF QGraphicsDropShadowEffect::boundingRectFor(const QRectF &rect) const +{ + Q_D(const QGraphicsDropShadowEffect); + return d->filter->boundingRectFor(rect); +} + +void QGraphicsDropShadowEffect::draw(QPainter *painter, QGraphicsEffectSource *source) +{ + Q_D(QGraphicsDropShadowEffect); + if (d->filter->blurRadius() <= 0 && d->filter->offset().isNull()) { + source->draw(painter); + return; + } + + QPoint offset; + if (source->isPixmap()) { + // No point in drawing in device coordinates (pixmap will be scaled anyways). + const QPixmap pixmap = source->pixmap(Qt::LogicalCoordinates, &offset); + d->filter->draw(painter, offset, pixmap); + return; + } + + // Draw pixmap in device coordinates to avoid pixmap scaling. + const QPixmap pixmap = source->pixmap(Qt::DeviceCoordinates, &offset); + QTransform restoreTransform = painter->worldTransform(); + painter->setWorldTransform(QTransform()); + d->filter->draw(painter, offset, pixmap); + painter->setWorldTransform(restoreTransform); +} + +QT_END_NAMESPACE + |