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Diffstat (limited to 'src/gui/effects/qgraphicseffect.cpp')
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diff --git a/src/gui/effects/qgraphicseffect.cpp b/src/gui/effects/qgraphicseffect.cpp new file mode 100644 index 0000000000..7ba38f6d3a --- /dev/null +++ b/src/gui/effects/qgraphicseffect.cpp @@ -0,0 +1,1235 @@ +/**************************************************************************** +** +** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (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 Technology Preview License Agreement accompanying +** this package. +** +** 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 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@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(false). If effects are disabled, the source + is rendered directly. + + To add a visual effect to a QGraphicsItem, for example, you can use one of + the standard effects, or alternately, create your own effect by creating a + subclass of QGraphicsEffect. The effect can then be installed on the item + using QGraphicsItem::setGraphicsEffect(). + + Qt provides the following standard effects: + + \list + \o QGraphicsBlurEffect - blurs the item by a given radius + \o QGraphicsDropShadowEffect - renders a dropshadow behind the item + \o QGraphicsColorizeEffect - renders the item in shades of any given color + \o QGraphicsOpacityEffect - renders the item with an opacity + \endlist + + \table + \row + \o{2,1} \img graphicseffect-plain.png + \row + \o \img graphicseffect-blur.png + \o \img graphicseffect-colorize.png + \row + \o \img graphicseffect-opacity.png + \o \img graphicseffect-drop-shadow.png + \endtable + + \img graphicseffect-widget.png + + For more information on how to use each effect, refer to the specific + effect's documentation. + + To create your own custom effect, create a subclass of QGraphicsEffect (or + any other existing effects) and reimplement the virtual function draw(). + This function is called whenever the effect needs to redraw. The draw() + function takes the painter with which to draw as an argument. For more + information, refer to the documenation for draw(). In the draw() function + you can call sourcePixmap() to get a pixmap of the graphics effect source + which you can then process. + + If your effect changes, use update() to request for 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 + sourceChanged() function is called to notify the effects that + the source has changed in some way - e.g., if the source is a + QGraphicsRectItem and its rectangle parameters have changed. + + \sa QGraphicsItem::setGraphicsEffect(), QWidget::setGraphicsEffect() +*/ + +#include "qgraphicseffect_p.h" +#include "private/qgraphicsitem_p.h" + +#include <QtGui/qgraphicsitem.h> + +#include <QtGui/qimage.h> +#include <QtGui/qpainter.h> +#include <QtGui/qpaintengine.h> +#include <QtCore/qrect.h> +#include <QtCore/qdebug.h> +#include <private/qdrawhelper_p.h> + +#ifndef QT_NO_GRAPHICSEFFECT +QT_BEGIN_NAMESPACE + +/*! + \internal + \class QGraphicsEffectSource + \brief The QGraphicsEffectSource class represents the source on which a + QGraphicsEffect is installed on. + + When a QGraphicsEffect is installed on a QGraphicsItem, for example, this + class will act as a wrapper around QGraphicsItem. Then, calling update() is + effectively the same as calling QGraphicsItem::update(). + + QGraphicsEffectSource also provides a pixmap() function which creates a + pixmap with the source painted into it. + + \sa QGraphicsItem::setGraphicsEffect(), QWidget::setGraphicsEffect(). +*/ + +/*! + \internal +*/ +QGraphicsEffectSource::QGraphicsEffectSource(QGraphicsEffectSourcePrivate &dd, QObject *parent) + : QObject(dd, parent) +{} + +/*! + Destroys the effect source. +*/ +QGraphicsEffectSource::~QGraphicsEffectSource() +{} + +/*! + Returns the bounding rectangle of the source mapped to the given \a system. + + \sa draw() +*/ +QRectF QGraphicsEffectSource::boundingRect(Qt::CoordinateSystem system) const +{ + return d_func()->boundingRect(system); +} + +/*! + Returns the bounding rectangle of the source mapped to the given \a system. + + Calling this function with Qt::DeviceCoordinates outside of + QGraphicsEffect::draw() will give undefined results, as there is no device + context available. + + \sa draw() +*/ +QRectF QGraphicsEffect::sourceBoundingRect(Qt::CoordinateSystem system) const +{ + Q_D(const QGraphicsEffect); + if (d->source) + return d->source->boundingRect(system); + return QRectF(); +} + +/*! + Returns a pointer to the item if this source is a QGraphicsItem; otherwise + returns 0. + + \sa widget() +*/ +const QGraphicsItem *QGraphicsEffectSource::graphicsItem() const +{ + return d_func()->graphicsItem(); +} + +/*! + Returns a pointer to the widget if this source is a QWidget; otherwise + returns 0. + + \sa graphicsItem() +*/ +const QWidget *QGraphicsEffectSource::widget() const +{ + return d_func()->widget(); +} + +/*! + Returns a pointer to the style options (used when drawing the source) if + available; otherwise returns 0. + + \sa graphicsItem(), widget() +*/ +const QStyleOption *QGraphicsEffectSource::styleOption() const +{ + return d_func()->styleOption(); +} + +/*! + Draws the source using the given \a painter. + + This function should only be called from QGraphicsEffect::draw(). + + \sa QGraphicsEffect::draw() +*/ +void QGraphicsEffectSource::draw(QPainter *painter) +{ + Q_D(const QGraphicsEffectSource); + + QPixmap pm; + if (QPixmapCache::find(d->m_cacheKey, &pm)) { + QTransform restoreTransform; + if (d->m_cachedSystem == Qt::DeviceCoordinates) { + restoreTransform = painter->worldTransform(); + painter->setWorldTransform(QTransform()); + } + + painter->drawPixmap(d->m_cachedOffset, pm); + + if (d->m_cachedSystem == Qt::DeviceCoordinates) + painter->setWorldTransform(restoreTransform); + } else { + d_func()->draw(painter); + } +} + +/*! + Draws the source directly using the given \a painter. + + This function should only be called from QGraphicsEffect::draw(). + + For example: + + \snippet doc/src/snippets/code/src_gui_effects_qgraphicseffect.cpp 0 + + \sa QGraphicsEffect::draw() +*/ +void QGraphicsEffect::drawSource(QPainter *painter) +{ + Q_D(const QGraphicsEffect); + if (d->source) + d->source->draw(painter); +} + +/*! + Schedules a redraw of the source. Call this function whenever the source + needs to be redrawn. + + \sa QGraphicsEffect::updateBoundingRect(), QWidget::update(), + QGraphicsItem::update(), +*/ +void QGraphicsEffectSource::update() +{ + d_func()->update(); +} + +/*! + Returns true if the source effectively is a pixmap, e.g., a + QGraphicsPixmapItem. + + This function is useful for optimization purposes. For instance, there's no + point in drawing the source in device coordinates to avoid pixmap scaling + if this function returns true - the source pixmap will be scaled anyways. +*/ +bool QGraphicsEffectSource::isPixmap() const +{ + return d_func()->isPixmap(); +} + +/*! + Returns true if the source effectively is a pixmap, e.g., a + QGraphicsPixmapItem. + + This function is useful for optimization purposes. For instance, there's no + point in drawing the source in device coordinates to avoid pixmap scaling + if this function returns true - the source pixmap will be scaled anyways. +*/ +bool QGraphicsEffect::sourceIsPixmap() const +{ + return source() ? source()->isPixmap() : false; +} + +/*! + Returns a pixmap with the source painted into it. + + The \a system specifies which coordinate system to be used for the source. + The optional \a offset parameter returns the offset where the pixmap should + be painted at using the current painter. + + The \a mode determines how much of the effect the pixmap will contain. + By default, the pixmap will contain the whole effect. + + The returned pixmap is bound to the current painter's device rectangle when + \a system is Qt::DeviceCoordinates. + + \sa QGraphicsEffect::draw(), boundingRect() +*/ +QPixmap QGraphicsEffectSource::pixmap(Qt::CoordinateSystem system, QPoint *offset, QGraphicsEffect::PixmapPadMode mode) const +{ + Q_D(const QGraphicsEffectSource); + + // Shortcut, no cache for childless pixmap items... + const QGraphicsItem *item = graphicsItem(); + if (system == Qt::LogicalCoordinates && mode == QGraphicsEffect::NoPad && item && isPixmap()) { + const QGraphicsPixmapItem *pixmapItem = static_cast<const QGraphicsPixmapItem *>(item); + if (offset) + *offset = pixmapItem->offset().toPoint(); + return pixmapItem->pixmap(); + } + + if (system == Qt::DeviceCoordinates && item + && !static_cast<const QGraphicsItemEffectSourcePrivate *>(d_func())->info) { + qWarning("QGraphicsEffectSource::pixmap: Not yet implemented, lacking device context"); + return QPixmap(); + } + + QPixmap pm; + if (item && d->m_cachedSystem == system && d->m_cachedMode == mode) + QPixmapCache::find(d->m_cacheKey, &pm); + + if (pm.isNull()) { + pm = d->pixmap(system, &d->m_cachedOffset, mode); + d->m_cachedSystem = system; + d->m_cachedMode = mode; + + d->invalidateCache(); + d->m_cacheKey = QPixmapCache::insert(pm); + } + + if (offset) + *offset = d->m_cachedOffset; + + return pm; +} + +/*! + Returns a pixmap with the source painted into it. + + The \a system specifies which coordinate system to be used for the source. + The optional \a offset parameter returns the offset where the pixmap should + be painted at using the current painter. For control on how the pixmap is + padded use the \a mode parameter. + + The returned pixmap is clipped to the current painter's device rectangle when + \a system is Qt::DeviceCoordinates. + + Calling this function with Qt::DeviceCoordinates outside of + QGraphicsEffect::draw() will give undefined results, as there is no device + context available. + + \sa draw(), boundingRect() +*/ +QPixmap QGraphicsEffect::sourcePixmap(Qt::CoordinateSystem system, QPoint *offset, QGraphicsEffect::PixmapPadMode mode) const +{ + Q_D(const QGraphicsEffect); + if (d->source) + return d->source->pixmap(system, offset, mode); + return QPixmap(); +} + +QGraphicsEffectSourcePrivate::~QGraphicsEffectSourcePrivate() +{ + invalidateCache(); +} + +void QGraphicsEffectSourcePrivate::setCachedOffset(const QPoint &offset) +{ + m_cachedOffset = offset; +} + +void QGraphicsEffectSourcePrivate::invalidateCache(InvalidateReason reason) const +{ + if (m_cachedMode != QGraphicsEffect::PadToEffectiveBoundingRect + && (reason == EffectRectChanged + || (reason == TransformChanged && m_cachedSystem == Qt::LogicalCoordinates))) { + return; + } + + QPixmapCache::remove(m_cacheKey); +} + +/*! + Constructs a new QGraphicsEffect instance having the + specified \a parent. +*/ +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 effective bounding rectangle for this effect, i.e., the + bounding rectangle of the source in device coordinates, 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 effective bounding rectangle for this effect, given the + provided \a rect in the device coordinates. 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 sourceBoundingRect() +*/ +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, the source will + be rendered with the effect applied. + + This property is enabled by default. + + Using this property, 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->d_func()->effectBoundingRectChanged(); + d->source->d_func()->invalidateCache(); + } + emit enabledChanged(enable); +} + +/*! + \fn void QGraphicsEffect::enabledChanged(bool enabled) + + This signal is emitted whenever the effect is enabled or disabled. + The \a enabled parameter holds the effects's new enabled state. + + \sa isEnabled() +*/ + +/*! + Schedules a redraw of the effect. Call this function whenever the effect + needs to be redrawn. This function does not trigger a redraw of the source. + + \sa updateBoundingRect() +*/ +void QGraphicsEffect::update() +{ + Q_D(QGraphicsEffect); + if (d->source) + d->source->update(); +} + +/*! + \internal + + 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 when 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. + + This function will call update() if this is necessary. + + \sa boundingRectFor(), boundingRect(), sourceBoundingRect() +*/ +void QGraphicsEffect::updateBoundingRect() +{ + Q_D(QGraphicsEffect); + if (d->source) { + d->source->d_func()->effectBoundingRectChanged(); + d->source->d_func()->invalidateCache(QGraphicsEffectSourcePrivate::EffectRectChanged); + } +} + +/*! + \fn virtual void QGraphicsEffect::draw(QPainter *painter) = 0 + + This pure virtual function draws the effect and is called whenever the + source needs to be drawn. + + Reimplement this function in a QGraphicsEffect subclass to provide the + effect's drawing implementation, using \a painter. + + For example: + + \snippet doc/src/snippets/code/src_gui_effects_qgraphicseffect.cpp 1 + + This function should not be called explicitly by the user, since it is + meant for reimplementation purposes only. +*/ + +/*! + \enum QGraphicsEffect::ChangeFlag + + This enum describes what has changed in QGraphicsEffectSource. + + \value SourceAttached The effect is installed on a source. + \value SourceDetached The effect is uninstalled on a source. + \value SourceBoundingRectChanged The bounding rect of the source has + changed. + \value SourceInvalidated The visual appearance of the source has changed. +*/ + +/*! + \enum QGraphicsEffect::PixmapPadMode + + This enum describes how the pixmap returned from sourcePixmap should be + padded. + + \value NoPad The pixmap should not receive any additional + padding. + \value PadToTransparentBorder The pixmap should be padded + to ensure it has a completely transparent border. + \value PadToEffectiveBoundingRect The pixmap should be padded to + match the effective bounding rectangle of the effect. +*/ + +/*! + 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); +} + +/*! + \class QGraphicsColorizeEffect + \brief The QGraphicsColorizeEffect class provides a colorize effect. + \since 4.6 + + A colorize effect renders the source with a tint of its color(). The color + can be modified using the setColor() function. + + By default, the color is light blue (QColor(0, 0, 192)). + + \img graphicseffect-colorize.png + + \sa QGraphicsDropShadowEffect, QGraphicsBlurEffect, QGraphicsOpacityEffect +*/ + +/*! + Constructs a new QGraphicsColorizeEffect instance. + The \a parent parameter is passed to QGraphicsEffect's constructor. +*/ +QGraphicsColorizeEffect::QGraphicsColorizeEffect(QObject *parent) + : QGraphicsEffect(*new QGraphicsColorizeEffectPrivate, parent) +{ +} + +/*! + Destroys the effect. +*/ +QGraphicsColorizeEffect::~QGraphicsColorizeEffect() +{ +} + +/*! + \property QGraphicsColorizeEffect::color + \brief the color of the effect. + + By default, the color is light blue (QColor(0, 0, 192)). +*/ +QColor QGraphicsColorizeEffect::color() const +{ + Q_D(const QGraphicsColorizeEffect); + return d->filter->color(); +} + +void QGraphicsColorizeEffect::setColor(const QColor &color) +{ + Q_D(QGraphicsColorizeEffect); + if (d->filter->color() == color) + return; + + d->filter->setColor(color); + update(); + emit colorChanged(color); +} + +/*! + \property QGraphicsColorizeEffect::strength + \brief the strength of the effect. + + By default, the strength is 1.0. + A strength 0.0 equals to no effect, while 1.0 means full colorization. +*/ +qreal QGraphicsColorizeEffect::strength() const +{ + Q_D(const QGraphicsColorizeEffect); + return d->filter->strength(); +} + +void QGraphicsColorizeEffect::setStrength(qreal strength) +{ + Q_D(QGraphicsColorizeEffect); + if (qFuzzyCompare(d->filter->strength(), strength)) + return; + + d->filter->setStrength(strength); + d->opaque = !qFuzzyIsNull(strength); + update(); + emit strengthChanged(strength); +} + +/*! \fn void QGraphicsColorizeEffect::strengthChanged(qreal strength) + This signal is emitted whenever setStrength() changes the colorize + strength property. \a strength contains the new strength value of + the colorize effect. + */ + +/*! + \fn void QGraphicsColorizeEffect::colorChanged(const QColor &color) + + This signal is emitted whenever the effect's color changes. + The \a color parameter holds the effect's new color. +*/ + +/*! + \reimp +*/ +void QGraphicsColorizeEffect::draw(QPainter *painter) +{ + Q_D(QGraphicsColorizeEffect); + + if (!d->opaque) { + drawSource(painter); + return; + } + + QPoint offset; + if (sourceIsPixmap()) { + // No point in drawing in device coordinates (pixmap will be scaled anyways). + const QPixmap pixmap = sourcePixmap(Qt::LogicalCoordinates, &offset, NoPad); + if (!pixmap.isNull()) + d->filter->draw(painter, offset, pixmap); + + return; + } + + // Draw pixmap in deviceCoordinates to avoid pixmap scaling. + const QPixmap pixmap = sourcePixmap(Qt::DeviceCoordinates, &offset); + if (pixmap.isNull()) + return; + + QTransform restoreTransform = painter->worldTransform(); + painter->setWorldTransform(QTransform()); + d->filter->draw(painter, offset, pixmap); + painter->setWorldTransform(restoreTransform); +} + +/*! + \class QGraphicsBlurEffect + \brief The QGraphicsBlurEffect class provides a blur effect. + \since 4.6 + + A blur effect blurs the source. This effect is useful for reducing details, + such as when the source loses focus and you want to draw attention to other + elements. The level of detail can be modified using the setBlurRadius() + function. Use setBlurHints() to choose the blur hints. + + By default, the blur radius is 5 pixels. The blur radius is specified in + device coordinates. + + \img graphicseffect-blur.png + + \sa QGraphicsDropShadowEffect, QGraphicsColorizeEffect, QGraphicsOpacityEffect +*/ + +/*! + \enum QGraphicsBlurEffect::BlurHint + \since 4.6 + + This enum describes the possible hints that can be used to control how + blur effects are applied. The hints might not have an effect in all the + paint engines. + + \value PerformanceHint Indicates that rendering performance is the most important factor, + at the potential cost of lower quality. + + \value QualityHint Indicates that rendering quality is the most important factor, + at the potential cost of lower performance. + + \value AnimationHint Indicates that the blur radius is going to be animated, hinting + that the implementation can keep a cache of blurred verisons of the source. + Do not use this hint if the source is going to be dynamically changing. + + \sa blurHints(), setBlurHints() +*/ + + +/*! + Constructs a new QGraphicsBlurEffect instance. + The \a parent parameter is passed to QGraphicsEffect's constructor. +*/ +QGraphicsBlurEffect::QGraphicsBlurEffect(QObject *parent) + : QGraphicsEffect(*new QGraphicsBlurEffectPrivate, parent) +{ + Q_D(QGraphicsBlurEffect); + d->filter->setBlurHints(QGraphicsBlurEffect::PerformanceHint); +} + +/*! + Destroys the effect. +*/ +QGraphicsBlurEffect::~QGraphicsBlurEffect() +{ +} + +/*! + \property QGraphicsBlurEffect::blurRadius + \brief the blur radius of the effect. + + Using a smaller radius results in a sharper appearance, whereas a bigger + radius results in a more blurred appearance. + + By default, the blur radius is 5 pixels. + + The radius is given in device coordinates, meaning it is + unaffected by scale. +*/ +qreal QGraphicsBlurEffect::blurRadius() const +{ + Q_D(const QGraphicsBlurEffect); + return d->filter->radius(); +} + +void QGraphicsBlurEffect::setBlurRadius(qreal radius) +{ + Q_D(QGraphicsBlurEffect); + if (qFuzzyCompare(d->filter->radius(), radius)) + return; + + d->filter->setRadius(radius); + updateBoundingRect(); + emit blurRadiusChanged(radius); +} + +/*! + \fn void QGraphicsBlurEffect::blurRadiusChanged(qreal radius) + + This signal is emitted whenever the effect's blur radius changes. + The \a radius parameter holds the effect's new blur radius. +*/ + +/*! + \property QGraphicsBlurEffect::blurHints + \brief the blur hint of the effect. + + Use the PerformanceHint hint to say that you want a faster blur, + the QualityHint hint to say that you prefer a higher quality blur, + or the AnimationHint when you want to animate the blur radius. + + By default, the blur hint is PerformanceHint. +*/ +QGraphicsBlurEffect::BlurHints QGraphicsBlurEffect::blurHints() const +{ + Q_D(const QGraphicsBlurEffect); + return d->filter->blurHints(); +} + +void QGraphicsBlurEffect::setBlurHints(QGraphicsBlurEffect::BlurHints hints) +{ + Q_D(QGraphicsBlurEffect); + if (d->filter->blurHints() == hints) + return; + + d->filter->setBlurHints(hints); + emit blurHintsChanged(hints); +} + +/*! + \fn void QGraphicsBlurEffect::blurHintsChanged(QGraphicsBlurEffect::BlurHints hints) + + This signal is emitted whenever the effect's blur hints changes. + The \a hints parameter holds the effect's new blur hints. +*/ + +/*! + \reimp +*/ +QRectF QGraphicsBlurEffect::boundingRectFor(const QRectF &rect) const +{ + Q_D(const QGraphicsBlurEffect); + return d->filter->boundingRectFor(rect); +} + +/*! + \reimp +*/ +void QGraphicsBlurEffect::draw(QPainter *painter) +{ + Q_D(QGraphicsBlurEffect); + if (d->filter->radius() < 1) { + drawSource(painter); + return; + } + + PixmapPadMode mode = PadToEffectiveBoundingRect; + if (painter->paintEngine()->type() == QPaintEngine::OpenGL2) + mode = NoPad; + + QPoint offset; + QPixmap pixmap = sourcePixmap(Qt::LogicalCoordinates, &offset, mode); + if (pixmap.isNull()) + return; + + d->filter->draw(painter, offset, pixmap); +} + +/*! + \class QGraphicsDropShadowEffect + \brief The QGraphicsDropShadowEffect class provides a drop shadow effect. + \since 4.6 + + A drop shadow effect renders the source with a drop shadow. The color of + the drop shadow can be modified using the setColor() function. The drop + shadow offset can be modified using the setOffset() function and the blur + radius of the drop shadow can be changed with the setBlurRadius() + function. + + By default, the drop shadow is a semi-transparent dark gray + (QColor(63, 63, 63, 180)) shadow, blurred with a radius of 1 at an offset + of 8 pixels towards the lower right. The drop shadow offset is specified + in device coordinates. + + \img graphicseffect-drop-shadow.png + + \sa QGraphicsBlurEffect, QGraphicsColorizeEffect, QGraphicsOpacityEffect +*/ + +/*! + Constructs a new QGraphicsDropShadowEffect instance. + The \a parent parameter is passed to QGraphicsEffect's constructor. +*/ +QGraphicsDropShadowEffect::QGraphicsDropShadowEffect(QObject *parent) + : QGraphicsEffect(*new QGraphicsDropShadowEffectPrivate, parent) +{ +} + +/*! + Destroys the effect. +*/ +QGraphicsDropShadowEffect::~QGraphicsDropShadowEffect() +{ +} + +/*! + \property QGraphicsDropShadowEffect::offset + \brief the shadow offset in pixels. + + By default, the offset is 8 pixels towards the lower right. + + The offset is given in device coordinates, which means it is + unaffected by scale. + + \sa xOffset(), yOffset(), blurRadius(), color() +*/ +QPointF QGraphicsDropShadowEffect::offset() const +{ + Q_D(const QGraphicsDropShadowEffect); + return d->filter->offset(); +} + +void QGraphicsDropShadowEffect::setOffset(const QPointF &offset) +{ + Q_D(QGraphicsDropShadowEffect); + if (d->filter->offset() == offset) + return; + + d->filter->setOffset(offset); + updateBoundingRect(); + emit offsetChanged(offset); +} + +/*! + \property QGraphicsDropShadowEffect::xOffset + \brief the horizontal shadow offset in pixels. + + By default, the horizontal shadow offset is 8 pixels. + + + + \sa yOffset(), offset() +*/ + +/*! + \property QGraphicsDropShadowEffect::yOffset + \brief the vertical shadow offset in pixels. + + By default, the vertical shadow offset is 8 pixels. + + \sa xOffset(), offset() +*/ + +/*! + \fn void QGraphicsDropShadowEffect::offsetChanged(const QPointF &offset) + + This signal is emitted whenever the effect's shadow offset changes. + The \a offset parameter holds the effect's new shadow offset. +*/ + +/*! + \property QGraphicsDropShadowEffect::blurRadius + \brief the blur radius in pixels of the drop shadow. + + Using a smaller radius results in a sharper shadow, whereas using a bigger + radius results in a more blurred shadow. + + By default, the blur radius is 1 pixel. + + \sa color(), offset(). +*/ +qreal QGraphicsDropShadowEffect::blurRadius() const +{ + Q_D(const QGraphicsDropShadowEffect); + return d->filter->blurRadius(); +} + +void QGraphicsDropShadowEffect::setBlurRadius(qreal blurRadius) +{ + Q_D(QGraphicsDropShadowEffect); + if (qFuzzyCompare(d->filter->blurRadius(), blurRadius)) + return; + + d->filter->setBlurRadius(blurRadius); + updateBoundingRect(); + emit blurRadiusChanged(blurRadius); +} + +/*! + \fn void QGraphicsDropShadowEffect::blurRadiusChanged(qreal blurRadius) + + This signal is emitted whenever the effect's blur radius changes. + The \a blurRadius parameter holds the effect's new blur radius. +*/ + +/*! + \property QGraphicsDropShadowEffect::color + \brief the color of the drop shadow. + + By default, the drop color is a semi-transparent dark gray + (QColor(63, 63, 63, 180)). + + \sa offset(), 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); + update(); + emit colorChanged(color); +} + +/*! + \fn void QGraphicsDropShadowEffect::colorChanged(const QColor &color) + + This signal is emitted whenever the effect's color changes. + The \a color parameter holds the effect's new color. +*/ + +/*! + \reimp +*/ +QRectF QGraphicsDropShadowEffect::boundingRectFor(const QRectF &rect) const +{ + Q_D(const QGraphicsDropShadowEffect); + return d->filter->boundingRectFor(rect); +} + +/*! + \reimp +*/ +void QGraphicsDropShadowEffect::draw(QPainter *painter) +{ + Q_D(QGraphicsDropShadowEffect); + if (d->filter->blurRadius() <= 0 && d->filter->offset().isNull()) { + drawSource(painter); + return; + } + + PixmapPadMode mode = PadToEffectiveBoundingRect; + if (painter->paintEngine()->type() == QPaintEngine::OpenGL2) + mode = NoPad; + + // Draw pixmap in device coordinates to avoid pixmap scaling. + QPoint offset; + const QPixmap pixmap = sourcePixmap(Qt::DeviceCoordinates, &offset, mode); + if (pixmap.isNull()) + return; + + QTransform restoreTransform = painter->worldTransform(); + painter->setWorldTransform(QTransform()); + d->filter->draw(painter, offset, pixmap); + painter->setWorldTransform(restoreTransform); +} + +/*! + \class QGraphicsOpacityEffect + \brief The QGraphicsOpacityEffect class provides an opacity effect. + \since 4.6 + + An opacity effect renders the source with an opacity. This effect is useful + for making the source semi-transparent, similar to a fade-in/fade-out + sequence. The opacity can be modified using the setOpacity() function. + + By default, the opacity is 0.7. + + \img graphicseffect-opacity.png + + \sa QGraphicsDropShadowEffect, QGraphicsBlurEffect, QGraphicsColorizeEffect +*/ + +/*! + Constructs a new QGraphicsOpacityEffect instance. + The \a parent parameter is passed to QGraphicsEffect's constructor. +*/ +QGraphicsOpacityEffect::QGraphicsOpacityEffect(QObject *parent) + : QGraphicsEffect(*new QGraphicsOpacityEffectPrivate, parent) +{ +} + +/*! + Destroys the effect. +*/ +QGraphicsOpacityEffect::~QGraphicsOpacityEffect() +{ +} + +/*! + \property QGraphicsOpacityEffect::opacity + \brief the opacity of the effect. + + The value should be in the range of 0.0 to 1.0, where 0.0 is + fully transparent and 1.0 is fully opaque. + + By default, the opacity is 0.7. + + \sa setOpacityMask() +*/ +qreal QGraphicsOpacityEffect::opacity() const +{ + Q_D(const QGraphicsOpacityEffect); + return d->opacity; +} + +void QGraphicsOpacityEffect::setOpacity(qreal opacity) +{ + Q_D(QGraphicsOpacityEffect); + opacity = qBound(qreal(0.0), opacity, qreal(1.0)); + + if (qFuzzyCompare(d->opacity, opacity)) + return; + + d->opacity = opacity; + if ((d->isFullyTransparent = qFuzzyIsNull(d->opacity))) + d->isFullyOpaque = 0; + else + d->isFullyOpaque = qFuzzyIsNull(d->opacity - 1); + update(); + emit opacityChanged(opacity); +} + +/*! + \fn void QGraphicsOpacityEffect::opacityChanged(qreal opacity) + + This signal is emitted whenever the effect's opacity changes. + The \a opacity parameter holds the effect's new opacity. +*/ + +/*! + \property QGraphicsOpacityEffect::opacityMask + \brief the opacity mask of the effect. + + An opacity mask allows you apply opacity to portions of an element. + + For example: + + \snippet doc/src/snippets/code/src_gui_effects_qgraphicseffect.cpp 2 + + There is no opacity mask by default. + + \sa setOpacity() +*/ +QBrush QGraphicsOpacityEffect::opacityMask() const +{ + Q_D(const QGraphicsOpacityEffect); + return d->opacityMask; +} + +void QGraphicsOpacityEffect::setOpacityMask(const QBrush &mask) +{ + Q_D(QGraphicsOpacityEffect); + if (d->opacityMask == mask) + return; + + d->opacityMask = mask; + d->hasOpacityMask = (mask.style() != Qt::NoBrush); + update(); + + emit opacityMaskChanged(mask); +} + +/*! + \fn void QGraphicsOpacityEffect::opacityMaskChanged(const QBrush &mask) + + This signal is emitted whenever the effect's opacity mask changes. + The \a mask parameter holds the effect's new opacity mask. +*/ + +/*! + \reimp +*/ +void QGraphicsOpacityEffect::draw(QPainter *painter) +{ + Q_D(QGraphicsOpacityEffect); + + // Transparent; nothing to draw. + if (d->isFullyTransparent) + return; + + // Opaque; draw directly without going through a pixmap. + if (d->isFullyOpaque && !d->hasOpacityMask) { + drawSource(painter); + return; + } + + QPoint offset; + Qt::CoordinateSystem system = sourceIsPixmap() ? Qt::LogicalCoordinates : Qt::DeviceCoordinates; + QPixmap pixmap = sourcePixmap(system, &offset, QGraphicsEffect::NoPad); + if (pixmap.isNull()) + return; + + painter->save(); + painter->setOpacity(d->opacity); + + if (d->hasOpacityMask) { + QPainter pixmapPainter(&pixmap); + pixmapPainter.setRenderHints(painter->renderHints()); + pixmapPainter.setCompositionMode(QPainter::CompositionMode_DestinationIn); + if (system == Qt::DeviceCoordinates) { + QTransform worldTransform = painter->worldTransform(); + worldTransform *= QTransform::fromTranslate(-offset.x(), -offset.y()); + pixmapPainter.setWorldTransform(worldTransform); + pixmapPainter.fillRect(sourceBoundingRect(), d->opacityMask); + } else { + pixmapPainter.translate(-offset); + pixmapPainter.fillRect(pixmap.rect(), d->opacityMask); + } + } + + if (system == Qt::DeviceCoordinates) + painter->setWorldTransform(QTransform()); + + painter->drawPixmap(offset, pixmap); + painter->restore(); +} + + +QT_END_NAMESPACE + +#endif //QT_NO_GRAPHICSEFFECT |