              
QGraphicsOpacityEffect Class ReferenceThe QGraphicsOpacityEffect class provides an opacity effect. More... #include <QGraphicsOpacityEffect>Inherits: QGraphicsEffect. This class was introduced in Qt 4.6. Properties
Public Functions
Public Slots
Signals
Reimplemented Protected Functions
Additional Inherited Members
Detailed DescriptionThe QGraphicsOpacityEffect class provides an opacity effect. 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.
See also QGraphicsDropShadowEffect, QGraphicsBlurEffect, and QGraphicsColorizeEffect. Property Documentation
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| qreal | opacity () const |
| void | setOpacity ( qreal opacity ) |
Notifier signal:
| void | opacityChanged ( qreal opacity ) |
See also setOpacityMask().
opacityMask : QBrush
This property holds the opacity mask of the effect.
An opacity mask allows you apply opacity to portions of an element.
For example:
... 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); ...
There is no opacity mask by default.
Access functions:
| QBrush | opacityMask () const |
| void | setOpacityMask ( const QBrush & mask ) |
Notifier signal:
| void | opacityMaskChanged ( const QBrush & mask ) |
See also setOpacity().
Member Function Documentation
QGraphicsOpacityEffect::QGraphicsOpacityEffect ( QObject * parent = 0 )
Constructs a new QGraphicsOpacityEffect instance. The parent parameter is passed to QGraphicsEffect's constructor.
QGraphicsOpacityEffect::~QGraphicsOpacityEffect ()
Destroys the effect.
void QGraphicsOpacityEffect::draw ( QPainter * painter ) [virtual protected]
Reimplemented from QGraphicsEffect::draw().
void QGraphicsOpacityEffect::opacityChanged ( qreal opacity ) [signal]
This signal is emitted whenever the effect's opacity changes. The opacity parameter holds the effect's new opacity.
void QGraphicsOpacityEffect::opacityMaskChanged ( const QBrush & mask ) [signal]
This signal is emitted whenever the effect's opacity mask changes. The mask parameter holds the effect's new opacity mask.