- Qt 5.15
- Qt Widgets
- C++ Classes
- QGraphicsDropShadowEffect
- Qt 5.15.18 Reference Documentation

# QGraphicsDropShadowEffect Class

The QGraphicsDropShadowEffect class provides a drop shadow effect. More...

Header: | #include <QGraphicsDropShadowEffect>
qmake: | QT += widgets
Since: | Qt 4.6
Inherits: | QGraphicsEffect

This class was introduced in Qt 4.6.

- List of all members, including inherited members

## Properties

- blurRadius : qreal
- color : QColor
- offset : QPointF

- xOffset : qreal
- yOffset : qreal

## Public Functions

| QGraphicsDropShadowEffect(QObject *parent = nullptr)
virtual | ~QGraphicsDropShadowEffect()
qreal | blurRadius() const
QColor | color() const
QPointF | offset() const
qreal | xOffset() const
qreal | yOffset() const

## Reimplemented Public Functions

virtual QRectF | boundingRectFor(const QRectF &rect) const override

## Public Slots

void | setBlurRadius(qreal blurRadius)
void | setColor(const QColor &color)
void | setOffset(qreal d)
void | setOffset(qreal dx, qreal dy)
void | setOffset(const QPointF &ofs)
void | setXOffset(qreal dx)
void | setYOffset(qreal dy)

## Signals

void | blurRadiusChanged(qreal blurRadius)
void | colorChanged(const QColor &color)
void | offsetChanged(const QPointF &offset)

## Reimplemented Protected Functions

virtual void | draw(QPainter *painter) override

## Detailed Description

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.

See also QGraphicsBlurEffect, QGraphicsColorizeEffect, and QGraphicsOpacityEffect.

## Property Documentation

### blurRadius : qreal

This property holds 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.

Access functions:

qreal | blurRadius() const
void | setBlurRadius(qreal blurRadius)

Notifier signal:

void | blurRadiusChanged(qreal blurRadius)

See also color() and offset().

### color : QColor

This property holds the color of the drop shadow.

By default, the drop color is a semi-transparent dark gray (QColor(63, 63, 63, 180)).

Access functions:

QColor | color() const
void | setColor(const QColor &color)

Notifier signal:

void | colorChanged(const QColor &color)

See also offset() and blurRadius().

### offset : QPointF

This property holds 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.

Access functions:

QPointF | offset() const
void | setOffset(const QPointF &ofs)
void | setOffset(qreal dx, qreal dy)
void | setOffset(qreal d)

Notifier signal:

void | offsetChanged(const QPointF &offset)

See also xOffset(), yOffset(), blurRadius(), and color().

### xOffset : qreal

This property holds the horizontal shadow offset in pixels.

By default, the horizontal shadow offset is 8 pixels.

Access functions:

qreal | xOffset() const
void | setXOffset(qreal dx)

Notifier signal:

void | offsetChanged(const QPointF &offset)

See also yOffset() and offset().

### yOffset : qreal

This property holds the vertical shadow offset in pixels.

By default, the vertical shadow offset is 8 pixels.

Access functions:

qreal | yOffset() const
void | setYOffset(qreal dy)

Notifier signal:

void | offsetChanged(const QPointF &offset)

See also xOffset() and offset().

## Member Function Documentation

### QGraphicsDropShadowEffect::QGraphicsDropShadowEffect(QObject *parent = nullptr)

Constructs a new QGraphicsDropShadowEffect instance. The parent parameter is passed to QGraphicsEffect's constructor.

### `[signal]` void QGraphicsDropShadowEffect::blurRadiusChanged(qreal blurRadius)

This signal is emitted whenever the effect's blur radius changes. The blurRadius parameter holds the effect's new blur radius.

Note: Notifier signal for property blurRadius.

### `[signal]` void QGraphicsDropShadowEffect::colorChanged(const QColor &color)

This signal is emitted whenever the effect's color changes. The color parameter holds the effect's new color.

Note: Notifier signal for property color.

### `[signal]` void QGraphicsDropShadowEffect::offsetChanged(const QPointF &offset)

This signal is emitted whenever the effect's shadow offset changes. The offset parameter holds the effect's new shadow offset.

Note: Notifier signal for property offset. Notifier signal for property xOffset. Notifier signal for property yOffset.

### `[virtual]` QGraphicsDropShadowEffect::~QGraphicsDropShadowEffect()

Destroys the effect.

### `[override virtual]` QRectF QGraphicsDropShadowEffect::boundingRectFor(const QRectF &rect) const

Reimplements: QGraphicsEffect::boundingRectFor(const QRectF &rect) const.

### `[override virtual protected]` void QGraphicsDropShadowEffect::draw(QPainter *painter)

Reimplements: QGraphicsEffect::draw(QPainter *painter).