QRadialGradient gradient(50, 50, 50, 50, 50);
    gradient.setColorAt(0, QColor::fromRgbF(0, 1, 0, 1));
    gradient.setColorAt(1, QColor::fromRgbF(0, 0, 0, 0));

    QBrush brush(gradient);

QPainter painter(this);

painter.setBrush(Qt::cyan);
painter.setPen(Qt::darkCyan);
painter.drawRect(0, 0, 100,100);

painter.setBrush(Qt::NoBrush);
painter.setPen(Qt::darkGreen);
painter.drawRect(40, 40, 100, 100);

Member Function Documentation

QBrush::​QBrush()

Constructs a default black brush with the style Qt::NoBrush (i.e. this brush will not fill shapes).

QBrush::​QBrush(Qt::BrushStyle style)

Constructs a black brush with the given style.

See also setStyle().

QBrush::​QBrush(const QColor & color, Qt::BrushStyle style = Qt::SolidPattern)

Constructs a brush with the given color and style.

See also setColor() and setStyle().

QBrush::​QBrush(Qt::GlobalColor color, Qt::BrushStyle style = Qt::SolidPattern)

Constructs a brush with the given color and style.

See also setColor() and setStyle().

QBrush::​QBrush(const QColor & color, const QPixmap & pixmap)

Constructs a brush with the given color and the custom pattern stored in pixmap.

The style is set to Qt::TexturePattern. The color will only have an effect for QBitmaps.

See also setColor() and setTexture().

QBrush::​QBrush(Qt::GlobalColor color, const QPixmap & pixmap)

Constructs a brush with the given color and the custom pattern stored in pixmap.

The style is set to Qt::TexturePattern. The color will only have an effect for QBitmaps.

See also setColor() and setTexture().

QBrush::​QBrush(const QPixmap & pixmap)

Constructs a brush with a black color and a texture set to the given pixmap. The style is set to Qt::TexturePattern.

See also setTexture().

QBrush::​QBrush(const QImage & image)

Constructs a brush with a black color and a texture set to the given image. The style is set to Qt::TexturePattern.

See also setTextureImage().

QBrush::​QBrush(const QBrush & other)

Constructs a copy of other.

QBrush::​QBrush(const QGradient & gradient)

Constructs a brush based on the given gradient.

The brush style is set to the corresponding gradient style (either Qt::LinearGradientPattern, Qt::RadialGradientPattern or Qt::ConicalGradientPattern).

QBrush::​~QBrush()

Destroys the brush.

const QColor & QBrush::​color() const

Returns the brush color.

See also setColor().

const QGradient * QBrush::​gradient() const

Returns the gradient describing this brush.

bool QBrush::​isOpaque() const

Returns true if the brush is fully opaque otherwise false. A brush is considered opaque if:

• The alpha component of the color() is 255.
• Its texture() does not have an alpha channel and is not a QBitmap.
• The colors in the gradient() all have an alpha component that is 255.
• It is an extended radial gradient.

const QMatrix & QBrush::​matrix() const

Returns the current transformation matrix for the brush.

This function was introduced in Qt 4.2.

See also setMatrix().

void QBrush::​setColor(const QColor & color)

Sets the brush color to the given color.

Note that calling setColor() will not make a difference if the style is a gradient. The same is the case if the style is Qt::TexturePattern style unless the current texture is a QBitmap.

See also color().

void QBrush::​setColor(Qt::GlobalColor color)

This is an overloaded function.

Sets the brush color to the given color.

void QBrush::​setMatrix(const QMatrix & matrix)

Sets matrix as an explicit transformation matrix on the current brush. The brush transformation matrix is merged with QPainter transformation matrix to produce the final result.

This function was introduced in Qt 4.2.

See also matrix().

void QBrush::​setStyle(Qt::BrushStyle style)

Sets the brush style to style.

See also style().

void QBrush::​setTexture(const QPixmap & pixmap)

Sets the brush pixmap to pixmap. The style is set to Qt::TexturePattern.

The current brush color will only have an effect for monochrome pixmaps, i.e. for QPixmap::depth() == 1 (QBitmaps).

See also texture().

void QBrush::​setTextureImage(const QImage & image)

Sets the brush image to image. The style is set to Qt::TexturePattern.

Note the current brush color will not have any affect on monochrome images, as opposed to calling setTexture() with a QBitmap. If you want to change the color of monochrome image brushes, either convert the image to QBitmap with QBitmap::fromImage() and set the resulting QBitmap as a texture, or change the entries in the color table for the image.

This function was introduced in Qt 4.2.

See also textureImage() and setTexture().

void QBrush::​setTransform(const QTransform & matrix)

Sets matrix as an explicit transformation matrix on the current brush. The brush transformation matrix is merged with QPainter transformation matrix to produce the final result.

This function was introduced in Qt 4.3.

See also transform().

Qt::BrushStyle QBrush::​style() const

Returns the brush style.

See also setStyle().

void QBrush::​swap(QBrush & other)

Swaps brush other with this brush. This operation is very fast and never fails.

This function was introduced in Qt 4.8.

QPixmap QBrush::​texture() const

Returns the custom brush pattern, or a null pixmap if no custom brush pattern has been set.

See also setTexture().

QImage QBrush::​textureImage() const

Returns the custom brush pattern, or a null image if no custom brush pattern has been set.

If the texture was set as a QPixmap it will be converted to a QImage.

This function was introduced in Qt 4.2.

See also setTextureImage().

QTransform QBrush::​transform() const

Returns the current transformation matrix for the brush.

This function was introduced in Qt 4.3.

See also setTransform().

QBrush::​operator QVariant() const

Returns the brush as a QVariant

bool QBrush::​operator!=(const QBrush & brush) const

Returns true if the brush is different from the given brush; otherwise returns false.

Two brushes are different if they have different styles, colors or transforms or different pixmaps or gradients depending on the style.

See also operator==().

QBrush & QBrush::​operator=(const QBrush & brush)

Assigns the given brush to this brush and returns a reference to this brush.

QBrush & QBrush::​operator=(QBrush && other)

Move-assigns other to this QBrush instance.

This function was introduced in Qt 5.2.

bool QBrush::​operator==(const QBrush & brush) const

Returns true if the brush is equal to the given brush; otherwise returns false.

Two brushes are equal if they have equal styles, colors and transforms and equal pixmaps or gradients depending on the style.

See also operator!=().