QSizeF Class

Member Function Documentation

QSizeF::QSizeF()

Constructs an invalid size.

See also isValid().

QSizeF::QSizeF(const QSize & size)

Constructs a size with floating point accuracy from the given size.

See also toSize().

QSizeF::QSizeF(qreal width, qreal height)

Constructs a size with the given width and height.

QSizeF QSizeF::boundedTo(const QSizeF & otherSize) const

Returns a size holding the minimum width and height of this size and the given otherSize.

See also expandedTo() and scale().

QSizeF QSizeF::expandedTo(const QSizeF & otherSize) const

Returns a size holding the maximum width and height of this size and the given otherSize.

See also boundedTo() and scale().

qreal QSizeF::height() const

Returns the height.

See also width() and setHeight().

bool QSizeF::isEmpty() const

Returns true if either of the width and height is less than or equal to 0; otherwise returns false.

See also isNull() and isValid().

bool QSizeF::isNull() const

Returns true if both the width and height are +0.0; otherwise returns false.

Note: Since this function treats +0.0 and -0.0 differently, sizes with zero width and height where either or both values have a negative sign are not defined to be null sizes.

See also isValid() and isEmpty().

bool QSizeF::isValid() const

Returns true if both the width and height is equal to or greater than 0; otherwise returns false.

See also isNull() and isEmpty().

qreal & QSizeF::rheight()

Returns a reference to the height.

Using a reference makes it possible to manipulate the height directly. For example:

 QSizeF size(100, 10.2);
 size.rheight() += 5.5;

 // size becomes (100,15.7)

See also rwidth() and setHeight().

qreal & QSizeF::rwidth()

Returns a reference to the width.

Using a reference makes it possible to manipulate the width directly. For example:

 QSizeF size(100.3, 10);
 size.rwidth() += 20.5;

  // size becomes (120.8,10)

See also rheight() and setWidth().

void QSizeF::scale(qreal width, qreal height, Qt::AspectRatioMode mode)

Scales the size to a rectangle with the given width and height, according to the specified mode.

• If mode is Qt::IgnoreAspectRatio, the size is set to (width, height).
• If mode is Qt::KeepAspectRatio, the current size is scaled to a rectangle as large as possible inside (width, height), preserving the aspect ratio.
• If mode is Qt::KeepAspectRatioByExpanding, the current size is scaled to a rectangle as small as possible outside (width, height), preserving the aspect ratio.

Example:

 QSizeF t1(10, 12);
 t1.scale(60, 60, Qt::IgnoreAspectRatio);
 // t1 is (60, 60)

 QSizeF t2(10, 12);
 t2.scale(60, 60, Qt::KeepAspectRatio);
 // t2 is (50, 60)

 QSizeF t3(10, 12);
 t3.scale(60, 60, Qt::KeepAspectRatioByExpanding);
 // t3 is (60, 72)

See also setWidth(), setHeight(), and scaled().

void QSizeF::scale(const QSizeF & size, Qt::AspectRatioMode mode)

This is an overloaded function.

Scales the size to a rectangle with the given size, according to the specified mode.

QSizeF QSizeF::scaled(qreal width, qreal height, Qt::AspectRatioMode mode) const

Returns a size scaled to a rectangle with the given width and height, according to the specified mode.

This function was introduced in Qt 5.0.

See also scale().

QSizeF QSizeF::scaled(const QSizeF & s, Qt::AspectRatioMode mode) const

This is an overloaded function.

This function was introduced in Qt 5.0.

void QSizeF::setHeight(qreal height)

Sets the height to the given height.

See also height(), rheight(), and setWidth().

void QSizeF::setWidth(qreal width)

Sets the width to the given width.

See also width(), rwidth(), and setHeight().

QSize QSizeF::toSize() const

Returns an integer based copy of this size.

Note that the coordinates in the returned size will be rounded to the nearest integer.

See also QSizeF().

void QSizeF::transpose()

Swaps the width and height values.

See also setWidth(), setHeight(), and transposed().

QSizeF QSizeF::transposed() const

Returns the size with width and height values swapped.

This function was introduced in Qt 5.0.

See also transpose().

qreal QSizeF::width() const

Returns the width.

See also height() and setWidth().

QSizeF & QSizeF::operator*=(qreal factor)

This is an overloaded function.

Multiplies both the width and height by the given factor and returns a reference to the size.

See also scale().

QSizeF & QSizeF::operator+=(const QSizeF & size)

Adds the given size to this size and returns a reference to this size. For example:

 QSizeF s( 3, 7);
 QSizeF r(-1, 4);
 s += r;

 // s becomes (2,11)

QSizeF & QSizeF::operator-=(const QSizeF & size)

Subtracts the given size from this size and returns a reference to this size. For example:

 QSizeF s( 3, 7);
 QSizeF r(-1, 4);
 s -= r;

 // s becomes (4,3)

QSizeF & QSizeF::operator/=(qreal divisor)

This is an overloaded function.

Divides both the width and height by the given divisor and returns a reference to the size.

See also scale().