QSizeF Class Reference

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() and setHeight().

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.

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() and setHeight().

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().