QSize Class

Member Function Documentation

QSize::QSize()

Constructs a size with an invalid width and height (i.e., isValid() returns false).

See also isValid().

QSize::QSize(int width, int height)

Constructs a size with the given width and height.

See also setWidth() and setHeight().

QSize QSize::boundedTo(const QSize & otherSize) const

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

See also expandedTo() and scale().

QSize QSize::expandedTo(const QSize & otherSize) const

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

See also boundedTo() and scale().

int QSize::height() const

Returns the height.

See also width() and setHeight().

bool QSize::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 QSize::isNull() const

Returns true if both the width and height is 0; otherwise returns false.

See also isValid() and isEmpty().

bool QSize::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().

int & QSize::rheight()

Returns a reference to the height.

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

 QSize size(100, 10);
 size.rheight() += 5;

 // size becomes (100,15)

See also rwidth() and setHeight().

int & QSize::rwidth()

Returns a reference to the width.

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

 QSize size(100, 10);
 size.rwidth() += 20;

 // size becomes (120,10)

See also rheight() and setWidth().

void QSize::scale(int width, int 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:

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

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

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

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

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

This is an overloaded function.

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

QSize QSize::scaled(int width, int height, Qt::AspectRatioMode mode) const

Return 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().

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

This is an overloaded function.

This function was introduced in Qt 5.0.

void QSize::setHeight(int height)

Sets the height to the given height.

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

void QSize::setWidth(int width)

Sets the width to the given width.

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

void QSize::transpose()

Swaps the width and height values.

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

QSize QSize::transposed() const

Returns a QSize with width and height swapped.

This function was introduced in Qt 5.0.

See also transpose().

int QSize::width() const

Returns the width.

See also height() and setWidth().

QSize & QSize::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.

Note that the result is rounded to the nearest integer.

See also scale().

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

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

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

 // s becomes (2,11)

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

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

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

 // s becomes (4,3)

QSize & QSize::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.

Note that the result is rounded to the nearest integer.

See also QSize::scale().