QSize Class▲
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Header: QSize
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CMake:
find_package(Qt6 REQUIRED COMPONENTS Core)
target_link_libraries(mytarget PRIVATE Qt6::Core)
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qmake: QT += core
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Group: QSize is part of painting
Detailed Description▲
A size is specified by a width() and a height(). It can be set in the constructor and changed using the setWidth(), setHeight(), or scale() functions, or using arithmetic operators. A size can also be manipulated directly by retrieving references to the width and height using the rwidth() and rheight() functions. Finally, the width and height can be swapped using the transpose() function.
The isValid() function determines if a size is valid (a valid size has both width and height greater than or equal to zero). The isEmpty() function returns true if either of the width and height is less than, or equal to, zero, while the isNull() function returns true only if both the width and the height is zero.
Use the expandedTo() function to retrieve a size which holds the maximum height and width of this size and a given size. Similarly, the boundedTo() function returns a size which holds the minimum height and width of this size and a given size.
QSize objects can be streamed as well as compared.
See Also▲
Member Function Documentation▲
[constexpr, since 5.14] QSize QSize::grownBy(QMargins margins) const▲
Returns the size that results from growing this size by margins.
This function was introduced in Qt 5.14.
See Also▲
See also shrunkBy()
[constexpr, since 5.14] QSize QSize::shrunkBy(QMargins margins) const▲
Returns the size that results from shrinking this size by margins.
This function was introduced in Qt 5.14.
See Also▲
See also grownBy()
[constexpr] QSize::QSize()▲
Constructs a size with an invalid width and height (i.e., isValid() returns false).
See Also▲
See also isValid()
[constexpr] QSize::QSize(int width, int height)▲
[constexpr] 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▲
See also expandedTo(), scale()
[constexpr] 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▲
[constexpr] int QSize::height() const▲
[constexpr] 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▲
[constexpr] bool QSize::isNull() const▲
Returns true if both the width and height is 0; otherwise returns false.
See Also▲
[constexpr] bool QSize::isValid() const▲
Returns true if both the width and height is equal to or greater than 0; otherwise returns false.
See Also▲
[constexpr] 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▲
[constexpr] 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▲
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:
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If mode is Qt::IgnoreAspectRatio, the size is set to (width, height).
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If mode is Qt::KeepAspectRatio, the current size is scaled to a rectangle as large as possible inside (width, height), preserving the aspect ratio.
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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▲
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.
[since 5.0] 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▲
See also scale()
[since 5.0] QSize QSize::scaled(const QSize &s, Qt::AspectRatioMode mode) const▲
This is an overloaded function.
Return a size scaled to a rectangle with the given size s, according to the specified mode.
This function was introduced in Qt 5.0.
[constexpr] void QSize::setHeight(int height)▲
[constexpr] void QSize::setWidth(int width)▲
[since 5.8] CGSize QSize::toCGSize() const▲
Creates a CGSize from a QSize.
This function was introduced in Qt 5.8.
See Also▲
See also QSizeF::fromCGSize()
[constexpr, since 6.4] QSizeF QSize::toSizeF() const▲
Returns this size as a size with floating point accuracy.
This function was introduced in Qt 6.4.
See Also▲
See also QSizeF::toSize()
void QSize::transpose()▲
[constexpr, since 5.0] QSize QSize::transposed() const▲
Returns a QSize with width and height swapped.
This function was introduced in Qt 5.0.
See Also▲
See also transpose()
[constexpr] int QSize::width() const▲
[constexpr] 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▲
See also scale()
[constexpr] 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)[constexpr] 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▲
See also QSize::scale()
Related Non-Members▲
[constexpr] bool operator!=(const QSize &s1, const QSize &s2)▲
Returns true if s1 and s2 are different; otherwise returns false.
[constexpr] QSize operator*(const QSize &size, qreal factor)▲
Multiplies the given size by the given factor, and returns the result rounded to the nearest integer.
See Also▲
See also QSize::scale()
[constexpr] QSize operator*(qreal factor, const QSize &size)▲
This is an overloaded function.
Multiplies the given size by the given factor, and returns the result rounded to the nearest integer.
[constexpr] QSize operator+(const QSize &s1, const QSize &s2)▲
Returns the sum of s1 and s2; each component is added separately.
[constexpr] QSize operator-(const QSize &s1, const QSize &s2)▲
Returns s2 subtracted from s1; each component is subtracted separately.
QSize operator/(const QSize &size, qreal divisor)▲
This is an overloaded function.
Divides the given size by the given divisor, and returns the result rounded to the nearest integer.
See Also▲
See also QSize::scale()
QDataStream &operator<<(QDataStream &stream, const QSize &size)▲
Writes the given size to the given stream, and returns a reference to the stream.
See Also▲
See also Serializing Qt Data Types
[constexpr] bool operator==(const QSize &s1, const QSize &s2)▲
Returns true if s1 and s2 are equal; otherwise returns false.
QDataStream &operator>>(QDataStream &stream, QSize &size)▲
Reads a size from the given stream into the given size, and returns a reference to the stream.
See Also▲
See also Serializing Qt Data Types