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QSizeF Class Reference

The QSizeF class defines the size of a two-dimensional object using floating point values for accuracy. More...

#include <QSizeF>

Public Functions

Related Non-Members


Detailed Description

The QSizeF class defines the size of a two-dimensional object using floating point values for accuracy.

A size is specified by a width and a height.

The coordinate type is float.

The size can be set in the constructor and changed with setWidth(), setHeight(), or scale(), or using operator+=(), operator-=(), operator*=() and operator/=(), etc. You can swap the width and height with transpose(). You can get a size which holds the maximum height and width of two sizes using expandedTo(), and the minimum height and width of two sizes using boundedTo().

See also QSize, QPointF, and QRectF.


Member Function Documentation

QSizeF::QSizeF ()

Constructs a size with invalid width and height.

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

QSizeF::QSizeF ( const QSize & size )

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

QSizeF::QSizeF ( float width, float height )

Constructs a size with width width and height height.

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

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

See also expandedTo(), scale(), setWidth(), and setHeight().

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

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

See also boundedTo(), scale(), setWidth(), and setHeight().

float QSizeF::height () const

Returns the height.

See also width().

bool QSizeF::isEmpty () const

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

See also isNull(), isValid(), width(), and height().

bool QSizeF::isNull () const

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

See also isValid(), isEmpty(), width(), and height().

bool QSizeF::isValid () const

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

See also isNull(), isEmpty(), width(), and height().

float & QSizeF::rheight ()

Returns a reference to the height.

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

Example:

    QSizeF s(100, 10);
    s.rheight() += 5;                // s becomes (100,15)

See also rwidth() and setHeight().

float & QSizeF::rwidth ()

Returns a reference to the width.

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

Example:

    QSizeF s(100, 10);
    s.rwidth() += 20;                // s becomes (120,10)

See also rheight() and setWidth().

void QSizeF::scale ( float w, float h, Qt::AspectRatioMode mode )

Scales the size to a rectangle of width w and height h according to the Qt::AspectRatioMode mode.

Example:

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

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

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

See also boundedTo(), expandedTo(), setWidth(), and setHeight().

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

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Equivalent to scale(s.width(), s.height(), mode).

void QSizeF::setHeight ( float height )

Sets the height to height.

See also height(), setWidth(), expandedTo(), boundedTo(), scale(), and transpose().

void QSizeF::setWidth ( float width )

Sets the width to width.

See also width(), setHeight(), expandedTo(), boundedTo(), scale(), and transpose().

QSize QSizeF::toSize () const

Returns a size with integer precision. Note that the coordinates in the returned size are less precise than those in the floating point size.

void QSizeF::transpose ()

Swaps the width and height values.

See also expandedTo(), boundedTo(), setWidth(), and setHeight().

float QSizeF::width () const

Returns the width.

See also height().

QSizeF & QSizeF::operator*= ( int c )

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

See also scale().

QSizeF & QSizeF::operator*= ( float c )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

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

Note that the result is truncated.

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

Adds s to the size and returns a reference to this size.

Example:

    QSizeF s( 3, 7);
    QSizeF r(-1, 4);
    s += r;                        // s becomes (2,11)

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

Subtracts s from the size and returns a reference to this size.

Example:

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

QSizeF & QSizeF::operator/= ( int c )

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

See also scale().

QSizeF & QSizeF::operator/= ( float c )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

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

Note that the result is truncated.

See also scale().


Related Non-Members

bool operator!= ( const QSizeF & s1, const QSizeF & s2 )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Returns true if s1 and s2 are different; otherwise returns false.

const QSizeF operator* ( const QSizeF & s, int c )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Multiplies s by c and returns the result.

See also scale().

const QSizeF operator* ( int c, const QSizeF & s )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Multiplies s by c and returns the result.

See also scale().

const QSizeF operator* ( const QSizeF & s, float c )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Multiplies s by c and returns the result.

See also scale().

const QSizeF operator* ( float c, const QSizeF & s )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Multiplies s by c and returns the result.

See also scale().

const QSizeF operator+ ( const QSizeF & s1, const QSizeF & s2 )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Returns the sum of s1 and s2; each component is added separately.

See also scale().

const QSizeF operator- ( const QSizeF & s1, const QSizeF & s2 )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Returns s2 subtracted from s1; each component is subtracted separately.

See also scale().

const QSizeF operator/ ( const QSizeF & s, int c )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Divides s by c and returns the result.

See also scale().

const QSizeF operator/ ( const QSizeF & s, float c )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Divides s by c and returns the result.

Note that the result is truncated.

See also scale().

QDataStream & operator<< ( QDataStream & s, const QSizeF & sz )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Writes the size sz to the stream s and returns a reference to the stream.

See also Format of the QDataStream operators.

bool operator== ( const QSizeF & s1, const QSizeF & s2 )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Returns true if s1 and s2 are equal; otherwise returns false.

QDataStream & operator>> ( QDataStream & s, QSizeF & sz )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Reads the size from the stream s into size sz and returns a reference to the stream.

See also Format of the QDataStream operators.


Copyright © 2004 Trolltech. Trademarks
Qt 4.0.0-tp2