The QRectF class defines a rectangle in the plane using floating point precision. More...

Public Methods
	QRectF ()

	QRectF (const QPointF &topLeft, const QPointF &bottomRight)

	QRectF (const QPointF &topLeft, const QSizeF &size)

	QRectF (const QRect &rect)

	QRectF (qreal left, qreal top, qreal width, qreal height)

void	adjust (qreal x1, qreal y1, qreal x2, qreal y2)

QRectF	adjusted (qreal x1, qreal y1, qreal x2, qreal y2) const

qreal	bottom () const

QPointF	bottomLeft () const

QPointF	bottomRight () const

QPointF	center () const

bool	contains (const QPointF &point) const

bool	contains (const QRectF &rect) const

bool	contains (qreal x, qreal y) const

void	getCoords (qreal x1, qreal y1, qreal x2, qreal y2) const

void	getRect (qreal x, qreal y, qreal width, qreal height) const

qreal	height () const

QRectF	intersected (const QRectF &rect) const

bool	intersects (const QRectF &rect) const

bool	isEmpty () const

bool	isNull () const

bool	isValid () const

qreal	left () const

QRectF	marginsAdded (const QMarginsF &margins) const

QRectF	marginsRemoved (const QMarginsF &margins) const

void	moveBottom (qreal pos)

void	moveBottomLeft (const QPointF &point)

void	moveBottomRight (const QPointF &point)

void	moveCenter (const QPointF &point)

void	moveLeft (qreal pos)

void	moveRight (qreal pos)

void	moveTo (const QPointF &point)

void	moveTo (qreal x, qreal y)

void	moveTop (qreal pos)

void	moveTopLeft (const QPointF &point)

void	moveTopRight (const QPointF &point)

QRectF	normalized () const

QRectF	operator& (const QRectF &rect) const

QRectF &	operator&= (const QRectF &rect)

QRectF &	operator+= (const QMarginsF &margins)

QRectF &	operator-= (const QMarginsF &margins)

QRectF	operator\| (const QRectF &rect) const

QRectF &	operator\|= (const QRectF &rect)

qreal	right () const

void	setBottom (qreal pos)

void	setBottomLeft (const QPointF &point)

void	setBottomRight (const QPointF &point)

void	setCoords (qreal x1, qreal y1, qreal x2, qreal y2)

void	setHeight (qreal h)

void	setLeft (qreal pos)

void	setRect (qreal x, qreal y, qreal width, qreal height)

void	setRight (qreal pos)

void	setSize (const QSizeF &size)

void	setTop (qreal pos)

void	setTopLeft (const QPointF &point)

void	setTopRight (const QPointF &point)

void	setWidth (qreal w)

void	setX (qreal xPos)

void	setY (qreal yPos)

QSizeF	size () const

QRect	toAlignedRect () const

qreal	top () const

QPointF	topLeft () const

QPointF	topRight () const

QRect	toRect () const

void	translate (const QPointF &offset)

void	translate (qreal x, qreal y)

QRectF	translated (const QPointF &offset) const

QRectF	translated (qreal x, qreal y) const

QRectF	united (const QRectF &rect) const

qreal	width () const

qreal	x () const

qreal	y () const

Friends
bool	operator!= (const QRectF &rect1, const QRectF &rect2)

bool	operator== (const QRectF &rect1, const QRectF &rect2)

Related Functions
These are not member functions
QDataStream &	operator<< (QDataStream &stream, const QRectF &rectF)

QDataStream &	operator>> (QDataStream &stream, QRectF &rectF)

Detailed Description

The QRectF class defines a rectangle in the plane using floating point precision. A rectangle is normally expressed as an upper-left corner and a size. The size (width and height) of a QRectF is always equivalent to the mathematical rectangle that forms the basis for its rendering.

A QRectF can be constructed with a set of left, top, width and height integers, or from a QPoint and a QSize. The following code creates two identical rectangles.

QRectF r1(100, 200, 11, 16);

QRectF r2(QPoint(100, 200), QSize(11, 16));

There is also a third constructor which creates a QRectF from a QRect and a corresponding toRect() method which returns a QRect object based on the values of this rectangle. The coordinates in the returned rectangle are rounded to the nearest integer.

The QRectF class provides a collection of functions that return the various rectangle coordinates, and enable manipulation of these. QRectF also provide functions to move the rectangle relative to the various coordinates. In addition there is a moveTo() function that moves the rectangle, leaving its top left corner at the given coordinates. Alternatively, the translate() function moves the rectangle the given offset relative to the current position, and the translated() function returns a translated copy of this rectangle.

The size() function returns the rectangles dimensions as a QSize. The dimensions can also be retrieved separately using the width() and height() functions. To manipulate the dimensions use the setSize(), setWidth() or setHeight() functions. Alternatively, the size can be changed by applying either of the functions setting the rectangle coordinates, for example, setBottom() or setRight().

The contains() method tells whether a given point is inside the rectangle or not, and the intersects() function returns true if this rectangle intersects with a given rectangle (otherwise false). The QRectF class also provides the intersected() method which returns the intersection rectangle, and the united() function which returns the rectangle that encloses the given rectangle.


intersected()	united()

The isEmpty() method returns true if the rectangle's width or height is less than or equal to, 0. An empty rectangle is not valid. The isValid() method returns true if both width and height is larger than 0. A null rectangle has both width and height set to 0. An empty QRectF is defined in essentially the same way as QRect. QRectF objects can be streamed as well as compared.

Rendering

When using an anti-aliased painter, the boundary line of a QRectF will be rendered symmetrically on both sides of the mathematical rectangle's boundary line. But when using an aliased painter (the default) other rules apply.

Then, when rendering with a one pixel wide pen the QRectF's boundary line will be rendered to the right and below the mathematical rectangle's boundary line.

When rendering with a two pixels wide pen the boundary line will be split in the middle by the mathematical rectangle. This will be the case whenever the pen is set to an even number of pixels, while rendering with a pen with an odd number of pixels, the spare pixel will be rendered to the right and below the mathematical rectangle as in the one pixel case.


Logical representation	One pixel wide pen

Two pixel wide pen	Three pixel wide pen

Coordinates

The QRectF class provides a collection of functions that return the various rectangle coordinates, and enable manipulation of these. QRectF also provide functions to move the rectangle relative to the various coordinates.

For example: the bottom(), setBottom() and moveBottom() functions: bottom() returns the y-coordinate of the rectangle's bottom edge, setBottom() sets the bottom edge of the rectangle to the given y coordinate (it may change the height, but will never change the rectangle's top edge) and moveBottom() moves the entire rectangle vertically, leaving the rectangle's bottom edge at the given y coordinate and its size unchanged.

It is also possible to add offsets to this rectangle's coordinates using the adjust() function, as well as retrieve a new rectangle based on adjustments of the original one using the adjusted() function. If either of the width and height is negative, use the normalized() function to retrieve a rectangle where the corners are swapped.

In addition, QRectF provides the getCoords() function which extracts the position of the rectangle's top-left and bottom-right corner, and the getRect() function which extracts the rectangle's top-left corner, width and height. Use the setCoords() and setRect() function to manipulate the rectangle's coordinates and dimensions in one go.

See also: QRect, QRegion

Constructor & Destructor Documentation

QRectF::QRectF ( )

inline

Constructs a null rectangle.

See also: isNull()

QRectF::QRectF	(	const QPointF &	topLeft,
		const QSizeF &	size
	)

inline

Constructs a rectangle with the given topLeft corner and the given size.

See also: setTopLeft(), setSize()

QRectF::QRectF	(	const QPointF &	topLeft,
		const QPointF &	bottomRight
	)

inline

Constructs a rectangle with the given topLeft and bottomRight corners.

See also: setTopLeft(), setBottomRight()

QRectF::QRectF	(	qreal	left,
		qreal	top,
		qreal	width,
		qreal	height
	)

inline

Constructs a rectangle with (left, top) as its top-left corner and the given width and height.

See also: setRect()

QRectF::QRectF ( const QRect & rect )

inline

Constructs a QRectF rectangle from the given QRect rectangle.

See also: toRect()

Method Documentation

void QRectF::adjust	(	qreal	x1,
		qreal	y1,
		qreal	x2,
		qreal	y2
	)

inline

Adds x1, y1, x2 and y2 respectively to the existing coordinates of the rectangle.

See also: adjusted(), setRect()

QRectF QRectF::adjusted	(	qreal	x1,
		qreal	y1,
		qreal	x2,
		qreal	y2
	)		const

inline

Returns a new rectangle with x1, y1, x2 and y2 added respectively to the existing coordinates of this rectangle.

See also: adjust()

qreal QRectF::bottom ( ) const

inline

Returns the y-coordinate of the rectangle's bottom edge.

See also: setBottom(), bottomLeft(), bottomRight()

QPointF QRectF::bottomLeft ( ) const

inline

Returns the position of the rectangle's bottom-left corner.

See also: setBottomLeft(), bottom(), left()

QPointF QRectF::bottomRight ( ) const

inline

Returns the position of the rectangle's bottom-right corner.

See also: setBottomRight(), bottom(), right()

QPointF QRectF::center ( ) const

inline

Returns the center point of the rectangle.

See also: moveCenter()

bool QRectF::contains ( const QPointF & point ) const

Returns true if the given point is inside or on the edge of the rectangle, otherwise returns false.

See also: intersects()

bool QRectF::contains ( const QRectF & rect ) const

Returns true if the given rect is inside this rectangle, otherwise returns false.

bool QRectF::contains	(	qreal	x,
		qreal	y
	)		const

inline

Returns true if the point (x, y) is inside or on the edge of the rectangle, otherwise returns false.

void QRectF::getCoords	(	qreal *	x1,
		qreal *	y1,
		qreal *	x2,
		qreal *	y2
	)		const

inline

Extracts the position of the rectangle's top-left corner to x1 and y1, and the position of the bottom-right corner to x2 and y2.

See also: setCoords(), getRect()

void QRectF::getRect	(	qreal *	x,
		qreal *	y,
		qreal *	width,
		qreal *	height
	)		const

inline

Extracts the position of the rectangle's top-left corner to x and y, and its dimensions to width and height.

See also: setRect(), getCoords()

qreal QRectF::height ( ) const

inline

Returns the height of the rectangle.

See also: setHeight(), width(), size()

QRectF QRectF::intersected ( const QRectF & rect ) const

inline

Returns the intersection of this rectangle and the given rect. Calling a.intersected(b) is equivalent to a & b.

See also: intersects(), united(), operator&=()

bool QRectF::intersects ( const QRectF & rect ) const

Returns true if this rectangle intersects with the given rect. This means there is a non-empty area of overlap between them. The intersection rectangle can be retrieved using intersected().

See also: contains()

bool QRectF::isEmpty ( ) const

inline

Returns true if the rectangle is empty, otherwise returns false. An empty rectangle has width() <= 0 or height() <= 0. An empty rectangle is not valid (i.e., isEmpty() == !isValid()). Use the normalized() function to retrieve a rectangle where the corners are swapped.

See also: isNull(), isValid(), normalized()

bool QRectF::isNull ( ) const

inline

Returns true if the rectangle is a null rectangle, otherwise returns false. A null rectangle has both the width and the height set to 0. A null rectangle is also empty, and hence not valid.

See also: isEmpty(), isValid()

bool QRectF::isValid ( ) const

inline

Returns true if the rectangle is valid, otherwise returns false. A valid rectangle has a width() > 0 and height() > 0. Non-trivial operations like intersections are not defined for invalid rectangles. A valid rectangle is not empty (i.e., isValid() == !isEmpty()).

See also: isNull(), isEmpty(), normalized()

qreal QRectF::left ( ) const

inline

Returns the x-coordinate of the rectangle's left edge. Equivalent to x().

See also: setLeft(), topLeft(), bottomLeft()

QRectF QRectF::marginsAdded ( const QMarginsF & margins ) const

inline

Returns a new rectangle grown by margins.

See also: marginsRemoved(), operator+=(), operator-=()

QRectF QRectF::marginsRemoved ( const QMarginsF & margins ) const

inline

Returns a new rectangle shrunk by margins

See also: marginsAdded(), operator+=(), operator-=()

void QRectF::moveBottom ( qreal pos )

inline

Moves the rectangle vertically, leaving the rectangle's bottom edge at the given pos coordinate. The rectangle's size is unchanged.

See also: bottom(), setBottom(), moveTop()

void QRectF::moveBottomLeft ( const QPointF & point )

inline

Moves the rectangle, leaving the bottom-left corner at the given point. The rectangle's size is unchanged.

See also: setBottomLeft(), moveBottom(), moveLeft()

void QRectF::moveBottomRight ( const QPointF & point )

inline

Moves the rectangle, leaving the bottom-right corner at the given point. The rectangle's size is unchanged.

See also: setBottomRight(), moveBottom(), moveRight()

void QRectF::moveCenter ( const QPointF & point )

inline

Moves the rectangle, leaving the center point at the given point. The rectangle's size is unchanged.

See also: center()

void QRectF::moveLeft ( qreal pos )

inline

Moves the rectangle horizontally, leaving the rectangle's left edge at the given pos coordinate. The rectangle's size is unchanged.

See also: left(), setLeft(), moveRight()

void QRectF::moveRight ( qreal pos )

inline

Moves the rectangle horizontally, leaving the rectangle's right edge at the given pos coordinate. The rectangle's size is unchanged.

See also: right(), setRight(), moveLeft()

void QRectF::moveTo ( const QPointF & point )

inline

Moves the rectangle, leaving the top-left corner at the given point.

void QRectF::moveTo	(	qreal	x,
		qreal	y
	)

inline

Moves the rectangle, leaving the top-left corner at the given position (x, y). The rectangle's size is unchanged.

See also: translate(), moveTopLeft()

void QRectF::moveTop ( qreal pos )

inline

Moves the rectangle vertically, leaving the rectangle's top line at the given pos coordinate. The rectangle's size is unchanged.

See also: top(), setTop(), moveBottom()

void QRectF::moveTopLeft ( const QPointF & point )

inline

Moves the rectangle, leaving the top-left corner at the given point. The rectangle's size is unchanged.

See also: setTopLeft(), moveTop(), moveLeft()

void QRectF::moveTopRight ( const QPointF & point )

inline

Moves the rectangle, leaving the top-right corner at the given point. The rectangle's size is unchanged.

See also: setTopRight(), moveTop(), moveRight()

QRectF QRectF::normalized ( ) const

Returns a normalized rectangle; i.e., a rectangle that has a non-negative width and height. If width() < 0 the method swaps the left and right corners, and it swaps the top and bottom corners if height() < 0.

See also: isValid(), isEmpty()

QRectF QRectF::operator& ( const QRectF & rect ) const

Returns the intersection of this rectangle and the given rect. Returns an empty rectangle if there is no intersection.

See also: operator&=(), intersected()

QRectF & QRectF::operator&= ( const QRectF & rect )

inline

Intersects this rectangle with the given rect.

See also: intersected(), operator|=()

QRectF & QRectF::operator+= ( const QMarginsF & margins )

inline

Grows this rectangle by margins.

See also: marginsAdded(), marginsRemoved(), operator-=()

QRectF & QRectF::operator-= ( const QMarginsF & margins )

inline

Shrinks this rectangle by margins.

See also: marginsAdded(), marginsRemoved(), operator+=()

QRectF QRectF::operator| ( const QRectF & rect ) const

Returns the bounding rectangle of this rectangle and the given rect.

See also: united(), operator|=()

QRectF & QRectF::operator|= ( const QRectF & rect )

inline

Unites this rectangle with the given rect.

See also: united(), operator|()

qreal QRectF::right ( ) const

inline

Returns the x-coordinate of the rectangle's right edge.

See also: setRight(), topRight(), bottomRight()

void QRectF::setBottom ( qreal pos )

inline

Sets the bottom edge of the rectangle to the given pos coordinate. May change the height, but will never change the top edge of the rectangle.

See also: bottom(), moveBottom()

void QRectF::setBottomLeft ( const QPointF & point )

inline

Set the bottom-left corner of the rectangle to the given point. May change the size, but will never change the top-right corner of the rectangle.

See also: bottomLeft(), moveBottomLeft()

void QRectF::setBottomRight ( const QPointF & point )

inline

Set the bottom-right corner of the rectangle to the given point. May change the size, but will never change the top-left corner of the rectangle.

See also: bottomRight(), moveBottomRight()

void QRectF::setCoords	(	qreal	x1,
		qreal	y1,
		qreal	x2,
		qreal	y2
	)

inline

Sets the coordinates of the rectangle's top-left corner to (x1, y1), and the coordinates of its bottom-right corner to (x2, y2).

See also: getCoords(), setRect()

void QRectF::setHeight ( qreal h )

inline

Sets the height of the rectangle to the given h. The bottom edge is changed, but not the top one.

See also: height(), setSize()

void QRectF::setLeft ( qreal pos )

inline

Sets the left edge of the rectangle to the given pos coordinate. May change the width, but will never change the right edge of the rectangle.

Equivalent to setX().

See also: left(), moveLeft()

void QRectF::setRect	(	qreal	x,
		qreal	y,
		qreal	width,
		qreal	height
	)

inline

Sets the coordinates of the rectangle's top-left corner to (x, y), and its size to the given width and height.

See also: getRect(), setCoords()

void QRectF::setRight ( qreal pos )

inline

Sets the right edge of the rectangle to the given pos coordinate. May change the width, but will never change the left edge of the rectangle.

See also: right(), moveRight()

void QRectF::setSize ( const QSizeF & size )

inline

Sets the size of the rectangle to the given size. The top-left corner is not moved.

See also: size(), setWidth(), setHeight()

void QRectF::setTop ( qreal pos )

inline

Sets the top edge of the rectangle to the given pos coordinate. May change the height, but will never change the bottom edge of the rectangle.

Equivalent to setY().

See also: top(), moveTop()

void QRectF::setTopLeft ( const QPointF & point )

inline

Set the top-left corner of the rectangle to the given point. May change the size, but will never change the bottom-right corner of the rectangle.

See also: topLeft(), moveTopLeft()

void QRectF::setTopRight ( const QPointF & point )

inline

Set the top-right corner of the rectangle to the given point. May change the size, but will never change the bottom-left corner of the rectangle.

See also: topRight(), moveTopRight()

void QRectF::setWidth ( qreal w )

inline

Sets the width of the rectangle to the given w. The right edge is changed, but not the left one.

See also: width(), setSize()

void QRectF::setX ( qreal xPos )

inline

Sets the left edge of the rectangle to the given xPos coordinate. May change the width, but will never change the right edge of the rectangle.

Equivalent to setLeft().

See also: x(), setY(), setTopLeft()

void QRectF::setY ( qreal yPos )

inline

Sets the top edge of the rectangle to the given yPos coordinate. May change the height, but will never change the bottom edge of the rectangle.

Equivalent to setTop().

See also: y(), setX(), setTopLeft()

QSizeF QRectF::size ( ) const

inline

Returns the size of the rectangle.

See also: setSize(), width(), height()

QRect QRectF::toAlignedRect ( ) const

Returns a QRect based on the values of this rectangle that is the smallest possible integer rectangle that completely contains this rectangle.

See also: toRect()

qreal QRectF::top ( ) const

inline

Returns the y-coordinate of the rectangle's top edge. Equivalent to y().

See also: setTop(), topLeft(), topRight()

QPointF QRectF::topLeft ( ) const

inline

Returns the position of the rectangle's top-left corner.

See also: setTopLeft(), top(), left()

QPointF QRectF::topRight ( ) const

inline

Returns the position of the rectangle's top-right corner.

See also: setTopRight(), top(), right()

QRect QRectF::toRect ( ) const

inline

Returns a QRect based on the values of this rectangle. The coordinates in the returned rectangle are rounded to the nearest integer.

See also: QRectF(), toAlignedRect()

void QRectF::translate ( const QPointF & offset )

inline

Moves the rectangle offset.x() along the x axis and offset.y() along the y axis, relative to the current position.

void QRectF::translate	(	qreal	x,
		qreal	y
	)

inline

Moves the rectangle x along the x-axis and y along the y-axis, relative to the current position. Positive values move the rectangle to the right and downwards.

See also: moveTopLeft(), moveTo(), translated()

QRectF QRectF::translated ( const QPointF & offset ) const

inline

Returns a copy of the rectangle that is translated offset.x() along the x axis and offset.y() along the y axis, relative to the current position.

QRectF QRectF::translated	(	qreal	x,
		qreal	y
	)		const

inline

Returns a copy of the rectangle that is translated x along the x axis and y along the y axis, relative to the current position. Positive values move the rectangle to the right and down.

See also: translate()

QRectF QRectF::united ( const QRectF & rect ) const

inline

Returns the bounding rectangle of this QRectF and the given rect.

See also: intersected()

qreal QRectF::width ( ) const

inline

Returns the width of the rectangle.

See also: setWidth(), height(), size()

qreal QRectF::x ( ) const

inline

Returns the x-coordinate of the rectangle's left edge. Equivalent to left().

See also: setX(), y(), topLeft()

qreal QRectF::y ( ) const

inline

Returns the y-coordinate of the rectangle's top edge. Equivalent to top().

See also: setY(), x(), topLeft()

Friends And Related Function Documentation

bool operator!=	(	const QRectF &	rect1,
		const QRectF &	rect2
	)

friend

Returns true if the rectangles rect1 and rect2 are different, otherwise returns false.

QDataStream & operator<<	(	QDataStream &	stream,
		const QRectF &	rectF
	)

Refer to Serializing Data Types for additional information.

bool operator==	(	const QRectF &	rect1,
		const QRectF &	rect2
	)

friend

Returns true if the rectangles rect1 and rect2 are equal, otherwise returns false.

QDataStream & operator>>	(	QDataStream &	stream,
		QRectF &	rectF
	)

Refer to Serializing Data Types for additional information.

Public Methods

Friends

Related Functions

Detailed Description

Rendering

Coordinates

Constructor & Destructor Documentation

Method Documentation

Friends And Related Function Documentation