The QRect class defines a rectangle in the plane using integer precision. More...

Public Methods
	QRect ()

	QRect (const QPoint &topLeft, const QPoint &bottomRight)

	QRect (const QPoint &topLeft, const QSize &size)

	QRect (int left, int top, int width, int height)

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

QRect	adjusted (int x1, int y1, int x2, int y2) const

int	bottom () const

QPoint	bottomLeft () const

QPoint	bottomRight () const

QPoint	center () const

bool	contains (const QPoint &point, bool proper=false) const

bool	contains (const QRect &rect, bool proper=false) const

bool	contains (int x, int y) const

bool	contains (int x, int y, bool proper) const

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

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

int	height () const

QRect	intersected (const QRect &rect) const

bool	intersects (const QRect &rect) const

bool	isEmpty () const

bool	isNull () const

bool	isValid () const

int	left () const

QRect	marginsAdded (const QMargins &margins) const

QRect	marginsRemoved (const QMargins &margins) const

void	moveBottom (int pos)

void	moveBottomLeft (const QPoint &point)

void	moveBottomRight (const QPoint &point)

void	moveCenter (const QPoint &point)

void	moveLeft (int pos)

void	moveRight (int pos)

void	moveTo (const QPoint &point)

void	moveTo (int x, int y)

void	moveTop (int pos)

void	moveTopLeft (const QPoint &point)

void	moveTopRight (const QPoint &point)

QRect	normalized () const

QRect	operator& (const QRect &rect) const

QRect &	operator&= (const QRect &rect)

QRect &	operator+= (const QMargins &margins)

QRect &	operator-= (const QMargins &margins)

QRect	operator\| (const QRect &rect) const

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

int	right () const

void	setBottom (int pos)

void	setBottomLeft (const QPoint &point)

void	setBottomRight (const QPoint &point)

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

void	setHeight (int h)

void	setLeft (int pos)

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

void	setRight (int pos)

void	setSize (const QSize &size)

void	setTop (int pos)

void	setTopLeft (const QPoint &point)

void	setTopRight (const QPoint &point)

void	setWidth (int w)

void	setX (int xPos)

void	setY (int yPos)

QSize	size () const

int	top () const

QPoint	topLeft () const

QPoint	topRight () const

void	translate (const QPoint &offset)

void	translate (int x, int y)

QRect	translated (const QPoint &offset) const

QRect	translated (int x, int y) const

QRect	united (const QRect &rect) const

int	width () const

int	x () const

int	y () const

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

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

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

QDataStream &	operator>> (QDataStream &stream, QRect &rect)

Detailed Description

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

A QRect 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.

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

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

There is a third constructor that creates a QRect using the top-left and bottom-right coordinates, but we recommend that you avoid using it. The rationale is that for historical reasons the values returned by the bottom() and right() functions deviate from the true bottom-right corner of the rectangle.

The QRect class provides a collection of functions that return the various rectangle coordinates, and enable manipulation of these. QRect also provide functions to move the rectangle relative to the various coordinates. In addition there is a moveTo() method which 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() method returns the rectangles dimensions as a QSize. The dimensions can also be retrieved separately using the width() and height() methods. To manipulate the dimensions use the setSize(), setWidth() or setHeight() methods. Alternatively, the size can be changed by applying either of the methods setting the rectangle coordinates using setBottom() or setRight().

The contains() method indicates whether a given point is inside the rectangle or not and the intersects() method returns true if the current rectangle intersects with some other rectangle. The QRect class also provides the intersected() method which returns the intersection rectangle. The united() method returns a rectangle which encloses the given rectangle and the current rectangle.


intersected()	united()

The isEmpty() function returns true if left() > right() or top() > bottom(). An empty rectangle is not valid: The isValid() function returns true if left() <= right() and top() <= bottom(). A null rectangle (isNull() == true) on the other hand, has both width and height set to 0.

Due to the way QRect and QRectF are defined an empty QRect is defined in essentially the same way as QRectF.

Finally, QRect objects can be streamed as well as compared.

Rendering

When using an anti-aliased painter the boundary line of a QRect will be rendered symmetrically on both sides of the mathematical rectangle's boundary line. When using an aliased painter (the default) other rules apply. When rendering with a one pixel wide pen the QRect'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 QRect class provides methods which return the rectangle coordinates. This allows the rectangle to be moved relative to its current position. For example, the method left() returns the x-coordinate of the rectangle's left edge and calling setLeft() modifies the coordinate of the left edge of the rectangle. Calling this method may change the width, but will not change the location for the right edge.

The method moveLeft() moves the entire rectangle horizontally, leaving the rectangle's size unchanged.

The values returned by the bottom() and right() methods do not match the true bottom-right corner of the rectangle. The right() method returns left() + width() - 1 and the bottom() method returns top() + height() - 1. The point returned by the bottomRight() method is located one unit up and to the left of the true bottom-right corner. The x and y coordinate of the topRight() and bottomLeft() methods, contain the same deviation from the true right and bottom edges.

You can use x() + width() and y() + height() to find the true bottom-right corner. Another solution is to use QRectF class which defines a rectangle using floating point. The QRectF::right() and QRectF::bottom() methods return the right and bottom coordinates.

To add offsets to the rectangle coordinates use the adjust() method. If you want a new rectangle offset from the original one, use adjusted().

QRect provides the getCoords() method which extracts the position of the rectangle's top-left and bottom-right corner and the getRect() method which returns the top-left corner width and height. Call setCoords() or setRect() to modify all four coordinates.

See also: QRectF, QRegion

Constructor & Destructor Documentation

QRect::QRect ( )

inline

Constructs a null QRect object.

See also: isNull()

QRect::QRect	(	const QPoint &	topLeft,
		const QPoint &	bottomRight
	)

inline

Constructs a rectangle with the given topLeft and bottomRight corners.

See also: setTopLeft(), setBottomRight()

QRect::QRect	(	const QPoint &	topLeft,
		const QSize &	size
	)

inline

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

See also: setTopLeft(), setSize()

QRect::QRect	(	int	left,
		int	top,
		int	width,
		int	height
	)

inline

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

See also: setRect()

Method Documentation

void QRect::adjust	(	int	x1,
		int	y1,
		int	x2,
		int	y2
	)

inline

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

See also: adjusted(), setRect()

QRect QRect::adjusted	(	int	x1,
		int	y1,
		int	x2,
		int	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()

int QRect::bottom ( ) const

inline

Returns the y-coordinate of the rectangle's bottom edge. This method returns top() + height() - 1. Use y() + height() to retrieve the actual y-coordinate.

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

QPoint QRect::bottomLeft ( ) const

inline

Returns the position of the rectangle's bottom-left corner. This method returns QPoint(left(), top() + height() - 1).

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

QPoint QRect::bottomRight ( ) const

inline

Returns the position of the rectangle's bottom-right corner. This method returns QPoint(left() + width() -1, top() + height() - 1).

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

QPoint QRect::center ( ) const

inline

Returns the center point of the rectangle.

See also: moveCenter()

bool QRect::contains	(	const QPoint &	point,
		bool	proper = `false`
	)		const

Returns true if the given point is inside or on the edge of the rectangle, otherwise returns false. If proper is true, this function only returns true if the given point is inside the rectangle and not on the edge.

See also: intersects()

bool QRect::contains	(	const QRect &	rect,
		bool	proper = `false`
	)		const

Returns true if the given rect is inside this rectangle. otherwise returns false. If proper is true, this method only returns true if the rect is entirely inside this rectangle (not on the edge).

bool QRect::contains	(	int	x,
		int	y
	)		const

inline

Returns true if the point (x, y) is inside this rectangle, otherwise returns false.

bool QRect::contains	(	int	x,
		int	y,
		bool	proper
	)		const

inline

Returns true if the point (x, y) is inside or on the edge of the rectangle, otherwise returns false. If proper is true, this function only returns true if the point is entirely inside the rectangle(not on the edge).

void QRect::getCoords	(	int *	x1,
		int *	y1,
		int *	x2,
		int *	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 QRect::getRect	(	int *	x,
		int *	y,
		int *	width,
		int *	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()

int QRect::height ( ) const

inline

Returns the height of the rectangle.

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

QRect QRect::intersected ( const QRect & 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 QRect::intersects ( const QRect & rect ) const

Returns true if this rectangle intersects with the given rect. This means there is at least one pixel that is within both rectangles. The intersection rectangle can be retrieved using intersected().

See also: contains()

bool QRect::isEmpty ( ) const

inline

Returns true if the rectangle is empty, otherwise returns false. An empty rectangle has a left() > right() or top() > bottom(). An empty rectangle is not valid (i.e., isEmpty() == ! isValid()). Use the normalized() method to retrieve a rectangle where the corners are swapped.

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

bool QRect::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 (i.e., right() == left() - 1 and bottom() == top() - 1). A null rectangle is also empty, and hence is not valid.

See also: isEmpty(), isValid()

bool QRect::isValid ( ) const

inline

Returns true if the rectangle is valid, otherwise returns false. A valid rectangle has a left() < right() and top() < bottom(). 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()

int QRect::left ( ) const

inline

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

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

QRect QRect::marginsAdded ( const QMargins & margins ) const

inline

Returns a new rectangle grown by margins.

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

QRect QRect::marginsRemoved ( const QMargins & margins ) const

inline

Returns a new rectangle shrunk by margins

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

void QRect::moveBottom ( int 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 QRect::moveBottomLeft ( const QPoint & 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 QRect::moveBottomRight ( const QPoint & point )

inline

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

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

void QRect::moveCenter ( const QPoint & point )

inline

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

See also: center()

void QRect::moveLeft ( int 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 QRect::moveRight ( int 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 QRect::moveTo ( const QPoint & point )

inline

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

void QRect::moveTo	(	int	x,
		int	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 QRect::moveTop ( int pos )

inline

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

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

void QRect::moveTopLeft ( const QPoint & 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 QRect::moveTopRight ( const QPoint & 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()

QRect QRect::normalized ( ) const

Returns a normalized rectangle. This is a rectangle which has a non-negative width and height. If width() is less than 0 the method swaps the left and right corners. It will swap the top and bottom corners if height() is less than 0.

See also: isValid(), isEmpty()

QRect QRect::operator& ( const QRect & 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()

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

inline

Intersects this rectangle with the given rect.

See also: intersected(), operator&()

QRect & QRect::operator+= ( const QMargins & margins )

inline

Grows this rectangle by margins.

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

QRect & QRect::operator-= ( const QMargins & margins )

inline

Shrinks this rectangle by margins.

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

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

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

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

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

inline

Unites this rectangle with the given rect.

See also: united(), operator|()

int QRect::right ( ) const

inline

Returns the x-coordinate of the rectangle's right edge. This method returns left() + width() - 1; use x() + width() to retrieve the actual x-coordinate.

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

void QRect::setBottom ( int 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 QRect::setBottomLeft ( const QPoint & 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 QRect::setBottomRight ( const QPoint & 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 QRect::setCoords	(	int	x1,
		int	y1,
		int	x2,
		int	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 QRect::setHeight ( int 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 QRect::setLeft ( int 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 QRect::setRect	(	int	x,
		int	y,
		int	width,
		int	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 QRect::setRight ( int 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 QRect::setSize ( const QSize & 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 QRect::setTop ( int 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 QRect::setTopLeft ( const QPoint & 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 QRect::setTopRight ( const QPoint & 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 QRect::setWidth ( int 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 QRect::setX ( int 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 QRect::setY ( int 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()

QSize QRect::size ( ) const

inline

Returns the size of the rectangle.

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

int QRect::top ( ) const

inline

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

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

QPoint QRect::topLeft ( ) const

inline

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

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

QPoint QRect::topRight ( ) const

inline

Returns the position of the rectangle's top-right corner. This method returns QPoint(left() + width() -1, top()).

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

void QRect::translate ( const QPoint & offset )

inline

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

void QRect::translate	(	int	x,
		int	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 down.

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

QRect QRect::translated ( const QPoint & 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.

QRect QRect::translated	(	int	x,
		int	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()

QRect QRect::united ( const QRect & rect ) const

inline

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

See also: intersected()

int QRect::width ( ) const

inline

Returns the width of the rectangle.

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

int QRect::x ( ) const

inline

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

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

int QRect::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 QRect &	rect1,
		const QRect &	rect2
	)

friend

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

QDataStream & operator<<	(	QDataStream &	stream,
		const QRect &	rect
	)

Refer to Serializing Data Types for additional information.

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

friend

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

QDataStream & operator>>	(	QDataStream &	stream,
		QRect &	rect
	)

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