CopperSpice API  1.7.2
QRect Class Reference

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 *w, int *h) 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 &p)
 
void moveBottomRight (const QPoint &p)
 
void moveCenter (const QPoint &p)
 
void moveLeft (int pos)
 
void moveRight (int pos)
 
void moveTo (const QPoint &position)
 
void moveTo (int x, int y)
 
void moveTop (int pos)
 
void moveTopLeft (const QPoint &p)
 
void moveTopRight (const QPoint &p)
 
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 w, int h)
 
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 &p)
 
void translate (int x, int y)
 
QRect translated (const QPoint &p) 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 &, const QRect &)
 
bool operator== (const QRect &, const QRect &)
 

Related Functions

These are not member functions

QDataStreamoperator<< (QDataStream &stream, const QRect &rectangle)
 
QDataStreamoperator>> (QDataStream &stream, QRect &rectangle)
 

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() 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() function 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. The QRect class also provides the intersected() function which returns the intersection rectangle, and the united() function which returns the rectangle that encloses the given rectangle and this:

intersected()united()

The isEmpty() function returns true if left() > right() or top() > bottom(). Note that 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. But when using an aliased painter (the default) other rules apply.

Then, 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 representationOne pixel wide pen
Two pixel wide penThree pixel wide pen

Coordinates

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.

For example the left(), setLeft() and moveLeft() functions as an example: left() returns the x-coordinate of the rectangle's left edge, setLeft() sets the left edge of the rectangle to the given x coordinate (it may change the width, but will never change the rectangle's right edge) and moveLeft() moves the entire rectangle horizontally, leaving the rectangle's left edge at the given x coordinate and its size unchanged.

Note that for historical reasons the values returned by the bottom() and right() functions deviate from the true bottom-right corner of the rectangle: The right() function returns left() + width() - 1 and the bottom() function returns top() + height() - 1. The same is the case for the point returned by the bottomRight() convenience function. In addition, the x and y coordinate of the topRight() and bottomLeft() functions, respectively, contain the same deviation from the true right and bottom edges.

We recommend that you use x() + width() and y() + height() to find the true bottom-right corner, and avoid right() and bottom(). Another solution is to use QRectF: The QRectF class defines a rectangle in the plane using floating point accuracy for coordinates, and the QRectF::right() and QRectF::bottom() functions do return the right and bottom coordinates.

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, QRect 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
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 (x, y) 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 dx1, dy1, dx2 and dy2 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 dx1, dy1, dx2 and dy2 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 *  w,
int *  h 
) 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() function 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(). Note that 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 y coordinate. The rectangle's size is unchanged.

See also
bottom(), setBottom(), moveTop()
void QRect::moveBottomLeft ( const QPoint p)
inline

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

See also
setBottomLeft(), moveBottom(), moveLeft()
void QRect::moveBottomRight ( const QPoint p)
inline

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

See also
setBottomRight(), moveRight(), moveBottom()
void QRect::moveCenter ( const QPoint p)
inline

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

See also
right(), setRight(), moveLeft()
void QRect::moveTo ( const QPoint position)
inline

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

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 y coordinate. The rectangle's size is unchanged.

See also
top(), setTop(), moveBottom()
void QRect::moveTopLeft ( const QPoint p)
inline

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

See also
setTopLeft(), moveTop(), moveLeft()
void QRect::moveTopRight ( const QPoint p)
inline

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

See also
setTopRight(), moveTop(), moveRight()
QRect QRect::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. It will swap the top and bottom corners if height() < 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 rectangle.

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 y 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 position. 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 position. 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 height. 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 x 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  w,
int  h 
)
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 x 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 y 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 position. 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 position. 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 width. 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 p)
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 dx along the x axis and dy 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 p) 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 dx along the x axis and dy 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 rectangle.

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 &  r1,
const QRect &  r2 
)
friend

Returns true if the rectangles r1 and r2 are different, otherwise returns false.

QDataStream & operator<< ( QDataStream stream,
const QRect &  rectangle 
)
related

Writes the given rectangle to the given stream, and returns a reference to the stream.

Refer to Serializing Data Types for additional information.

bool operator== ( const QRect &  r1,
const QRect &  r2 
)
friend

Returns true if the rectangles r1 and r2 are equal, otherwise returns false.

QDataStream & operator>> ( QDataStream stream,
QRect &  rectangle 
)
related

Reads a rectangle from the given stream into the given rectangle, and returns a reference to the stream.

Refer to Serializing Data Types for additional information.