class QRect¶

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

Synopsis¶

Methods¶

def __init__()
def __reduce__()
def __repr__()
def adjust()
def adjusted()
def bottom()
def bottomLeft()
def bottomRight()
def center()
def contains()
def getCoords()
def getRect()
def height()
def intersected()
def intersects()
def isEmpty()
def isNull()
def isValid()
def left()
def marginsAdded()
def marginsRemoved()
def moveBottom()
def moveBottomLeft()
def moveBottomRight()
def moveCenter()
def moveLeft()
def moveRight()
def moveTo()
def moveTop()
def moveTopLeft()
def moveTopRight()
def normalized()
def __ne__()
def __and__()
def __iand__()
def __add__()
def __iadd__()
def __sub__()
def __isub__()
def __eq__()
def __or__()
def __ior__()
def right()
def setBottom()
def setBottomLeft()
def setBottomRight()
def setCoords()
def setHeight()
def setLeft()
def setRect()
def setRight()
def setSize()
def setTop()
def setTopLeft()
def setTopRight()
def setWidth()
def setX()
def setY()
def size()
def toRectF()
def top()
def topLeft()
def topRight()
def translate()
def translated()
def transposed()
def united()
def width()
def x()
def y()

Static functions¶

def span()

Note

This documentation may contain snippets that were automatically translated from C++ to Python. We always welcome contributions to the snippet translation. If you see an issue with the translation, you can also let us know by creating a ticket on https:/bugreports.qt.io/projects/PYSIDE

Detailed Description¶

Warning

This section contains snippets that were automatically translated from C++ to Python and may contain errors.

A rectangle is normally expressed as a top-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.

r1 = QRect(100, 200, 11, 16)
r2 = QRect(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 provides 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 rectangle’s 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.

Note that 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 representation

One pixel wide pen

Two pixel wide pen

Three pixel wide pen

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 right() and 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.

Constraints¶

QRect is limited to the minimum and maximum values for the int type. Operations on a QRect that could potentially result in values outside this range will result in undefined behavior.

See also

QRectF QRegion

__init__()¶

Constructs a null rectangle.

See also

isNull()

__init__(topleft, bottomright)

Parameters:

topleft – QPoint
bottomright – QPoint

Constructs a rectangle with the given topLeft and bottomRight corners, both included.

If bottomRight is to higher and to the left of topLeft, the rectangle defined is instead non-inclusive of the corners.

Note

To ensure both points are included regardless of relative order, use span() .


Logical representation	One pixel wide pen

Two pixel wide pen	Three pixel wide pen