QRectF¶

PyQt5.QtCore.QRectF

Description¶

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

A rectangle is normally expressed as a top-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 coordinates, or from a QPointF and a QSizeF. The following code creates two identical rectangles.

# QRectF r1(100.0, 200.1, 11.2, 16.3);
# QRectF r2(QPointF(100.0, 200.1), QSizeF(11.2, 16.3));

There is also a third constructor creating a QRectF from a QRect, and a corresponding toRect() function that returns a QRect object based on the values of this rectangle (note that 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 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 rectange’s dimensions as a QSizeF. 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 (otherwise false). The QRectF 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 the rectangle’s width or height is less than, or equal to, 0. Note that an empty rectangle is not valid: The isValid() function returns true if both width and height is larger than 0. 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 QRectF is defined in essentially the same way as QRect.

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

Rendering¶

When using an Antialiasing 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 provides 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.

Methods¶

__init__(): TODO

__init__(QRect): TODO

__init__(QRectF): TODO

__init__(Union[QPointF, QPoint], QSizeF): TODO

__init__(Union[QPointF, QPoint], Union[QPointF, QPoint]): TODO

__init__(float, float, float, float): TODO

__add__(QMarginsF) → QRectF: TODO

adjust(float, float, float, float): TODO

adjusted(float, float, float, float) → QRectF: TODO

__and__(QRectF) → QRectF: TODO

__bool__() → int: TODO

bottom() → float: See also

setBottom().

bottomLeft() → QPointF: See also

setBottomLeft().

bottomRight() → QPointF: See also

setBottomRight().

center() → QPointF: TODO

__contains__(Union[QPointF, QPoint]) → int: TODO

__contains__(QRectF) → int: TODO

contains(Union[QPointF, QPoint]) → bool: TODO

contains(QRectF) → bool: TODO

contains(float, float) → bool: TODO

__eq__(QRectF) → bool: TODO

getCoords() → (float, float, float, float): TODO

getRect() → (float, float, float, float): TODO

height() → float: See also

setHeight().

__iadd__(QMarginsF) → QRectF: TODO

__iand__(QRectF) → QRectF: TODO

intersected(QRectF) → QRectF: TODO

intersects(QRectF) → bool: TODO

__ior__(QRectF) → QRectF: TODO

isEmpty() → bool: TODO

isNull() → bool: TODO

__isub__(QMarginsF) → QRectF: TODO

isValid() → bool: TODO

left() → float: See also

setLeft().

marginsAdded(QMarginsF) → QRectF: TODO

marginsRemoved(QMarginsF) → QRectF: TODO

moveBottom(float): TODO

moveBottomLeft(Union[QPointF, QPoint]): TODO

moveBottomRight(Union[QPointF, QPoint]): TODO

moveCenter(Union[QPointF, QPoint]): TODO

moveLeft(float): TODO

moveRight(float): TODO

moveTo(Union[QPointF, QPoint]): TODO

moveTo(float, float): TODO

moveTop(float): TODO

moveTopLeft(Union[QPointF, QPoint]): TODO

moveTopRight(Union[QPointF, QPoint]): TODO

__ne__(QRectF) → bool: TODO

normalized() → QRectF: TODO

__or__(QRectF) → QRectF: TODO

__repr__() → str: TODO

right() → float: See also

setRight().

setBottom(float): See also

bottom().

setBottomLeft(Union[QPointF, QPoint]): See also

bottomLeft().

setBottomRight(Union[QPointF, QPoint]): See also

bottomRight().

setCoords(float, float, float, float): TODO

setHeight(float): See also

height().

setLeft(float): See also

left().

setRect(float, float, float, float): TODO

setRight(float): See also

right().

setSize(QSizeF): See also

size().

setTop(float): See also

top().

setTopLeft(Union[QPointF, QPoint]): See also

topLeft().

setTopRight(Union[QPointF, QPoint]): See also

topRight().

setWidth(float): See also

width().

setX(float): See also

x().

setY(float): See also

y().

size() → QSizeF: See also

setSize().

__sub__(QMarginsF) → QRectF: TODO

toAlignedRect() → QRect: TODO

top() → float: See also

setTop().

topLeft() → QPointF: See also

setTopLeft().

topRight() → QPointF: See also

setTopRight().

toRect() → QRect: TODO

translate(Union[QPointF, QPoint]): TODO

translate(float, float): TODO

translated(Union[QPointF, QPoint]) → QRectF: TODO

translated(float, float) → QRectF: TODO

transposed() → QRectF: TODO

united(QRectF) → QRectF: TODO

width() → float: See also

setWidth().

x() → float: See also

setX().

y() → float: See also

setY().