Home · All Classes · Modules |

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

**__init__**(*self*)**__init__**(*self*, QRectF)- float
**bottom**(*self*) - QPointF
**bottomLeft**(*self*) - QPointF
**bottomRight**(*self*) - QPointF
**center**(*self*) - float
**height**(*self*) - bool
**isEmpty**(*self*) - bool
**isNull**(*self*) - bool
**isValid**(*self*) - float
**left**(*self*) - QRectF
**normalized**(*self*) - float
**right**(*self*) - QSizeF
**size**(*self*) - QRect
**toAlignedRect**(*self*) - float
**top**(*self*) - QPointF
**topLeft**(*self*) - QPointF
**topRight**(*self*) - QRect
**toRect**(*self*) - float
**width**(*self*) - float
**x**(*self*) - float
**y**(*self*)

This class can be pickled.

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 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 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 rectange'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 (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.

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 |

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.

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

**See also** setTopLeft() and setSize().

Constructs a rectangle with the given *topLeft* and
*bottomRight* corners.

This function was introduced in Qt 4.3.

**See also** setTopLeft() and setBottomRight().

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

Constructs a QRectF rectangle from the
given QRect *rectangle*.

**See also** toRect().

Adds *dx1*, *dy1*, *dx2* and *dy2*
respectively to the existing coordinates of the rectangle.

**See also** adjusted()
and setRect().

Returns a new rectangle with *dx1*, *dy1*, *dx2*
and *dy2* added respectively to the existing coordinates of
this rectangle.

**See also** adjust().

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

**See also** setBottom(),
bottomLeft(), and bottomRight().

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

**See also** setBottomLeft(), bottom(), and left().

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

**See also** setBottomRight(), bottom(), and right().

Returns the center point of the rectangle.

**See also** moveCenter().

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

**See also** intersects().

This is an overloaded function.

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

This is an overloaded function.

Returns true if the given *rectangle* is inside this
rectangle; otherwise returns false.

**See also** setCoords()
and getRect().

**See also** setRect() and
getCoords().

Returns the height of the rectangle.

**See also** setHeight(),
width(), and size().

Returns the intersection of this rectangle and the given
*rectangle*. Note that `r.intersected(s)` is equivalent
to `r & s`.

This function was introduced in Qt 4.2.

**See also** intersects(), united(), and operator&=().

Returns true if this rectangle intersects with the given
*rectangle* (i.e. there is a non-empty area of overlap between
them), otherwise returns false.

The intersection rectangle can be retrieved using the intersected() function.

**See also** contains().

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(), and normalized().

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() and
isValid().

Returns true if the rectangle is valid, otherwise returns false.

A valid rectangle has a width() > 0 and height() > 0. 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(), and normalized().

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

**See also** setLeft(),
topLeft(), and bottomLeft().

**See also** bottom(),
setBottom(), and moveTop().

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

**See also** setBottomLeft(), moveBottom(), and moveLeft().

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

**See also** setBottomRight(), moveBottom(), and moveRight().

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

**See also** center().

**See also** left(), setLeft(), and moveRight().

**See also** right(),
setRight(), and moveLeft().

**See also** translate()
and moveTopLeft().

This is an overloaded function.

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

**See also** top(), setTop(), and moveBottom().

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

**See also** setTopLeft(), moveTop(), and moveLeft().

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

**See also** setTopRight(), moveTop(), and moveRight().

Returns a normalized rectangle; i.e., a rectangle that has a non-negative width and height.

If width() < 0 the function swaps the left and right corners, and it swaps the top and bottom corners if height() < 0.

**See also** isValid() and
isEmpty().

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

**See also** setRight(),
topRight(), and bottomRight().

**See also** bottom() and
moveBottom().

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() and moveBottomLeft().

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() and moveBottomRight().

**See also** getCoords()
and setRect().

**See also** height() and
setSize().

**See also** left() and
moveLeft().

**See also** getRect() and
setCoords().

**See also** right() and
moveRight().

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

**See also** size(), setWidth(), and setHeight().

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() and
moveTopLeft().

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()
and moveTopRight().

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

**See also** width() and
setSize().

**See also** x(), setY(), and setTopLeft().

**See also** y(), setX(), and setTopLeft().

Returns the size of the rectangle.

**See also** setSize(),
width(), and height().

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

This function was introduced in Qt 4.3.

**See also** toRect().

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

**See also** setTop(),
topLeft(), and topRight().

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

**See also** setTopLeft(), top(), and left().

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

**See also** setTopRight(), top(), and right().

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

**See also** QRectF() and
toAlignedRect().

**See also** moveTopLeft(), moveTo(), and translated().

This is an overloaded function.

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

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().

This is an overloaded function.

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.

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

This function was introduced in Qt 4.2.

**See also** intersected().

Returns the width of the rectangle.

**See also** setWidth(),
height(), and size().

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

**See also** setX(), y(), and topLeft().

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

**See also** setY(), x(), and topLeft().

PyQt 4.9.4 for Windows | Copyright © Riverbank Computing Ltd and Nokia 2012 | Qt 4.8.2 |