QRegion¶

PyQt5.QtGui.QRegion

Description¶

The QRegion class specifies a clip region for a painter.

QRegion is used with setClipRegion() to limit the paint area to what needs to be painted. There is also a repaint() function that takes a QRegion parameter. QRegion is the best tool for minimizing the amount of screen area to be updated by a repaint.

This class is not suitable for constructing shapes for rendering, especially as outlines. Use QPainterPath to create paths and shapes for use with QPainter.

QRegion is an implicitly shared class.

Creating and Using Regions¶

A region can be created from a rectangle, an ellipse, a polygon or a bitmap. Complex regions may be created by combining simple regions using united(), intersected(), subtracted(), or xored() (exclusive or). You can move a region using translate().

You can test whether a region isEmpty() or if it contains() a QPoint or QRect. The bounding rectangle can be found with boundingRect().

Iteration over the region (with begin(), end(), or C++11 ranged-for loops) gives a decomposition of the region into rectangles.

Example of using complex regions:

# void MyWidget::paintEvent(QPaintEvent *)
# {
#     QRegion r1(QRect(100, 100, 200, 80),    // r1: elliptic region
#                QRegion::Ellipse);
#     QRegion r2(QRect(100, 120, 90, 30));    // r2: rectangular region
#     QRegion r3 = r1.intersected(r2);        // r3: intersection

#     QPainter painter(this);
#     painter.setClipRegion(r3);
#     ...                                     // paint clipped graphics
# }

Additional License Information¶

On Embedded Linux and X11 platforms, parts of this class rely on code obtained under the following licenses:

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name of the X Consortium shall not be used in advertising or otherwise to promote the sale, use or other dealings in this Software without prior written authorization from the X Consortium.

Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation, and that the name of Digital not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission.

DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

Enums¶

RegionType

Specifies the shape of the region to be created.

Member	Value	Description
Ellipse	1	the region is an ellipse inside the rectangle.
Rectangle	0	the region covers the entire rectangle.

Methods¶

__init__(): TODO

__init__(QBitmap): TODO

__init__(QRegion): TODO

__init__(Any): TODO

__init__(QRect, type: RegionType = Rectangle): TODO

__init__(QPolygon, fillRule: FillRule = OddEvenFill): TODO

__init__(int, int, int, int, type: RegionType = Rectangle)

Constructs a rectangular or elliptic region.

If t is Rectangle, the region is the filled rectangle (x, y, w, h). If t is Ellipse, the region is the filled ellipse with center at (x + w / 2, y + h / 2) and size (w ,h).

__add__(QRegion) → QRegion: TODO

__add__(QRect) → QRegion: TODO

__and__(QRegion) → QRegion: TODO

__and__(QRect) → QRegion: TODO

__bool__() → int: TODO

boundingRect() → QRect: TODO

__contains__(QPoint) → int: TODO

__contains__(QRect) → int: TODO

contains(QPoint) → bool: TODO

contains(QRect) → bool: TODO

__eq__(QRegion) → bool: TODO

__iadd__(QRegion) → QRegion: TODO

__iadd__(QRect) → QRegion: TODO

__iand__(QRegion) → QRegion: TODO

__iand__(QRect) → QRegion: TODO

intersected(QRegion) → QRegion: TODO

intersected(QRect) → QRegion: TODO

intersects(QRegion) → bool: Returns true if this region intersects with region, otherwise returns false.

intersects(QRect) → bool: TODO

__ior__(QRegion) → QRegion: TODO

isEmpty() → bool: TODO

isNull() → bool: TODO

__isub__(QRegion) → QRegion: TODO

__ixor__(QRegion) → QRegion: TODO

__mul__(QTransform) → QRegion: TODO

__ne__(QRegion) → bool: TODO

__or__(QRegion) → QRegion: TODO

rectCount() → int: TODO

rects() → List[QRect]: See also

setRects().

setRects(Iterable[QRect]): TODO

__sub__(QRegion) → QRegion: TODO

subtracted(QRegion) → QRegion: TODO

swap(QRegion): TODO

translate(QPoint): TODO

translate(int, int): TODO

translated(QPoint) → QRegion: TODO

translated(int, int) → QRegion: Returns a copy of the region that is translated dx along the x axis and dy along the y axis, relative to the current position. Positive values move the region to the right and down.

See also

translate().

united(QRegion) → QRegion: TODO

united(QRect) → QRegion: TODO

__xor__(QRegion) → QRegion: TODO

xored(QRegion) → QRegion: TODO