QRegion¶
Synopsis¶
Functions¶
def
__add__
(r)def
__add__
(r)def
__and__
(r)def
__and__
(r)def
__eq__
(r)def
__iadd__
(r)def
__iadd__
(r)def
__ior__
(r)def
__isub__
(r)def
__ixor__
(r)def
__mul__
(, m)def
__mul__
(, m)def
__ne__
(r)def
__or__
(r)def
__sub__
(r)def
__xor__
(r)def
begin
()def
boundingRect
()def
cbegin
()def
cend
()def
contains
(p)def
contains
(r)def
end
()def
intersected
(r)def
intersected
(r)def
intersects
(r)def
intersects
(r)def
isEmpty
()def
isNull
()def
rectCount
()def
rects
()def
setRects
(rect, num)def
subtracted
(r)def
swap
(other)def
translate
(dx, dy)def
translate
(p)def
translated
(dx, dy)def
translated
(p)def
united
(r)def
united
(r)def
xored
(r)
Detailed Description¶
QRegion
is used withsetClipRegion()
to limit the paint area to what needs to be painted. There is also arepaint()
function that takes aQRegion
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 withQPainter
.
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()
, orxored()
(exclusive or). You can move a region usingtranslate()
.You can test whether a region
isEmpty()
or if itcontains()
aQPoint
orQRect
. The bounding rectangle can be found withboundingRect()
.Iteration over the region (with
begin()
,end()
, or C++11 rangedfor loops) gives a decomposition of the region into rectangles.Example of using complex regions:
class MyWidget (QWidget): # ... def paintEvent(self): r1 = QRegion(QRect(100, 100, 200, 80), QRegion.Ellipse) # r1: elliptic region ) r2 = QRect(100, 120, 90, 30) # r2: rectangular region r3 = r1.intersected(r2) # r3: intersection painter = QPainter(self) 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:
Copyright (c) 1987 X Consortium 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.Copyright 1987 by Digital Equipment Corporation, Maynard, Massachusetts. All Rights Reserved 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.See also

class
QRegion
¶ Constructs an empty region.
See also
Constructs a rectangular or elliptic region.
If
t
isRectangle
, the region is the filled rectangle (x
,y
,w
,h
). Ift
isEllipse
, the region is the filled ellipse with center at (x
+w
/ 2,y
+h
/ 2) and size (w
,``h`` ).

PySide2.QtGui.QRegion.
RegionType
¶ Specifies the shape of the region to be created.
Constant
Description
QRegion.Rectangle
the region covers the entire rectangle.
QRegion.Ellipse
the region is an ellipse inside the rectangle.

PySide2.QtGui.QRegion.
begin
()¶  Return type
QRect
Returns a
const_iterator
pointing to the beginning of the range of nonoverlapping rectangles that make up the region.The union of all the rectangles is equal to the original region.

PySide2.QtGui.QRegion.
boundingRect
()¶  Return type
QRect
Returns the bounding rectangle of this region. An empty region gives a rectangle that is
isNull()
.

PySide2.QtGui.QRegion.
contains
(p)¶  Parameters
p –
QPoint
 Return type
bool

PySide2.QtGui.QRegion.
contains
(r)  Parameters
r –
QRect
 Return type
bool

PySide2.QtGui.QRegion.
end
()¶  Return type
QRect
Returns a
const_iterator
pointing to one past the end of nonoverlapping rectangles that make up the region.The union of all the rectangles is equal to the original region.

PySide2.QtGui.QRegion.
intersects
(r)¶  Parameters
r –
QRect
 Return type
bool

PySide2.QtGui.QRegion.
intersects
(r)  Parameters
r –
QRegion
 Return type
bool

PySide2.QtGui.QRegion.
isEmpty
()¶  Return type
bool
Returns
true
if the region is empty; otherwise returnsfalse
. An empty region is a region that contains no points.Example:
r1 = QRegion(10, 10, 20, 20) r1.isNull() // false r1.isEmpty() // false r2 = QRegion(40, 40, 20, 20) r3 = QRegion() r3.isNull() // true r3.isEmpty() // true r3 = r1.intersected(r2) // r3: intersection of r1 and r2 r3.isNull() // false r3.isEmpty() // true r3 = r1.united(r2) // r3: union of r1 and r2 r3.isNull() // false r3.isEmpty() // false

PySide2.QtGui.QRegion.
isNull
()¶  Return type
bool
Returns
true
if the region is empty; otherwise returnsfalse
. An empty region is a region that contains no points. This function is the same asisEmpty
See also

PySide2.QtGui.QRegion.
__ne__
(r)¶  Parameters
r –
QRegion
 Return type
bool
Returns
true
if this region is different from theother
region; otherwise returnsfalse
.

PySide2.QtGui.QRegion.
__mul__
(m)  Parameters
m –
QTransform
 Return type

PySide2.QtGui.QRegion.
__sub__
(r)¶ 
Applies the
subtracted()
function to this region andr
.r1r2
is equivalent tor1.subtracted(r2)
.See also

PySide2.QtGui.QRegion.
__isub__
(r)¶ 
Applies the
subtracted()
function to this region andr
and assigns the result to this region.r1=r2
is equivalent tor1 = r1.subtracted(r2)
.See also

PySide2.QtGui.QRegion.
__eq__
(r)¶  Parameters
r –
QRegion
 Return type
bool
Returns
true
if the region is equal tor
; otherwise returns false.

PySide2.QtGui.QRegion.
__xor__
(r)¶ 
Applies the
xored()
function to this region andr
.r1^r2
is equivalent tor1.xored(r2)
.See also

PySide2.QtGui.QRegion.
__ixor__
(r)¶ 
Applies the
xored()
function to this region andr
and assigns the result to this region.r1^=r2
is equivalent tor1 = r1.xored(r2)
.See also

PySide2.QtGui.QRegion.
__or__
(r)¶ 
Applies the
united()
function to this region andr
.r1r2
is equivalent tor1.united(r2)
.See also
united()
operator+()

PySide2.QtGui.QRegion.
__ior__
(r)¶ 
Applies the
united()
function to this region andr
and assigns the result to this region.r1=r2
is equivalent tor1 = r1.united(r2)
.See also

PySide2.QtGui.QRegion.
rectCount
()¶  Return type
int
Returns the number of rectangles that this region is composed of. Same as
end()  begin()
.

PySide2.QtGui.QRegion.
rects
()¶  Return type
Use
begin()
andend()
instead.Returns an array of nonoverlapping rectangles that make up the region.
The union of all the rectangles is equal to the original region.
See also

PySide2.QtGui.QRegion.
setRects
(rect, num)¶  Parameters
rect –
QRect
num –
int
Sets the region using the array of rectangles specified by
rects
andnumber
. The rectangles must be optimally YX sorted and follow these restrictions:The rectangles must not intersect.
All rectangles with a given top coordinate must have the same height.
No two rectangles may abut horizontally (they should be combined into a single wider rectangle in that case).
The rectangles must be sorted in ascending order, with Y as the major sort key and X as the minor sort key.
See also

PySide2.QtGui.QRegion.
subtracted
(r)¶ 
Returns a region which is
r
subtracted from this region.The figure shows the result when the ellipse on the right is subtracted from the ellipse on the left (
left  right
).See also

PySide2.QtGui.QRegion.
swap
(other)¶  Parameters
other –
QRegion
Swaps region
other
with this region. This operation is very fast and never fails.

PySide2.QtGui.QRegion.
translate
(p)¶  Parameters
p –
QPoint
This is an overloaded function.
Translates the region
point
.x() along the x axis andpoint
.y() along the y axis, relative to the current position. Positive values move the region to the right and down.Translates to the given
point
.

PySide2.QtGui.QRegion.
translate
(dx, dy)  Parameters
dx –
int
dy –
int
Translates (moves) the region
dx
along the X axis anddy
along the Y axis.

PySide2.QtGui.QRegion.
translated
(p)¶  Parameters
p –
QPoint
 Return type
This is an overloaded function.
Returns a copy of the regtion that is translated
p
.x() along the x axis andp
.y() along the y axis, relative to the current position. Positive values move the rectangle to the right and down.See also

PySide2.QtGui.QRegion.
translated
(dx, dy)  Parameters
dx –
int
dy –
int
 Return type
Returns a copy of the region that is translated
dx
along the x axis anddy
along the y axis, relative to the current position. Positive values move the region to the right and down.See also

PySide2.QtGui.QRegion.
xored
(r)¶ 
Returns a region which is the exclusive or (XOR) of this region and
r
.The figure shows the exclusive or of two elliptical regions.
See also
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