QRegion¶
The QRegion
class specifies a clip region for a painter. More…
Synopsis¶
Functions¶
def
__add__
(r)def
__add__
(r)def
__and__
(r)def
__and__
(r)def
__eq__
(r)def
__getitem__
()def
__iadd__
(r)def
__iadd__
(r)def
__ior__
(r)def
__isub__
(r)def
__ixor__
(r)def
__len__
()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
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 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:
def paintEvent(self, arg__0): r1 = QRegion(QRect(100, 100, 200, 80) QRegion.Ellipse) r2 = QRegion(QRect(100, 120, 90, 30)) r3 = r1.intersected(r2) # r3: intersection painter = QPainter(self) painter.setClipRegion(r3) # ... // paint clipped graphicsSee also
- class PySide6.QtGui.QRegion¶
PySide6.QtGui.QRegion(bitmap)
PySide6.QtGui.QRegion(pa[, fillRule=Qt.OddEvenFill])
PySide6.QtGui.QRegion(r[, t=QRegion.RegionType.Rectangle])
PySide6.QtGui.QRegion(region)
PySide6.QtGui.QRegion(x, y, w, h[, t=QRegion.RegionType.Rectangle])
- Parameters
t –
RegionType
y – int
w – int
h – int
bitmap –
PySide6.QtGui.QBitmap
region –
PySide6.QtGui.QRegion
fillRule –
FillRule
x – int
Constructs an empty region.
See also
Constructs a region from the bitmap bm
.
The resulting region consists of the pixels in bitmap bm
that are color1
, as if each pixel was a 1 by 1 rectangle.
This constructor may create complex regions that will slow down painting when used. Note that drawing masked pixmaps can be done much faster using setMask()
.
Constructs a polygon region from the point array a
with the fill rule specified by fillRule
.
If fillRule
is WindingFill
, the polygon region is defined using the winding algorithm; if it is OddEvenFill
, the odd-even fill algorithm is used.
Warning
This constructor can be used to create complex regions that will slow down painting when used.
This is an overloaded function.
Create a region based on the rectangle r
with region type t
.
If the rectangle is invalid a null region will be created.
See also
RegionType
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``).
- PySide6.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.
- PySide6.QtGui.QRegion.__getitem__()¶
- PySide6.QtGui.QRegion.__len__()¶
- PySide6.QtGui.QRegion.begin()¶
- Return type
Returns a const_iterator
pointing to the beginning of the range of non-overlapping rectangles that make up the region.
The union of all the rectangles is equal to the original region.
- PySide6.QtGui.QRegion.boundingRect()¶
- Return type
Returns the bounding rectangle of this region. An empty region gives a rectangle that is isNull()
.
- PySide6.QtGui.QRegion.cbegin()¶
- Return type
Same as begin()
.
- PySide6.QtGui.QRegion.cend()¶
- Return type
Same as end()
.
- PySide6.QtGui.QRegion.contains(p)¶
- Parameters
- Return type
bool
Returns true
if the region contains the point p
; otherwise returns false
.
- PySide6.QtGui.QRegion.contains(r)
- Parameters
- Return type
bool
This is an overloaded function.
Returns true
if the region overlaps the rectangle r
; otherwise returns false
.
- PySide6.QtGui.QRegion.end()¶
- Return type
Returns a const_iterator
pointing to one past the end of non-overlapping rectangles that make up the region.
The union of all the rectangles is equal to the original region.
- PySide6.QtGui.QRegion.intersected(r)¶
- Parameters
- Return type
Returns a region which is the intersection of this region and the given rect
.
See also
- PySide6.QtGui.QRegion.intersected(r)
- Parameters
- Return type
Returns a region which is the intersection of this region and r
.
The figure shows the intersection of two elliptical regions.
See also
- PySide6.QtGui.QRegion.intersects(r)¶
- Parameters
- Return type
bool
Returns true
if this region intersects with rect
, otherwise returns false
.
- PySide6.QtGui.QRegion.intersects(r)
- Parameters
- Return type
bool
Returns true
if this region intersects with region
, otherwise returns false
.
- PySide6.QtGui.QRegion.isEmpty()¶
- Return type
bool
Returns true
if the region is empty; otherwise returns false
. An empty region is a region that contains no points.
Example:
r1 = QRegion(10, 10, 20, 20) r1.isEmpty() # false r3 = QRegion() r3.isEmpty() # true r2 = QRegion(40, 40, 20, 20) r3 = r1.intersected(r2) # r3: intersection of r1 and r2 r3.isEmpty() # true r3 = r1.united(r2) # r3: union of r1 and r2 r3.isEmpty() # false
- PySide6.QtGui.QRegion.isNull()¶
- Return type
bool
Returns true
if the region is empty; otherwise returns false
. An empty region is a region that contains no points. This function is the same as isEmpty
See also
- PySide6.QtGui.QRegion.__ne__(r)¶
- Parameters
- Return type
bool
Returns true
if this region is different from the other
region; otherwise returns false
.
- PySide6.QtGui.QRegion.__and__(r)¶
- Parameters
- Return type
- PySide6.QtGui.QRegion.__and__(r)
- Parameters
- Return type
- PySide6.QtGui.QRegion.__mul__(m)¶
- Parameters
- Return type
- PySide6.QtGui.QRegion.__add__(r)¶
- Parameters
- Return type
This is an overloaded function.
- PySide6.QtGui.QRegion.__add__(r)
- Parameters
- Return type
Applies the united()
function to this region and r
. r1+r2
is equivalent to r1.united(r2)
.
See also
united()
operator|()
- PySide6.QtGui.QRegion.__iadd__(r)¶
- Parameters
- Return type
Returns a region that is the union of this region with the specified rect
.
See also
- PySide6.QtGui.QRegion.__iadd__(r)
- Parameters
- Return type
Applies the united()
function to this region and r
and assigns the result to this region. r1+=r2
is equivalent to r1 = r1.united(r2)
.
See also
- PySide6.QtGui.QRegion.__sub__(r)¶
- Parameters
- Return type
Applies the subtracted()
function to this region and r
. r1-r2
is equivalent to r1.subtracted(r2)
.
See also
- PySide6.QtGui.QRegion.__isub__(r)¶
- Parameters
- Return type
Applies the subtracted()
function to this region and r
and assigns the result to this region. r1-=r2
is equivalent to r1 = r1.subtracted(r2)
.
See also
- PySide6.QtGui.QRegion.__eq__(r)¶
- Parameters
- Return type
bool
Returns true
if the region is equal to r
; otherwise returns false.
- PySide6.QtGui.QRegion.__xor__(r)¶
- Parameters
- Return type
Applies the xored()
function to this region and r
. r1^r2
is equivalent to r1.xored(r2)
.
See also
- PySide6.QtGui.QRegion.__ixor__(r)¶
- Parameters
- Return type
Applies the xored()
function to this region and r
and assigns the result to this region. r1^=r2
is equivalent to r1 = r1.xored(r2)
.
See also
- PySide6.QtGui.QRegion.__or__(r)¶
- Parameters
- Return type
Applies the united()
function to this region and r
. r1|r2
is equivalent to r1.united(r2)
.
See also
united()
operator+()
- PySide6.QtGui.QRegion.__ior__(r)¶
- Parameters
- Return type
Applies the united()
function to this region and r
and assigns the result to this region. r1|=r2
is equivalent to r1 = r1.united(r2)
.
See also
- PySide6.QtGui.QRegion.rectCount()¶
- Return type
int
Returns the number of rectangles that this region is composed of. Same as end() - begin()
.
- PySide6.QtGui.QRegion.setRects(rect, num)¶
- Parameters
rect –
PySide6.QtCore.QRect
num – int
Sets the region using the array of rectangles specified by rects
and number
. The rectangles must be optimally Y-X 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.
- PySide6.QtGui.QRegion.subtracted(r)¶
- Parameters
- Return type
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
- PySide6.QtGui.QRegion.swap(other)¶
- Parameters
other –
PySide6.QtGui.QRegion
Swaps region other
with this region. This operation is very fast and never fails.
- PySide6.QtGui.QRegion.translate(p)¶
- Parameters
This is an overloaded function.
Translates the region point
.x() along the x axis and point
.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
.
- PySide6.QtGui.QRegion.translate(dx, dy)
- Parameters
dx – int
dy – int
Translates (moves) the region dx
along the X axis and dy
along the Y axis.
- PySide6.QtGui.QRegion.translated(p)¶
- Parameters
- Return type
This is an overloaded function.
Returns a copy of the regtion that is translated p
.x() along the x axis and p
.y() along the y axis, relative to the current position. Positive values move the rectangle to the right and down.
See also
- PySide6.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 and dy
along the y axis, relative to the current position. Positive values move the region to the right and down.
See also
- PySide6.QtGui.QRegion.united(r)¶
- Parameters
- Return type
Returns a region which is the union of this region and the given rect
.
See also
- PySide6.QtGui.QRegion.united(r)
- Parameters
- Return type
Returns a region which is the union of this region and r
.
The figure shows the union of two elliptical regions.
See also
- PySide6.QtGui.QRegion.xored(r)¶
- Parameters
- Return type
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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