QRegion#
The QRegion class specifies a clip region for a painter. More…
Synopsis#
Functions#
def
__getitem__()def
__len__()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
__ne__(r)def
__and__(r)def
__and__(r)def
__mul__(m)def
__add__(r)def
__add__(r)def
__iadd__(r)def
__iadd__(r)def
__sub__(r)def
__isub__(r)def
__eq__(r)def
__xor__(r)def
__ixor__(r)def
__or__(r)def
__ior__(r)def
rectCount()def
setRects(rect, num)def
subtracted(r)def
swap(other)def
translate(p)def
translate(dx, dy)def
translated(p)def
translated(dx, dy)def
united(r)def
united(r)def
xored(r)
Note
This documentation may contain snippets that were automatically translated from C++ to Python. We always welcome contributions to the snippet translation. If you see an issue with the translation, you can also let us know by creating a ticket on https:/bugreports.qt.io/projects/PYSIDE
Detailed Description#
Warning
This section contains snippets that were automatically translated from C++ to Python and may contain errors.
QRegion is used with setClipRegion() to limit the paint area to what needs to be painted. There is also a QWidget::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 ranged-for loops) gives a decomposition of the region into rectangles.
Example of using complex regions:
def paintEvent(self, arg__0): QRegion r1(QRect(100, 100, 200, 80), // r1: elliptic region QRegion.Ellipse) QRegion r2(QRect(100, 120, 90, 30)) # r2: rectangular region 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 –
RegionTypebitmap –
PySide6.QtGui.QBitmapw – int
h – int
fillRule –
FillRulex – int
y – int
region –
PySide6.QtGui.QRegion
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 Qt::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 Qt::WindingFill, the polygon region is defined using the winding algorithm; if it is Qt::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 new region which is equal to region r.
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 QRect::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
Warning
This section contains snippets that were automatically translated from C++ to Python and may contain errors.
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:
This is an overloaded function.
- PySide6.QtGui.QRegion.__and__(r)
- Parameters:
- Return type:
Applies the intersected() function to this region and r. r1&r2 is equivalent to r1.intersected(r2).
See also
- PySide6.QtGui.QRegion.__mul__(m)#
- Parameters:
- Return type:
- 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.__add__(r)
- Parameters:
- Return type:
This is an overloaded function.
- 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.QRectnum – 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