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# QPolygon Class Reference
[QtGui module]

The QPolygon class provides a vector of points using integer precision. More...

### Methods

- __init__ (self)
- __init__ (self, QPolygon a)
- __init__ (self, QPoint-list v)
- __init__ (self, QRect r, bool closed = False)
- __init__ (self, int asize)
- __init__ (self, list)
- __init__ (self, QVariant variant)
- append (self, QPoint value)
- QPoint at (self, int i)
- QRect boundingRect (self)
- clear (self)
- bool contains (self, QPoint value)
- bool containsPoint (self, QPoint pt, Qt.FillRule fillRule)
- int count (self, QPoint value)
- int count (self)
- fill (self, QPoint value, int size = -1)
- QPoint first (self)
- int indexOf (self, QPoint value, int from = 0)
- insert (self, int i, QPoint value)
- QPolygon intersected (self, QPolygon r)
- bool isEmpty (self)
- QPoint last (self)
- int lastIndexOf (self, QPoint value, int from = -1)
- QPolygon mid (self, int pos, int length = -1)
- QPoint point (self, int index)
- prepend (self, QPoint value)
- putPoints (self, int index, int firstx, int firsty, ...)
- putPoints (self, int index, int nPoints, QPolygon from, int fromIndex = 0)
- remove (self, int i)
- remove (self, int i, int count)
- replace (self, int i, QPoint value)
- setPoint (self, int index, QPoint pt)
- setPoint (self, int index, int x, int y)
- setPoints (self, list)
- setPoints (self, int firstx, int firsty, ...)
- int size (self)
- QPolygon subtracted (self, QPolygon r)
- translate (self, int dx, int dy)
- translate (self, QPoint offset)
- QPolygon united (self, QPolygon r)
- QPoint value (self, int i)
- QPoint value (self, int i, QPoint defaultValue)

### Special Methods

- QPolygon __add__ (self, QPolygon other)
- int __contains__ (self, QPoint value)
- __delitem__ (self, int i)
- __delitem__ (self, slice slice)
- bool __eq__ (self, QPolygon other)
- QPoint __getitem__ (self, int i)
- QPolygon __getitem__ (self, slice slice)
- QPolygon __iadd__ (self, QPolygon other)
- QPolygon __iadd__ (self, QPoint value)
- int __len__ (self)
- QPolygon __mul__ (self, QTransform m)
- QPolygon __mul__ (self, QMatrix m)
- bool __ne__ (self, QPolygon other)
- __setitem__ (self, int i, QPoint value)
- __setitem__ (self, slice slice, QPolygon list)

## Detailed Description

This class can be pickled.

The QPolygon class provides a vector of points using integer precision.

A QPolygon object is a QVector<QPoint>. The easiest way to add points to a QPolygon is to use QVector's streaming operator, as illustrated below:

             QPolygon polygon;
             polygon << QPoint(10, 20) << QPoint(20, 30);

In addition to the functions provided by QVector, QPolygon provides some point-specific functions.

Each point in a polygon can be retrieved by passing its index to the point() function. To populate the polygon, QPolygon provides the setPoint() function to set the point at a given index, the setPoints() function to set all the points in the polygon (resizing it to the given number of points), and the putPoints() function which copies a number of given points into the polygon from a specified index (resizing the polygon if necessary).

QPolygon provides the boundingRect() and translate() functions for geometry functions. Use the QMatrix.map() function for more general transformations of QPolygons.

The QPolygon class is implicitly shared.

See also QVector, QPolygonF, and QLine.

## Method Documentation

### QPolygon.__init__ (self)

Constructs a polygon with no points.

See also QVector.isEmpty().

### QPolygon.__init__ (self, QPolygon a)

Constructs a polygon of the given size. Creates an empty polygon if size == 0.

See also QVector.isEmpty().

### QPolygon.__init__ (self, QPoint-list v)

Constructs a copy of the given polygon.

See also setPoints().

### QPolygon.__init__ (self, QRect r, bool closed = False)

Constructs a polygon containing the specified points.

See also setPoints().

### QPolygon.__init__ (self, int asize)

Constructs a polygon from the given rectangle. If closed is false, the polygon just contains the four points of the rectangle ordered clockwise, otherwise the polygon's fifth point is set to rectangle.topLeft().

Note that the bottom-right corner of the rectangle is located at (rectangle.x() + rectangle.width(), rectangle.y() + rectangle.height()).

See also setPoints().

### QPolygon.__init__ (self, list)

### QPolygon.__init__ (self, QVariant variant)

### QPolygon.append (self, QPoint value)

### QPoint QPolygon.at (self, int i)

### QRect QPolygon.boundingRect (self)

Returns the bounding rectangle of the polygon, or QRect(0, 0, 0, 0) if the polygon is empty.

See also QVector.isEmpty().

### QPolygon.clear (self)

### bool QPolygon.contains (self, QPoint value)

### bool QPolygon.containsPoint (self, QPoint pt, Qt.FillRule fillRule)

Returns true if the given point is inside the polygon according to the specified fillRule; otherwise returns false.

This function was introduced in Qt 4.3.

### int QPolygon.count (self, QPoint value)

### int QPolygon.count (self)

### QPolygon.fill (self, QPoint value, int size = -1)

### QPoint QPolygon.first (self)

### int QPolygon.indexOf (self, QPoint value, int from = 0)

### QPolygon.insert (self, int i, QPoint value)

### QPolygon QPolygon.intersected (self, QPolygon r)

Returns a polygon which is the intersection of this polygon and r.

This function was introduced in Qt 4.3.

### bool QPolygon.isEmpty (self)

### QPoint QPolygon.last (self)

### int QPolygon.lastIndexOf (self, QPoint value, int from = -1)

### QPolygon QPolygon.mid (self, int pos, int length = -1)

### QPoint QPolygon.point (self, int index)

Extracts the coordinates of the point at the given index to *x and *y (if they are valid pointers).

See also setPoint().

### QPolygon.prepend (self, QPoint value)

### QPolygon.putPoints (self, int index, int firstx, int firsty, ...)

Copies nPoints points from the variable argument list into this polygon from the given index.

The points are given as a sequence of integers, starting with firstx then firsty, and so on. The polygon is resized if `index+nPoints` exceeds its current size.

The example code creates a polygon with three points (4,5), (6,7) and (8,9), by expanding the polygon from 1 to 3 points:

             QPolygon polygon(1);
             polygon[0] = QPoint(4, 5);
             polygon.putPoints(1, 2, 6,7, 8,9);

The following code has the same result, but here the putPoints() function overwrites rather than extends:

             QPolygon polygon(3);
             polygon.putPoints(0, 3, 4,5, 0,0, 8,9);
             polygon.putPoints(1, 1, 6,7);

See also setPoints().

### QPolygon.putPoints (self, int index, int nPoints, QPolygon from, int fromIndex = 0)

### QPolygon.remove (self, int i)

### QPolygon.remove (self, int i, int count)

### QPolygon.replace (self, int i, QPoint value)

### QPolygon.setPoint (self, int index, QPoint pt)

Sets the point at the given index to the point specified by (x, y).

See also point(), putPoints(), and setPoints().

### QPolygon.setPoint (self, int index, int x, int y)

This is an overloaded member function, provided for convenience.

Sets the point at the given index to the given point.

### QPolygon.setPoints (self, list)

Resizes the polygon to nPoints and populates it with the given points.

The example code creates a polygon with two points (10, 20) and (30, 40):

             static const int points[] = { 10, 20, 30, 40 };
             QPolygon polygon;
             polygon.setPoints(2, points);

See also setPoint() and putPoints().

### QPolygon.setPoints (self, int firstx, int firsty, ...)

This is an overloaded member function, provided for convenience.

Resizes the polygon to nPoints and populates it with the points specified by the variable argument list. The points are given as a sequence of integers, starting with firstx then firsty, and so on.

The example code creates a polygon with two points (10, 20) and (30, 40):

             QPolygon polygon;
             polygon.setPoints(2, 10, 20, 30, 40);

### int QPolygon.size (self)

### QPolygon QPolygon.subtracted (self, QPolygon r)

Returns a polygon which is r subtracted from this polygon.

This function was introduced in Qt 4.3.

### QPolygon.translate (self, int dx, int dy)

Translates all points in the polygon by (dx, dy).

### QPolygon.translate (self, QPoint offset)

This is an overloaded member function, provided for convenience.

Translates all points in the polygon by the given offset.

### QPolygon QPolygon.united (self, QPolygon r)

Returns a polygon which is the union of this polygon and r.

This function was introduced in Qt 4.3.

See also intersected() and subtracted().

### QPoint QPolygon.value (self, int i)

### QPoint QPolygon.value (self, int i, QPoint defaultValue)

### QPolygon QPolygon.__add__ (self, QPolygon other)

### int QPolygon.__contains__ (self, QPoint value)

### QPolygon.__delitem__ (self, int i)

### QPolygon.__delitem__ (self, slice slice)

### bool QPolygon.__eq__ (self, QPolygon other)

### QPoint QPolygon.__getitem__ (self, int i)

### QPolygon QPolygon.__getitem__ (self, slice slice)

### QPolygon QPolygon.__iadd__ (self, QPolygon other)

### QPolygon QPolygon.__iadd__ (self, QPoint value)

### int QPolygon.__len__ (self)

### QPolygon QPolygon.__mul__ (self, QTransform m)

### QPolygon QPolygon.__mul__ (self, QMatrix m)

### bool QPolygon.__ne__ (self, QPolygon other)

### QPolygon.__setitem__ (self, int i, QPoint value)

### QPolygon.__setitem__ (self, slice slice, QPolygon list)