If a start angle and length angle are set then an ellipse segment
will be drawn. The start angle is the angle that goes from zero in a
counter-clockwise direction (shown in green in the diagram). The
length angle is the angle from the start angle in a
counter-clockwise direction (shown in blue in the diagram). The blue
segment is the segment of the ellipse that would be drawn. If no
start angle and length angle are specified the entire ellipse is
drawn.
The ellipse can be drawn on a painter with drawShape().
Like any other canvas item ellipses can be moved with move() and
moveBy(), or by setting coordinates with setX(), setY() and setZ().
Note: QCanvasEllipse does not use the pen.
See also Graphics Classes and Image Processing Classes.
Member Function Documentation
QCanvasEllipse::QCanvasEllipse ( QCanvas * canvas )
Constructs a 32x32 ellipse, centered at (0, 0) on canvas.
QCanvasEllipse::QCanvasEllipse ( int width, int height, QCanvas * canvas )
Constructs a width by height pixel ellipse, centered at
(0, 0) on canvas.
QCanvasEllipse::QCanvasEllipse ( int width, int height, int startangle, int angle, QCanvas * canvas )
Constructs a width by height pixel ellipse, centered at
(0, 0) on canvas. Only a segment of the ellipse is drawn,
starting at angle startangle, and extending for angle angle
(the angle length).
Note that angles are specified in
1/16ths of a degree.
QCanvasEllipse::~QCanvasEllipse ()
Destroys the ellipse.
int QCanvasEllipse::angleLength () const
Returns the length angle (the extent of the ellipse segment) in
16ths of a degree. Initially this will be 360 * 16 (a complete
ellipse).
See also setAngles() and angleStart().
int QCanvasEllipse::angleStart () const
Returns the start angle in 16ths of a degree. Initially
this will be 0.
See also setAngles() and angleLength().
void QCanvasEllipse::drawShape ( QPainter & p ) [virtual protected]
Draws the ellipse, centered at x(), y() using the painter p.
Note that QCanvasEllipse does not support an outline (the pen is
always NoPen).
Reimplemented from QCanvasPolygonalItem.
int QCanvasEllipse::height () const
Returns the height of the ellipse.
int QCanvasEllipse::rtti () const [virtual]
Returns 6 (QCanvasItem::Rtti_Ellipse).
See also QCanvasItem::rtti().
Reimplemented from QCanvasPolygonalItem.
void QCanvasEllipse::setAngles ( int start, int length )
Sets the angles for the ellipse. The start angle is start and
the extent of the segment is length (the angle length) from the
start. The angles are specified in 16ths of a degree. By
default the ellipse will start at 0 and have an angle length of
360 * 16 (a complete ellipse).
See also angleStart() and angleLength().
void QCanvasEllipse::setSize ( int width, int height )
Sets the width and height of the ellipse.
int QCanvasEllipse::width () const
Returns the width of the ellipse.
This file is part of the Qt toolkit.
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