QPainter Class Reference

Member Function Documentation

QPainter::QPainter ()

Constructs a painter.

See also begin() and end().

QPainter::QPainter ( QPaintDevice * device )

Constructs a painter that begins painting the paint device immediately.

This constructor is convenient for short-lived painters, e.g. in a QWidget::paintEvent() and should be used only once. The constructor calls begin() for you and the QPainter destructor automatically calls end().

Here's an example using begin() and end():

 void MyWidget::paintEvent(QPaintEvent *)
 {
     QPainter p;
     p.begin(this);
     p.drawLine(...);        // drawing code
     p.end();
 }

The same example using this constructor:

 void MyWidget::paintEvent(QPaintEvent *)
 {
     QPainter p(this);
     p.drawLine(...);        // drawing code
 }

Since the constructor cannot provide feedback when the initialization of the painter failed you should rather use begin() and end() to paint on external devices, e.g. printers.

See also begin() and end().

QPainter::~QPainter ()

Destroys the painter.

const QBrush & QPainter::background () const

Returns the current background brush.

See also setBackground() and Settings.

Qt::BGMode QPainter::backgroundMode () const

Returns the current background mode.

See also setBackgroundMode() and Settings.

bool QPainter::begin ( QPaintDevice * device )

Begins painting the paint device and returns true if successful; otherwise returns false.

Notice that all painter settings (setPen(), setBrush() etc.) are reset to default values when begin() is called.

The errors that can occur are serious problems, such as these:

 painter->begin(0); // impossible - paint device cannot be 0

 QPixmap image(0, 0);
 painter->begin(&image); // impossible - image.isNull() == true;

 painter->begin(myWidget);
 painter2->begin(myWidget); // impossible - only one painter at a time

Note that most of the time, you can use one of the constructors instead of begin(), and that end() is automatically done at destruction.

Warning: A paint device can only be painted by one painter at a time.

Warning: Painting on a QImage with the format QImage::Format_Indexed8 is not supported.

See also end() and QPainter().

void QPainter::beginNativePainting ()

Flushes the painting pipeline and prepares for the user issuing commands directly to the underlying graphics context. Must be followed by a call to endNativePainting().

Note that only the states the underlying paint engine changes will be reset to their respective default states. The states we reset may change from release to release. The following states are currently reset in the OpenGL 2 engine:

• blending is disabled
• the depth, stencil and scissor tests are disabled
• the active texture unit is reset to 0
• the depth mask, depth function and the clear depth are reset to their default values
• the stencil mask, stencil operation and stencil function are reset to their default values
• the current color is reset to solid white

If, for example, the OpenGL polygon mode is changed by the user inside a beginNativePaint()/endNativePainting() block, it will not be reset to the default state by endNativePainting(). Here is an example that shows intermixing of painter commands and raw OpenGL commands:

 QPainter painter(this);
 painter.fillRect(0, 0, 128, 128, Qt::green);
 painter.beginNativePainting();

 glEnable(GL_SCISSOR_TEST);
 glScissor(0, 0, 64, 64);

 glClearColor(1, 0, 0, 1);
 glClear(GL_COLOR_BUFFER_BIT);

 glDisable(GL_SCISSOR_TEST);

 painter.endNativePainting();

This function was introduced in Qt 4.6.

See also endNativePainting().

QRectF QPainter::boundingRect ( const QRectF & rectangle, int flags, const QString & text )

Returns the bounding rectangle of the text as it will appear when drawn inside the given rectangle with the specified flags using the currently set font(); i.e the function tells you where the drawText() function will draw when given the same arguments.

If the text does not fit within the given rectangle using the specified flags, the function returns the required rectangle.

The flags argument is a bitwise OR of the following flags:

• Qt::AlignLeft
• Qt::AlignRight
• Qt::AlignHCenter
• Qt::AlignTop
• Qt::AlignBottom
• Qt::AlignVCenter
• Qt::AlignCenter
• Qt::TextSingleLine
• Qt::TextExpandTabs
• Qt::TextShowMnemonic
• Qt::TextWordWrap
• Qt::TextIncludeTrailingSpaces

If several of the horizontal or several of the vertical alignment flags are set, the resulting alignment is undefined.

See also drawText(), Qt::Alignment, and Qt::TextFlag.

QRect QPainter::boundingRect ( const QRect & rectangle, int flags, const QString & text )

This is an overloaded function.

Returns the bounding rectangle of the text as it will appear when drawn inside the given rectangle with the specified flags using the currently set font().

QRect QPainter::boundingRect ( int x, int y, int w, int h, int flags, const QString & text )

This is an overloaded function.

Returns the bounding rectangle of the given text as it will appear when drawn inside the rectangle beginning at the point (x, y) with width w and height h.

QRectF QPainter::boundingRect ( const QRectF & rectangle, const QString & text, const QTextOption & option = QTextOption() )

This is an overloaded function.

Instead of specifying flags as a bitwise OR of the Qt::AlignmentFlag and Qt::TextFlag, this overloaded function takes an option argument. The QTextOption class provides a description of general rich text properties.

See also QTextOption.

const QBrush & QPainter::brush () const

Returns the painter's current brush.

See also QPainter::setBrush() and Settings.

QPoint QPainter::brushOrigin () const

Returns the currently set brush origin.

See also setBrushOrigin() and Settings.

QPainterPath QPainter::clipPath () const

Returns the currently clip as a path. Note that the clip path is given in logical coordinates.

Warning: QPainter does not store the combined clip explicitly as this is handled by the underlying QPaintEngine, so the path is recreated on demand and transformed to the current logical coordinate system. This is potentially an expensive operation.

See also setClipPath(), clipRegion(), and setClipping().

QRegion QPainter::clipRegion () const

Returns the currently set clip region. Note that the clip region is given in logical coordinates.

Warning: QPainter does not store the combined clip explicitly as this is handled by the underlying QPaintEngine, so the path is recreated on demand and transformed to the current logical coordinate system. This is potentially an expensive operation.

See also setClipRegion(), clipPath(), and setClipping().

QTransform QPainter::combinedTransform () const

Returns the transformation matrix combining the current window/viewport and world transformation.

See also setWorldTransform(), setWindow(), and setViewport().

CompositionMode QPainter::compositionMode () const

Returns the current composition mode.

See also CompositionMode and setCompositionMode().

QPaintDevice * QPainter::device () const

Returns the paint device on which this painter is currently painting, or 0 if the painter is not active.

See also isActive().

const QTransform & QPainter::deviceTransform () const

Returns the matrix that transforms from logical coordinates to device coordinates of the platform dependent paint device.

This function is only needed when using platform painting commands on the platform dependent handle (Qt::HANDLE), and the platform does not do transformations nativly.

The QPaintEngine::PaintEngineFeature enum can be queried to determine whether the platform performs the transformations or not.

See also worldTransform() and QPaintEngine::hasFeature().

void QPainter::drawArc ( const QRectF & rectangle, int startAngle, int spanAngle )

Draws the arc defined by the given rectangle, startAngle and spanAngle.

The startAngle and spanAngle must be specified in 1/16th of a degree, i.e. a full circle equals 5760 (16 * 360). Positive values for the angles mean counter-clockwise while negative values mean the clockwise direction. Zero degrees is at the 3 o'clock position.

 QRectF rectangle(10.0, 20.0, 80.0, 60.0);
 int startAngle = 30 * 16;
 int spanAngle = 120 * 16;

 QPainter painter(this);
 painter.drawArc(rectangle, startAngle, spanAngle);

See also drawPie(), drawChord(), and Coordinate System.

void QPainter::drawArc ( const QRect & rectangle, int startAngle, int spanAngle )

This is an overloaded function.

Draws the arc defined by the given rectangle, startAngle and spanAngle.

void QPainter::drawArc ( int x, int y, int width, int height, int startAngle, int spanAngle )

This is an overloaded function.

Draws the arc defined by the rectangle beginning at (x, y) with the specified width and height, and the given startAngle and spanAngle.

void QPainter::drawChord ( const QRectF & rectangle, int startAngle, int spanAngle )

Draws the chord defined by the given rectangle, startAngle and spanAngle. The chord is filled with the current brush().

The startAngle and spanAngle must be specified in 1/16th of a degree, i.e. a full circle equals 5760 (16 * 360). Positive values for the angles mean counter-clockwise while negative values mean the clockwise direction. Zero degrees is at the 3 o'clock position.

 QRectF rectangle(10.0, 20.0, 80.0, 60.0);
 int startAngle = 30 * 16;
 int spanAngle = 120 * 16;

 QPainter painter(this);
 painter.drawChord(rect, startAngle, spanAngle);

See also drawArc(), drawPie(), and Coordinate System.

void QPainter::drawChord ( const QRect & rectangle, int startAngle, int spanAngle )

This is an overloaded function.

Draws the chord defined by the given rectangle, startAngle and spanAngle.

void QPainter::drawChord ( int x, int y, int width, int height, int startAngle, int spanAngle )

This is an overloaded function.

Draws the chord defined by the rectangle beginning at (x, y) with the specified width and height, and the given startAngle and spanAngle.

void QPainter::drawConvexPolygon ( const QPointF * points, int pointCount )

Draws the convex polygon defined by the first pointCount points in the array points using the current pen.

 static const QPointF points[4] = {
     QPointF(10.0, 80.0),
     QPointF(20.0, 10.0),
     QPointF(80.0, 30.0),
     QPointF(90.0, 70.0)
 };

 QPainter painter(this);
 painter.drawConvexPolygon(points, 4);

The first point is implicitly connected to the last point, and the polygon is filled with the current brush(). If the supplied polygon is not convex, i.e. it contains at least one angle larger than 180 degrees, the results are undefined.

On some platforms (e.g. X11), the drawConvexPolygon() function can be faster than the drawPolygon() function.

See also drawPolygon(), drawPolyline(), and Coordinate System.

void QPainter::drawConvexPolygon ( const QPoint * points, int pointCount )

This is an overloaded function.

Draws the convex polygon defined by the first pointCount points in the array points using the current pen.

void QPainter::drawConvexPolygon ( const QPolygonF & polygon )

This is an overloaded function.

Draws the convex polygon defined by polygon using the current pen and brush.

void QPainter::drawConvexPolygon ( const QPolygon & polygon )

This is an overloaded function.

Draws the convex polygon defined by polygon using the current pen and brush.

void QPainter::drawEllipse ( const QRectF & rectangle )

Draws the ellipse defined by the given rectangle.

A filled ellipse has a size of rectangle.size(). A stroked ellipse has a size of rectangle.size() plus the pen width.

 QRectF rectangle(10.0, 20.0, 80.0, 60.0);

 QPainter painter(this);
 painter.drawEllipse(rectangle);

See also drawPie() and Coordinate System.

void QPainter::drawEllipse ( const QRect & rectangle )

This is an overloaded function.

Draws the ellipse defined by the given rectangle.

void QPainter::drawEllipse ( int x, int y, int width, int height )

This is an overloaded function.

Draws the ellipse defined by the rectangle beginning at (x, y) with the given width and height.

void QPainter::drawEllipse ( const QPointF & center, qreal rx, qreal ry )

This is an overloaded function.

Draws the ellipse positioned at center with radii rx and ry.

This function was introduced in Qt 4.4.

void QPainter::drawEllipse ( const QPoint & center, int rx, int ry )

This is an overloaded function.

Draws the ellipse positioned at center with radii rx and ry.

This function was introduced in Qt 4.4.

void QPainter::drawImage ( const QRectF & target, const QImage & image, const QRectF & source, Qt::ImageConversionFlags flags = Qt::AutoColor )

Draws the rectangular portion source of the given image into the target rectangle in the paint device.

Note: The image is scaled to fit the rectangle, if both the image and rectangle size disagree.

If the image needs to be modified to fit in a lower-resolution result (e.g. converting from 32-bit to 8-bit), use the flags to specify how you would prefer this to happen.

 QRectF target(10.0, 20.0, 80.0, 60.0);
 QRectF source(0.0, 0.0, 70.0, 40.0);
 QImage image(":/images/myImage.png");

 QPainter painter(this);
 painter.drawImage(target, image, source);

See also drawPixmap().

void QPainter::drawImage ( const QRect & target, const QImage & image, const QRect & source, Qt::ImageConversionFlags flags = Qt::AutoColor )

This is an overloaded function.

Draws the rectangular portion source of the given image into the target rectangle in the paint device.

Note: The image is scaled to fit the rectangle, if both the image and rectangle size disagree.

void QPainter::drawImage ( const QPointF & point, const QImage & image )

This is an overloaded function.

Draws the given image at the given point.

void QPainter::drawImage ( const QPoint & point, const QImage & image )

This is an overloaded function.

Draws the given image at the given point.

void QPainter::drawImage ( const QPointF & point, const QImage & image, const QRectF & source, Qt::ImageConversionFlags flags = Qt::AutoColor )

This is an overloaded function.

Draws the rectangular portion source of the given image with its origin at the given point.

void QPainter::drawImage ( const QPoint & point, const QImage & image, const QRect & source, Qt::ImageConversionFlags flags = Qt::AutoColor )

This is an overloaded function.

Draws the rectangular portion source of the given image with its origin at the given point.

void QPainter::drawImage ( const QRectF & rectangle, const QImage & image )

This is an overloaded function.

Draws the given image into the given rectangle.

Note: The image is scaled to fit the rectangle, if both the image and rectangle size disagree.

void QPainter::drawImage ( const QRect & rectangle, const QImage & image )

This is an overloaded function.

Draws the given image into the given rectangle.

Note: The image is scaled to fit the rectangle, if both the image and rectangle size disagree.

void QPainter::drawImage ( int x, int y, const QImage & image, int sx = 0, int sy = 0, int sw = -1, int sh = -1, Qt::ImageConversionFlags flags = Qt::AutoColor )

This is an overloaded function.

Draws an image at (x, y) by copying a part of image into the paint device.

(x, y) specifies the top-left point in the paint device that is to be drawn onto. (sx, sy) specifies the top-left point in image that is to be drawn. The default is (0, 0).

(sw, sh) specifies the size of the image that is to be drawn. The default, (0, 0) (and negative) means all the way to the bottom-right of the image.

void QPainter::drawLine ( const QLineF & line )

Draws a line defined by line.

 QLineF line(10.0, 80.0, 90.0, 20.0);

 QPainter(this);
 painter.drawLine(line);

See also drawLines(), drawPolyline(), and Coordinate System.

void QPainter::drawLine ( const QLine & line )

This is an overloaded function.

Draws a line defined by line.

void QPainter::drawLine ( const QPoint & p1, const QPoint & p2 )

This is an overloaded function.

Draws a line from p1 to p2.

void QPainter::drawLine ( const QPointF & p1, const QPointF & p2 )

This is an overloaded function.

Draws a line from p1 to p2.

void QPainter::drawLine ( int x1, int y1, int x2, int y2 )

This is an overloaded function.

Draws a line from (x1, y1) to (x2, y2) and sets the current pen position to (x2, y2).

void QPainter::drawLines ( const QLineF * lines, int lineCount )

Draws the first lineCount lines in the array lines using the current pen.

See also drawLine() and drawPolyline().

void QPainter::drawLines ( const QLine * lines, int lineCount )

This is an overloaded function.

Draws the first lineCount lines in the array lines using the current pen.

void QPainter::drawLines ( const QPointF * pointPairs, int lineCount )

This is an overloaded function.

Draws the first lineCount lines in the array pointPairs using the current pen. The lines are specified as pairs of points so the number of entries in pointPairs must be at least lineCount * 2.

void QPainter::drawLines ( const QPoint * pointPairs, int lineCount )

This is an overloaded function.

Draws the first lineCount lines in the array pointPairs using the current pen.

void QPainter::drawLines ( const QVector<QPointF> & pointPairs )

This is an overloaded function.

Draws a line for each pair of points in the vector pointPairs using the current pen. If there is an odd number of points in the array, the last point will be ignored.

void QPainter::drawLines ( const QVector<QPoint> & pointPairs )

This is an overloaded function.

Draws a line for each pair of points in the vector pointPairs using the current pen.

void QPainter::drawLines ( const QVector<QLineF> & lines )

This is an overloaded function.

Draws the set of lines defined by the list lines using the current pen and brush.

void QPainter::drawLines ( const QVector<QLine> & lines )

This is an overloaded function.

Draws the set of lines defined by the list lines using the current pen and brush.

void QPainter::drawPath ( const QPainterPath & path )

Draws the given painter path using the current pen for outline and the current brush for filling.

 QPainterPath path;
 path.moveTo(20, 80);
 path.lineTo(20, 30);
 path.cubicTo(80, 0, 50, 50, 80, 80);

 QPainter painter(this);
 painter.drawPath(path);

See also the Painter Paths example and the Vector Deformation demo.

void QPainter::drawPicture ( const QPointF & point, const QPicture & picture )

Replays the given picture at the given point.

The QPicture class is a paint device that records and replays QPainter commands. A picture serializes the painter commands to an IO device in a platform-independent format. Everything that can be painted on a widget or pixmap can also be stored in a picture.

This function does exactly the same as QPicture::play() when called with point = QPoint(0, 0).

 QPicture picture;
 QPointF point(10.0, 20.0)
 picture.load("drawing.pic");

 QPainter painter(this);
 painter.drawPicture(0, 0, picture);

See also QPicture::play().

void QPainter::drawPicture ( const QPoint & point, const QPicture & picture )

This is an overloaded function.

Replays the given picture at the given point.

void QPainter::drawPicture ( int x, int y, const QPicture & picture )

This is an overloaded function.

Draws the given picture at point (x, y).

void QPainter::drawPie ( const QRectF & rectangle, int startAngle, int spanAngle )

Draws a pie defined by the given rectangle, startAngle and and spanAngle.

The pie is filled with the current brush().

The startAngle and spanAngle must be specified in 1/16th of a degree, i.e. a full circle equals 5760 (16 * 360). Positive values for the angles mean counter-clockwise while negative values mean the clockwise direction. Zero degrees is at the 3 o'clock position.

 QRectF rectangle(10.0, 20.0, 80.0, 60.0);
 int startAngle = 30 * 16;
 int spanAngle = 120 * 16;

 QPainter painter(this);
 painter.drawPie(rectangle, startAngle, spanAngle);

See also drawEllipse(), drawChord(), and Coordinate System.

void QPainter::drawPie ( const QRect & rectangle, int startAngle, int spanAngle )

This is an overloaded function.

Draws a pie defined by the given rectangle, startAngle and and spanAngle.

void QPainter::drawPie ( int x, int y, int width, int height, int startAngle, int spanAngle )

This is an overloaded function.

Draws the pie defined by the rectangle beginning at (x, y) with the specified width and height, and the given startAngle and spanAngle.

void QPainter::drawPixmap ( const QRectF & target, const QPixmap & pixmap, const QRectF & source )

Draws the rectangular portion source of the given pixmap into the given target in the paint device.

Note: The pixmap is scaled to fit the rectangle, if both the pixmap and rectangle size disagree.

 QRectF target(10.0, 20.0, 80.0, 60.0);
 QRectF source(0.0, 0.0, 70.0, 40.0);
 QPixmap pixmap(":myPixmap.png");

 QPainter(this);
 painter.drawPixmap(target, image, source);

If pixmap is a QBitmap it is drawn with the bits that are "set" using the pens color. If backgroundMode is Qt::OpaqueMode, the "unset" bits are drawn using the color of the background brush; if backgroundMode is Qt::TransparentMode, the "unset" bits are transparent. Drawing bitmaps with gradient or texture colors is not supported.

See also drawImage().

void QPainter::drawPixmap ( const QRect & target, const QPixmap & pixmap, const QRect & source )

This is an overloaded function.

Draws the rectangular portion source of the given pixmap into the given target in the paint device.

Note: The pixmap is scaled to fit the rectangle, if both the pixmap and rectangle size disagree.

void QPainter::drawPixmap ( const QPointF & point, const QPixmap & pixmap, const QRectF & source )

This is an overloaded function.

Draws the rectangular portion source of the given pixmap with its origin at the given point.

void QPainter::drawPixmap ( const QPoint & point, const QPixmap & pixmap, const QRect & source )

This is an overloaded function.

Draws the rectangular portion source of the given pixmap with its origin at the given point.

void QPainter::drawPixmap ( const QPointF & point, const QPixmap & pixmap )

This is an overloaded function.

Draws the given pixmap with its origin at the given point.

void QPainter::drawPixmap ( const QPoint & point, const QPixmap & pixmap )

This is an overloaded function.

Draws the given pixmap with its origin at the given point.

void QPainter::drawPixmap ( int x, int y, const QPixmap & pixmap )

This is an overloaded function.

Draws the given pixmap at position (x, y).

void QPainter::drawPixmap ( const QRect & rectangle, const QPixmap & pixmap )

This is an overloaded function.

Draws the given pixmap into the given rectangle.

Note: The pixmap is scaled to fit the rectangle, if both the pixmap and rectangle size disagree.

void QPainter::drawPixmap ( int x, int y, int width, int height, const QPixmap & pixmap )

This is an overloaded function.

Draws the pixmap into the rectangle at position (x, y) with the given width and height.

void QPainter::drawPixmap ( int x, int y, int w, int h, const QPixmap & pixmap, int sx, int sy, int sw, int sh )

This is an overloaded function.

Draws the rectangular portion with the origin (sx, sy), width sw and height sh, of the given pixmap , at the point (x, y), with a width of w and a height of h. If sw or sh are equal to zero the width/height of the pixmap is used and adjusted by the offset sx/sy;

void QPainter::drawPixmap ( int x, int y, const QPixmap & pixmap, int sx, int sy, int sw, int sh )

This is an overloaded function.

Draws a pixmap at (x, y) by copying a part of the given pixmap into the paint device.

(x, y) specifies the top-left point in the paint device that is to be drawn onto. (sx, sy) specifies the top-left point in pixmap that is to be drawn. The default is (0, 0).

(sw, sh) specifies the size of the pixmap that is to be drawn. The default, (0, 0) (and negative) means all the way to the bottom-right of the pixmap.

void QPainter::drawPixmapFragments ( const PixmapFragment * fragments, int fragmentCount, const QPixmap & pixmap, PixmapFragmentHints hints = 0 )

This function is used to draw pixmap, or a sub-rectangle of pixmap, at multiple positions with different scale, rotation and opacity. fragments is an array of fragmentCount elements specifying the parameters used to draw each pixmap fragment. The hints parameter can be used to pass in drawing hints.

This function is potentially faster than multiple calls to drawPixmap(), since the backend can optimize state changes.

This function was introduced in Qt 4.7.

See also QPainter::PixmapFragment and QPainter::PixmapFragmentHint.

void QPainter::drawPoint ( const QPointF & position )

Draws a single point at the given position using the current pen's color.

See also Coordinate System.

void QPainter::drawPoint ( const QPoint & position )

This is an overloaded function.

Draws a single point at the given position using the current pen's color.

void QPainter::drawPoint ( int x, int y )

This is an overloaded function.

Draws a single point at position (x, y).

void QPainter::drawPoints ( const QPointF * points, int pointCount )

Draws the first pointCount points in the array points using the current pen's color.

See also Coordinate System.

void QPainter::drawPoints ( const QPoint * points, int pointCount )

This is an overloaded function.

Draws the first pointCount points in the array points using the current pen's color.

void QPainter::drawPoints ( const QPolygonF & points )

This is an overloaded function.

Draws the points in the vector points.

void QPainter::drawPoints ( const QPolygon & points )

This is an overloaded function.

Draws the points in the vector points.

void QPainter::drawPolygon ( const QPointF * points, int pointCount, Qt::FillRule fillRule = Qt::OddEvenFill )

Draws the polygon defined by the first pointCount points in the array points using the current pen and brush.

 static const QPointF points[4] = {
     QPointF(10.0, 80.0),
     QPointF(20.0, 10.0),
     QPointF(80.0, 30.0),
     QPointF(90.0, 70.0)
 };

 QPainter painter(this);
 painter.drawPolygon(points, 4);

The first point is implicitly connected to the last point, and the polygon is filled with the current brush().

If fillRule is Qt::WindingFill, the polygon is filled using the winding fill algorithm. If fillRule is Qt::OddEvenFill, the polygon is filled using the odd-even fill algorithm. See Qt::FillRule for a more detailed description of these fill rules.

See also drawConvexPolygon(), drawPolyline(), and Coordinate System.

void QPainter::drawPolygon ( const QPoint * points, int pointCount, Qt::FillRule fillRule = Qt::OddEvenFill )

This is an overloaded function.

Draws the polygon defined by the first pointCount points in the array points.

void QPainter::drawPolygon ( const QPolygonF & points, Qt::FillRule fillRule = Qt::OddEvenFill )

This is an overloaded function.

Draws the polygon defined by the given points using the fill rule fillRule.

void QPainter::drawPolygon ( const QPolygon & points, Qt::FillRule fillRule = Qt::OddEvenFill )

This is an overloaded function.

Draws the polygon defined by the given points using the fill rule fillRule.

void QPainter::drawPolyline ( const QPointF * points, int pointCount )

Draws the polyline defined by the first pointCount points in points using the current pen.

Note that unlike the drawPolygon() function the last point is not connected to the first, neither is the polyline filled.

 static const QPointF points[3] = {
     QPointF(10.0, 80.0),
     QPointF(20.0, 10.0),
     QPointF(80.0, 30.0),
 };

 QPainter painter(this);
 painter.drawPolyline(points, 3);

See also drawLines(), drawPolygon(), and Coordinate System.

void QPainter::drawPolyline ( const QPoint * points, int pointCount )

This is an overloaded function.

Draws the polyline defined by the first pointCount points in points using the current pen.

void QPainter::drawPolyline ( const QPolygonF & points )

This is an overloaded function.

Draws the polyline defined by the given points using the current pen.

void QPainter::drawPolyline ( const QPolygon & points )

This is an overloaded function.

Draws the polyline defined by the given points using the current pen.

void QPainter::drawRect ( const QRectF & rectangle )

Draws the current rectangle with the current pen and brush.

A filled rectangle has a size of rectangle.size(). A stroked rectangle has a size of rectangle.size() plus the pen width.

 QRectF rectangle(10.0, 20.0, 80.0, 60.0);

 QPainter painter(this);
 painter.drawRect(rectangle);

See also drawRects(), drawPolygon(), and Coordinate System.

void QPainter::drawRect ( const QRect & rectangle )

This is an overloaded function.

Draws the current rectangle with the current pen and brush.

void QPainter::drawRect ( int x, int y, int width, int height )

This is an overloaded function.

Draws a rectangle with upper left corner at (x, y) and with the given width and height.

void QPainter::drawRects ( const QRectF * rectangles, int rectCount )

Draws the first rectCount of the given rectangles using the current pen and brush.

See also drawRect().

void QPainter::drawRects ( const QRect * rectangles, int rectCount )

This is an overloaded function.

Draws the first rectCount of the given rectangles using the current pen and brush.

void QPainter::drawRects ( const QVector<QRectF> & rectangles )

This is an overloaded function.

Draws the given rectangles using the current pen and brush.

void QPainter::drawRects ( const QVector<QRect> & rectangles )

This is an overloaded function.

Draws the given rectangles using the current pen and brush.

void QPainter::drawRoundedRect ( const QRectF & rect, qreal xRadius, qreal yRadius, Qt::SizeMode mode = Qt::AbsoluteSize )

Draws the given rectangle rect with rounded corners.

The xRadius and yRadius arguments specify the radii of the ellipses defining the corners of the rounded rectangle. When mode is Qt::RelativeSize, xRadius and yRadius are specified in percentage of half the rectangle's width and height respectively, and should be in the range 0.0 to 100.0.

A filled rectangle has a size of rect.size(). A stroked rectangle has a size of rect.size() plus the pen width.

 QRectF rectangle(10.0, 20.0, 80.0, 60.0);

 QPainter painter(this);
 painter.drawRoundedRect(rectangle, 20.0, 15.0);

This function was introduced in Qt 4.4.

See also drawRect() and QPen.

void QPainter::drawRoundedRect ( const QRect & rect, qreal xRadius, qreal yRadius, Qt::SizeMode mode = Qt::AbsoluteSize )

This is an overloaded function.

Draws the given rectangle rect with rounded corners.

This function was introduced in Qt 4.4.

void QPainter::drawRoundedRect ( int x, int y, int w, int h, qreal xRadius, qreal yRadius, Qt::SizeMode mode = Qt::AbsoluteSize )

This is an overloaded function.

Draws the given rectangle x, y, w, h with rounded corners.

This function was introduced in Qt 4.4.

void QPainter::drawStaticText ( const QPointF & topLeftPosition, const QStaticText & staticText )

Draws the given staticText at the given topLeftPosition.

The text will be drawn using the font and the transformation set on the painter. If the font and/or transformation set on the painter are different from the ones used to initialize the layout of the QStaticText, then the layout will have to be recalculated. Use QStaticText::prepare() to initialize staticText with the font and transformation with which it will later be drawn.

If topLeftPosition is not the same as when staticText was initialized, or when it was last drawn, then there will be a slight overhead when translating the text to its new position.

Note: If the painter's transformation is not affine, then staticText will be drawn using regular calls to drawText(), losing any potential for performance improvement.

Note: The y-position is used as the top of the font.

This function was introduced in Qt 4.7.

See also QStaticText.

void QPainter::drawStaticText ( const QPoint & topLeftPosition, const QStaticText & staticText )

This is an overloaded function.

Draws the staticText at the topLeftPosition.

Note: The y-position is used as the top of the font.

This function was introduced in Qt 4.7.

void QPainter::drawStaticText ( int left, int top, const QStaticText & staticText )

This is an overloaded function.

Draws the staticText at coordinates left and top.

Note: The y-position is used as the top of the font.

This function was introduced in Qt 4.7.

void QPainter::drawText ( const QPointF & position, const QString & text )

Draws the given text with the currently defined text direction, beginning at the given position.

This function does not handle the newline character (\n), as it cannot break text into multiple lines, and it cannot display the newline character. Use the QPainter::drawText() overload that takes a rectangle instead if you want to draw multiple lines of text with the newline character, or if you want the text to be wrapped.

By default, QPainter draws text anti-aliased.

Note: The y-position is used as the baseline of the font.

void QPainter::drawText ( const QPoint & position, const QString & text )

This is an overloaded function.

Draws the given text with the currently defined text direction, beginning at the given position.

By default, QPainter draws text anti-aliased.

Note: The y-position is used as the baseline of the font.

void QPainter::drawText ( const QRectF & rectangle, int flags, const QString & text, QRectF * boundingRect = 0 )

This is an overloaded function.

Draws the given text within the provided rectangle.

 QPainter painter(this);
 painter.drawText(rect, Qt::AlignCenter, tr("Qt by\nNokia"));

The boundingRect (if not null) is set to the what the bounding rectangle should be in order to enclose the whole text. The flags argument is a bitwise OR of the following flags:

• Qt::AlignLeft
• Qt::AlignRight
• Qt::AlignHCenter
• Qt::AlignJustify
• Qt::AlignTop
• Qt::AlignBottom
• Qt::AlignVCenter
• Qt::AlignCenter
• Qt::TextDontClip
• Qt::TextSingleLine
• Qt::TextExpandTabs
• Qt::TextShowMnemonic
• Qt::TextWordWrap
• Qt::TextIncludeTrailingSpaces

By default, QPainter draws text anti-aliased.

Note: The y-coordinate of rectangle is used as the top of the font.

See also Qt::AlignmentFlag, Qt::TextFlag, boundingRect(), and layoutDirection().

void QPainter::drawText ( const QRect & rectangle, int flags, const QString & text, QRect * boundingRect = 0 )

This is an overloaded function.

Draws the given text within the provided rectangle according to the specified flags. The boundingRect (if not null) is set to the what the bounding rectangle should be in order to enclose the whole text.

By default, QPainter draws text anti-aliased.

Note: The y-coordinate of rectangle is used as the top of the font.

void QPainter::drawText ( int x, int y, const QString & text )

This is an overloaded function.

Draws the given text at position (x, y), using the painter's currently defined text direction.

By default, QPainter draws text anti-aliased.

Note: The y-position is used as the baseline of the font.

void QPainter::drawText ( int x, int y, int width, int height, int flags, const QString & text, QRect * boundingRect = 0 )

This is an overloaded function.

Draws the given text within the rectangle with origin (x, y), width and height.

The boundingRect (if not null) is set to the actual bounding rectangle of the output. The flags argument is a bitwise OR of the following flags:

• Qt::AlignLeft
• Qt::AlignRight
• Qt::AlignHCenter
• Qt::AlignJustify
• Qt::AlignTop
• Qt::AlignBottom
• Qt::AlignVCenter
• Qt::AlignCenter
• Qt::TextSingleLine
• Qt::TextExpandTabs
• Qt::TextShowMnemonic
• Qt::TextWordWrap

By default, QPainter draws text anti-aliased.

Note: The y-position is used as the baseline of the font.

See also Qt::AlignmentFlag and Qt::TextFlag.

void QPainter::drawText ( const QRectF & rectangle, const QString & text, const QTextOption & option = QTextOption() )

This is an overloaded function.

Draws the given text in the rectangle specified using the option to control its positioning and orientation.

By default, QPainter draws text anti-aliased.

Note: The y-coordinate of rectangle is used as the top of the font.

void QPainter::drawTiledPixmap ( const QRectF & rectangle, const QPixmap & pixmap, const QPointF & position = QPointF() )

Draws a tiled pixmap, inside the given rectangle with its origin at the given position.

Calling drawTiledPixmap() is similar to calling drawPixmap() several times to fill (tile) an area with a pixmap, but is potentially much more efficient depending on the underlying window system.

See also drawPixmap().

void QPainter::drawTiledPixmap ( const QRect & rectangle, const QPixmap & pixmap, const QPoint & position = QPoint() )

This is an overloaded function.

Draws a tiled pixmap, inside the given rectangle with its origin at the given position.

void QPainter::drawTiledPixmap ( int x, int y, int width, int height, const QPixmap & pixmap, int sx = 0, int sy = 0 )

This is an overloaded function.

Draws a tiled pixmap in the specified rectangle.

(x, y) specifies the top-left point in the paint device that is to be drawn onto; with the given width and height. (sx, sy) specifies the top-left point in the pixmap that is to be drawn; this defaults to (0, 0).

bool QPainter::end ()

Ends painting. Any resources used while painting are released. You don't normally need to call this since it is called by the destructor.

Returns true if the painter is no longer active; otherwise returns false.

See also begin() and isActive().

void QPainter::endNativePainting ()

Restores the painter after manually issuing native painting commands. Lets the painter restore any native state that it relies on before calling any other painter commands.

This function was introduced in Qt 4.6.

See also beginNativePainting().

void QPainter::eraseRect ( const QRectF & rectangle )

Erases the area inside the given rectangle. Equivalent to calling

 fillRect(rectangle, background()).

See also fillRect().

void QPainter::eraseRect ( const QRect & rectangle )

This is an overloaded function.

Erases the area inside the given rectangle.

void QPainter::eraseRect ( int x, int y, int width, int height )

This is an overloaded function.

Erases the area inside the rectangle beginning at (x, y) with the given width and height.

void QPainter::fillPath ( const QPainterPath & path, const QBrush & brush )

Fills the given path using the given brush. The outline is not drawn.

Alternatively, you can specify a QColor instead of a QBrush; the QBrush constructor (taking a QColor argument) will automatically create a solid pattern brush.

See also drawPath().

void QPainter::fillRect ( const QRectF & rectangle, const QBrush & brush )

Fills the given rectangle with the brush specified.

Alternatively, you can specify a QColor instead of a QBrush; the QBrush constructor (taking a QColor argument) will automatically create a solid pattern brush.

See also drawRect().

void QPainter::fillRect ( int x, int y, int width, int height, Qt::BrushStyle style )

This is an overloaded function.

Fills the rectangle beginning at (x, y) with the given width and height, using the brush style specified.

This function was introduced in Qt 4.5.

void QPainter::fillRect ( const QRect & rectangle, Qt::BrushStyle style )

This is an overloaded function.

Fills the given rectangle with the brush style specified.

This function was introduced in Qt 4.5.

void QPainter::fillRect ( const QRectF & rectangle, Qt::BrushStyle style )

This is an overloaded function.

Fills the given rectangle with the brush style specified.

This function was introduced in Qt 4.5.

void QPainter::fillRect ( const QRect & rectangle, const QBrush & brush )

This is an overloaded function.

Fills the given rectangle with the specified brush.

void QPainter::fillRect ( const QRect & rectangle, const QColor & color )

This is an overloaded function.

Fills the given rectangle with the color specified.

This function was introduced in Qt 4.5.

void QPainter::fillRect ( const QRectF & rectangle, const QColor & color )

This is an overloaded function.

Fills the given rectangle with the color specified.

This function was introduced in Qt 4.5.

void QPainter::fillRect ( int x, int y, int width, int height, const QBrush & brush )

This is an overloaded function.

Fills the rectangle beginning at (x, y) with the given width and height, using the given brush.

void QPainter::fillRect ( int x, int y, int width, int height, const QColor & color )

This is an overloaded function.

Fills the rectangle beginning at (x, y) with the given width and height, using the given color.

This function was introduced in Qt 4.5.

void QPainter::fillRect ( int x, int y, int width, int height, Qt::GlobalColor color )

This is an overloaded function.

Fills the rectangle beginning at (x, y) with the given width and height, using the given color.

This function was introduced in Qt 4.5.

void QPainter::fillRect ( const QRect & rectangle, Qt::GlobalColor color )

This is an overloaded function.

Fills the given rectangle with the specified color.

This function was introduced in Qt 4.5.

void QPainter::fillRect ( const QRectF & rectangle, Qt::GlobalColor color )

This is an overloaded function.

Fills the given rectangle with the specified color.

This function was introduced in Qt 4.5.

const QFont & QPainter::font () const

Returns the currently set font used for drawing text.

See also setFont(), drawText(), and Settings.

QFontInfo QPainter::fontInfo () const

Returns the font info for the painter if the painter is active. Otherwise, the return value is undefined.

See also font(), isActive(), and Settings.

QFontMetrics QPainter::fontMetrics () const

Returns the font metrics for the painter if the painter is active. Otherwise, the return value is undefined.

See also font(), isActive(), and Settings.

bool QPainter::hasClipping () const

Returns true if clipping has been set; otherwise returns false.

See also setClipping() and Clipping.

void QPainter::initFrom ( const QWidget * widget )

Initializes the painters pen, background and font to the same as the given widget. This function is called automatically when the painter is opened on a QWidget.

See also begin() and Settings.

bool QPainter::isActive () const

Returns true if begin() has been called and end() has not yet been called; otherwise returns false.

See also begin() and QPaintDevice::paintingActive().

Qt::LayoutDirection QPainter::layoutDirection () const

Returns the layout direction used by the painter when drawing text.

See also QTextOption::textDirection(), setLayoutDirection(), drawText(), and Settings.

qreal QPainter::opacity () const

Returns the opacity of the painter. The default value is 1.

This function was introduced in Qt 4.2.

See also setOpacity().

QPaintEngine * QPainter::paintEngine () const

Returns the paint engine that the painter is currently operating on if the painter is active; otherwise 0.

See also isActive().

const QPen & QPainter::pen () const

Returns the painter's current pen.

See also setPen() and Settings.

RenderHints QPainter::renderHints () const

Returns a flag that specifies the rendering hints that are set for this painter.

See also setRenderHints(), testRenderHint(), and Rendering Quality.

void QPainter::resetTransform ()

Resets any transformations that were made using translate(), scale(), shear(), rotate(), setWorldTransform(), setViewport() and setWindow().

See also Coordinate Transformations.

void QPainter::restore ()

Restores the current painter state (pops a saved state off the stack).

See also save().

void QPainter::rotate ( qreal angle )

Rotates the coordinate system the given angle clockwise.

See also setWorldTransform() and Coordinate Transformations.

void QPainter::save ()

Saves the current painter state (pushes the state onto a stack). A save() must be followed by a corresponding restore(); the end() function unwinds the stack.

See also restore().

void QPainter::scale ( qreal sx, qreal sy )

Scales the coordinate system by (sx, sy).

See also setWorldTransform() and Coordinate Transformations.

void QPainter::setBackground ( const QBrush & brush )

Sets the background brush of the painter to the given brush.

The background brush is the brush that is filled in when drawing opaque text, stippled lines and bitmaps. The background brush has no effect in transparent background mode (which is the default).

See also background(), setBackgroundMode(), and Settings.

void QPainter::setBackgroundMode ( Qt::BGMode mode )

Sets the background mode of the painter to the given mode

Qt::TransparentMode (the default) draws stippled lines and text without setting the background pixels. Qt::OpaqueMode fills these space with the current background color.

Note that in order to draw a bitmap or pixmap transparently, you must use QPixmap::setMask().

See also backgroundMode(), setBackground(), and Settings.

void QPainter::setBrush ( const QBrush & brush )

Sets the painter's brush to the given brush.

The painter's brush defines how shapes are filled.

See also brush() and Settings.

void QPainter::setBrush ( Qt::BrushStyle style )

This is an overloaded function.

Sets the painter's brush to black color and the specified style.

void QPainter::setBrushOrigin ( const QPointF & position )

Sets the brush origin to position.

The brush origin specifies the (0, 0) coordinate of the painter's brush.

Note that while the brushOrigin() was necessary to adopt the parent's background for a widget in Qt 3, this is no longer the case since the Qt 4 painter doesn't paint the background unless you explicitly tell it to do so by setting the widget's autoFillBackground property to true.

See also brushOrigin() and Settings.

void QPainter::setBrushOrigin ( const QPoint & position )

This is an overloaded function.

Sets the brush's origin to the given position.

void QPainter::setBrushOrigin ( int x, int y )

This is an overloaded function.

Sets the brush's origin to point (x, y).

void QPainter::setClipPath ( const QPainterPath & path, Qt::ClipOperation operation = Qt::ReplaceClip )

Enables clipping, and sets the clip path for the painter to the given path, with the clip operation.

Note that the clip path is specified in logical (painter) coordinates.

See also clipPath(), clipRegion(), and Clipping.

void QPainter::setClipRect ( const QRectF & rectangle, Qt::ClipOperation operation = Qt::ReplaceClip )

Enables clipping, and sets the clip region to the given rectangle using the given clip operation. The default operation is to replace the current clip rectangle.

Note that the clip rectangle is specified in logical (painter) coordinates.

See also clipRegion(), setClipping(), and Clipping.

void QPainter::setClipRect ( int x, int y, int width, int height, Qt::ClipOperation operation = Qt::ReplaceClip )

Enables clipping, and sets the clip region to the rectangle beginning at (x, y) with the given width and height.

void QPainter::setClipRect ( const QRect & rectangle, Qt::ClipOperation operation = Qt::ReplaceClip )

This is an overloaded function.

Enables clipping, and sets the clip region to the given rectangle using the given clip operation.

void QPainter::setClipRegion ( const QRegion & region, Qt::ClipOperation operation = Qt::ReplaceClip )

Sets the clip region to the given region using the specified clip operation. The default clip operation is to replace the current clip region.

Note that the clip region is given in logical coordinates.

See also clipRegion(), setClipRect(), and Clipping.

void QPainter::setClipping ( bool enable )

Enables clipping if enable is true, or disables clipping if enable is false.

See also hasClipping() and Clipping.

void QPainter::setCompositionMode ( CompositionMode mode )

Sets the composition mode to the given mode.

Warning: Only a QPainter operating on a QImage fully supports all composition modes. The RasterOp modes are supported for X11 as described in compositionMode().

See also compositionMode().

void QPainter::setFont ( const QFont & font )

Sets the painter's font to the given font.

This font is used by subsequent drawText() functions. The text color is the same as the pen color.

If you set a font that isn't available, Qt finds a close match. font() will return what you set using setFont() and fontInfo() returns the font actually being used (which may be the same).

See also font(), drawText(), and Settings.

void QPainter::setLayoutDirection ( Qt::LayoutDirection direction )

Sets the layout direction used by the painter when drawing text, to the specified direction.

The default is Qt::LayoutDirectionAuto, which will implicitly determine the direction from the text drawn.

See also QTextOption::setTextDirection(), layoutDirection(), drawText(), and Settings.

void QPainter::setOpacity ( qreal opacity )

Sets the opacity of the painter to opacity. The value should be in the range 0.0 to 1.0, where 0.0 is fully transparent and 1.0 is fully opaque.

Opacity set on the painter will apply to all drawing operations individually.

This function was introduced in Qt 4.2.

See also opacity().

void QPainter::setPen ( const QPen & pen )

Sets the painter's pen to be the given pen.

The pen defines how to draw lines and outlines, and it also defines the text color.

See also pen() and Settings.

void QPainter::setPen ( const QColor & color )

This is an overloaded function.

Sets the painter's pen to have style Qt::SolidLine, width 0 and the specified color.

void QPainter::setPen ( Qt::PenStyle style )

This is an overloaded function.

Sets the painter's pen to have the given style, width 0 and black color.

void QPainter::setRenderHint ( RenderHint hint, bool on = true )

Sets the given render hint on the painter if on is true; otherwise clears the render hint.

See also setRenderHints(), renderHints(), and Rendering Quality.

void QPainter::setRenderHints ( RenderHints hints, bool on = true )

Sets the given render hints on the painter if on is true; otherwise clears the render hints.

This function was introduced in Qt 4.2.

See also setRenderHint(), renderHints(), and Rendering Quality.

void QPainter::setTransform ( const QTransform & transform, bool combine = false )

Sets the world transformation matrix. If combine is true, the specified transform is combined with the current matrix; otherwise it replaces the current matrix.

This function was introduced in Qt 4.3.

See also transform() and setWorldTransform().

void QPainter::setViewTransformEnabled ( bool enable )

Enables view transformations if enable is true, or disables view transformations if enable is false.

See also viewTransformEnabled() and Window-Viewport Conversion.

void QPainter::setViewport ( const QRect & rectangle )

Sets the painter's viewport rectangle to the given rectangle, and enables view transformations.

The viewport rectangle is part of the view transformation. The viewport specifies the device coordinate system. Its sister, the window(), specifies the logical coordinate system.

The default viewport rectangle is the same as the device's rectangle.

See also viewport(), viewTransformEnabled(), and Window-Viewport Conversion.

void QPainter::setViewport ( int x, int y, int width, int height )

This is an overloaded function.

Sets the painter's viewport rectangle to be the rectangle beginning at (x, y) with the given width and height.

void QPainter::setWindow ( const QRect & rectangle )

Sets the painter's window to the given rectangle, and enables view transformations.

The window rectangle is part of the view transformation. The window specifies the logical coordinate system. Its sister, the viewport(), specifies the device coordinate system.

The default window rectangle is the same as the device's rectangle.

See also window(), viewTransformEnabled(), and Window-Viewport Conversion.

void QPainter::setWindow ( int x, int y, int width, int height )

This is an overloaded function.

Sets the painter's window to the rectangle beginning at (x, y) and the given width and height.

void QPainter::setWorldMatrixEnabled ( bool enable )

Enables transformations if enable is true, or disables transformations if enable is false. The world transformation matrix is not changed.

This function was introduced in Qt 4.2.

See also worldMatrixEnabled(), worldTransform(), and Coordinate Transformations.

void QPainter::setWorldTransform ( const QTransform & matrix, bool combine = false )

Sets the world transformation matrix. If combine is true, the specified matrix is combined with the current matrix; otherwise it replaces the current matrix.

See also worldTransform(), transform(), and setTransform().

void QPainter::shear ( qreal sh, qreal sv )

Shears the coordinate system by (sh, sv).

See also setWorldTransform() and Coordinate Transformations.

void QPainter::strokePath ( const QPainterPath & path, const QPen & pen )

Draws the outline (strokes) the path path with the pen specified by pen

See also fillPath() and Drawing.

bool QPainter::testRenderHint ( RenderHint hint ) const

Returns true if hint is set; otherwise returns false.

This function was introduced in Qt 4.3.

See also renderHints() and setRenderHint().

const QTransform & QPainter::transform () const

Returns the world transformation matrix.

See also setTransform() and worldTransform().

void QPainter::translate ( const QPointF & offset )

Translates the coordinate system by the given offset; i.e. the given offset is added to points.

See also setWorldTransform() and Coordinate Transformations.

void QPainter::translate ( const QPoint & offset )

This is an overloaded function.

Translates the coordinate system by the given offset.

void QPainter::translate ( qreal dx, qreal dy )

This is an overloaded function.

Translates the coordinate system by the vector (dx, dy).

bool QPainter::viewTransformEnabled () const

Returns true if view transformation is enabled; otherwise returns false.

See also setViewTransformEnabled() and worldTransform().

QRect QPainter::viewport () const

Returns the viewport rectangle.

See also setViewport() and setViewTransformEnabled().

QRect QPainter::window () const

Returns the window rectangle.

See also setWindow() and setViewTransformEnabled().

bool QPainter::worldMatrixEnabled () const

Returns true if world transformation is enabled; otherwise returns false.

This function was introduced in Qt 4.2.

See also setWorldMatrixEnabled(), worldTransform(), and Coordinate System.

const QTransform & QPainter::worldTransform () const

Returns the world transformation matrix.

See also setWorldTransform().