Qt Reference Documentation

# Qt 3 Support Members for QPainter

The following class members are part of the Qt 3 support layer. They are provided to help you port old code to Qt 4. We advise against using them in new code.

- QPainter class reference

## Public Functions

const QColor & | backgroundColor () const
bool | begin ( QPaintDevice * device, const QWidget * init )
QRect | boundingRect ( const QRect & rectangle, int flags, const QString & text, int length )
QRect | boundingRect ( int x, int y, int width, int height, int flags, const QString & text, int length )
void | drawConvexPolygon ( const QPolygonF & polygon, int index, int count = -1 )
void | drawConvexPolygon ( const QPolygon & polygon, int index, int count = -1 )
void | drawCubicBezier ( const QPolygon & controlPoints, int index = 0 )
void | drawLineSegments ( const QPolygon & polygon, int index = 0, int count = -1 )
void | drawPoints ( const QPolygon & polygon, int index, int count = -1 )
void | drawPolygon ( const QPolygonF & polygon, bool winding, int index = 0, int count = -1 )
void | drawPolygon ( const QPolygon & polygon, bool winding, int index = 0, int count = -1 )
void | drawPolyline ( const QPolygon & polygon, int index, int count = -1 )
void | drawText ( int x, int y, const QString & text, int pos, int length )
void | drawText ( const QPoint & point, const QString & text, int pos, int length )
void | drawText ( int x, int y, const QString & text, int length )
void | drawText ( const QPoint & point, const QString & text, int length )
void | drawText ( const QRect & rectangle, int flags, const QString & text, int length, QRect * br = 0 )
void | drawText ( int x, int y, int width, int height, int flags, const QString & text, int length, QRect * br = 0 )
bool | hasViewXForm () const
bool | hasWorldXForm () const
void | resetXForm ()
void | setBackgroundColor ( const QColor & color )
void | setViewXForm ( bool enabled )
void | setWorldXForm ( bool enabled )
qreal | translationX () const
qreal | translationY () const
QPoint | xForm ( const QPoint & point ) const
QRect | xForm ( const QRect & rectangle ) const
QPolygon | xForm ( const QPolygon & polygon ) const
QPolygon | xForm ( const QPolygon & polygon, int index, int count ) const
QPoint | xFormDev ( const QPoint & point ) const
QRect | xFormDev ( const QRect & rectangle ) const
QPolygon | xFormDev ( const QPolygon & polygon ) const
QPolygon | xFormDev ( const QPolygon & polygon, int index, int count ) const

## Static Public Members

void | redirect ( QPaintDevice * pdev, QPaintDevice * replacement )
QPaintDevice * | redirect ( QPaintDevice * pdev )

## Member Function Documentation

### const QColor & QPainter::backgroundColor () const

Use background() and QBrush::color() instead.

For example, if you have code like

     QColor myColor = backgroundColor();

you can rewrite it as

     QColor myColor = background().color();

Note that the background can be a complex brush such as a texture or a gradient.

See also setBackgroundColor().

### bool QPainter::begin ( QPaintDevice * device, const QWidget * init )

Use begin() instead.

If the paint device is a QWidget, QPainter is initialized after the widget's settings automatically. Otherwise, you must call the initFrom() function to initialize the painters pen, background and font to the same as any given widget.

For example, if you have code like

     QPainter painter(this);
     painter.begin(device, init);

you can rewrite it as

     QPainter painter(this);
     painter.begin(device);
     painter.initFrom(init);

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

Returns the bounding rectangle for the given length of the text constrained by the provided rectangle.

Use boundingRect() combined with QString::left() instead.

For example, if you have code like

     QRect rectangle = boundingRect(rect, flags, text, length);

you can rewrite it as

     QRect rectangle = boundingRect(rect, flags, text.left(length));

### QRect QPainter::boundingRect ( int x, int y, int width, int height, int flags, const QString & text, int length )

Returns the bounding rectangle for the given length of the text constrained by the rectangle that begins at point (x, y) with the given width and height.

Use boundingRect() combined with QString::left() instead.

For example, if you have code like

     QRect rectangle = boundingRect(x, y, width, height, flags, text, length);

you can rewrite it as

     QRect rectangle = boundingRect(x, y, width, height, flags, text.left(length));

### void QPainter::drawConvexPolygon ( const QPolygonF & polygon, int index, int count = -1 )

This is an overloaded function.

Use drawConvexPolygon() combined with QPolygonF::constData() instead.

For example, if you have code like

     QPainter painter(this);
     painter.drawConvexPolygon(polygon, index, count);

you can rewrite it as

     int pointCount = (count == -1) ?  polygon.size() - index : count;

     QPainter painter(this);
     painter.drawConvexPolygon(polygon.constData() + index, pointCount);

### void QPainter::drawConvexPolygon ( const QPolygon & polygon, int index, int count = -1 )

This is an overloaded function.

Use drawConvexPolygon() combined with QPolygon::constData() instead.

For example, if you have code like

     QPainter painter(this);
     painter.drawConvexPolygon(polygon, index, count);

you can rewrite it as

     int pointCount = (count == -1) ?  polygon.size() - index : count;

     QPainter painter(this);
     painter.drawConvexPolygon(polygon.constData() + index, pointCount);

### void QPainter::drawCubicBezier ( const QPolygon & controlPoints, int index = 0 )

Draws a cubic Bezier curve defined by the controlPoints, starting at controlPoints[index] (index defaults to 0). Points after controlPoints[index + 3] are ignored. Nothing happens if there aren't enough control points.

Use strokePath() instead.

For example, if you have code like

     QPainter painter(this);
     painter.drawCubicBezier(controlPoints, index)

you can rewrite it as

     QPainterPath path;
     path.moveTo(controlPoints.at(index));
     path.cubicTo(controlPoints.at(index+1),
                         controlPoints.at(index+2),
                         controlPoints.at(index+3));

     QPainter painter(this);
     painter.strokePath(path, painter.pen());

### void QPainter::drawLineSegments ( const QPolygon & polygon, int index = 0, int count = -1 )

Draws count separate lines from points defined by the polygon, starting at polygon[index] (index defaults to 0). If count is -1 (the default) all points until the end of the array are used.

Use drawLines() combined with QPolygon::constData() instead.

For example, if you have code like

     QPainter painter(this);
     painter.drawLineSegments(polygon, index, count);

you can rewrite it as

     int lineCount = (count == -1) ?  (polygon.size() - index) / 2  : count;

     QPainter painter(this);
     painter.drawLines(polygon.constData() + index * 2, lineCount);

### void QPainter::drawPoints ( const QPolygon & polygon, int index, int count = -1 )

This is an overloaded function.

Draws count points in the vector polygon starting on index using the current pen.

Use drawPoints() combined with QPolygon::constData() instead.

For example, if you have code like

     QPainter painter(this);
     painter.drawPoints(polygon, index, count);

you can rewrite it as

     int pointCount = (count == -1) ?  polygon.size() - index : count;

     QPainter painter(this);
     painter.drawPoints(polygon.constData() + index, pointCount);

### void QPainter::drawPolygon ( const QPolygonF & polygon, bool winding, int index = 0, int count = -1 )

This is an overloaded function.

Use drawPolygon() combined with QPolygonF::constData() instead.

For example, if you have code like

     QPainter painter(this);
     painter.drawPolygon(polygon, winding, index, count);

you can rewrite it as

     int pointCount = (count == -1) ?  polygon.size() - index : count;
     int fillRule = winding ? Qt::WindingFill : Qt::OddEvenFill;

     QPainter painter(this);
     painter.drawPolygon( polygon.constData() + index, pointCount, fillRule);

### void QPainter::drawPolygon ( const QPolygon & polygon, bool winding, int index = 0, int count = -1 )

This is an overloaded function.

Use drawPolygon() combined with QPolygon::constData() instead.

For example, if you have code like

     QPainter painter(this);
     painter.drawPolygon(polygon, winding, index, count);

you can rewrite it as

     int pointCount = (count == -1) ?  polygon.size() - index : count;
     int fillRule = winding ? Qt::WindingFill : Qt::OddEvenFill;

     QPainter painter(this);
     painter.drawPolygon( polygon.constData() + index, pointCount, fillRule);

### void QPainter::drawPolyline ( const QPolygon & polygon, int index, int count = -1 )

This is an overloaded function.

Draws the polyline defined by the count lines of the given polygon starting at index (index defaults to 0).

Use drawPolyline() combined with QPolygon::constData() instead.

For example, if you have code like

     QPainter painter(this);
     painter.drawPolyline(polygon, index, count);

you can rewrite it as

     int pointCount = (count == -1) ?  polygon.size() - index : count;

     QPainter painter(this);
     painter.drawPolyline(polygon.constData() + index, pointCount);

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

Use drawText() combined with QString::mid() instead.

For example, if you have code like

     QPainter painter(this);
     painter.drawText(x, y, text, pos, length);

you can rewrite it as

     QPainter painter(this);
     painter.drawText(x, y, text.mid(pos, length));

### void QPainter::drawText ( const QPoint & point, const QString & text, int pos, int length )

Use drawText() combined with QString::mid() instead.

For example, if you have code like

     QPainter painter(this);
     painter.drawText(point, text, pos, length);

you can rewrite it as

     QPainter painter(this);
     painter.drawText(point, text.mid(pos, length));

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

Use drawText() combined with QString::left() instead.

For example, if you have code like

     QPainter painter(this);
     painter.drawText(x, y, text, length);

you can rewrite it as

     QPainter painter(this);
     painter.drawText(x, y, text.left(length));

### void QPainter::drawText ( const QPoint & point, const QString & text, int length )

Use drawText() combined with QString::left() instead.

For example, if you have code like

     QPainter painter(this);
     painter.drawText(point, text, length);

you can rewrite it as

     QPainter painter(this);
     painter.drawText(point, text.left(length));

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

Use drawText() combined with QString::left() instead.

For example, if you have code like

     QPainter painter(this);
     painter.drawText(rectangle, flags, text, length, br );

you can rewrite it as

     QPainter painter(this);
     painter.drawText(rectangle, flags, text.left(length), br );

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

Use drawText() combined with QString::left() instead.

For example, if you have code like

     QPainter painter(this);
     painter.drawText(x, y, width, height, flags, text, length, br );

you can rewrite it as

     QPainter painter(this);
     painter.drawText(x, y, width, height, flags, text.left(length), br );

### bool QPainter::hasViewXForm () const

Use viewTransformEnabled() instead.

### bool QPainter::hasWorldXForm () const

Use worldMatrixEnabled() instead.

### void QPainter::redirect ( QPaintDevice * pdev, QPaintDevice * replacement )`[static]`

Use setRedirected() instead.

### QPaintDevice * QPainter::redirect ( QPaintDevice * pdev )`[static]`

Use redirected() instead.

### void QPainter::resetXForm ()

Use resetTransform() instead.

### void QPainter::setBackgroundColor ( const QColor & color )

Use setBackground() instead.

See also backgroundColor().

### void QPainter::setViewXForm ( bool enabled )

Use setViewTransformEnabled() instead.

See also hasViewXForm().

### void QPainter::setWorldXForm ( bool enabled )

Use setWorldMatrixEnabled() instead.

See also hasWorldXForm().

### qreal QPainter::translationX () const

Use the worldTransform() combined with QTransform::dx() instead.

For example, if you have code like

     QPainter painter(this);
     qreal x = painter.translationX();

you can rewrite it as

     QPainter painter(this);
     qreal x = painter.worldTransform().dx();

### qreal QPainter::translationY () const

Use the worldTransform() combined with QTransform::dy() instead.

For example, if you have code like

     QPainter painter(this);
     qreal y = painter.translationY();

you can rewrite it as

     QPainter painter(this);
     qreal y = painter.worldTransform().dy();

### QPoint QPainter::xForm ( const QPoint & point ) const

Use combinedTransform() instead.

### QRect QPainter::xForm ( const QRect & rectangle ) const

This is an overloaded function.

Use combinedTransform() instead of this function and call mapRect() on the result to obtain a QRect.

### QPolygon QPainter::xForm ( const QPolygon & polygon ) const

This is an overloaded function.

Use combinedTransform() instead.

### QPolygon QPainter::xForm ( const QPolygon & polygon, int index, int count ) const

This is an overloaded function.

Use combinedTransform() combined with QPolygon::mid() instead.

For example, if you have code like

     QPainter painter(this);
     QPolygon transformed = painter.xForm(polygon, index, count)

you can rewrite it as

     QPainter painter(this);
     QPolygon transformed = polygon.mid(index, count) * painter.combinedTransform();

### QPoint QPainter::xFormDev ( const QPoint & point ) const

This is an overloaded function.

Use combinedTransform() combined with QTransform::inverted() instead.

For example, if you have code like

     QPainter painter(this);
     QPoint transformed = painter.xFormDev(point);

you can rewrite it as

     QPainter painter(this);
     QPoint transformed = point * painter.combinedTransform().inverted();

### QRect QPainter::xFormDev ( const QRect & rectangle ) const

This is an overloaded function.

Use combinedTransform() combined with QTransform::inverted() instead.

For example, if you have code like

     QPainter painter(this);
     QRect transformed = painter.xFormDev(rectangle);

you can rewrite it as

     QPainter painter(this);
     QRegion region = QRegion(rectangle) * painter.combinedTransform().inverted();
     QRect transformed = region.boundingRect();

### QPolygon QPainter::xFormDev ( const QPolygon & polygon ) const

This is an overloaded function.

Use combinedTransform() combined with QTransform::inverted() instead.

For example, if you have code like

     QPainter painter(this);
     QPolygon transformed = painter.xFormDev(rectangle);

you can rewrite it as

     QPainter painter(this);
     QPolygon transformed = polygon * painter.combinedTransform().inverted();

### QPolygon QPainter::xFormDev ( const QPolygon & polygon, int index, int count ) const

This is an overloaded function.

Use combinedTransform() combined with QPolygon::mid() and QTransform::inverted() instead.

For example, if you have code like

     QPainter painter(this);
     QPolygon transformed = painter.xFormDev(polygon, index, count);

you can rewrite it as

     QPainter painter(this);
     QPolygon transformed = polygon.mid(index, count) * painter.combinedTransform().inverted();