QGraphicsView

mapFromScene

public final QPoint mapFromScene(QPointF point)

Returns the scene coordinate point to viewport coordinates.

See also:

mapFromScene

public final QPolygon mapFromScene(QPolygonF polygon)

Returns the scene coordinate polygon polygon to a viewport coordinate polygon.

See also:

mapFromScene

public final QPolygon mapFromScene(QRectF rect)

Returns the scene rectangle rect to a viewport coordinate polygon.

See also:

mapFromScene

public final QPoint mapFromScene(double x,
                                 double y)

This function is provided for convenience. It's equivalent to calling mapFromScene(QPointF(x, y)).

mapFromScene

public final QPolygon mapFromScene(double x,
                                   double y,
                                   double w,
                                   double h)

This function is provided for convenience. It's equivalent to calling mapFromScene(QRectF(x, y, w, h)).

mapToScene

public final QPainterPath mapToScene(QPainterPath path)

Returns the viewport painter path path mapped to a scene coordinate painter path.

See also:

mapToScene

public final QPointF mapToScene(QPoint point)

Returns the viewport coordinate point mapped to scene coordinates.

Note: It can be useful to map the whole rectangle covered by the pixel at point instead of the point itself. To do this, you can call mapToScene(QRect(point, QSize(2, 2))).

See also:

mapToScene

public final QPolygonF mapToScene(QPolygon polygon)

Returns the viewport polygon polygon mapped to a scene coordinate polygon.

See also:

mapToScene

public final QPolygonF mapToScene(QRect rect)

Returns the viewport rectangle rect mapped to a scene coordinate polygon.

See also:

mapToScene

public final QPointF mapToScene(int x,
                                int y)

This function is provided for convenience. It's equivalent to calling mapToScene(QPoint(x, y)).

mapToScene

public final QPolygonF mapToScene(int x,
                                  int y,
                                  int w,
                                  int h)

This function is provided for convenience. It's equivalent to calling mapToScene(QRect(x, y, w, h)).

matrix

public final QMatrix matrix()

Returns the current transformation matrix for the view. If no current transformation is set, the identity matrix is returned.

See also:

setMatrix(), rotate(), scale(), shear(), and translate().

optimizationFlags

public final QGraphicsView.OptimizationFlags optimizationFlags()

This property holds flags that can be used to tune QGraphicsView's performance. QGraphicsView uses clipping, extra bounding rect adjustments, and certain other aids to improve rendering quality and performance for the common case graphics scene. However, depending on the target platform, the scene, and the viewport in use, some of these operations can degrade performance.

The effect varies from flag to flag; see the OptimizationFlags documentation for details.

By default, no optimization flags are enabled.

See also:

setOptimizationFlag().

render

public final void render(QPainter painter,
                         QRectF target,
                         QRect source)

Renders the source rect, which is in view coordinates, from the scene into target, which is in paint device coordinates, using painter. This function is useful for capturing the contents of the view onto a paint device, such as a QImage (e.g., to take a screenshot), or for printing to QPrinter. For example:

        QGraphicsScene scene = new QGraphicsScene();
        // scene.addItem(...

        QGraphicsView view = new QGraphicsView(scene);
        view.show();
        // ...

        QPrinter printer = new QPrinter(QPrinter.PrinterMode.HighResolution);
        printer.setPageSize(QPrinter.PageSize.A4);
        QPainter painter = new QPainter(printer);

        // print, fitting the viewport contents into a full page
        view.render(painter);

        // print the upper half of the viewport into the lower.
        // half of the page.
        QRect viewport = view.viewport().rect();
        view.render(painter,
                    new QRectF(0, printer.height() / 2, printer.width(), printer.height() / 2),
                    viewport.adjusted(0, 0, 0, -viewport.height() / 2)
        );

If source is a null rect, this function will use viewport()->rect() to determine what to draw. If target is a null rect, the full dimensions of painter's paint device (e.g., for a QPrinter, the page size) will be used.

The source rect contents will be transformed according to aspectRatioMode to fit into the target rect. By default, the aspect ratio is kept, and source is scaled to fit in target.

See also:

render

public final void render(QPainter painter,
                         QRectF target)

        QGraphicsScene scene = new QGraphicsScene();
        // scene.addItem(...

        QGraphicsView view = new QGraphicsView(scene);
        view.show();
        // ...

        QPrinter printer = new QPrinter(QPrinter.PrinterMode.HighResolution);
        printer.setPageSize(QPrinter.PageSize.A4);
        QPainter painter = new QPainter(printer);

        // print, fitting the viewport contents into a full page
        view.render(painter);

        // print the upper half of the viewport into the lower.
        // half of the page.
        QRect viewport = view.viewport().rect();
        view.render(painter,
                    new QRectF(0, printer.height() / 2, printer.width(), printer.height() / 2),
                    viewport.adjusted(0, 0, 0, -viewport.height() / 2)
        );

The source rect contents will be transformed according to aspectRatioMode to fit into the target rect. By default, the aspect ratio is kept, and source is scaled to fit in target.

See also:

render

public final void render(QPainter painter)

        QGraphicsScene scene = new QGraphicsScene();
        // scene.addItem(...

        QGraphicsView view = new QGraphicsView(scene);
        view.show();
        // ...

        QPrinter printer = new QPrinter(QPrinter.PrinterMode.HighResolution);
        printer.setPageSize(QPrinter.PageSize.A4);
        QPainter painter = new QPainter(printer);

        // print, fitting the viewport contents into a full page
        view.render(painter);

        // print the upper half of the viewport into the lower.
        // half of the page.
        QRect viewport = view.viewport().rect();
        view.render(painter,
                    new QRectF(0, printer.height() / 2, printer.width(), printer.height() / 2),
                    viewport.adjusted(0, 0, 0, -viewport.height() / 2)
        );

The source rect contents will be transformed according to aspectRatioMode to fit into the target rect. By default, the aspect ratio is kept, and source is scaled to fit in target.

See also:

render

public final void render(QPainter painter,
                         QRectF target,
                         QRect source,
                         Qt.AspectRatioMode aspectRatioMode)

        QGraphicsScene scene = new QGraphicsScene();
        // scene.addItem(...

        QGraphicsView view = new QGraphicsView(scene);
        view.show();
        // ...

        QPrinter printer = new QPrinter(QPrinter.PrinterMode.HighResolution);
        printer.setPageSize(QPrinter.PageSize.A4);
        QPainter painter = new QPainter(printer);

        // print, fitting the viewport contents into a full page
        view.render(painter);

        // print the upper half of the viewport into the lower.
        // half of the page.
        QRect viewport = view.viewport().rect();
        view.render(painter,
                    new QRectF(0, printer.height() / 2, printer.width(), printer.height() / 2),
                    viewport.adjusted(0, 0, 0, -viewport.height() / 2)
        );

The source rect contents will be transformed according to aspectRatioMode to fit into the target rect. By default, the aspect ratio is kept, and source is scaled to fit in target.

See also: