QChartView Class

The QChartView is a standalone widget that can display charts. More...

Header:	#include <QChartView>
Inherits:	QGraphicsView

• List of all members, including inherited members

Public Types

enum	RubberBand { NoRubberBand, VerticalRubberBand, HorizontalRubberBand, RectangleRubberBand }
flags	RubberBands

Public Functions

	QChartView(QChart *chart, QWidget *parent = nullptr)
	QChartView(QWidget *parent = nullptr)
virtual	~QChartView()
QChart *	chart() const
QChartView::RubberBands	rubberBand() const
void	setChart(QChart *chart)
void	setRubberBand(const QChartView::RubberBands &rubberBand)

Reimplemented Protected Functions

virtual void	mouseMoveEvent(QMouseEvent *event) override
virtual void	mousePressEvent(QMouseEvent *event) override
virtual void	mouseReleaseEvent(QMouseEvent *event) override
virtual void	resizeEvent(QResizeEvent *event) override

Detailed Description

A chart view does not require a QGraphicsScene object to work. To display a chart in an existing QGraphicsScene, the QChart or QPolarChart class should be used instead.

See also QChart and QPolarChart.

Member Type Documentation

enum QChartView::RubberBandflags QChartView::RubberBands

This enum describes the different types of rubber band effects that can be applied to the rectangular zooming area.

Constant	Value	Description
QChartView::NoRubberBand	0x0	No zooming area is specified, and therefore zooming is not enabled.
QChartView::VerticalRubberBand	0x1	The rubber band is locked to the size of the chart horizontally and can be pulled vertically to specify the zooming area.
QChartView::HorizontalRubberBand	0x2	The rubber band is locked to the size of the chart vertically and can be pulled horizontally to specify the zooming area.
QChartView::RectangleRubberBand	0x3	The rubber band is fixed to the point that was clicked and can be pulled both vertically and horizontally.

The RubberBands type is a typedef for QFlags<RubberBand>. It stores an OR combination of RubberBand values.

Member Function Documentation

QChartView::QChartView(QChart *chart, QWidget *parent = nullptr)

Constructs a chart view object with the parent parent to display the chart chart. The ownership of the chart is passed to the chart view.

QChartView::QChartView(QWidget *parent = nullptr)

Constructs a chart view object with the parent parent.

[virtual] QChartView::~QChartView()

Deletes the chart view object and the associated chart.

QChart *QChartView::chart() const

Returns the pointer to the associated chart.

See also setChart().

[override virtual protected] void QChartView::mouseMoveEvent(QMouseEvent *event)

Reimplements: QGraphicsView::mouseMoveEvent(QMouseEvent *event).

If the rubber band rectangle is displayed in the press event specified by event, the event data is used to update the rubber band geometry. Otherwise, the default QGraphicsView::mouseMoveEvent() implementation is called.

[override virtual protected] void QChartView::mousePressEvent(QMouseEvent *event)

Reimplements: QGraphicsView::mousePressEvent(QMouseEvent *event).

If the left mouse button is pressed and the rubber band is enabled, the event event is accepted and the rubber band is displayed on the screen. This enables the user to select the zoom area.

If some other mouse button is pressed or the rubber band is disabled, the event is passed to QGraphicsView::mousePressEvent().

[override virtual protected] void QChartView::mouseReleaseEvent(QMouseEvent *event)

Reimplements: QGraphicsView::mouseReleaseEvent(QMouseEvent *event).

If the left mouse button is released and the rubber band is enabled, the event event is accepted and the view is zoomed into the rectangle specified by the rubber band. If releasing the right mouse button triggered the event, the view is zoomed out.

[override virtual protected] void QChartView::resizeEvent(QResizeEvent *event)

Reimplements: QGraphicsView::resizeEvent(QResizeEvent *event).

Resizes and updates the chart area using the data specified by event.

QChartView::RubberBands QChartView::rubberBand() const

Returns the rubber band flags that are currently being used by the chart view.

See also setRubberBand().

void QChartView::setChart(QChart *chart)

Sets the current chart to chart. The ownership of the new chart is passed to the chart view and the ownership of the previous chart is released.

To avoid memory leaks, the previous chart must be deleted.

See also chart().

void QChartView::setRubberBand(const QChartView::RubberBands &rubberBand)

Sets the rubber band flags to rubberBand. The selected flags determine the way zooming is performed.

Note: Rubber band zooming is not supported for polar charts.

See also rubberBand().