- Qt 6.8
- Qt Charts
- C++ Classes
- QHXYModelMapper
- Qt Charts | Commercial or GPLv3

# QHXYModelMapper Class

The QHXYModelMapper class is a horizontal model mapper for line, spline, and scatter series. More...

Header: | `#include <QHXYModelMapper>`
In QML: | HXYModelMapper
Inherits: | QXYModelMapper

- List of all members, including inherited members

## Properties

columnCount : int firstColumn : int model : QAbstractItemModel* | series : QXYSeries* xRow : int yRow : int

## Public Functions

| QHXYModelMapper(QObject *parent = nullptr)
int | columnCount() const
int | firstColumn() const
QAbstractItemModel * | model() const
QXYSeries * | series() const
void | setColumnCount(int columnCount)
void | setFirstColumn(int firstColumn)
void | setModel(QAbstractItemModel *model)
void | setSeries(QXYSeries *series)
void | setXRow(int xRow)
void | setYRow(int yRow)
int | xRow() const
int | yRow() const

## Signals

void | columnCountChanged()
void | firstColumnChanged()
void | modelReplaced()
void | seriesReplaced()
void | xRowChanged()
void | yRowChanged()

## Detailed Description

Model mappers enable using a data model derived from the QAbstractItemModel class as a data source for a chart. A horizontal model mapper is used to create a connection between a line, spline, or scatter series and the data model that has X and Y rows for the coordinates and holds the data points for the XYSeries as columns. A TableModel is a natural choice for the model.

Both model and series properties can be used to manipulate the data. The model mapper keeps the series and the data model in sync.

See also QVXYModelMapper, QXYSeries, and Charts with Widgets Gallery.

## Property Documentation

### columnCount : int

This property holds the number of columns of the model that are mapped as the data for series.

The minimum and default value is -1 (the number is limited by the number of columns in the model).

Access functions:

int | columnCount() const
void | setColumnCount(int columnCount)

Notifier signal:

void | columnCountChanged()

### firstColumn : int

This property holds the column of the model that contains the data for the first point of the series.

The minimum and default value is 0.

Access functions:

int | firstColumn() const
void | setFirstColumn(int firstColumn)

Notifier signal:

void | firstColumnChanged()

### model : QAbstractItemModel*

This property holds the model that is used by the mapper.

Access functions:

QAbstractItemModel * | model() const
void | setModel(QAbstractItemModel *model)

Notifier signal:

void | modelReplaced()

### series : QXYSeries*

This property holds the series that is used by the mapper.

All the data in the series is discarded when it is set to the mapper. When a new series is specified, the old series is disconnected (but it preserves its data).

Access functions:

QXYSeries * | series() const
void | setSeries(QXYSeries *series)

Notifier signal:

void | seriesReplaced()

### xRow : int

This property holds the row of the model that contains the x-coordinates of the data points.

The default value is -1 (invalid mapping).

Access functions:

int | xRow() const
void | setXRow(int xRow)

Notifier signal:

void | xRowChanged()

### yRow : int

This property holds the row of the model that contains the y-coordinates of the data points.

The default value is -1 (invalid mapping).

Access functions:

int | yRow() const
void | setYRow(int yRow)

Notifier signal:

void | yRowChanged()

## Member Function Documentation

### `[explicit]` QHXYModelMapper::QHXYModelMapper(QObject *parent = nullptr)

Constructs a mapper object that is a child of parent.

### `[signal]` void QHXYModelMapper::columnCountChanged()

This signal is emitted when the number of columns changes.

Note: Notifier signal for property columnCount.

### `[signal]` void QHXYModelMapper::firstColumnChanged()

This signal is emitted when the first column changes.

Note: Notifier signal for property firstColumn.

### `[signal]` void QHXYModelMapper::modelReplaced()

This signal is emitted when the model that the mapper is connected to changes.

Note: Notifier signal for property model.

### `[signal]` void QHXYModelMapper::seriesReplaced()

This signal is emitted when the series that the mapper is connected to changes.

Note: Notifier signal for property series.

### `[signal]` void QHXYModelMapper::xRowChanged()

This signal is emitted when the row that contains the x-coordinates of data points changes.

Note: Notifier signal for property xRow.

### `[signal]` void QHXYModelMapper::yRowChanged()

This signal is emitted when the row that contains the y-coordinates of data points changes.

Note: Notifier signal for property yRow.