- Qt 6.9
- Qt Data Visualization
- C++ Classes
- QBarDataProxy
- Qt Data Visualization | Commercial or GPLv3

# QBarDataProxy Class

The QBarDataProxy class is the data proxy for a 3D bars graph. More...

Header: | `#include <QBarDataProxy>`
CMake: | `find_package(Qt6 REQUIRED COMPONENTS DataVisualization)` `target_link_libraries(mytarget PRIVATE Qt6::DataVisualization)`
qmake: | `QT += datavisualization`
Since: | QtDataVisualization 1.0
In QML: | BarDataProxy
Inherits: | QAbstractDataProxy
Inherited By: | QItemModelBarDataProxy

- List of all members, including inherited members

## Properties

- columnLabels : QStringList
- rowCount : const int
- rowLabels : QStringList
- series : QBar3DSeries* const

## Public Functions

| QBarDataProxy(QObject *parent = nullptr)
virtual | ~QBarDataProxy()
int | addRow(QBarDataRow *row)
int | addRow(QBarDataRow *row, const QString &label)
int | addRows(const QBarDataArray &rows)
int | addRows(const QBarDataArray &rows, const QStringList &labels)
const QBarDataArray * | array() const
QStringList | columnLabels() const
void | insertRow(int rowIndex, QBarDataRow *row)
void | insertRow(int rowIndex, QBarDataRow *row, const QString &label)
void | insertRows(int rowIndex, const QBarDataArray &rows)
void | insertRows(int rowIndex, const QBarDataArray &rows, const QStringList &labels)
const QBarDataItem * | itemAt(const QPoint &position) const
const QBarDataItem * | itemAt(int rowIndex, int columnIndex) const
void | removeRows(int rowIndex, int removeCount, bool removeLabels = true)
void | resetArray()
void | resetArray(QBarDataArray *newArray)
void | resetArray(QBarDataArray *newArray, const QStringList &rowLabels, const QStringList &columnLabels)
const QBarDataRow * | rowAt(int rowIndex) const
int | rowCount() const
QStringList | rowLabels() const
QBar3DSeries * | series() const
void | setColumnLabels(const QStringList &labels)
void | setItem(const QPoint &position, const QBarDataItem &item)
void | setItem(int rowIndex, int columnIndex, const QBarDataItem &item)
void | setRow(int rowIndex, QBarDataRow *row)
void | setRow(int rowIndex, QBarDataRow *row, const QString &label)
void | setRowLabels(const QStringList &labels)
void | setRows(int rowIndex, const QBarDataArray &rows)
void | setRows(int rowIndex, const QBarDataArray &rows, const QStringList &labels)

## Signals

void | arrayReset()
void | columnLabelsChanged()
void | itemChanged(int rowIndex, int columnIndex)
void | rowCountChanged(int count)
void | rowLabelsChanged()
void | rowsAdded(int startIndex, int count)
void | rowsChanged(int startIndex, int count)
void | rowsInserted(int startIndex, int count)
void | rowsRemoved(int startIndex, int count)
void | seriesChanged(QBar3DSeries *series)

## Related Non-Members

| QBarDataArray
| QBarDataRow

## Detailed Description

A bar data proxy handles adding, inserting, changing, and removing rows of data.

The data array is a list of vectors (rows) of QBarDataItem instances. Each row can contain a different number of items or even be null.

QBarDataProxy takes ownership of all QtDataVisualization::QBarDataRow objects passed to it, whether directly or in a QtDataVisualization::QBarDataArray container. If bar data row pointers are used to directly modify data after adding the array to the proxy, the appropriate signal must be emitted to update the graph.

QBarDataProxy optionally keeps track of row and column labels, which QCategory3DAxis can utilize to show axis labels. The row and column labels are stored in a separate array from the data and row manipulation methods provide alternate versions that do not affect the row labels. This enables the option of having row labels that relate to the position of the data in the array rather than the data itself.

See also Qt Data Visualization Data Handling.

## Property Documentation

### columnLabels : QStringList

This property holds the optional column labels for the array.

Indexes in this array match column indexes in rows. If the list is shorter than the longest row, all columns will not get labels.

Access functions:

QStringList | columnLabels() const
void | setColumnLabels(const QStringList &labels)

Notifier signal:

void | columnLabelsChanged()

### `[read-only]` rowCount : const int

This property holds the number of rows in the array.

Access functions:

int | rowCount() const

Notifier signal:

void | rowCountChanged(int count)

### rowLabels : QStringList

This property holds the optional row labels for the array.

Indexes in this array match the row indexes in the data array. If the list is shorter than the number of rows, all rows will not get labels.

Access functions:

QStringList | rowLabels() const
void | setRowLabels(const QStringList &labels)

Notifier signal:

void | rowLabelsChanged()

### `[read-only]` series : QBar3DSeries* const

This property holds the series this proxy is attached to.

Access functions:

QBar3DSeries * | series() const

Notifier signal:

void | seriesChanged(QBar3DSeries *series)

## Member Function Documentation

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

Constructs a bar data proxy with the given parent.

### `[virtual noexcept]` QBarDataProxy::~QBarDataProxy()

Deletes the bar data proxy.

### int QBarDataProxy::addRow(QBarDataRow *row)

Adds the new row row to the end of an array. Existing row labels are not affected.

Returns the index of the added row.

### int QBarDataProxy::addRow(QBarDataRow *row, const QString &label)

Adds a the new row row with the label label to the end of an array.

Returns the index of the added row.

### int QBarDataProxy::addRows(const QBarDataArray &rows)

Adds the new rows to the end of an array. Existing row labels are not affected.

Returns the index of the first added row.

### int QBarDataProxy::addRows(const QBarDataArray &rows, const QStringList &labels)

Adds the new rows with labels to the end of the array.

Returns the index of the first added row.

### const QBarDataArray *QBarDataProxy::array() const

Returns the pointer to the data array.

### `[signal]` void QBarDataProxy::arrayReset()

This signal is emitted when the data array is reset. If the contents of the whole array are changed without calling resetArray(), this signal needs to be emitted to update the graph.

### void QBarDataProxy::insertRow(int rowIndex, QBarDataRow *row)

Inserts the new row row into rowIndex. If rowIndex is equal to the array size, the rows are added to the end of the array. The existing row labels are not affected.

Note: The row labels array will be out of sync with the row array after this call if there were labeled rows beyond the inserted row.

### void QBarDataProxy::insertRow(int rowIndex, QBarDataRow *row, const QString &label)

Inserts the new row row with the label label into rowIndex. If rowIndex is equal to array size, rows are added to the end of the array.

### void QBarDataProxy::insertRows(int rowIndex, const QBarDataArray &rows)

Inserts new rows into rowIndex. If rowIndex is equal to the array size, the rows are added to the end of the array. The existing row labels are not affected.

Note: The row labels array will be out of sync with the row array after this call if there were labeled rows beyond the inserted rows.

### void QBarDataProxy::insertRows(int rowIndex, const QBarDataArray &rows, const QStringList &labels)

Inserts new rows with labels into rowIndex. If rowIndex is equal to the array size, the rows are added to the end of the array.

### const QBarDataItem *QBarDataProxy::itemAt(const QPoint &position) const

Returns the pointer to the item at the position position. The x-value of position indicates the row and the y-value indicates the column. The item is guaranteed to be valid only until the next call that modifies data.

### const QBarDataItem *QBarDataProxy::itemAt(int rowIndex, int columnIndex) const

Returns the pointer to the item at the position specified by rowIndex and columnIndex. It is guaranteed to be valid only until the next call that modifies data.

### `[signal]` void QBarDataProxy::itemChanged(int rowIndex, int columnIndex)

This signal is emitted when the item at the position specified by rowIndex and columnIndex changes. If the item is changed in the array without calling setItem(), this signal needs to be emitted to update the graph.

### void QBarDataProxy::removeRows(int rowIndex, int removeCount, bool removeLabels = true)

Removes the number of rows specified by removeCount starting at the position rowIndex. Attempting to remove rows past the end of the array does nothing. If removeLabels is `true`, the corresponding row labels are also removed. Otherwise, the row labels are not affected.

Note: If removeLabels is `false`, the row labels array will be out of sync with the row array if there are labeled rows beyond the removed rows.

### void QBarDataProxy::resetArray()

Clears the existing array and row and column labels.

### void QBarDataProxy::resetArray(QBarDataArray *newArray)

Takes ownership of the array newArray. Clears the existing array if the new array differs from it. If the arrays are the same, this function just triggers the arrayReset() signal.

Passing a null array deletes the old array and creates a new empty array. Row and column labels are not affected.

### void QBarDataProxy::resetArray(QBarDataArray *newArray, const QStringList &rowLabels, const QStringList &columnLabels)

Takes ownership of the array newArray. Clears the existing array if the new array differs from it. If the arrays are the same, this function just triggers the arrayReset() signal.

Passing a null array deletes the old array and creates a new empty array.

The rowLabels and columnLabels lists specify the new labels for rows and columns.

### const QBarDataRow *QBarDataProxy::rowAt(int rowIndex) const

Returns the pointer to the row at the position rowIndex. It is guaranteed to be valid only until the next call that modifies data.

### `[signal]` void QBarDataProxy::rowsAdded(int startIndex, int count)

This signal is emitted when the number of rows specified by count is added starting at the position startIndex. If rows are added to the array without calling addRow() or addRows(), this signal needs to be emitted to update the graph.

### `[signal]` void QBarDataProxy::rowsChanged(int startIndex, int count)

This signal is emitted when the number of rows specified by count is changed starting at the position startIndex. If rows are changed in the array without calling setRow() or setRows(), this signal needs to be emitted to update the graph.

### `[signal]` void QBarDataProxy::rowsInserted(int startIndex, int count)

This signal is emitted when the number of rows specified by count is inserted at the position startIndex.

If rows are inserted into the array without calling insertRow() or insertRows(), this signal needs to be emitted to update the graph.

### `[signal]` void QBarDataProxy::rowsRemoved(int startIndex, int count)

This signal is emitted when the number of rows specified by count is removed starting at the position startIndex.

The index is the current array size if the rows were removed from the end of the array. If rows are removed from the array without calling removeRows(), this signal needs to be emitted to update the graph.

### void QBarDataProxy::setItem(const QPoint &position, const QBarDataItem &item)

Changes a single item at the position position to the item item. The x-value of position indicates the row and the y-value indicates the column.

### void QBarDataProxy::setItem(int rowIndex, int columnIndex, const QBarDataItem &item)

Changes a single item at the position specified by rowIndex and columnIndex to the item item.

### void QBarDataProxy::setRow(int rowIndex, QBarDataRow *row)

Changes an existing row by replacing the row at the position rowIndex with the new row specified by row. The new row can be the same as the existing row already stored at rowIndex. Existing row labels are not affected.

### void QBarDataProxy::setRow(int rowIndex, QBarDataRow *row, const QString &label)

Changes an existing row by replacing the row at the position rowIndex with the new row specified by row. The new row can be the same as the existing row already stored at rowIndex. Changes the row label to label.

### void QBarDataProxy::setRows(int rowIndex, const QBarDataArray &rows)

Changes existing rows by replacing the rows starting at the position rowIndex with the new rows specifies by rows. Existing row labels are not affected. The rows in the rows array can be the same as the existing rows already stored at rowIndex.

### void QBarDataProxy::setRows(int rowIndex, const QBarDataArray &rows, const QStringList &labels)

Changes existing rows by replacing the rows starting at the position rowIndex with the new rows specifies by rows. The row labels are changed to labels. The rows in the rows array can be the same as the existing rows already stored at rowIndex.

## Related Non-Members

### QBarDataArray

A list of pointers to QBarDataRow objects.

### QBarDataRow

A list of QBarDataItem objects.