QItemModelSurfaceDataProxy Class▲
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Header: QItemModelSurfaceDataProxy
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Since: QtDataVisualization 1.0
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CMake:
find_package(Qt6 REQUIRED COMPONENTS DataVisualization)
target_link_libraries(mytarget PRIVATE Qt6::DataVisualization)
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qmake: QT += datavisualization
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Inherited By:
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Instantiated By: qml-qtdatavisualization-itemmodelsurfacedataproxy.xml
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Inherits: QSurfaceDataProxy
Detailed Description▲
QItemModelSurfaceDataProxy allows you to use QAbstractItemModel derived models as a data source for Q3DSurface. It uses the defined mappings to map data from the model to rows, columns, and surface points of Q3DSurface graph.
Data is resolved asynchronously whenever the mapping or the model changes. QSurfaceDataProxy::arrayReset() is emitted when the data has been resolved. However, when useModelCategories property is set to true, single item changes are resolved synchronously, unless the same frame also contains a change that causes the whole model to be resolved.
Mappings can be used in the following ways:
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If useModelCategories property is set to true, this proxy will map rows and columns of QAbstractItemModel to rows and columns of Q3DSurface, and uses the value returned for Qt::DisplayRole as Y-position by default. Row and column headers are used for Z-position and X-position by default, if they can be converted to floats. Otherwise row and column indices are used. The Y-position role to be used can be redefined if Qt::DisplayRole is not suitable. The Z-position and X-position roles to be used can be redefined if the headers or indices are not suitable.
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For models that do not have data already neatly sorted into rows and columns, such as QAbstractListModel based models, you can define a role from the model to map for each of row, column and Y-position.
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If you do not want to include all data contained in the model, or the autogenerated rows and columns are not ordered as you wish, you can specify which rows and columns should be included and in which order by defining an explicit list of categories for either or both of rows and columns.
For example, assume that you have a custom QAbstractItemModel storing surface topography data. Each item in the model has the roles "longitude", "latitude", and "height". The item model already contains the data properly sorted so that longitudes and latitudes are first encountered in correct order, which enables us to utilize the row and column category autogeneration. You could do the following to display the data in a surface graph:
QItemModelSurfaceDataProxy *proxy = new QItemModelSurfaceDataProxy(customModel,
QStringLiteral("longitude"), // Row role
QStringLiteral("latitude"), // Column role
QStringLiteral("height")); // Y-position roleIf the fields of the model do not contain the data in the exact format you need, you can specify a search pattern regular expression and a replace rule for each role to get the value in a format you need. For more information how the replace using regular expressions works, see QString::replace(const QRegularExpression &rx, const QString &after) function documentation. Note that using regular expressions has an impact on the performance, so it's more efficient to utilize item models where doing search and replace is not necessary to get the desired values.
For example about using the search patterns in conjunction with the roles, see ItemModelBarDataProxy usage in Qt Quick 2 Bars Example.
See Also▲
See also Qt Data Visualization Data Handling
Member Type Documentation▲
enum QItemModelSurfaceDataProxy::MultiMatchBehavior▲
Behavior types for QItemModelSurfaceDataProxy::multiMatchBehavior property.
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Constant |
Value |
Description |
|---|---|---|
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QItemModelSurfaceDataProxy::MMBFirst |
0 |
The position values are taken from the first item in the item model that matches each row/column combination. |
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QItemModelSurfaceDataProxy::MMBLast |
1 |
The position values are taken from the last item in the item model that matches each row/column combination. |
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QItemModelSurfaceDataProxy::MMBAverage |
2 |
The position values from all items matching each row/column combination are averaged together and the averages are used as the surface point position. |
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QItemModelSurfaceDataProxy::MMBCumulativeY |
3 |
For X and Z values this acts just like MMBAverage, but Y values are added together instead of averaged and the total is used as the surface point Y position. |
Property Documentation▲
autoColumnCategories : bool▲
This property holds whether column categories are generated automatically.
When set to true, the mapping ignores any explicitly set column categories and overwrites them with automatically generated ones whenever the data from the model is resolved. Defaults to true.
Access functions:
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bool autoColumnCategories() const
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void setAutoColumnCategories(bool enable)
Notifier signal:
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void autoColumnCategoriesChanged(bool enable)
autoRowCategories : bool▲
This property holds whether row categories are generated automatically.
When set to true, the mapping ignores any explicitly set row categories and overwrites them with automatically generated ones whenever the data from the model is resolved. Defaults to true.
Access functions:
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bool autoRowCategories() const
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void setAutoRowCategories(bool enable)
Notifier signal:
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void autoRowCategoriesChanged(bool enable)
columnCategories : QStringList▲
This property holds the column categories for the mapping.
Access functions:
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columnCategories() const
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void setColumnCategories(const &categories)
Notifier signal:
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void columnCategoriesChanged()
columnRole : QString▲
This property holds the item model role to map to the column category.
In addition to defining which column the data belongs to, the value indicated by the column role is also set as the X-coordinate value of QSurfaceDataItem when model data is resolved, unless a separate x position role is also defined.
Access functions:
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columnRole() const
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void setColumnRole(const &role)
Notifier signal:
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void columnRoleChanged(const &role)
columnRolePattern : QRegularExpression▲
This property holds whether a search and replace is done on the value mapped by the column role before it is used as a column category.
This property specifies the regular expression to find the portion of the mapped value to replace and the columnRoleReplace property contains the replacement string.
Access functions:
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columnRolePattern() const
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void setColumnRolePattern(const &pattern)
Notifier signal:
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void columnRolePatternChanged(const &pattern)
See Also▲
See also columnRole, columnRoleReplace
columnRoleReplace : QString▲
This property holds the replace content to be used in conjunction with a column role pattern.
Defaults to an empty string. For more information on how the search and replace using regular expressions works, see the QString::replace(const QRegularExpression &rx, const QString &after) function documentation.
Access functions:
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columnRoleReplace() const
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void setColumnRoleReplace(const &replace)
Notifier signal:
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void columnRoleReplaceChanged(const &replace)
See Also▲
See also columnRole, columnRolePattern
itemModel : QAbstractItemModel*▲
This property holds the item model used as a data source for the 3D surface.
Access functions:
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*itemModel() const
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void setItemModel( *itemModel)
Notifier signal:
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void itemModelChanged(const *itemModel)
multiMatchBehavior : MultiMatchBehavior▲
How multiple matches for each row/column combination are handled.
Defaults to MMBLast.
For example, you might have an item model with timestamped data taken at irregular intervals and you want to visualize an average position of data items on each hour with a surface graph. This can be done by specifying row and column categories so that each surface point represents an hour, and setting this property to MMBAverage.
Access functions:
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multiMatchBehavior() const
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void setMultiMatchBehavior( behavior)
Notifier signal:
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void multiMatchBehaviorChanged( behavior)
rowCategories : QStringList▲
This property holds the row categories for the mapping.
Access functions:
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rowCategories() const
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void setRowCategories(const &categories)
Notifier signal:
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void rowCategoriesChanged()
rowRole : QString▲
This property holds the item model role to map to the row category.
In addition to defining which row the data belongs to, the value indicated by the row role is also set as the Z-coordinate value of QSurfaceDataItem when model data is resolved, unless a separate z position role is also defined.
Access functions:
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rowRole() const
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void setRowRole(const &role)
Notifier signal:
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void rowRoleChanged(const &role)
rowRolePattern : QRegularExpression▲
This property holds whether a search and replace is performed on the value mapped by the row role before it is used as a row category.
This property specifies the regular expression to find the portion of the mapped value to replace and the rowRoleReplace property contains the replacement string.
Access functions:
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rowRolePattern() const
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void setRowRolePattern(const &pattern)
Notifier signal:
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void rowRolePatternChanged(const &pattern)
See Also▲
See also rowRole, rowRoleReplace
rowRoleReplace : QString▲
This property holds the replace content to be used in conjunction with the row role pattern.
Defaults to an empty string. For more information on how the search and replace using regular expressions works, see QString::replace(const QRegularExpression &rx, const QString &after) function documentation.
Access functions:
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rowRoleReplace() const
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void setRowRoleReplace(const &replace)
Notifier signal:
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void rowRoleReplaceChanged(const &replace)
See Also▲
See also rowRole, rowRolePattern
useModelCategories : bool▲
This property holds whether row and column roles and categories are used for mapping.
When set to true, the mapping ignores row and column roles and categories, and uses the rows and columns from the model instead. Defaults to false.
Access functions:
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bool useModelCategories() const
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void setUseModelCategories(bool enable)
Notifier signal:
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void useModelCategoriesChanged(bool enable)
xPosRole : QString▲
This property holds the item model role to map to the X position.
If this role is not defined, columnRole is used to determine the X-coordinate value of the resolved QSurfaceDataItem objects.
Access functions:
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xPosRole() const
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void setXPosRole(const &role)
Notifier signal:
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void xPosRoleChanged(const &role)
xPosRolePattern : QRegularExpression▲
This property holds whether a search and replace is done on the value mapped by the x position role before it is used as an item position value.
This property specifies the regular expression to find the portion of the mapped value to replace and the xPosRoleReplace property contains the replacement string.
Access functions:
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xPosRolePattern() const
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void setXPosRolePattern(const &pattern)
Notifier signal:
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void xPosRolePatternChanged(const &pattern)
See Also▲
See also xPosRole, xPosRoleReplace
xPosRoleReplace : QString▲
This property holds the replace content to be used in conjunction with an x position role pattern.
Defaults to an empty string. For more information on how the search and replace using regular expressions works, see the QString::replace(const QRegularExpression &rx, const QString &after) function documentation.
Access functions:
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xPosRoleReplace() const
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void setXPosRoleReplace(const &replace)
Notifier signal:
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void xPosRoleReplaceChanged(const &replace)
See Also▲
See also xPosRole, xPosRolePattern
yPosRole : QString▲
This property holds the item model role to map to the Y position.
Access functions:
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yPosRole() const
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void setYPosRole(const &role)
Notifier signal:
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void yPosRoleChanged(const &role)
yPosRolePattern : QRegularExpression▲
This property holds whether a search and replace is done on the value mapped by the y position role before it is used as an item position value.
This property specifies the regular expression to find the portion of the mapped value to replace and the yPosRoleReplace property contains the replacement string.
Access functions:
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yPosRolePattern() const
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void setYPosRolePattern(const &pattern)
Notifier signal:
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void yPosRolePatternChanged(const &pattern)
See Also▲
See also yPosRole, yPosRoleReplace
yPosRoleReplace : QString▲
This property holds the replace content to be used in conjunction with an y position role pattern.
Defaults to an empty string. For more information on how the search and replace using regular expressions works, see the QString::replace(const QRegularExpression &rx, const QString &after) function documentation.
Access functions:
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yPosRoleReplace() const
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void setYPosRoleReplace(const &replace)
Notifier signal:
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void yPosRoleReplaceChanged(const &replace)
See Also▲
See also yPosRole, yPosRolePattern
zPosRole : QString▲
This property holds the item model role to map to the Z position.
If this role is not defined, rowRole is used to determine the Z-coordinate value of resolved QSurfaceDataItem objects.
Access functions:
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zPosRole() const
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void setZPosRole(const &role)
Notifier signal:
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void zPosRoleChanged(const &role)
zPosRolePattern : QRegularExpression▲
This property holds whether a search and replace is done on the value mapped by the z position role before it is used as an item position value.
This property specifies the regular expression to find the portion of the mapped value to replace and the zPosRoleReplace property contains the replacement string.
Access functions:
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zPosRolePattern() const
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void setZPosRolePattern(const &pattern)
Notifier signal:
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void zPosRolePatternChanged(const &pattern)
See Also▲
See also zPosRole, zPosRoleReplace
zPosRoleReplace : QString▲
This property holds the replace content to be used in conjunction with a z position role pattern.
Defaults to an empty string. For more information on how the search and replace using regular expressions works, see the QString::replace(const QRegularExpression &rx, const QString &after) function documentation.
Access functions:
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zPosRoleReplace() const
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void setZPosRoleReplace(const &replace)
Notifier signal:
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void zPosRoleReplaceChanged(const &replace)
See Also▲
See also zPosRole, zPosRolePattern
Member Function Documentation▲
[explicit] QItemModelSurfaceDataProxy::QItemModelSurfaceDataProxy(QObject *parent = nullptr)▲
Constructs QItemModelSurfaceDataProxy with optional parent.
[explicit] QItemModelSurfaceDataProxy::QItemModelSurfaceDataProxy(QAbstractItemModel *itemModel, QObject *parent = nullptr)▲
Constructs QItemModelSurfaceDataProxy with itemModel and optional parent. Proxy doesn't take ownership of the itemModel, as typically item models are owned by other controls.
[explicit] QItemModelSurfaceDataProxy::QItemModelSurfaceDataProxy(QAbstractItemModel *itemModel, const QString &yPosRole, QObject *parent = nullptr)▲
Constructs QItemModelSurfaceDataProxy with itemModel and optional parent. Proxy doesn't take ownership of the itemModel, as typically item models are owned by other controls. The yPosRole role is set to yPosRole. This constructor is meant to be used with models that have data properly sorted in rows and columns already, so it also sets useModelCategories property to true.
[explicit] QItemModelSurfaceDataProxy::QItemModelSurfaceDataProxy(QAbstractItemModel *itemModel, const QString &rowRole, const QString &columnRole, const QString &yPosRole, QObject *parent = nullptr)▲
Constructs QItemModelSurfaceDataProxy with itemModel and optional parent. Proxy doesn't take ownership of the itemModel, as typically item models are owned by other controls. The role mappings are set with rowRole, columnRole, and yPosRole. The zPosRole and the xPosRole are set to rowRole and columnRole, respectively.
[explicit] QItemModelSurfaceDataProxy::QItemModelSurfaceDataProxy(QAbstractItemModel *itemModel, const QString &rowRole, const QString &columnRole, const QString &xPosRole, const QString &yPosRole, const QString &zPosRole, QObject *parent = nullptr)▲
Constructs QItemModelSurfaceDataProxy with itemModel and optional parent. Proxy doesn't take ownership of the itemModel, as typically item models are owned by other controls. The role mappings are set with rowRole, columnRole, xPosRole, yPosRole, and zPosRole.
[explicit] QItemModelSurfaceDataProxy::QItemModelSurfaceDataProxy(QAbstractItemModel *itemModel, const QString &rowRole, const QString &columnRole, const QString &yPosRole, const QStringList &rowCategories, const QStringList &columnCategories, QObject *parent = nullptr)▲
Constructs QItemModelSurfaceDataProxy with itemModel and optional parent. Proxy doesn't take ownership of the itemModel, as typically item models are owned by other controls. The role mappings are set with rowRole, columnRole, and yPosRole. The zPosRole and the xPosRole are set to rowRole and columnRole, respectively. Row and column categories are set with rowCategories and columnCategories. This constructor also sets autoRowCategories and autoColumnCategories to false.
[explicit] QItemModelSurfaceDataProxy::QItemModelSurfaceDataProxy(QAbstractItemModel *itemModel, const QString &rowRole, const QString &columnRole, const QString &xPosRole, const QString &yPosRole, const QString &zPosRole, const QStringList &rowCategories, const QStringList &columnCategories, QObject *parent = nullptr)▲
Constructs QItemModelSurfaceDataProxy with itemModel and optional parent. Proxy doesn't take ownership of the itemModel, as typically item models are owned by other controls. The role mappings are set with rowRole, columnRole, xPosRole, yPosRole, and zPosRole. Row and column categories are set with rowCategories and columnCategories. This constructor also sets autoRowCategories and autoColumnCategories to false.
[virtual] QItemModelSurfaceDataProxy::~QItemModelSurfaceDataProxy()▲
Destroys QItemModelSurfaceDataProxy.
int QItemModelSurfaceDataProxy::columnCategoryIndex(const QString &category)▲
Returns the index of the specified category in the column categories list. If the category is not found, -1 is returned.
If the automatic column categories generation is in use, this method will not return a valid index before the data in the model is resolved for the first time.
void QItemModelSurfaceDataProxy::remap(const QString &rowRole, const QString &columnRole, const QString &xPosRole, const QString &yPosRole, const QString &zPosRole, const QStringList &rowCategories, const QStringList &columnCategories)▲
Changes rowRole, columnRole, xPosRole, yPosRole, zPosRole, rowCategories and columnCategories to the mapping.
int QItemModelSurfaceDataProxy::rowCategoryIndex(const QString &category)▲
Returns the index of the specified category in the row categories list. If the row categories list is empty, -1 is returned.
If the automatic row categories generation is in use, this method will not return a valid index before the data in the model is resolved for the first time.