Wt: Wt::WAggregateProxyModel Class Reference

Wt 4.10.4

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Public Member Functions | List of all members
Wt::WAggregateProxyModel Class Reference
Model/view system

A proxy model for Wt's item models that provides column aggregation. More...

`#include <Wt/WAggregateProxyModel.h>`

Inheritance diagram for Wt::WAggregateProxyModel:
[legend]

## Public Member Functions
| WAggregateProxyModel ()
| Constructor.
virtual | ~WAggregateProxyModel ()
| Destructor.
void | addAggregate (int parentColumn, int firstColumn, int lastColumn)
| Adds a new column aggregation definition.
virtual WModelIndex | mapFromSource (const WModelIndex &sourceIndex) const override
| Maps a source model index to the proxy model.
virtual WModelIndex | mapToSource (const WModelIndex &proxyIndex) const override
| Maps a proxy model index to the source model.
virtual void | setSourceModel (const std::shared_ptr< WAbstractItemModel > &sourceModel) override
| Sets the source model.
virtual void | expandColumn (int column) override
| Expands a column.
virtual void | collapseColumn (int column) override
| Collapses a column.
virtual int | columnCount (const WModelIndex &parent=WModelIndex()) const override
| Returns the number of columns.
virtual int | rowCount (const WModelIndex &parent=WModelIndex()) const override
| Returns the number of rows.
virtual WFlags< HeaderFlag > | headerFlags (int section, Orientation orientation=Orientation::Horizontal) const override
| Returns the flags for a header.
virtual bool | setHeaderData (int section, Orientation orientation, const cpp17::any &value, ItemDataRole role=ItemDataRole::Edit) override
| Sets header data for a column or row.
virtual cpp17::any | headerData (int section, Orientation orientation=Orientation::Horizontal, ItemDataRole role=ItemDataRole::Display) const override
| Returns the row or column header data.
virtual WModelIndex | parent (const WModelIndex &index) const override
| Returns the parent for a model index.
virtual WModelIndex | index (int row, int column, const WModelIndex &parent=WModelIndex()) const override
| Returns the child index for the given row and column.
virtual void | sort (int column, SortOrder order=SortOrder::Ascending) override
| Sorts the model according to a particular column.
Public Member Functions inherited from Wt::WAbstractProxyModel
| WAbstractProxyModel ()
| Constructor.
std::shared_ptr< WAbstractItemModel > | sourceModel () const
| Returns the source model.
virtual cpp17::any | data (const WModelIndex &index, ItemDataRole role=ItemDataRole::Display) const override
| Returns the data at a specific model index.
virtual bool | setData (const WModelIndex &index, const cpp17::any &value, ItemDataRole role=ItemDataRole::Edit) override
| Sets the data at the given model index.
virtual bool | setItemData (const WModelIndex &index, const DataMap &values) override
| Sets the data at the given model index.
virtual WFlags< ItemFlag > | flags (const WModelIndex &index) const override
| Returns the flags for an item.
virtual bool | insertColumns (int column, int count, const WModelIndex &parent=WModelIndex()) override
| Inserts one or more columns.
virtual bool | removeColumns (int column, int count, const WModelIndex &parent=WModelIndex()) override
| Removes columns.
virtual std::string | mimeType () const override
| Returns a mime-type for dragging a set of indexes.
virtual std::vector< std::string > | acceptDropMimeTypes () const override
| Returns a list of mime-types that could be accepted for a drop event.
virtual void | dropEvent (const WDropEvent &e, DropAction action, int row, int column, const WModelIndex &parent) override
| Handles a drop event.
virtual void * | toRawIndex (const WModelIndex &index) const override
| Converts a model index to a raw pointer that remains valid while the model's layout is changed.
virtual WModelIndex | fromRawIndex (void *rawIndex) const override
| Converts a raw pointer to a model index.
bool | setData (int row, int column, const cpp17::any &value, ItemDataRole role=ItemDataRole::Edit, const WModelIndex &parent=WModelIndex())
| Sets data at the given row and column.
cpp17::any | data (int row, int column, ItemDataRole role=ItemDataRole::Display, const WModelIndex &parent=WModelIndex()) const
| Returns the data item at the given column and row.
bool | setHeaderData (int section, const cpp17::any &value)
| Sets column header data.
Public Member Functions inherited from Wt::WAbstractItemModel
| WAbstractItemModel ()
| Creates a new data model.
virtual bool | hasChildren (const WModelIndex &index) const
| Returns if there are children at an index.
virtual DataMap | itemData (const WModelIndex &index) const
| Returns all data at a specific index.
virtual WModelIndexList | match (const WModelIndex &start, ItemDataRole role, const cpp17::any &value, int hits=-1, WFlags< MatchFlag > flags=WFlags< MatchFlag >(MatchFlag::StartsWith|MatchFlag::Wrap)) const
| Returns an index list for data items that match.
cpp17::any | data (int row, int column, ItemDataRole role=ItemDataRole::Display, const WModelIndex &parent=WModelIndex()) const
| Returns the data item at the given column and row.
virtual bool | hasIndex (int row, int column, const WModelIndex &parent=WModelIndex()) const
| Returns if an index at the given position is valid (i.e. falls within the column-row bounds).
virtual bool | insertRows (int row, int count, const WModelIndex &parent=WModelIndex())
| Inserts one or more rows.
virtual bool | removeRows (int row, int count, const WModelIndex &parent=WModelIndex())
| Removes rows.
bool | setHeaderData (int section, const cpp17::any &value)
| Sets column header data.
virtual void | dropEvent (const WDropEvent &e, DropAction action, const WModelIndex &index, Wt::Side side)
| Handles a drop event.
bool | insertColumn (int column, const WModelIndex &parent=WModelIndex())
| Inserts one column.
bool | insertRow (int row, const WModelIndex &parent=WModelIndex())
| Inserts one row.
bool | removeColumn (int column, const WModelIndex &parent=WModelIndex())
| Removes one column.
bool | removeRow (int row, const WModelIndex &parent=WModelIndex())
| Removes one row.
bool | setData (int row, int column, const cpp17::any &value, ItemDataRole role=ItemDataRole::Edit, const WModelIndex &parent=WModelIndex())
| Sets data at the given row and column.
virtual Signal< WModelIndex, int, int > & | columnsAboutToBeInserted ()
| Signal emitted before a number of columns will be inserted.
virtual Signal< WModelIndex, int, int > & | columnsAboutToBeRemoved ()
| Signal emitted before a number of columns will be removed.
virtual Signal< WModelIndex, int, int > & | columnsInserted ()
| Signal emitted after a number of columns were inserted.
virtual Signal< WModelIndex, int, int > & | columnsRemoved ()
| Signal emitted after a number of columns were removed.
virtual Signal< WModelIndex, int, int > & | rowsAboutToBeInserted ()
| Signal emitted before a number of rows will be inserted.
virtual Signal< WModelIndex, int, int > & | rowsAboutToBeRemoved ()
| Signal emitted before a number of rows will be removed.
virtual Signal< WModelIndex, int, int > & | rowsInserted ()
| Signal emitted after a number of rows were inserted.
virtual Signal< WModelIndex, int, int > & | rowsRemoved ()
| Signal emitted after a number of rows were removed.
virtual Signal< WModelIndex, WModelIndex > & | dataChanged ()
| Signal emitted when some data was changed.
virtual Signal< Orientation, int, int > & | headerDataChanged ()
| Signal emitted when some header data was changed.
virtual Signal & | layoutAboutToBeChanged ()
| Signal emitted when the layout is about to be changed.
virtual Signal & | layoutChanged ()
| Signal emitted when the layout is changed.
virtual Signal & | modelReset ()
| Signal emitted when the model was reset.
Public Member Functions inherited from Wt::WObject
void | addChild (std::unique_ptr< WObject > child)
| Add a child WObject whose lifetime is determined by this WObject.
template<typename Child >
Child * | addChild (std::unique_ptr< Child > child)
| Add a child WObject, returning a raw pointer.
std::unique_ptr< WObject > | removeChild (WObject *child)
| Remove a child WObject, so its lifetime is no longer determined by this WObject.
template<typename Child >
std::unique_ptr< Child > | removeChild (Child *child)
| Remove a child WObject, so its lifetime is no longer determined by this WObject.
virtual const std::string | id () const
| Returns the (unique) identifier for this object.
virtual void | setObjectName (const std::string &name)
| Sets an object name.
virtual std::string | objectName () const
| Returns the object name.
void | resetLearnedSlots ()
| Resets learned stateless slot implementations.
template<class T >
void | resetLearnedSlot (void(T::*method)())
| Resets a learned stateless slot implementation.
template<class T >
WStatelessSlot * | implementStateless (void(T::*method)())
| Declares a slot to be stateless and learn client-side behaviour on first invocation.
template<class T >
WStatelessSlot * | implementStateless (void(T::*method)(), void(T::*undoMethod)())
| Declares a slot to be stateless and learn client-side behaviour in advance.
void | isNotStateless ()
| Marks the current function as not stateless.
template<class T >
WStatelessSlot * | implementJavaScript (void(T::*method)(), const std::string &jsCode)
| Provides a JavaScript implementation for a method.
Public Member Functions inherited from Wt::Core::observable
| observable () noexcept
| Default constructor.
virtual | ~observable ()
| Destructor.
template<typename... Args, typename C >
auto | bindSafe (void(C::*method)(Args...)) noexcept
| Protects a method call against object destruction.
template<typename... Args, typename C >
auto | bindSafe (void(C::*method)(Args...) const) const noexcept
| Protects a const method call against object destruction.
template<typename Function >
auto | bindSafe (const Function &function) noexcept
| Protects a function against object destruction.

## Additional Inherited Members
Public Types inherited from Wt::WAbstractItemModel
typedef std::map< ItemDataRole, cpp17::any > | DataMap
| Data map.
Public Types inherited from Wt::WObject
typedef void(WObject::*) | Method()
| Typedef for a WObject method without arguments.
Static Public Member Functions inherited from Wt::WObject
Protected Types inherited from Wt::WAbstractProxyModel
typedef std::map< WModelIndex, BaseItem * > | ItemMap
| A map for items.
Protected Member Functions inherited from Wt::WAbstractProxyModel
WModelIndex | createSourceIndex (int row, int column, void *ptr) const
| Create a source model index.
void | startShiftModelIndexes (const WModelIndex &sourceParent, int start, int count, ItemMap &items)
| Utility methods to shift items in an item map.
Protected Member Functions inherited from Wt::WAbstractItemModel
void | reset ()
| Resets the model and invalidate any data.
WModelIndex | createIndex (int row, int column, void *ptr) const
| Creates a model index for the given row and column.
WModelIndex | createIndex (int row, int column, ::uint64_t id) const
| Creates a model index for the given row and column.
void | beginInsertColumns (const WModelIndex &parent, int first, int last)
| Method to be called before inserting columns.
void | beginInsertRows (const WModelIndex &parent, int first, int last)
| Method to be called before inserting rows.
void | beginRemoveColumns (const WModelIndex &parent, int first, int last)
| Method to be called before removing columns.
void | beginRemoveRows (const WModelIndex &parent, int first, int last)
| Method to be called before removing rows.
void | endInsertColumns ()
| Method to be called after inserting columns.
void | endInsertRows ()
| Method to be called after inserting rows.
void | endRemoveColumns ()
| Method to be called after removing columns.
void | endRemoveRows ()
| Method to be called after removing rows.
virtual void | copyData (const WModelIndex &sIndex, const WModelIndex &dIndex)
| Copy data to an index in this model.
Protected Member Functions inherited from Wt::WObject
virtual WStatelessSlot * | getStateless (Method method)
| On-demand stateless slot implementation.

## Detailed Description

A proxy model for Wt's item models that provides column aggregation.

This proxy model does not store data itself, but presents data from a source model, and presents methods to organize columns using aggregation, through which a user may navigate (usually to obtain more detailed results related to a single aggregate quantity).

To use this proxy model, you should provide a source model using setSourceModel(), and define column ranges that can be aggregated using addAggregate().

Example:

int COLS = 18;
int ROWS = 20;
// set up the source model
model_ = std::make_shared<WStandardItemModel>(0, COLS);
std::string columns[] = {
"Supplier",
"2004",
"Q1",
"January",
"February",
"March",
"Q2",
"April",
"May",
"June",
"Q3",
"July",
"August",
"September",
"Q4",
"October",
"November",
"December"
};
for (unsigned i = 0; i < COLS; ++i) {
model_->setHeaderData(i, Orientation::Horizontal, columns[i]);
}
for (unsigned i = 0; i < ROWS; ++i) {
model_->insertRow(i);
for (unsigned j = 0; j < COLS; ++j)
model_->setData(i, j, "col " + std::to_string(j));
}
// set up the proxy model
auto proxy = std::make_shared<WAggregateProxyModel>();
proxy->setSourceModel(model_);
proxy->addAggregate(1, 2, 17);
proxy->addAggregate(2, 3, 5);
proxy->addAggregate(6, 7, 9);
proxy->addAggregate(10, 11, 13);
proxy->addAggregate(14, 15, 17);
proxy->expandColumn(1); // expand 2004 -> Q1 Q2 Q3 Q4
// define a view
treeView_ = root()->addWidget(std::make_unique<WTreeView>());
treeView_->setColumnBorder(Wt::StandardColor::Black);
treeView_->setModel(proxy);
treeView_->setColumnWidth(0, 160);
treeView_->setColumnResizeEnabled(true);
treeView_->setSortingEnabled(true);
Wt::StandardColor::Black
@ Black
Color black.
Wt::Orientation::Horizontal
@ Horizontal
Horizontal.

This example would render like this:

A WTreeView using a WAggregateProxyModel

Note
  This model does not support dynamic changes to the column definition of the source model (i.e. insertions or deletions of source model columns).

## Constructor & Destructor Documentation

## ◆ WAggregateProxyModel()

Wt::WAggregateProxyModel::WAggregateProxyModel | ( |  | ) |

Constructor.

Sets up the proxy without aggregation functionality.

## Member Function Documentation

## ◆ addAggregate()

void Wt::WAggregateProxyModel::addAggregate | ( | int | parentColumn,
|  | int | firstColumn,
|  | int | lastColumn )

Adds a new column aggregation definition.

The `parentColumn` is the column index in the source model that acts as an aggregate for columns `firstColumn` to `lastColumn`. `parentColumn` must border the range defined by `firstColumn` to `lastColumn:`

parentColumn == firstColumn - 1 || parentColumn == lastColumn + 1

Note that column parameters reference column indexes in the source model.

Aggregation definitions can be nested, but should be strictly hierarchical.

The aggregate column will initially be collapsed.

Only one aggregate can be defined per `parentColumn`.

## ◆ collapseColumn()

virtual void Wt::WAggregateProxyModel::collapseColumn | ( | int | column | ) |
| overridevirtual

Collapses a column.

Collapses a column. This may only be called by a view when the Wt::HeaderFlag::ColumnIsExpandedLeft or Wt::HeaderFlag::ColumnIsExpandedRight flag is set.

The default implementation does nothing.

See also
  WAggregateProxyModel

Reimplemented from Wt::WAbstractItemModel.

## ◆ columnCount()

virtual int Wt::WAggregateProxyModel::columnCount | ( | const WModelIndex & | parent = WModelIndex() | ) | const
| overridevirtual

Returns the number of columns.

This returns the number of columns at index `parent`.

See also
  rowCount()

Implements Wt::WAbstractItemModel.

## ◆ expandColumn()

virtual void Wt::WAggregateProxyModel::expandColumn | ( | int | column | ) |
| overridevirtual

Expands a column.

Expands a column. This may only be called by a view when the Wt::HeaderFlag::ColumnIsCollapsed flag is set.

The default implementation does nothing.

See also
  WAggregateProxyModel

Reimplemented from Wt::WAbstractItemModel.

## ◆ headerData()

virtual cpp17::any Wt::WAggregateProxyModel::headerData | ( | int | section,
|  | Orientation | orientation = Orientation::Horizontal,
|  | ItemDataRole | role = ItemDataRole::Display ) const
| overridevirtual

Returns the row or column header data.

The default proxy implementation constructs a dummy WModelIndex with the row set to 0 and column set to `section` if the orientation is Wt::Orientation::Horizontal, or with the row set to `section` and the column set to 0 if the orientation is Wt::Orientation::Vertical.

The resulting section that is forwarded to sourceModel()->headerData() depends on how the WModelIndex is transformed with mapToSource().

Reimplemented from Wt::WAbstractProxyModel.

## ◆ headerFlags()

virtual WFlags< HeaderFlag > Wt::WAggregateProxyModel::headerFlags | ( | int | section,
|  | Orientation | orientation = Orientation::Horizontal ) const
| overridevirtual

Returns the flags for a header.

The default proxy implementation constructs a dummy WModelIndex with the row set to 0 and column set to `section` if the orientation is Wt::Orientation::Horizontal, or with the row set to `section` and the column set to 0 if the orientation is Wt::Orientation::Vertical.

The resulting section that is forwarded to sourceModel()->headerFlags() depends on how the WModelIndex is transformed with mapToSource().

Reimplemented from Wt::WAbstractProxyModel.

## ◆ index()

virtual WModelIndex Wt::WAggregateProxyModel::index | ( | int | row,
|  | int | column,
|  | const WModelIndex & | parent = WModelIndex() ) const
| overridevirtual

Returns the child index for the given row and column.

When implementing this method, you can use createIndex() to create an index that corresponds to the item at `row` and `column` within `parent`.

If the location is invalid (out of bounds at the parent), then an invalid index must be returned.

See also
  parent()

Implements Wt::WAbstractItemModel.

## ◆ mapFromSource()

virtual WModelIndex Wt::WAggregateProxyModel::mapFromSource | ( | const WModelIndex & | sourceIndex | ) | const
| overridevirtual

Maps a source model index to the proxy model.

This method returns a model index in the proxy model that corresponds to the model index `sourceIndex` in the source model. This method must only be implemented for source model indexes that are mapped and thus are the result of mapToSource().

See also
  mapToSource()

Implements Wt::WAbstractProxyModel.

## ◆ mapToSource()

virtual WModelIndex Wt::WAggregateProxyModel::mapToSource | ( | const WModelIndex & | proxyIndex | ) | const
| overridevirtual

Maps a proxy model index to the source model.

This method returns a model index in the source model that corresponds to the proxy model index `proxyIndex`.

See also
  mapFromSource()

Implements Wt::WAbstractProxyModel.

## ◆ parent()

virtual WModelIndex Wt::WAggregateProxyModel::parent | ( | const WModelIndex & | index | ) | const
| overridevirtual

Returns the parent for a model index.

An implementation should use createIndex() to create a model index that corresponds to the parent of a given index.

Note that the index itself may be stale (referencing a row/column within the parent that is outside the model geometry), but its parent (identified by the WModelIndex::internalPointer()) is referencing an existing parent. A stale index can only be used while the model geometry is being updated, i.e. during the emission of the corresponding [rows/columns](Being)[Removed/Inserted]() signals.

See also
  index()

Implements Wt::WAbstractItemModel.

## ◆ rowCount()

virtual int Wt::WAggregateProxyModel::rowCount | ( | const WModelIndex & | parent = WModelIndex() | ) | const
| overridevirtual

Returns the number of rows.

This returns the number of rows at index `parent`.

See also
  columnCount()

Implements Wt::WAbstractItemModel.

## ◆ setHeaderData()

virtual bool Wt::WAggregateProxyModel::setHeaderData | ( | int | section,
|  | Orientation | orientation,
|  | const cpp17::any & | value,
|  | ItemDataRole | role = ItemDataRole::Edit )
| overridevirtual

Sets header data for a column or row.

Returns `true` if the operation was successful.

See also
  headerData()

Reimplemented from Wt::WAbstractProxyModel.

## ◆ setSourceModel()

virtual void Wt::WAggregateProxyModel::setSourceModel | ( | const std::shared_ptr< WAbstractItemModel > & | sourceModel | ) |
| overridevirtual

Sets the source model.

The source model provides the actual data for the proxy model.

Ownership of the source model is not transferred.

Note that the source model's signals are not forwarded to the proxy model by default, but some specializations, like WBatchEditProxyModel and WSortFilterProxyModel do. If you want to reimplement data() with no changes to row or column indices, consider the use of WIdentityProxyModel.

Reimplemented from Wt::WAbstractProxyModel.

## ◆ sort()

virtual void Wt::WAggregateProxyModel::sort | ( | int | column,
|  | SortOrder | order = SortOrder::Ascending )
| overridevirtual

Sorts the model according to a particular column.

If the model supports sorting, then it should emit the layoutAboutToBeChanged() signal, rearrange its items, and afterwards emit the layoutChanged() signal.

See also
  layoutAboutToBeChanged(), layoutChanged()

Reimplemented from Wt::WAbstractItemModel.