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Class RowSorter<M>

java.lang.Object

javax.swing.RowSorter<M>

Type Parameters:: M - the type of the underlying model

Direct Known Subclasses:: DefaultRowSorter

public abstract class RowSorter<M> extends Object

RowSorter provides the basis for sorting and filtering. Beyond creating and installing a RowSorter, you very rarely need to interact with one directly. Refer to TableRowSorter for a concrete implementation of RowSorter for JTable.

RowSorter's primary role is to provide a mapping between two coordinate systems: that of the view (for example a JTable) and that of the underlying data source, typically a model.

The view invokes the following methods on the RowSorter:

toggleSortOrder — The view invokes this when the appropriate user gesture has occurred to trigger a sort. For example, the user clicked a column header in a table.
One of the model change methods — The view invokes a model change method when the underlying model has changed. There may be order dependencies in how the events are delivered, so a RowSorter should not update its mapping until one of these methods is invoked.

Because the view makes extensive use of the convertRowIndexToModel, convertRowIndexToView and getViewRowCount methods, these methods need to be fast.

RowSorter provides notification of changes by way of RowSorterListener. Two types of notification are sent:

RowSorterEvent.Type.SORT_ORDER_CHANGED — notifies listeners that the sort order has changed. This is typically followed by a notification that the sort has changed.
RowSorterEvent.Type.SORTED — notifies listeners that the mapping maintained by the RowSorter has changed in some way.

RowSorter implementations typically don't have a one-to-one mapping with the underlying model, but they can. For example, if a database does the sorting, toggleSortOrder might call through to the database (on a background thread), and override the mapping methods to return the argument that is passed in.

Concrete implementations of RowSorter need to reference a model such as TableModel or ListModel. The view classes, such as JTable and JList, will also have a reference to the model. To avoid ordering dependencies, RowSorter implementations should not install a listener on the model. Instead the view class will call into the RowSorter when the model changes. For example, if a row is updated in a TableModel JTable invokes rowsUpdated. When the model changes, the view may call into any of the following methods: modelStructureChanged, allRowsChanged, rowsInserted, rowsDeleted and rowsUpdated.

Since:

1.6

See Also:

Nested Class Summary

Modifier and Type	Class	Description
`static class`	`RowSorter.SortKey`	SortKey describes the sort order for a particular column.

Constructor Summary

Constructor	Description
`RowSorter()`	Creates a `RowSorter`.

Method Summary

Modifier and Type	Method	Description
`void`	`addRowSorterListener(RowSorterListener l)`	Adds a `RowSorterListener` to receive notification about this `RowSorter`.
`abstract void`	`allRowsChanged()`	Invoked when the contents of the underlying model have completely changed.
`abstract int`	`convertRowIndexToModel(int index)`	Returns the location of `index` in terms of the underlying model.
`abstract int`	`convertRowIndexToView(int index)`	Returns the location of `index` in terms of the view.
`protected void`	`fireRowSorterChanged(int[] lastRowIndexToModel)`	Notifies listener that the mapping has changed.
`protected void`	`fireSortOrderChanged()`	Notifies listener that the sort order has changed.
`abstract M`	`getModel()`	Returns the underlying model.
`abstract int`	`getModelRowCount()`	Returns the number of rows in the underlying model.
`abstract List<? extends RowSorter.SortKey>`	`getSortKeys()`	Returns the current sort keys.
`abstract int`	`getViewRowCount()`	Returns the number of rows in the view.
`abstract void`	`modelStructureChanged()`	Invoked when the underlying model structure has completely changed.
`void`	`removeRowSorterListener(RowSorterListener l)`	Removes a `RowSorterListener`.
`abstract void`	`rowsDeleted(int firstRow, int endRow)`	Invoked when rows have been deleted from the underlying model in the specified range (inclusive).
`abstract void`	`rowsInserted(int firstRow, int endRow)`	Invoked when rows have been inserted into the underlying model in the specified range (inclusive).
`abstract void`	`rowsUpdated(int firstRow, int endRow)`	Invoked when rows have been changed in the underlying model between the specified range (inclusive).
`abstract void`	`rowsUpdated(int firstRow, int endRow, int column)`	Invoked when the column in the rows have been updated in the underlying model between the specified range.
`abstract void`	`setSortKeys(List<? extends RowSorter.SortKey> keys)`	Sets the current sort keys.
`abstract void`	`toggleSortOrder(int column)`	Reverses the sort order of the specified column.

Methods declared in class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

RowSorter

public RowSorter()

Creates a RowSorter.

Method Details

getModel

public abstract M getModel()

Returns the underlying model.

Returns:: the underlying model

toggleSortOrder

public abstract void toggleSortOrder(int column)

Reverses the sort order of the specified column. It is up to subclasses to provide the exact behavior when invoked. Typically this will reverse the sort order from ascending to descending (or descending to ascending) if the specified column is already the primary sorted column; otherwise, makes the specified column the primary sorted column, with an ascending sort order. If the specified column is not sortable, this method has no effect.

If this results in changing the sort order and sorting, the appropriate RowSorterListener notification will be sent.

Parameters:: column - the column to toggle the sort ordering of, in terms of the underlying model
Throws:: IndexOutOfBoundsException - if column is outside the range of the underlying model

convertRowIndexToModel

public abstract int convertRowIndexToModel(int index)

Returns the location of index in terms of the underlying model. That is, for the row index in the coordinates of the view this returns the row index in terms of the underlying model.

Parameters:: index - the row index in terms of the underlying view
Returns:: row index in terms of the view
Throws:: IndexOutOfBoundsException - if index is outside the range of the view

convertRowIndexToView

public abstract int convertRowIndexToView(int index)

Returns the location of index in terms of the view. That is, for the row index in the coordinates of the underlying model this returns the row index in terms of the view.

Parameters:: index - the row index in terms of the underlying model
Returns:: row index in terms of the view, or -1 if index has been filtered out of the view
Throws:: IndexOutOfBoundsException - if index is outside the range of the model

setSortKeys

public abstract void setSortKeys(List<? extends RowSorter.SortKey> keys)

Sets the current sort keys.

Parameters:: keys - the new SortKeys; null is a shorthand for specifying an empty list, indicating that the view should be unsorted

getSortKeys

public abstract List<? extends RowSorter.SortKey> getSortKeys()

Returns the current sort keys. This must return a


 non-null List

and may return an unmodifiable List. If you need to change the sort keys, make a copy of the returned List, mutate the copy and invoke setSortKeys with the new list.

Returns:: the current sort order

getViewRowCount

public abstract int getViewRowCount()

Returns the number of rows in the view. If the contents have been filtered this might differ from the row count of the underlying model.

Returns:

number of rows in the view

See Also:

getModelRowCount

public abstract int getModelRowCount()

Returns the number of rows in the underlying model.

Returns:

number of rows in the underlying model

See Also:

modelStructureChanged

public abstract void modelStructureChanged()

Invoked when the underlying model structure has completely changed. For example, if the number of columns in a TableModel changed, this method would be invoked.