# Class DefaultTableColumnModel

java.lang.Object
javax.swing.table.DefaultTableColumnModel

All Implemented Interfaces:
  `PropertyChangeListener, Serializable, EventListener, ListSelectionListener, TableColumnModel`

public class DefaultTableColumnModel extends Object implements TableColumnModel, PropertyChangeListener, ListSelectionListener, Serializable
The standard column-handler for a `JTable`.

Warning: Serialized objects of this class will not be compatible with future Swing releases. The current serialization support is appropriate for short term storage or RMI between applications running the same version of Swing. As of 1.4, support for long term storage of all JavaBeans has been added to the `java.beans` package. Please see `XMLEncoder`.

See Also:
  - `JTable`

## Field Summary

Fields
Modifier and Type
Field
Description
`protected ChangeEvent`
`changeEvent`
Change event (only one needed)
`protected int`
`columnMargin`
Width margin between each column
`protected boolean`
`columnSelectionAllowed`
Column selection allowed in this column model
`protected EventListenerList`
`listenerList`
List of TableColumnModelListener
`protected ListSelectionModel`
`selectionModel`
Model for keeping track of column selections
`protected Vector<TableColumn>`
`tableColumns`
Array of TableColumn objects in this model
`protected int`
`totalColumnWidth`
A local cache of the combined width of all columns

## Constructor Summary

Constructors
Constructor
Description
`DefaultTableColumnModel()`
Creates a default table column model.

## Method Summary

Modifier and Type
Method
Description
`void`
`addColumn(TableColumn aColumn)`
Appends `aColumn` to the end of the `tableColumns` array.
`void`
`addColumnModelListener(TableColumnModelListener x)`
Adds a listener for table column model events.
`protected ListSelectionModel`
`createSelectionModel()`
Creates a new default list selection model.
`protected void`
`fireColumnAdded(TableColumnModelEvent e)`
Notifies all listeners that have registered interest for notification on this event type.
`protected void`
`fireColumnMarginChanged()`
Notifies all listeners that have registered interest for notification on this event type.
`protected void`
`fireColumnMoved(TableColumnModelEvent e)`
Notifies all listeners that have registered interest for notification on this event type.
`protected void`
`fireColumnRemoved(TableColumnModelEvent e)`
Notifies all listeners that have registered interest for notification on this event type.
`protected void`
`fireColumnSelectionChanged(ListSelectionEvent e)`
Notifies all listeners that have registered interest for notification on this event type.
`TableColumn`
`getColumn(int columnIndex)`
Returns the `TableColumn` object for the column at `columnIndex`.
`int`
`getColumnCount()`
Returns the number of columns in the `tableColumns` array.
`int`
`getColumnIndex(Object identifier)`
Returns the index of the first column in the `tableColumns` array whose identifier is equal to `identifier`, when compared using `equals`.
`int`
`getColumnIndexAtX(int x)`
Returns the index of the column that lies at position `x`, or -1 if no column covers this point.
`int`
`getColumnMargin()`
Returns the width margin for `TableColumn`.
`TableColumnModelListener[]`
`getColumnModelListeners()`
Returns an array of all the column model listeners registered on this model.
`Enumeration<TableColumn>`
`getColumns()`
Returns an `Enumeration` of all the columns in the model.
`boolean`
`getColumnSelectionAllowed()`
Returns true if column selection is allowed, otherwise false.
`<T extends EventListener>
T[]`
`getListeners(Class<T> listenerType)`
Returns an array of all the objects currently registered as `FooListener`s upon this model.
`int`
`getSelectedColumnCount()`
Returns the number of columns selected.
`int[]`
`getSelectedColumns()`
Returns an array of selected columns.
`ListSelectionModel`
`getSelectionModel()`
Returns the `ListSelectionModel` that is used to maintain column selection state.
`int`
`getTotalColumnWidth()`
Returns the total combined width of all columns.
`void`
`moveColumn(int columnIndex, int newIndex)`
Moves the column and heading at `columnIndex` to `newIndex`.
`void`
`propertyChange(PropertyChangeEvent evt)`
Property Change Listener change method.
`protected void`
`recalcWidthCache()`
Recalculates the total combined width of all columns.
`void`
`removeColumn(TableColumn column)`
Deletes the `column` from the `tableColumns` array.
`void`
`removeColumnModelListener(TableColumnModelListener x)`
Removes a listener for table column model events.
`void`
`setColumnMargin(int newMargin)`
Sets the column margin to `newMargin`.
`void`
`setColumnSelectionAllowed(boolean flag)`
Sets whether column selection is allowed.
`void`
`setSelectionModel(ListSelectionModel newModel)`
Sets the selection model for this `TableColumnModel` to `newModel` and registers for listener notifications from the new selection model.
`void`
`valueChanged(ListSelectionEvent e)`
A `ListSelectionListener` that forwards `ListSelectionEvents` when there is a column selection change.

### Methods declared in class Object

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

## Field Details

### tableColumns

protected Vector<TableColumn> tableColumns
Array of TableColumn objects in this model

### selectionModel

protected ListSelectionModel selectionModel
Model for keeping track of column selections

### columnMargin

protected int columnMargin
Width margin between each column

### listenerList

protected EventListenerList listenerList
List of TableColumnModelListener

### changeEvent

protected transient ChangeEvent changeEvent
Change event (only one needed)

### columnSelectionAllowed

protected boolean columnSelectionAllowed
Column selection allowed in this column model

### totalColumnWidth

protected int totalColumnWidth
A local cache of the combined width of all columns

## Constructor Details

### DefaultTableColumnModel

public DefaultTableColumnModel()
Creates a default table column model.

## Method Details

### addColumn

public void addColumn(TableColumn aColumn)
Appends `aColumn` to the end of the `tableColumns` array. This method also posts the `columnAdded` event to its listeners.

Specified by:
  `addColumn` in interface `TableColumnModel`
Parameters:
  `aColumn` - the `TableColumn` to be added
Throws:
  `IllegalArgumentException` - if `aColumn` is `null`
See Also:
  - `removeColumn(TableColumn)`

### removeColumn

public void removeColumn(TableColumn column)
Deletes the `column` from the `tableColumns` array. This method will do nothing if `column` is not in the table's columns list. `tile` is called to resize both the header and table views. This method also posts a `columnRemoved` event to its listeners.

Specified by:
  `removeColumn` in interface `TableColumnModel`
Parameters:
  `column` - the `TableColumn` to be removed
See Also:
  - `addColumn(TableColumn)`

### moveColumn

public void moveColumn(int columnIndex, int newIndex)
Moves the column and heading at `columnIndex` to `newIndex`. The old column at `columnIndex` will now be found at `newIndex`. The column that used to be at `newIndex` is shifted left or right to make room. This will not move any columns if `columnIndex` equals `newIndex`. This method also posts a `columnMoved` event to its listeners.

Specified by:
  `moveColumn` in interface `TableColumnModel`
Parameters:
  `columnIndex` - the index of column to be moved
  `newIndex` - new index to move the column
Throws:
  `IllegalArgumentException` - if `column` or `newIndex` are not in the valid range

### setColumnMargin

public void setColumnMargin(int newMargin)
Sets the column margin to `newMargin`. This method also posts a `columnMarginChanged` event to its listeners.

Specified by:
  `setColumnMargin` in interface `TableColumnModel`
Parameters:
  `newMargin` - the new margin width, in pixels
See Also:
  - `getColumnMargin()`
  - `getTotalColumnWidth()`

### getColumnCount

public int getColumnCount()
Returns the number of columns in the `tableColumns` array.

Specified by:
  `getColumnCount` in interface `TableColumnModel`
Returns:
  the number of columns in the `tableColumns` array
See Also:
  - `getColumns()`

### getColumns

public Enumeration<TableColumn> getColumns()
Returns an `Enumeration` of all the columns in the model.

Specified by:
  `getColumns` in interface `TableColumnModel`
Returns:
  an `Enumeration` of the columns in the model

### getColumnIndex

public int getColumnIndex(Object identifier)
Returns the index of the first column in the `tableColumns` array whose identifier is equal to `identifier`, when compared using `equals`.

Specified by:
  `getColumnIndex` in interface `TableColumnModel`
Parameters:
  `identifier` - the identifier object
Returns:
  the index of the first column in the `tableColumns` array whose identifier is equal to `identifier`
Throws:
  `IllegalArgumentException` - if `identifier` is `null`, or if no `TableColumn` has this `identifier`
See Also:
  - `getColumn(int)`

### getColumn

public TableColumn getColumn(int columnIndex)
Returns the `TableColumn` object for the column at `columnIndex`.

Specified by:
  `getColumn` in interface `TableColumnModel`
Parameters:
  `columnIndex` - the index of the column desired
Returns:
  the `TableColumn` object for the column at `columnIndex`
Throws:
  `ArrayIndexOutOfBoundsException` - if `columnIndex` is out of range: (`columnIndex < 0 || columnIndex >= getColumnCount()`)

### getColumnMargin

public int getColumnMargin()
Returns the width margin for `TableColumn`. The default `columnMargin` is 1.

Specified by:
  `getColumnMargin` in interface `TableColumnModel`
Returns:
  the maximum width for the `TableColumn`
See Also:
  - `setColumnMargin(int)`

### getColumnIndexAtX

public int getColumnIndexAtX(int x)
Returns the index of the column that lies at position `x`, or -1 if no column covers this point. In keeping with Swing's separable model architecture, a TableColumnModel does not know how the table columns actually appear on screen. The visual presentation of the columns is the responsibility of the view/controller object using this model (typically JTable). The view/controller need not display the columns sequentially from left to right. For example, columns could be displayed from right to left to accommodate a locale preference or some columns might be hidden at the request of the user. Because the model does not know how the columns are laid out on screen, the given `xPosition` should not be considered to be a coordinate in 2D graphics space. Instead, it should be considered to be a width from the start of the first column in the model. If the column index for a given X coordinate in 2D space is required, `JTable.columnAtPoint` can be used instead.

Specified by:
  `getColumnIndexAtX` in interface `TableColumnModel`
Parameters:
  `x` - the horizontal location of interest
Returns:
  the index of the column or -1 if no column is found
See Also:
  - `JTable.columnAtPoint(Point)`

### getTotalColumnWidth

public int getTotalColumnWidth()
Returns the total combined width of all columns.

Specified by:
  `getTotalColumnWidth` in interface `TableColumnModel`
Returns:
  the `totalColumnWidth` property

### setSelectionModel

public void setSelectionModel(ListSelectionModel newModel)
Sets the selection model for this `TableColumnModel` to `newModel` and registers for listener notifications from the new selection model. If `newModel` is `null`, an exception is thrown.

Specified by:
  `setSelectionModel` in interface `TableColumnModel`
Parameters:
  `newModel` - the new selection model
Throws:
  `IllegalArgumentException` - if `newModel` is `null`
See Also:
  - `getSelectionModel()`

### getSelectionModel

public ListSelectionModel getSelectionModel()
Returns the `ListSelectionModel` that is used to maintain column selection state.

Specified by:
  `getSelectionModel` in interface `TableColumnModel`
Returns:
  the object that provides column selection state. Or `null` if row selection is not allowed.
See Also:
  - `setSelectionModel(ListSelectionModel)`

### setColumnSelectionAllowed

public void setColumnSelectionAllowed(boolean flag)
Sets whether column selection is allowed. The default is false.

Specified by:
  `setColumnSelectionAllowed` in interface `TableColumnModel`
Parameters:
  `flag` - true if column selection will be allowed, false otherwise
See Also:
  - `TableColumnModel.getColumnSelectionAllowed()`

### getColumnSelectionAllowed

public boolean getColumnSelectionAllowed()
Returns true if column selection is allowed, otherwise false. The default is false.

Specified by:
  `getColumnSelectionAllowed` in interface `TableColumnModel`
Returns:
  the `columnSelectionAllowed` property
See Also:
  - `TableColumnModel.setColumnSelectionAllowed(boolean)`

### getSelectedColumns

public int[] getSelectedColumns()
Returns an array of selected columns. If `selectionModel` is `null`, returns an empty array.

Specified by:
  `getSelectedColumns` in interface `TableColumnModel`
Returns:
  an array of selected columns or an empty array if nothing is selected or the `selectionModel` is `null`

### getSelectedColumnCount

public int getSelectedColumnCount()
Returns the number of columns selected.

Specified by:
  `getSelectedColumnCount` in interface `TableColumnModel`
Returns:
  the number of columns selected

### addColumnModelListener

public void addColumnModelListener(TableColumnModelListener x)
Adds a listener for table column model events.

Specified by:
  `addColumnModelListener` in interface `TableColumnModel`
Parameters:
  `x` - a `TableColumnModelListener` object

### removeColumnModelListener

public void removeColumnModelListener(TableColumnModelListener x)
Removes a listener for table column model events.

Specified by:
  `removeColumnModelListener` in interface `TableColumnModel`
Parameters:
  `x` - a `TableColumnModelListener` object

### getColumnModelListeners

public TableColumnModelListener[] getColumnModelListeners()
Returns an array of all the column model listeners registered on this model.

Returns:
  all of this default table column model's `ColumnModelListener`s or an empty array if no column model listeners are currently registered
Since:
  1.4
See Also:
  - `addColumnModelListener(TableColumnModelListener)`
  - `removeColumnModelListener(TableColumnModelListener)`

### fireColumnAdded

protected void fireColumnAdded(TableColumnModelEvent e)
Notifies all listeners that have registered interest for notification on this event type. The event instance is lazily created using the parameters passed into the fire method.

Parameters:
  `e` - the event received
See Also:
  - `EventListenerList`

### fireColumnRemoved

protected void fireColumnRemoved(TableColumnModelEvent e)
Notifies all listeners that have registered interest for notification on this event type. The event instance is lazily created using the parameters passed into the fire method.

Parameters:
  `e` - the event received
See Also:
  - `EventListenerList`

### fireColumnMoved

protected void fireColumnMoved(TableColumnModelEvent e)
Notifies all listeners that have registered interest for notification on this event type. The event instance is lazily created using the parameters passed into the fire method.

Parameters:
  `e` - the event received
See Also:
  - `EventListenerList`

### fireColumnSelectionChanged

protected void fireColumnSelectionChanged(ListSelectionEvent e)
Notifies all listeners that have registered interest for notification on this event type. The event instance is lazily created using the parameters passed into the fire method.

Parameters:
  `e` - the event received
See Also:
  - `EventListenerList`

### fireColumnMarginChanged

protected void fireColumnMarginChanged()
Notifies all listeners that have registered interest for notification on this event type. The event instance is lazily created using the parameters passed into the fire method.

See Also:
  - `EventListenerList`

### getListeners

public <T extends EventListener> T[] getListeners(Class<T> listenerType)
Returns an array of all the objects currently registered as `FooListener`s upon this model. `FooListener`s are registered using the `addFooListener` method.

You can specify the `listenerType` argument with a class literal, such as `FooListener.class`. For example, you can query a `DefaultTableColumnModel` `m` for its column model listeners with the following code:

    ColumnModelListener[] cmls = (ColumnModelListener[])(m.getListeners(ColumnModelListener.class));

If no such listeners exist, this method returns an empty array.

Type Parameters:
  `T` - the listener type
Parameters:
  `listenerType` - the type of listeners requested
Returns:
  an array of all objects registered as `FooListener`s on this model, or an empty array if no such listeners have been added
Throws:
  `ClassCastException` - if `listenerType` doesn't specify a class or interface that implements `java.util.EventListener`
Since:
  1.3
See Also:
  - `getColumnModelListeners()`

### propertyChange

public void propertyChange(PropertyChangeEvent evt)
Property Change Listener change method. Used to track changes to the column width or preferred column width.

Specified by:
  `propertyChange` in interface `PropertyChangeListener`
Parameters:
  `evt` - `PropertyChangeEvent`

### valueChanged

public void valueChanged(ListSelectionEvent e)
A `ListSelectionListener` that forwards `ListSelectionEvents` when there is a column selection change.

Specified by:
  `valueChanged` in interface `ListSelectionListener`
Parameters:
  `e` - the change event

### createSelectionModel

protected ListSelectionModel createSelectionModel()
Creates a new default list selection model.

Returns:
  a newly created default list selection model.

### recalcWidthCache

protected void recalcWidthCache()
Recalculates the total combined width of all columns. Updates the `totalColumnWidth` property.