Java(TM) 2 Platform, Standard Edition, v1.2.2 API Specification: Interface CellEditor - JDK 5 Documentation v1.2.2, Java 2 SDK 英文文档

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javax.swing
Interface CellEditor

All Known Subinterfaces:: TableCellEditor, TreeCellEditor

public interface CellEditor

This interface defines the methods any general editor should be able to implement.

Having this interface enables complex components (the client of the editor) such as JList, JTree, and JTable to allow any generic editor to edit values in a table cell, or tree cell, etc. Without this generic editor interface, JTable would have to know about specific editors, such as JTextField, JCheckBox, JComboBox, etc. In addition, without this interface, clients of editors such as JTable would not be able to work with any editors developed in the future by the user or a 3rd party ISV.

To use this interface, a developer creating a new editor can have the new component implement the interface. Or the developer can choose a wrapper based approch and provide a companion object which implements the CellEditor interface (See JCellEditor for example). The wrapper approch is particularly useful if the user want to use a 3rd party ISV editor with JTable, but the ISV didn't implement the CellEditor interface. The user can simply create an object that contains an instance of the 3rd party editor object and "translate" the CellEditor API into the 3rd party editor's API.

See Also:: CellEditorListener

Method Summary

void addCellEditorListener(CellEditorListener l)
          Add a listener to the list that's notified when the editor starts, stops, or cancels editing.

void cancelCellEditing()
          Tell the editor to cancel editing and not accept any partially edited value.

Object getCellEditorValue()
          Returns the value contained in the editor

boolean isCellEditable(EventObject anEvent)
          Ask the editor if it can start editing using anEvent.

void removeCellEditorListener(CellEditorListener l)
          Remove a listener from the list that's notified

boolean shouldSelectCell(EventObject anEvent)
          Tell the editor to start editing using anEvent.

boolean stopCellEditing()
          Tell the editor to stop editing and accept any partially edited value as the value of the editor.

Method Detail

getCellEditorValue

public Object getCellEditorValue()

Returns the value contained in the editor

isCellEditable

public boolean isCellEditable(EventObject anEvent)

Ask the editor if it can start editing using anEvent. anEvent is in the invoking component coordinate system. The editor can not assume the Component returned by getCellEditorComponent() is installed. This method is intended for the use of client to avoid the cost of setting up and installing the editor component if editing is not possible. If editing can be started this method returns true.

Parameters:: anEvent - the event the editor should use to consider whether to begin editing or not.
Returns:: true if editing can be started.
See Also:: shouldSelectCell(java.util.EventObject)

shouldSelectCell

public boolean shouldSelectCell(EventObject anEvent)

Tell the editor to start editing using anEvent. It is up to the editor if it want to start editing in different states depending on the exact type of anEvent. For example, with a text field editor, if the event is a mouse event the editor might start editing with the cursor at the clicked point. If the event is a keyboard event, it might want replace the value of the text field with that first key, etc. anEvent is in the invoking component's coordinate system. A null value is a valid parameter for anEvent, and it is up to the editor to determine what is the default starting state. For example, a text field editor might want to select all the text and start editing if anEvent is null. The editor can assume the Component returned by getCellEditorComponent() is properly installed in the clients Component hierarchy before this method is called.

The return value of shouldSelectCell() is a boolean indicating whether the editing cell should be selected or not. Typically, the return value is true, because is most cases the editing cell should be selected. However, it is useful to return false to keep the selection from changing for some types of edits. eg. A table that contains a column of check boxes, the user might want to be able to change those checkboxes without altering the selection. (See Netscape Communicator for just such an example) Of course, it is up to the client of the editor to use the return value, but it doesn't need to if it doesn't want to.

Parameters:: anEvent - the event the editor should use to start editing.
Returns:: true if the editor would like the editing cell to be selected
See Also:: isCellEditable(java.util.EventObject)

stopCellEditing

public boolean stopCellEditing()

Tell the editor to stop editing and accept any partially edited value as the value of the editor. The editor returns false if editing was not stopped, useful for editors which validates and can not accept invalid entries.

Returns:: true if editing was stopped

cancelCellEditing

public void cancelCellEditing()

Tell the editor to cancel editing and not accept any partially edited value.

addCellEditorListener

public void addCellEditorListener(CellEditorListener l)

Add a listener to the list that's notified when the editor starts, stops, or cancels editing.

Parameters:: l - the CellEditorListener

removeCellEditorListener

public void removeCellEditorListener(CellEditorListener l)

Remove a listener from the list that's notified

Parameters:: l - the CellEditorListener