org.geotools.swing.event

Class MapPaneKeyHandler

Object

KeyAdapter

MapPaneKeyHandler

All Implemented Interfaces:

KeyListener, EventListener

public class MapPaneKeyHandler
extends KeyAdapter

Handles keyboard events for a map pane. This is the default handler for classes derived from AbstractMapPane. It provides for keyboard-controlled scrolling and zooming of the display. The default key bindings for actions should be suitable for most keyboards.

While the Java Swing toolkit provides its own mechanism for linking key events to actions, this class is somewhat easier to use and provides a model that could be implemented in other toolkits such as SWT. However, you are free to ignore this class and use your own key handler instead since the map pane classes only require that the handler implements the KeyListener interface.

Key bindings for an individual action can be set like this:

 // Bind left-scroll action to the 'h' key (for Vim fans)
 KeyInfo key = new KeyInfo(KeyEvent.VK_H, 0);
 mapPaneKeyHandler.setBinding(key, MapPaneKeyHandler.Action.SCROLL_LEFT);
 

Multiple bindings can be set with the setBindings(Map) or setAllBindings(Map) methods:

 Map<KeyInfo, MapPaneKeyHandler.Action> bindings =
         new HashMap<KeyInfo, MapPaneKeyHandler.Action>();

 bindings.put(new KeyInfo(KeyEvent.VK_H, 0), MapPaneKeyHandler.Action.SCROLL_LEFT);
 bindings.put(new KeyInfo(KeyEvent.VK_L, 0), MapPaneKeyHandler.Action.SCROLL_RIGHT);
 bindings.put(new KeyInfo(KeyEvent.VK_K, 0), MapPaneKeyHandler.Action.SCROLL_UP);
 bindings.put(new KeyInfo(KeyEvent.VK_J, 0), MapPaneKeyHandler.Action.SCROLL_DOWN);

 mapPaneKeyHandler.setBindings( bindings );
 

Since:

8.0

Author:

Michael Bedward

See Also:

KeyInfo, AbstractMapPane#setKeyHandler(java.awt.event.KeyListener)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	MapPaneKeyHandler.Action Constants for supported actions.

Constructor Summary

Constructors

Constructor and Description
MapPaneKeyHandler(MapPane mapPane) Creates a new instance with the default key bindings for actions.

Method Summary

Modifier and Type	Method and Description
KeyInfo	getBindingForAction(MapPaneKeyHandler.Action action) Gets the current key binding for the given action.
Map<KeyInfo,MapPaneKeyHandler.Action>	getBindings() Gets the current key bindings.
void	keyPressed(KeyEvent e) Handles a key-pressed event.
void	setAllBindings(Map<KeyInfo,MapPaneKeyHandler.Action> newBindings) Sets the bindings to those specified in newBindings.
void	setBinding(KeyInfo keyInfo, MapPaneKeyHandler.Action action) Sets the key binding for a single action.
void	setBindings(Map<KeyInfo,MapPaneKeyHandler.Action> newBindings) Sets one or more key bindings for actions.
void	setDefaultBindings() Sets all key bindings to their default value.

Methods inherited from class KeyAdapter

keyReleased, keyTyped

Methods inherited from class Object

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

Constructor Detail

MapPaneKeyHandler

public MapPaneKeyHandler(MapPane mapPane)

Creates a new instance with the default key bindings for actions.

Parameters:

mapPane - the map pane associated with this handler

Method Detail

setDefaultBindings

public void setDefaultBindings()

Sets all key bindings to their default value.

getBindings

public Map<KeyInfo,MapPaneKeyHandler.Action> getBindings()

Gets the current key bindings. The bindings are copied into the destination Map, so subsequent changes to it will not affect this handler.

Returns:

the current key bindings

getBindingForAction

public KeyInfo getBindingForAction(MapPaneKeyHandler.Action action)

Gets the current key binding for the given action. The object returned is a copy.

Parameters:

action - the action

Returns:

the key binding; or null if there is no binding

Throws:

IllegalArgumentException - if action is null

setBinding

public void setBinding(KeyInfo keyInfo,
                       MapPaneKeyHandler.Action action)

Sets the key binding for a single action.

Parameters:

keyInfo - the key binding

action - the action

Throws:

IllegalArgumentException - if either argument is null

setBindings

public void setBindings(Map<KeyInfo,MapPaneKeyHandler.Action> newBindings)

Sets one or more key bindings for actions. This method can be used to set a subset of the key bindings while leaving others unchanged.

Parameters:

newBindings - new key bindings

Throws:

IllegalArgumentException - if newBindings is null

setAllBindings

public void setAllBindings(Map<KeyInfo,MapPaneKeyHandler.Action> newBindings)

Sets the bindings to those specified in newBindings. This method differs to setBindings(java.util.Map) in that any actions which do not appear in the input map are disabled.

Parameters:

newBindings - new key bindings

Throws:

IllegalArgumentException - if newBindings is null

keyPressed

public void keyPressed(KeyEvent e)

Handles a key-pressed event.

Specified by:

keyPressed in interface KeyListener

Overrides:

keyPressed in class KeyAdapter

Parameters:

e - input key event