org.openide.util.actions

Class NodeAction

java.lang.Object

org.openide.util.SharedClassObject

org.openide.util.actions.SystemAction

org.openide.util.actions.CallableSystemAction

org.openide.util.actions.NodeAction

All Implemented Interfaces:

ActionListener, Externalizable, Serializable, EventListener, Action, Presenter, Presenter.Menu, Presenter.Popup, Presenter.Toolbar, ContextAwareAction, HelpCtx.Provider

Direct Known Subclasses:

CookieAction

public abstract class NodeAction
extends CallableSystemAction
implements ContextAwareAction

A type of action that listens on change in activated nodes selection and allows its subclasses to simply change their enabled state and handle action invocation requests.

Whenever a list of activated nodes changes (a new TopComponent is selected or its internal selection changes like in explorer) the overriden method NodeAction.enable(org.openide.nodes.Node[]) is called and state of the action is updated according to the result. When the action is performed, the subclasses are notified by a call to their NodeAction.performAction(Node[]) where they can perform their operation on the currently selected array of nodes.

Note: if your action involves getting cookies from nodes, which in many cases is the correct design, please use CookieAction instead, as that permits sensitivity to cookies and also listens to changes in supplied cookies.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface org.openide.util.actions.Presenter

Presenter.Menu, Presenter.Popup, Presenter.Toolbar

Field Summary

Fields inherited from class org.openide.util.actions.SystemAction

PROP_ENABLED, PROP_ICON

Fields inherited from interface javax.swing.Action

ACCELERATOR_KEY, ACTION_COMMAND_KEY, DEFAULT, DISPLAYED_MNEMONIC_INDEX_KEY, LARGE_ICON_KEY, LONG_DESCRIPTION, MNEMONIC_KEY, NAME, SELECTED_KEY, SHORT_DESCRIPTION, SMALL_ICON

Constructor Summary

Constructors

Constructor and Description
NodeAction()

Method Summary

Modifier and Type	Method and Description
void	actionPerformed(ActionEvent ev) Deprecated. Using a special action event in this way is deprecated. Better is to use NodeAction.createContextAwareInstance(org.openide.util.Lookup) and pass a lookup containing all desired Node instances.
protected void	addNotify() Initializes selection listener.
Action	createContextAwareInstance(Lookup actionContext) Implements ContextAwareAction interface method.
protected abstract boolean	enable(Node[] activatedNodes) Test whether the action should be enabled based on the currently activated nodes.
Node[]	getActivatedNodes() Get the currently activated nodes.
protected void	initialize()
boolean	isEnabled() Test for enablement based on NodeAction.enable(org.openide.nodes.Node[]).
void	performAction() Deprecated. Do not call this programmatically. Use NodeAction.createContextAwareInstance(org.openide.util.Lookup) to pass in a node selection. Do not override this method.
protected abstract void	performAction(Node[] activatedNodes) Perform the action based on the currently activated nodes.
protected void	removeNotify() Shuts down the selection listener.
void	setEnabled(boolean e)
protected boolean	surviveFocusChange() Specify the behavior of the action when a window with no activated nodes is selected.

Methods inherited from class org.openide.util.actions.CallableSystemAction

asynchronous, getMenuPresenter, getPopupPresenter, getToolbarPresenter

Methods inherited from class org.openide.util.actions.SystemAction

clearSharedData, createPopupMenu, createToolbarPresenter, get, getHelpCtx, getIcon, getIcon, getName, getValue, iconResource, linkActions, putValue, setIcon

Methods inherited from class org.openide.util.SharedClassObject

addPropertyChangeListener, equals, finalize, findObject, findObject, firePropertyChange, getLock, getProperty, hashCode, putProperty, putProperty, readExternal, removePropertyChangeListener, reset, writeExternal, writeReplace

Methods inherited from class java.lang.Object

clone, getClass, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface javax.swing.Action

accept, addPropertyChangeListener, getValue, putValue, removePropertyChangeListener

Constructor Detail

NodeAction

public NodeAction()

Method Detail

initialize

protected void initialize()

Overrides:

initialize in class SystemAction

addNotify

protected void addNotify()

Initializes selection listener. If you override this method, you must always call the super method first.

Overrides:

addNotify in class SharedClassObject

removeNotify

protected void removeNotify()

Shuts down the selection listener. If you override this method, you must always call the super method last.

Overrides:

removeNotify in class SharedClassObject

isEnabled

public boolean isEnabled()

Test for enablement based on NodeAction.enable(org.openide.nodes.Node[]). You probably ought not ever override this.

Specified by:

isEnabled in interface Action

Overrides:

isEnabled in class SystemAction

Returns:

true to enable

setEnabled

public void setEnabled(boolean e)

Specified by:

setEnabled in interface Action

Overrides:

setEnabled in class SystemAction

actionPerformed

@Deprecated
public void actionPerformed(ActionEvent ev)

Deprecated. Using a special action event in this way is deprecated. Better is to use NodeAction.createContextAwareInstance(org.openide.util.Lookup) and pass a lookup containing all desired Node instances.

Perform the action with a specific action event. Normally this simply calls NodeAction.performAction(), that is using the global node selection. However you may call this directly, with an action event whose source is either a node or an array of nodes, to invoke the action directly on that nodes or nodes. If you do this, the action must be such that it would be enabled on that node selection, otherwise the action is not required to behave correctly (that is, it can be written to assume that it is never called with a node selection it is not enabled on).

Specified by:

actionPerformed in interface ActionListener

Overrides:

actionPerformed in class CallableSystemAction

Parameters:

ev - action event

performAction

@Deprecated
public void performAction()

Deprecated. Do not call this programmatically. Use NodeAction.createContextAwareInstance(org.openide.util.Lookup) to pass in a node selection. Do not override this method.

Performs the action. In the default implementation, calls NodeAction.performAction(Node[]).

Specified by:

performAction in class CallableSystemAction

getActivatedNodes

public final Node[] getActivatedNodes()

Get the currently activated nodes.

Returns:

the nodes (may be empty but not null)

surviveFocusChange

protected boolean surviveFocusChange()

Specify the behavior of the action when a window with no activated nodes is selected. If the action should then be disabled, return false here; if the action should stay in the previous state, return true.

Note that NodeAction.getActivatedNodes() and NodeAction.performAction() are still passed the set of selected nodes from the old window, if you keep this feature on. This is useful, e.g., for an action like Compilation which should remain active even if the user switches to a window like the Output Window that has no associated nodes; then running the action will still use the last selection from e.g. an Explorer window or the Editor, if there was one to begin with.

Returns:

true in the default implementation

performAction

protected abstract void performAction(Node[] activatedNodes)

Perform the action based on the currently activated nodes. Note that if the source of the event triggering this action was itself a node, that node will be the sole argument to this method, rather than the activated nodes.

Parameters:

activatedNodes - current activated nodes, may be empty but not null

enable

protected abstract boolean enable(Node[] activatedNodes)

Test whether the action should be enabled based on the currently activated nodes.

Parameters:

activatedNodes - current activated nodes, may be empty but not null

Returns:

true to be enabled, false to be disabled

createContextAwareInstance

public Action createContextAwareInstance(Lookup actionContext)

Implements ContextAwareAction interface method. Returns a delegate action that is associated with a specific lookup and extracts the nodes it operates on from it. Otherwise it delegates to the regular NodeAction (especially to NodeAction.enable(org.openide.nodes.Node[]) and NodeAction.performAction() methods). Note: Never call directly methods setEnabled or putValue of this delegate action, it is useless, they are empty. The enablement state of the action is driven by the content of the actionContext.

Specified by:

createContextAwareInstance in interface ContextAwareAction

Parameters:

actionContext - a lookup contains action context, cannot be null

Returns:

a delegate action