org.jhotdraw.draw.action

Class AbstractDrawingViewAction

java.lang.Object

javax.swing.AbstractAction

org.jhotdraw.draw.action.AbstractDrawingViewAction

All Implemented Interfaces:

java.awt.event.ActionListener, java.io.Serializable, java.lang.Cloneable, java.util.EventListener, javax.swing.Action, Disposable

Direct Known Subclasses:

DrawingAttributeAction, DrawingColorChooserHandler, EditCanvasAction, EditGridAction, ToggleGridAction, ZoomAction

public abstract class AbstractDrawingViewAction
extends javax.swing.AbstractAction
implements Disposable

This abstract class can be extended to implement an Action that acts on behalf of a DrawingView.

By default the enabled state of this action reflects the enabled state of the DrawingView. If no drawing view is active, this action is disabled. When many actions listen to the enabled state this can considerably slow down the editor. If updating the enabled state is not necessary, you can disable it using setUpdateEnabledState(boolean).

If the AbstractDrawingEditorAction acts on the currently active DrawingView it listens for property changes in the DrawingEditor. It listens using a WeakPropertyChangeListener on the DrawingEditor and thus may become garbage collected if it is not referenced by any other object.

See Also:

Serialized Form

Field Summary

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
AbstractDrawingViewAction(DrawingEditor editor) Creates a view action which acts on the current view of the editor.
AbstractDrawingViewAction(DrawingView view) Creates a view action which acts on the specified view.

Method Summary

Modifier and Type	Method and Description
void	dispose() Frees all resources held by this object, so that it can be garbage collected.
boolean	isUpdatEnabledState() Returns true, if this action automatically updates its enabled state to reflect the enabled state of the active DrawingView.
void	setUpdateEnabledState(boolean newValue) By default, the enabled state of this action is updated to reflect the enabled state of the active DrawingView.

Methods inherited from class javax.swing.AbstractAction

addPropertyChangeListener, getKeys, getPropertyChangeListeners, getValue, isEnabled, putValue, removePropertyChangeListener, setEnabled

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.awt.event.ActionListener

actionPerformed

Constructor Detail

AbstractDrawingViewAction

public AbstractDrawingViewAction(@Nullable
                                 DrawingEditor editor)

Creates a view action which acts on the current view of the editor.

AbstractDrawingViewAction

public AbstractDrawingViewAction(@Nullable
                                 DrawingView view)

Creates a view action which acts on the specified view.

Method Detail

dispose

public void dispose()

Frees all resources held by this object, so that it can be garbage collected.

Specified by:

dispose in interface Disposable

setUpdateEnabledState

public void setUpdateEnabledState(boolean newValue)

By default, the enabled state of this action is updated to reflect the enabled state of the active DrawingView. Since this is not always necessary, and since many listening actions may considerably slow down the drawing editor, you can switch this behavior off here.

Parameters:

newValue - Specify false to prevent automatic updating of the enabled state.

isUpdatEnabledState

public boolean isUpdatEnabledState()

Returns true, if this action automatically updates its enabled state to reflect the enabled state of the active DrawingView.