/*******************************************************************************
* Copyright (c) 2000, 2005 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.ui.texteditor;
import java.util.ResourceBundle;
import org.eclipse.swt.events.HelpEvent;
import org.eclipse.swt.events.HelpListener;
import org.eclipse.jface.action.IAction;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;
/**
* Action used by an editor action bar contributor to establish placeholders in
* menus or action bars which can be retargeted to dynamically changing actions,
* for example, those which come from the active editor. This action assumes that
* the "wrapped" action sends out property change events in response to state
* changes. It uses these change notifications to adapt its enabling state and
* its visual presentation.
*/
public final class RetargetTextEditorAction extends ResourceAction {
/** The target action. */
private IAction fAction;
/** The default label if there is no target action. */
private String fDefaultText;
/**
* The local help listener
* @since 2.1
*/
private HelpListener fLocalHelpListener;
/** The listener to pick up changes of the target action. */
private IPropertyChangeListener fListener= new IPropertyChangeListener() {
public void propertyChange(PropertyChangeEvent event) {
update(event);
}
};
/**
* Creates a new action. The action configures its initial visual
* representation from the given resource bundle. If this action's
* wrapped action is set to <code>null</code> it also uses the
* information in the resource bundle.
*
* @param bundle the resource bundle
* @param prefix a prefix to be prepended to the various resource keys
* (described in <code>ResourceAction</code> constructor), or
* <code>null</code> if none
* @param style one of <code>IAction.AS_PUSH_BUTTON</code>, <code>IAction.AS_CHECK_BOX</code>,
* and <code>IAction.AS_RADIO_BUTTON</code>.
*
* @see ResourceAction#ResourceAction(ResourceBundle, String, int)
* @see IAction#AS_CHECK_BOX
* @see IAction#AS_DROP_DOWN_MENU
* @see IAction#AS_PUSH_BUTTON
* @see IAction#AS_RADIO_BUTTON
* @since 2.1
*/
public RetargetTextEditorAction(ResourceBundle bundle, String prefix, int style) {
super(bundle, prefix, style);
fDefaultText= getText();
installHelpListener();
}
/**
* Creates a new action. The action configures its initial visual
* representation from the given resource bundle. If this action's
* wrapped action is set to <code>null</code> it also uses the
* information in the resource bundle.
*
* @param bundle the resource bundle
* @param prefix a prefix to be prepended to the various resource keys
* (described in <code>ResourceAction</code> constructor), or
* <code>null</code> if none
* @see ResourceAction#ResourceAction(ResourceBundle, String)
*/
public RetargetTextEditorAction(ResourceBundle bundle, String prefix) {
super(bundle, prefix);
fDefaultText= getText();
installHelpListener();
}
/**
* Creates a new action. The action configures its initial visual
* representation from the given resource bundle. If this action's
* wrapped action is set to <code>null</code> it also uses the
* information in the resource bundle. The action gets the given
* action id.
*
* @param bundle the resource bundle
* @param prefix a prefix to be prepended to the various resource keys
* (described in <code>ResourceAction</code> constructor), or <code>null</code> if none
* @param actionId the action id
* @param style one of <code>IAction.AS_PUSH_BUTTON</code>, <code>IAction.AS_CHECK_BOX</code>,
* and <code>IAction.AS_RADIO_BUTTON</code>.
*
* @see ResourceAction#ResourceAction(ResourceBundle, String, int)
* @see IAction#AS_CHECK_BOX
* @see IAction#AS_DROP_DOWN_MENU
* @see IAction#AS_PUSH_BUTTON
* @see IAction#AS_RADIO_BUTTON
* @since 2.1
*/
public RetargetTextEditorAction(ResourceBundle bundle, String prefix, String actionId, int style) {
super(bundle, prefix, style);
fDefaultText= getText();
setId(actionId);
installHelpListener();
}
/**
* Creates a new action. The action configures its initial visual
* representation from the given resource bundle. If this action's
* wrapped action is set to <code>null</code> it also uses the
* information in the resource bundle. The action gets the given
* action id.
*
* @param bundle the resource bundle
* @param prefix a prefix to be prepended to the various resource keys
* (described in <code>ResourceAction</code> constructor), or <code>null</code> if none
* @param actionId the action id
* @see ResourceAction#ResourceAction(ResourceBundle, String)
* @since 2.0
*/
public RetargetTextEditorAction(ResourceBundle bundle, String prefix, String actionId) {
super(bundle, prefix);
fDefaultText= getText();
setId(actionId);
installHelpListener();
}
/**
* Updates to the changes of the underlying action.
*
* @param event the change event describing the state change
*/
private void update(PropertyChangeEvent event) {
if (ENABLED.equals(event.getProperty())) {
Boolean bool= (Boolean) event.getNewValue();
setEnabled(bool.booleanValue());
} else if (TEXT.equals(event.getProperty()))
setText((String) event.getNewValue());
else if (TOOL_TIP_TEXT.equals(event.getProperty()))
setToolTipText((String) event.getNewValue());
else if (CHECKED.equals(event.getProperty())) {
Boolean bool= (Boolean) event.getNewValue();
setChecked(bool.booleanValue());
}
}
/**
* Sets the underlying action.
*
* @param action the underlying action
*/
public void setAction(IAction action) {
if (fAction != null) {
fAction.removePropertyChangeListener(fListener);
fAction= null;
}
fAction= action;
if (fAction == null) {
setEnabled(false);
if (getStyle() == AS_CHECK_BOX || getStyle() == AS_RADIO_BUTTON)
setChecked(false);
setText(fDefaultText);
setToolTipText(""); //$NON-NLS-1$
} else {
setEnabled(fAction.isEnabled());
if (fAction.getStyle() == AS_CHECK_BOX || fAction.getStyle() == AS_RADIO_BUTTON)
super.setChecked(fAction.isChecked());
setText(fAction.getText());
setToolTipText(fAction.getToolTipText());
fAction.addPropertyChangeListener(fListener);
}
}
/**
* Installs the help listener.
*
* @since 2.1
*/
private void installHelpListener() {
super.setHelpListener(new HelpListener() {
public void helpRequested(HelpEvent e) {
HelpListener listener= null;
if (fAction != null) {
// if we have a handler, see if it has a help listener
listener= fAction.getHelpListener();
if (listener == null)
// use our own help listener
listener= fLocalHelpListener;
}
if (listener != null)
// pass on the event
listener.helpRequested(e);
}
});
}
/**
* The <code>RetargetTextEditorAction</code> implementation of this method declared on
* <code>IAction</code> stores the help listener in a local field. The
* supplied listener is only used if there is no handler.
*
* @param listener the help listener
* @since 2.1
*/
public void setHelpListener(HelpListener listener) {
fLocalHelpListener= listener;
}
/*
* @see IAction#run()
*/
public void run() {
if (fAction != null)
fAction.run();
}
}