/*******************************************************************************
* Copyright (c) 2000, 2006 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.jface.action;
import java.text.MessageFormat;
import java.util.*;
import org.eclipse.core.commands.*;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.jface.util.*;
/**
* <p>
* A manager for a callback facility which is capable of querying external
* interfaces for additional information about actions and action contribution
* items. This information typically includes things like accelerators and
* textual representations.
* </p>
* <p>
* <em>It is only necessary to use this mechanism if you will be using a mix of
* actions and commands, and wish the interactions to work properly.</em>
* </p>
* <p>
* For example, in the Eclipse workbench, this mechanism is used to allow the
* command architecture to override certain values in action contribution items.
* </p>
* <p>
* This class is not intended to be called or extended by any external clients.
* </p>
*
* @since 1.0
*/
public final class ExternalActionManager {
/**
* A simple implementation of the <code>ICallback</code> mechanism that
* simply takes a <code>BindingManager</code> and a
* <code>CommandManager</code>.
*
* @since 1.0
*/
public static final class CommandCallback /*implements
IBindingManagerListener, IBindingManagerCallback */ {
/**
* The internationalization bundle for text produced by this class.
*/
private static final ResourceBundle RESOURCE_BUNDLE = ResourceBundle
.getBundle(ExternalActionManager.class.getName());
/**
* The callback capable of responding to whether a command is active.
*/
private final IActiveChecker activeChecker;
/**
* The binding manager for your application. Must not be
* <code>null</code>.
*/
// private final BindingManager bindingManager;
/**
* Whether a listener has been attached to the binding manager yet.
*/
// private boolean bindingManagerListenerAttached = false;
/**
* The command manager for your application. Must not be
* <code>null</code>.
*/
private final CommandManager commandManager;
/**
* A set of all the command identifiers that have been logged as broken
* so far. For each of these, there will be a listener on the
* corresponding command. If the command ever becomes defined, the item
* will be removed from this set and the listener removed. This value
* may be empty, but never <code>null</code>.
*/
private final Set loggedCommandIds = new HashSet();
/**
* The list of listeners that have registered for property change
* notification. This is a map of command identifiers (<code>String</code>)
* to listeners (<code>IPropertyChangeListener</code>).
*/
private final Map registeredListeners = new HashMap();
/**
* Constructs a new instance of <code>CommandCallback</code> with the
* workbench it should be using. All commands will be considered active.
*
* @param bindingManager
* The binding manager which will provide the callback; must
* not be <code>null</code>.
* @param commandManager
* The command manager which will provide the callback; must
* not be <code>null</code>.
*
* @since 1.0
*/
public CommandCallback(final /*BindingManager */ Object bindingManager,
final CommandManager commandManager) {
this(bindingManager, commandManager, new IActiveChecker() {
public boolean isActive(String commandId) {
return true;
}
});
}
/**
* Constructs a new instance of <code>CommandCallback</code> with the
* workbench it should be using.
*
* @param bindingManager
* The binding manager which will provide the callback; must
* not be <code>null</code>.
* @param commandManager
* The command manager which will provide the callback; must
* not be <code>null</code>.
* @param activeChecker
* The callback mechanism for checking whether a command is
* active; must not be <code>null</code>.
*
* @since 1.0
*/
public CommandCallback(final /* BindingManager */ Object bindingManager,
final CommandManager commandManager,
final IActiveChecker activeChecker) {
if (bindingManager == null) {
throw new NullPointerException(
"The callback needs a binding manager"); //$NON-NLS-1$
}
if (commandManager == null) {
throw new NullPointerException(
"The callback needs a command manager"); //$NON-NLS-1$
}
if (activeChecker == null) {
throw new NullPointerException(
"The callback needs an active callback"); //$NON-NLS-1$
}
this.activeChecker = activeChecker;
// this.bindingManager = bindingManager;
this.commandManager = commandManager;
}
/**
* @see org.eclipse.jface.action.ExternalActionManager.ICallback#addPropertyChangeListener(String,
* IPropertyChangeListener)
*/
public final void addPropertyChangeListener(final String commandId,
final IPropertyChangeListener listener) {
registeredListeners.put(commandId, listener);
// if (!bindingManagerListenerAttached) {
// bindingManager.addBindingManagerListener(this);
// bindingManagerListenerAttached = true;
// }
}
// public final void bindingManagerChanged(final BindingManagerEvent event) {
// if (event.isActiveBindingsChanged()) {
// final Iterator listenerItr = registeredListeners.entrySet()
// .iterator();
// while (listenerItr.hasNext()) {
// final Map.Entry entry = (Map.Entry) listenerItr.next();
// final String commandId = (String) entry.getKey();
// final Command command = commandManager
// .getCommand(commandId);
// final ParameterizedCommand parameterizedCommand = new ParameterizedCommand(
// command, null);
// if (event.isActiveBindingsChangedFor(parameterizedCommand)) {
// final IPropertyChangeListener listener = (IPropertyChangeListener) entry
// .getValue();
// listener.propertyChange(new PropertyChangeEvent(event
// .getManager(), IAction.TEXT, null, null));
// }
// }
// }
// }
/**
* @see org.eclipse.jface.action.ExternalActionManager.ICallback#getAccelerator(String)
*/
// public final Integer getAccelerator(final String commandId) {
// final TriggerSequence triggerSequence = bindingManager
// .getBestActiveBindingFor(commandId);
// if (triggerSequence != null) {
// final Trigger[] triggers = triggerSequence.getTriggers();
// if (triggers.length == 1) {
// final Trigger trigger = triggers[0];
// if (trigger instanceof KeyStroke) {
// final KeyStroke keyStroke = (KeyStroke) trigger;
// final int accelerator = SWTKeySupport
// .convertKeyStrokeToAccelerator(keyStroke);
// return new Integer(accelerator);
// }
// }
// }
//
// return null;
// }
/**
* @see org.eclipse.jface.action.ExternalActionManager.ICallback#getAcceleratorText(String)
*/
// public final String getAcceleratorText(final String commandId) {
// final TriggerSequence triggerSequence = bindingManager
// .getBestActiveBindingFor(commandId);
// if (triggerSequence == null) {
// return null;
// }
//
// return triggerSequence.format();
// }
/**
* Returns the active bindings for a particular command identifier.
*
* @param commandId
* The identifier of the command whose bindings are
* requested. This argument may be <code>null</code>. It
* is assumed that the command has no parameters.
* @return The array of active triggers (<code>TriggerSequence</code>)
* for a particular command identifier. This value is guaranteed
* not to be <code>null</code>, but it may be empty.
* @since 1.0
*/
// public final TriggerSequence[] getActiveBindingsFor(
// final String commandId) {
// return bindingManager.getActiveBindingsFor(commandId);
// }
/**
* @see org.eclipse.jface.action.ExternalActionManager.ICallback#isAcceleratorInUse(int)
*/
// public final boolean isAcceleratorInUse(final int accelerator) {
// final KeySequence keySequence = KeySequence
// .getInstance(SWTKeySupport
// .convertAcceleratorToKeyStroke(accelerator));
// return bindingManager.isPerfectMatch(keySequence)
// || bindingManager.isPartialMatch(keySequence);
// }
/**
* {@inheritDoc}
*
* Calling this method with an undefined command id will generate a log
* message.
*/
public final boolean isActive(final String commandId) {
if (commandId != null) {
final Command command = commandManager.getCommand(commandId);
if (!command.isDefined()
&& (!loggedCommandIds.contains(commandId))) {
// The command is not yet defined, so we should log this.
final String message = MessageFormat.format(Util
.translateString(RESOURCE_BUNDLE,
"undefinedCommand.WarningMessage", null), //$NON-NLS-1$
new String[] { command.getId() });
IStatus status = new Status(IStatus.ERROR,
"org.eclipse.jface", //$NON-NLS-1$
0, message, new Exception());
Policy.getLog().log(status);
// And remember this item so we don't log it again.
loggedCommandIds.add(commandId);
command.addCommandListener(new ICommandListener() {
/*
* (non-Javadoc)
*
* @see org.eclipse.ui.commands.ICommandListener#commandChanged(org.eclipse.ui.commands.CommandEvent)
*/
public final void commandChanged(
final CommandEvent commandEvent) {
if (command.isDefined()) {
command.removeCommandListener(this);
loggedCommandIds.remove(commandId);
}
}
});
return true;
}
return activeChecker.isActive(commandId);
}
return true;
}
/**
* @see org.eclipse.jface.action.ExternalActionManager.ICallback#removePropertyChangeListener(String,
* IPropertyChangeListener)
*/
public final void removePropertyChangeListener(final String commandId,
final IPropertyChangeListener listener) {
final IPropertyChangeListener existingListener = (IPropertyChangeListener) registeredListeners
.get(commandId);
if (existingListener == listener) {
registeredListeners.remove(commandId);
if (registeredListeners.isEmpty()) {
// bindingManager.removeBindingManagerListener(this);
// bindingManagerListenerAttached = false;
}
}
}
}
/**
* Defines a callback mechanism for developer who wish to further control
* the visibility of legacy action-based contribution items.
*
* @since 1.0
*/
public static interface IActiveChecker {
/**
* Checks whether the command with the given identifier should be
* considered active. This can be used in systems using some kind of
* user interface filtering (e.g., activities in the Eclipse workbench).
*
* @param commandId
* The identifier for the command; must not be
* <code>null</code>
* @return <code>true</code> if the command is active;
* <code>false</code> otherwise.
*/
public boolean isActive(String commandId);
}
/**
* <p>
* A callback which communicates with the applications binding manager. This
* interface provides more information from the binding manager, which
* allows greater integration. Implementing this interface is preferred over
* {@link ExternalActionManager.ICallback}.
* </p>
* <p>
* Clients may implement this interface, but must not extend.
* </p>
*
* @since 1.0
*/
// public static interface IBindingManagerCallback extends ICallback {
//
// /**
// * <p>
// * Returns the active bindings for a particular command identifier.
// * </p>
// *
// * @param commandId
// * The identifier of the command whose bindings are
// * requested. This argument may be <code>null</code>. It
// * is assumed that the command has no parameters.
// * @return The array of active triggers (<code>TriggerSequence</code>)
// * for a particular command identifier. This value is guaranteed
// * not to be <code>null</code>, but it may be empty.
// */
// public TriggerSequence[] getActiveBindingsFor(String commandId);
// }
/**
* A callback mechanism for some external tool to communicate extra
* information to actions and action contribution items.
*
* @since 1.0
*/
public static interface ICallback {
/**
* <p>
* Adds a listener to the object referenced by <code>identifier</code>.
* This listener will be notified if a property of the item is to be
* changed. This identifier is specific to mechanism being used. In the
* case of the Eclipse workbench, this is the command identifier.
* </p>
* <p>
* A single instance of the listener may only ever be associated with
* one identifier. Attempts to add the listener twice (without a removal
* in between) has undefined behaviour.
* </p>
*
* @param identifier
* The identifier of the item to which the listener should be
* attached; must not be <code>null</code>.
* @param listener
* The listener to be added; must not be <code>null</code>.
*/
public void addPropertyChangeListener(String identifier,
IPropertyChangeListener listener);
/**
* An accessor for the accelerator associated with the item indicated by
* the identifier. This identifier is specific to mechanism being used.
* In the case of the Eclipse workbench, this is the command identifier.
*
* @param identifier
* The identifier of the item from which the accelerator
* should be obtained ; must not be <code>null</code>.
* @return An integer representation of the accelerator. This is the
* same accelerator format used by SWT.
*/
public Integer getAccelerator(String identifier);
/**
* An accessor for the accelerator text associated with the item
* indicated by the identifier. This identifier is specific to mechanism
* being used. In the case of the Eclipse workbench, this is the command
* identifier.
*
* @param identifier
* The identifier of the item from which the accelerator text
* should be obtained ; must not be <code>null</code>.
* @return A string representation of the accelerator. This is the
* string representation that should be displayed to the user.
*/
public String getAcceleratorText(String identifier);
/**
* Checks to see whether the given accelerator is being used by some
* other mechanism (outside of the menus controlled by JFace). This is
* used to keep JFace from trying to grab accelerators away from someone
* else.
*
* @param accelerator
* The accelerator to check -- in SWT's internal accelerator
* format.
* @return <code>true</code> if the accelerator is already being used
* and shouldn't be used again; <code>false</code> otherwise.
*/
public boolean isAcceleratorInUse(int accelerator);
/**
* Checks whether the item matching this identifier is active. This is
* used to decide whether a contribution item with this identifier
* should be made visible. An inactive item is not visible.
*
* @param identifier
* The identifier of the item from which the active state
* should be retrieved; must not be <code>null</code>.
* @return <code>true</code> if the item is active; <code>false</code>
* otherwise.
*/
public boolean isActive(String identifier);
/**
* Removes a listener from the object referenced by
* <code>identifier</code>. This identifier is specific to mechanism
* being used. In the case of the Eclipse workbench, this is the command
* identifier.
*
* @param identifier
* The identifier of the item to from the listener should be
* removed; must not be <code>null</code>.
* @param listener
* The listener to be removed; must not be <code>null</code>.
*/
public void removePropertyChangeListener(String identifier,
IPropertyChangeListener listener);
}
/**
* The singleton instance of this class. This value may be <code>null</code>--
* if it has not yet been initialized.
*/
private static ExternalActionManager instance;
/**
* Retrieves the current singleton instance of this class.
*
* @return The singleton instance; this value is never <code>null</code>.
*/
public static ExternalActionManager getInstance() {
if (instance == null) {
instance = new ExternalActionManager();
}
return instance;
}
/**
* The callback mechanism to use to retrieve extra information.
*/
private ICallback callback;
/**
* Constructs a new instance of <code>ExternalActionManager</code>.
*/
private ExternalActionManager() {
// This is a singleton class. Only this class should create an instance.
}
/**
* An accessor for the current call back.
*
* @return The current callback mechanism being used. This is the callback
* that should be queried for extra information about actions and
* action contribution items. This value may be <code>null</code>
* if there is no extra information.
*/
public ICallback getCallback() {
return callback;
}
/**
* A mutator for the current call back
*
* @param callbackToUse
* The new callback mechanism to use; this value may be
* <code>null</code> if the default is acceptable (i.e., no
* extra information will provided to actions).
*/
public void setCallback(ICallback callbackToUse) {
callback = callbackToUse;
}
}