Java tutorial
/******************************************************************************* * Copyright (c) 2004, 2017 IBM Corporation and others. * * This program and the accompanying materials * are made available under the terms of the Eclipse Public License 2.0 * which accompanies this distribution, and is available at * https://www.eclipse.org/legal/epl-2.0/ * * SPDX-License-Identifier: EPL-2.0 * * Contributors: * IBM Corporation - initial API and implementation *******************************************************************************/ package org.eclipse.jface.bindings; import java.util.Arrays; import java.util.Collection; import java.util.Map; import org.eclipse.core.commands.ParameterizedCommand; import org.eclipse.core.commands.common.AbstractBitSetEvent; /** * An instance of this class describes changes to an instance of * <code>BindingManager</code>. * <p> * This class is not intended to be extended by clients. * </p> * * @since 3.1 * @see IBindingManagerListener#bindingManagerChanged(BindingManagerEvent) */ public final class BindingManagerEvent extends AbstractBitSetEvent { private static final TriggerSequence[] EMTPY_SEQUENCE = new TriggerSequence[0]; /** * The bit used to represent whether the map of active bindings has changed. */ private static final int CHANGED_ACTIVE_BINDINGS = 1; /** * The bit used to represent whether the active scheme has changed. */ private static final int CHANGED_ACTIVE_SCHEME = 1 << 1; /** * The bit used to represent whether the active locale has changed. */ private static final int CHANGED_LOCALE = 1 << 2; /** * The bit used to represent whether the active platform has changed. */ private static final int CHANGED_PLATFORM = 1 << 3; /** * The bit used to represent whether the scheme's defined state has changed. */ private static final int CHANGED_SCHEME_DEFINED = 1 << 4; /** * The binding manager that has changed; this value is never * <code>null</code>. */ private final BindingManager manager; /** * The map of triggers (<code>Collection</code> of * <code>TriggerSequence</code>) by parameterized command (<code>ParameterizedCommand</code>) * before the change occurred. This map may be empty and it may be * <code>null</code>. */ private final Map previousTriggersByParameterizedCommand; /** * The scheme that became defined or undefined. This value may be * <code>null</code> if no scheme changed its defined state. */ private final Scheme scheme; /** * Creates a new instance of this class. * * @param manager * the instance of the binding manager that changed; must not be * <code>null</code>. * @param activeBindingsChanged * Whether the active bindings have changed. * @param previousTriggersByParameterizedCommand * The map of triggers (<code>TriggerSequence</code>) by * fully-parameterized command (<code>ParameterizedCommand</code>) * before the change occured. This map may be <code>null</code> * or empty. * @param activeSchemeChanged * true, iff the active scheme changed. * @param scheme * The scheme that became defined or undefined; <code>null</code> * if no scheme changed state. * @param schemeDefined * <code>true</code> if the given scheme became defined; * <code>false</code> otherwise. * @param localeChanged * <code>true</code> iff the active locale changed * @param platformChanged * <code>true</code> iff the active platform changed */ public BindingManagerEvent(final BindingManager manager, final boolean activeBindingsChanged, final Map previousTriggersByParameterizedCommand, final boolean activeSchemeChanged, final Scheme scheme, final boolean schemeDefined, final boolean localeChanged, final boolean platformChanged) { if (manager == null) { throw new NullPointerException("A binding manager event needs a binding manager"); //$NON-NLS-1$ } this.manager = manager; if (schemeDefined && (scheme == null)) { throw new NullPointerException( "If a scheme changed defined state, then there should be a scheme identifier"); //$NON-NLS-1$ } this.scheme = scheme; this.previousTriggersByParameterizedCommand = previousTriggersByParameterizedCommand; if (activeBindingsChanged) { changedValues |= CHANGED_ACTIVE_BINDINGS; } if (activeSchemeChanged) { changedValues |= CHANGED_ACTIVE_SCHEME; } if (localeChanged) { changedValues |= CHANGED_LOCALE; } if (platformChanged) { changedValues |= CHANGED_PLATFORM; } if (schemeDefined) { changedValues |= CHANGED_SCHEME_DEFINED; } } /** * Returns the instance of the manager that changed. * * @return the instance of the manager that changed. Guaranteed not to be * <code>null</code>. */ public final BindingManager getManager() { return manager; } /** * Returns the scheme that changed. * * @return The changed scheme */ public final Scheme getScheme() { return scheme; } /** * Returns whether the active bindings have changed. * * @return <code>true</code> if the active bindings have changed; * <code>false</code> otherwise. */ public final boolean isActiveBindingsChanged() { return ((changedValues & CHANGED_ACTIVE_BINDINGS) != 0); } /** * Computes whether the active bindings have changed for a given command * identifier. * * @param parameterizedCommand * The fully-parameterized command whose bindings might have * changed; must not be <code>null</code>. * @return <code>true</code> if the active bindings have changed for the * given command identifier; <code>false</code> otherwise. */ public final boolean isActiveBindingsChangedFor(final ParameterizedCommand parameterizedCommand) { final TriggerSequence[] currentBindings = manager.getActiveBindingsFor(parameterizedCommand); final TriggerSequence[] previousBindings; if (previousTriggersByParameterizedCommand != null) { final Collection<TriggerSequence> previousBindingCollection = (Collection<TriggerSequence>) previousTriggersByParameterizedCommand .get(parameterizedCommand); if (previousBindingCollection == null) { previousBindings = EMTPY_SEQUENCE; } else { previousBindings = previousBindingCollection .toArray(new TriggerSequence[previousBindingCollection.size()]); } } else { previousBindings = EMTPY_SEQUENCE; } return !Arrays.equals(currentBindings, previousBindings); } /** * Returns whether or not the active scheme changed. * * @return true, iff the active scheme property changed. */ public final boolean isActiveSchemeChanged() { return ((changedValues & CHANGED_ACTIVE_SCHEME) != 0); } /** * Returns whether the locale has changed * * @return <code>true</code> if the locale changed; <code>false</code> * otherwise. */ public boolean isLocaleChanged() { return ((changedValues & CHANGED_LOCALE) != 0); } /** * Returns whether the platform has changed * * @return <code>true</code> if the platform changed; <code>false</code> * otherwise. */ public boolean isPlatformChanged() { return ((changedValues & CHANGED_PLATFORM) != 0); } /** * Returns whether the list of defined scheme identifiers has changed. * * @return <code>true</code> if the list of scheme identifiers has * changed; <code>false</code> otherwise. */ public final boolean isSchemeChanged() { return (scheme != null); } /** * Returns whether or not the scheme became defined * * @return <code>true</code> if the scheme became defined. */ public final boolean isSchemeDefined() { return (((changedValues & CHANGED_SCHEME_DEFINED) != 0) && (scheme != null)); } }