FocusManager.java

/*******************************************************************************
 * Copyright (c) 2012-2015 Codenvy, S.A.
 * 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:
 *   Codenvy, S.A. - initial API and implementation
 *******************************************************************************/
package org.eclipse.che.ide.part;

import org.eclipse.che.ide.api.event.ActivePartChangedEvent;
import org.eclipse.che.ide.api.parts.HasView;
import org.eclipse.che.ide.api.parts.Focusable;
import org.eclipse.che.ide.api.parts.PartPresenter;
import org.eclipse.che.ide.api.parts.PartStack;
import org.eclipse.che.ide.part.PartStackPresenter.PartStackEventHandler;
import com.google.gwt.core.client.Scheduler;
import com.google.inject.Inject;
import com.google.inject.Singleton;
import com.google.web.bindery.event.shared.EventBus;


/**
 * FocusManager is responsible for granting a focus for a stack when requested.
 *
 * @author <a href="mailto:nzamosenchuk@exoplatform.com">Nikolay Zamosenchuk</a>
 */
@Singleton
public class FocusManager {

    private PartStack activePartStack;

    private PartPresenter activePart;

    private final EventBus eventBus;

    /**
     * Provides a handler, that is injected into PartStack, for the FocusManager to be able to track
     * PartStack focus requests and changes of the active Part.
     *
     * @return instance of PartStackEventHandler
     */
    public PartStackEventHandler getPartStackHandler() {
        return partStackHandler;
    }

    /** Instantiates PartAgent with provided factory and event bus */
    @Inject
    public FocusManager(EventBus eventBus) {
        this.eventBus = eventBus;
    }

    public static final String HIGHLIGHT_COLOR = "rgb(77, 113, 145)";

    private final PartStackEventHandler partStackHandler = new PartStackEventHandler() {
        @Override
        public void onRequestFocus(PartStack partStack) {
            if (partStack == null || partStack.getActivePart() == null) {
                return;
            }

            if (partStack == activePartStack && partStack.getActivePart() == activePart) {
                return;
            }

            /** unfocus active part stack */
            if (activePartStack != null) {
                activePartStack.setFocus(false);
            }

            /** unfocus active part */
            if (activePart != null &&
                activePart instanceof HasView && ((HasView)activePart).getView() instanceof Focusable) {
                ((Focusable)((HasView)activePart).getView()).setFocus(false);
            }

            /** remember active part stack and part */
            activePartStack = partStack;
            activePart = partStack.getActivePart();

            /** focus part stack */
            activePartStack.setFocus(true);

            /** focus part if it has view and focusable */
            if (activePart != null) {
                if (activePart instanceof HasView && ((HasView)activePart).getView() instanceof Focusable) {
                    Scheduler.get().scheduleDeferred(new Scheduler.ScheduledCommand() {
                        @Override
                        public void execute() {
                            ((Focusable)((HasView)activePart).getView()).setFocus(true);
                        }
                    });
                }
            }

            Scheduler.get().scheduleDeferred(new Scheduler.ScheduledCommand() {
                @Override
                public void execute() {
                    eventBus.fireEvent(new ActivePartChangedEvent(activePart));
                }
            });

        }
    };

}