KeyboardNavigationHandler.java

/*******************************************************************************
 * Copyright (c) 2012-2017 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.ui.smartTree;

import com.google.gwt.dom.client.NativeEvent;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyDownEvent;
import com.google.gwt.event.dom.client.KeyDownHandler;
import com.google.gwt.event.dom.client.KeyPressEvent;
import com.google.gwt.event.dom.client.KeyPressHandler;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.user.client.Event;
import com.google.gwt.user.client.ui.Widget;

import org.eclipse.che.ide.util.browser.UserAgent;

/**
 * @author Vlad Zhukovskiy
 */
public class KeyboardNavigationHandler {
    class InternalHandler implements KeyDownHandler, KeyPressHandler {
        @Override
        public void onKeyDown(KeyDownEvent event) {
            handleEvent(event.getNativeEvent());
        }

        @Override
        public void onKeyPress(KeyPressEvent event) {
            handleEvent(event.getNativeEvent());
        }
    }

    private static int     keyEvent = Event.ONKEYDOWN;
    private        Widget  component;
    private        boolean preventDefault;

    static {
        if (UserAgent.isIE() || UserAgent.isWebkit()) {
            keyEvent = Event.ONKEYDOWN;
        } else {
            keyEvent = Event.ONKEYPRESS;
        }
    }

    public static int getKeyEvent() {
        return keyEvent;
    }

    private InternalHandler handler = new InternalHandler();
    private HandlerRegistration registration;

    public KeyboardNavigationHandler() {
    }

    public KeyboardNavigationHandler(Widget target) {
        bind(target);
    }

    public void bind(Widget target) {
        if (component != null) {
            registration.removeHandler();
        }

        if (target != null) {
            if (keyEvent == Event.ONKEYDOWN) {
                registration = target.addDomHandler(handler, KeyDownEvent.getType());
            } else {
                registration = target.addDomHandler(handler, KeyPressEvent.getType());
            }
        }

        component = target;
    }

    public Widget getComponent() {
        return component;
    }

    public boolean getPreventDefault() {
        return preventDefault;
    }

    public void handleEvent(NativeEvent event) {
        int code = event.getKeyCode();

        NativeEvent e = event;

        String type = event.getType();

        if ("keydown".equals(type) && keyEvent == Event.ONKEYDOWN || "keypress".equals(type) && keyEvent == Event.ONKEYPRESS) {

        } else {
            return;
        }

        if (component != null && component.getElement() != e.getCurrentEventTarget().cast()) {
            return;
        }

        if (preventDefault) {
            event.preventDefault();
        }

        onKeyPress(e);

        switch (code) {
            case KeyCodes.KEY_ALT:
                onAlt(e);
                break;
            case KeyCodes.KEY_BACKSPACE:
                onBackspace(e);
                break;
            case KeyCodes.KEY_CTRL:
                onControl(e);
                break;
            case KeyCodes.KEY_DELETE:
                onDelete(e);
                break;
            case KeyCodes.KEY_DOWN:
                onDown(e);
                break;
            case KeyCodes.KEY_END:
                onEnd(e);
                break;
            case KeyCodes.KEY_ENTER:
                onEnter(e);
                break;
            case KeyCodes.KEY_ESCAPE:
                onEsc(e);
                break;
            case KeyCodes.KEY_HOME:
                onHome(e);
                break;
            case KeyCodes.KEY_LEFT:
                onLeft(e);
                break;
            case KeyCodes.KEY_PAGEDOWN:
                onPageDown(e);
                break;
            case KeyCodes.KEY_PAGEUP:
                onPageUp(e);
                break;
            case KeyCodes.KEY_SHIFT:
                onShift(e);
                break;
            case KeyCodes.KEY_TAB:
                onTab(e);
                break;
            case KeyCodes.KEY_RIGHT:
                onRight(e);
                break;
            case KeyCodes.KEY_UP:
                onUp(e);
                break;
        }
    }

    public void onAlt(NativeEvent evt) {

    }

    public void onBackspace(NativeEvent evt) {

    }

    public void onControl(NativeEvent evt) {

    }

    public void onDelete(NativeEvent evt) {

    }

    public void onDown(NativeEvent evt) {

    }

    public void onEnd(NativeEvent evt) {

    }

    public void onEnter(NativeEvent evt) {

    }

    public void onEsc(NativeEvent evt) {

    }

    public void onHome(NativeEvent evt) {

    }

    public void onKeyPress(NativeEvent evt) {

    }

    public void onLeft(NativeEvent evt) {

    }

    public void onPageDown(NativeEvent evt) {

    }

    public void onPageUp(NativeEvent evt) {

    }

    public void onRight(NativeEvent evt) {

    }

    public void onShift(NativeEvent evt) {

    }

    public void onTab(NativeEvent evt) {

    }

    public void onUp(NativeEvent evt) {

    }

    public void setPreventDefault(boolean preventDefault) {
        this.preventDefault = preventDefault;
    }
}