ch.unifr.pai.twice.widgets.client.RemoteKeyRecorder.java Source code

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Here is the source code for ch.unifr.pai.twice.widgets.client.RemoteKeyRecorder.java

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package ch.unifr.pai.twice.widgets.client;

/*
 * Copyright 2013 Oliver Schmid
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import ch.unifr.pai.twice.comm.serverPush.client.RemoteWidget;
import ch.unifr.pai.twice.comm.serverPush.client.ServerPushEventBus;
import ch.unifr.pai.twice.widgets.client.events.UndoableRemoteKeyPressEvent;
import ch.unifr.pai.twice.widgets.client.events.UndoableRemoteKeyPressEvent.UndoableRemoteKeyPressHandler;

import com.google.gwt.core.client.GWT;
import com.google.gwt.event.dom.client.BlurEvent;
import com.google.gwt.event.dom.client.BlurHandler;
import com.google.gwt.event.dom.client.FocusEvent;
import com.google.gwt.event.dom.client.FocusHandler;
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.KeyUpEvent;
import com.google.gwt.event.dom.client.KeyUpHandler;
import com.google.gwt.user.client.Event;
import com.google.gwt.user.client.Event.NativePreviewEvent;
import com.google.gwt.user.client.Event.NativePreviewHandler;
import com.google.gwt.user.client.ui.TextBox;
import com.google.web.bindery.event.shared.HandlerRegistration;

public class RemoteKeyRecorder extends TextBox implements RemoteWidget {

    private String uniqueIdentifier;
    private ServerPushEventBus eventBus;
    private HandlerRegistration keyRegistration;

    @Override
    public String getEventSource() {
        return uniqueIdentifier;
    }

    private void send(Integer keycode, String text, Integer cursorPos) {
        UndoableRemoteKeyPressEvent e = GWT.create(UndoableRemoteKeyPressEvent.class);
        if (keycode != null)
            e.setKeyCode(keycode);
        if (text != null)
            e.setText(text);
        if (cursorPos != null)
            e.setCursorPos(cursorPos);
        eventBus.fireEventFromSource(e, this);
    }

    /**
     * Define a static, unique identifier for this text box. This is needed for
     * the linkage between the different clients. Make sure that this value is
     * not composed dynamically - the best is a usage of a simple string not
     * coming from any other method.
     * 
     * @param uniqueIdentifier
     */
    public RemoteKeyRecorder(String uniqueIdentifier, ServerPushEventBus eventBus) {
        super();
        this.uniqueIdentifier = uniqueIdentifier;
        this.eventBus = eventBus;
        addFocusHandler(new FocusHandler() {

            @Override
            public void onFocus(FocusEvent event) {
                keyRegistration = Event.addNativePreviewHandler(new NativePreviewHandler() {

                    @Override
                    public void onPreviewNativeEvent(NativePreviewEvent event) {
                        switch (event.getTypeInt()) {
                        case Event.ONKEYUP:
                            switch (event.getNativeEvent().getKeyCode()) {
                            case KeyCodes.KEY_DELETE:
                            case KeyCodes.KEY_BACKSPACE:
                                send(event.getNativeEvent().getKeyCode(), null, null);
                                break;
                            case KeyCodes.KEY_LEFT:
                                send(null, null, -1);
                                break;
                            case KeyCodes.KEY_RIGHT:
                                send(null, null, 1);
                            }
                            event.cancel();
                            break;
                        case Event.ONKEYPRESS:
                            send(null, String.valueOf((char) event.getNativeEvent().getCharCode()), null);
                            event.cancel();
                            break;

                        }

                    }
                });
            }
        });
        addBlurHandler(new BlurHandler() {

            @Override
            public void onBlur(BlurEvent event) {
                if (keyRegistration != null)
                    keyRegistration.removeHandler();
                keyRegistration = null;
            }
        });
    }
}