org.opennms.features.topology.ssh.internal.gwt.client.ui.VTerminal.java Source code

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Here is the source code for org.opennms.features.topology.ssh.internal.gwt.client.ui.VTerminal.java

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/*******************************************************************************
 * This file is part of OpenNMS(R).
 *
 * Copyright (C) 2012-2014 The OpenNMS Group, Inc.
 * OpenNMS(R) is Copyright (C) 1999-2014 The OpenNMS Group, Inc.
 *
 * OpenNMS(R) is a registered trademark of The OpenNMS Group, Inc.
 *
 * OpenNMS(R) is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published
 * by the Free Software Foundation, either version 3 of the License,
 * or (at your option) any later version.
 *
 * OpenNMS(R) is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with OpenNMS(R).  If not, see:
 *      http://www.gnu.org/licenses/
 *
 * For more information contact:
 *     OpenNMS(R) Licensing <license@opennms.org>
 *     http://www.opennms.org/
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package org.opennms.features.topology.ssh.internal.gwt.client.ui;

import com.vaadin.client.ApplicationConnection;
import com.vaadin.client.Paintable;
import com.vaadin.client.UIDL;

/**
 * The VTerminal class is associated with the GwtTerminal widget and handles all of the communication 
 * from the client and sends it to the server.  It also listens for responses from the server and 
 * updates the client side view.
 * @author Leonardo Bell
 * @author Philip Grenon
 */
public class VTerminal extends GwtTerminal implements Paintable {

    String uidlId; //Component identifier in UIDL communications.
    ApplicationConnection client; //Reference to the server connection object.
    private TermHandler termHandler; //Key handler for VT100 codes
    private boolean isClosed; //Lets the server know the status of the Handler
    private boolean isFocused; //Lets the server know whether the widget is focused

    /**
     * The VTerminal() constructor creates a GwtTerminal Widget and assigns the TermHandler
     * to each of its key handlers and initializes the status of the Terminal
     */
    public VTerminal() {
        super();
        termHandler = new TermHandler(this);
        addKeyDownHandler(termHandler);
        addKeyPressHandler(termHandler);
        addKeyUpHandler(termHandler);
        isClosed = false;
        isFocused = false;
    }

    /**
     * The update method is used by the server whenever it requests an update from 
     * the TermHandler in order to receive the current key presses from the client.
     */
    public void update() {
        termHandler.update();
    }

    /**
     * The updateFromUIDL method handles all communication from the server and passes
     * the data along to the GwtTerminal widget which updates the client side view.
     */
    @Override
    public void updateFromUIDL(UIDL uidl, ApplicationConnection client) {

        // This call should be made first. Ensure correct implementation,
        // and let the containing layout manage caption, etc.
        if (client.updateComponent(this, uidl, true)) {
            return;
        }

        // Save reference to server connection object to be able to send
        // user interaction later
        this.client = client;

        // Save the UIDL identifier for the component
        this.uidlId = uidl.getId();

        // Check if the server wants the TermHandler to close, if so, send a
        // response back to the server that it was closed successfully
        if (uidl.getBooleanVariable("closeClient")) {
            termHandler.close();
            isClosed = true;
            sendBytes("");
        }

        // Check if the server wants the TermHandler to update manually
        if (uidl.getBooleanVariable("update"))
            update();
        if (uidl.getBooleanVariable("focus")) {
            super.focus();
            isFocused = true;
        }

        // Take the current representation of the Terminal from the server
        // and set the Inner HTML of the widget
        dump(uidl.getStringVariable("fromSSH"));
    }

    public void sendBytes(String inputKeys) {

        // Send the server the current state of the TermHandler
        client.updateVariable(uidlId, "isClosed", isClosed, true);

        // Send the server the current KeyBuffer from the client
        if (!isClosed) {
            client.updateVariable(uidlId, "toSSH", inputKeys, true);
        }

        // Tell the server if the widget is focused or not
        client.updateVariable(uidlId, "isFocused", isFocused, true);

    }

}