name.martingeisse.stackd.client.console.Console.java Source code

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Here is the source code for name.martingeisse.stackd.client.console.Console.java

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/**
 * Copyright (c) 2010 Martin Geisse
 *
 * This file is distributed under the terms of the MIT license.
 */

package name.martingeisse.stackd.client.console;

import java.util.concurrent.ConcurrentLinkedQueue;
import org.apache.commons.lang3.ArrayUtils;
import org.apache.commons.lang3.StringUtils;

/**
 * This class handles the client-side console and command execution.
 */
public class Console {

    /**
     * the commandHandler
     */
    private IConsoleCommandHandler commandHandler;

    /**
     * the inputLine
     */
    private final StringBuilder inputLine;

    /**
     * the outputLines
     */
    private final ConcurrentLinkedQueue<String> outputLines;

    /**
     * Constructor.
     */
    public Console() {
        setCommandHandler(null);
        inputLine = new StringBuilder();
        outputLines = new ConcurrentLinkedQueue<>();
    }

    /**
     * Setter method for the commandHandler.
     * @param commandHandler the commandHandler to set
     */
    public void setCommandHandler(IConsoleCommandHandler commandHandler) {
        this.commandHandler = (commandHandler == null ? new NullConsoleCommandHandler() : commandHandler);
    }

    /**
     * Getter method for the commandHandler.
     * @return the commandHandler
     */
    public IConsoleCommandHandler getCommandHandler() {
        return commandHandler;
    }

    /**
     * Returns the currently visible output lines.
     * @return the output lines
     */
    public ConcurrentLinkedQueue<String> getCurrentOutputLines() {
        return outputLines;
    }

    /**
     * Returns the current contents of the input line
     * @return the input line
     */
    public CharSequence getCurrentInputLine() {
        return inputLine;
    }

    /**
     * Consumes a whole string of input characters at once.
     * @param s the string of input characters to consume
     */
    public final void consumeInputString(final String s) {
        for (int i = 0; i < s.length(); i++) {
            consumeInputCharacter(s.charAt(i));
        }
    }

    /**
     * Consumes a single input character.
     * @param c the input character to consume
     */
    public final void consumeInputCharacter(final char c) {
        if (c == '\n' || c == '\r') {
            executeCommandLine(inputLine.toString());
            inputLine.setLength(0);
        } else if (c == '\b' || c == 127) {
            if (inputLine.length() > 0) {
                inputLine.setLength(inputLine.length() - 1);
            }
        } else {
            inputLine.append(c);
        }
    }

    /**
     * Causes the console to execute a command line programmatically.
     * @param commandLine the command line to execute
     */
    public final void executeCommandLine(String commandLine) {

        // remove special characters
        {
            StringBuilder builder = new StringBuilder();
            for (int i = 0; i < commandLine.length(); i++) {
                char c = commandLine.charAt(i);
                if (c >= 32) {
                    builder.append(c);
                }
            }
            commandLine = builder.toString();
        }

        // split into segments
        String[] segments = StringUtils.split(commandLine);
        if (segments.length == 0) {
            return;
        }

        // invoke the command handler
        String command = segments[0];
        String[] args = ArrayUtils.subarray(segments, 1, segments.length);
        commandHandler.handleCommand(this, command, args);

    }

    /**
     * Prints the specified string on the console.
     * @param s the string to print
     */
    public final void print(final String s) {
        for (final String line : StringUtils.split(s, '\n')) {
            outputLines.add(line);
        }
        while (outputLines.size() > 15) {
            outputLines.poll();
        }
    }

    /**
     * Prints the specified string on the console, followed by a newline character
     * @param line the line to print
     */
    public final void println(final String line) {
        print(line);
        print("\n");
    }

    /**
     * Prints a newline character on the console.
     */
    public final void println() {
        print("\n");
    }

}