com.iamcontent.io.cli.CommandLineDriver.java Source code

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Here is the source code for com.iamcontent.io.cli.CommandLineDriver.java

Source

/**
  IAmContent Public Libraries.
  Copyright (C) 2015 Greg Elderfield
  @author Greg Elderfield, support@jarchitect.co.uk
     
  This program is free software; you can redistribute it and/or modify it under the terms of the
  GNU General Public License as published by the Free Software Foundation; either version 2 of 
  the License, or (at your option) any later version.
    
  This program 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 General Public License for more details.
    
  You should have received a copy of the GNU General Public License along with this program;
  if not, write to the Free Software Foundation, Inc., 
  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
package com.iamcontent.io.cli;

import static com.google.common.base.Predicates.not;
import static com.google.common.base.Predicates.or;
import static com.iamcontent.io.license.LicenseWriter.licenseWriter;
import static com.iamcontent.io.util.Readers.bufferedReader;

import java.io.BufferedReader;
import java.util.ArrayList;
import java.util.List;

import com.google.common.base.Predicate;
import com.google.common.collect.Iterables;
import com.iamcontent.io.license.LicenseWriter;
import com.iamcontent.io.util.BufferedReaderIterator;

/**
 * Foundation class for Command Line Interface (CLI) drivers.
 * @author Greg Elderfield
 */
public abstract class CommandLineDriver {

    private final LicenseWriter licenseWriter = licenseWriter();

    protected final BufferedReader in;
    private final List<Predicate<String>> commandHandlers = new ArrayList<>();

    public CommandLineDriver() {
        this(bufferedReader(System.in));
        addCommandHandler(warrantyCommandHandler());
        addCommandHandler(licenseCommandHandler());
        addCommandHandler(quitCommandHandler());
    }

    public CommandLineDriver(BufferedReader in) {
        this.in = in;
    }

    public static String tidied(String command) {
        return command.trim().toLowerCase();
    }

    protected Iterable<String> commandStrings() {
        licenseWriter.printInteractiveInstructions();
        return Iterables.filter(inputLines(), commandShouldBeProcessed());
    }

    private BufferedReaderIterator inputLines() {
        return new BufferedReaderIterator(in) {
            @Override
            public String next() {
                System.out.print("> ");
                System.out.flush();
                return super.next();
            }
        };
    }

    protected Predicate<String> commandShouldBeProcessed() {
        return not(commandExecutedByAnyHandler());
    }

    private Predicate<String> commandExecutedByAnyHandler() {
        return or(commandHandlers);
    }

    protected void onQuit() {
    }

    protected void addCommandHandler(Predicate<String> handler) {
        commandHandlers.add(handler);
    }

    private CommandHandler warrantyCommandHandler() {
        return new LiteralCommandHandler("warranty") {
            @Override
            protected void executeCommand(String argument) {
                licenseWriter.printWarranty();
            }
        };
    }

    private CommandHandler licenseCommandHandler() {
        return new LiteralCommandHandler("license", "licence") {
            @Override
            protected void executeCommand(String argument) {
                licenseWriter.printTermsAndConditions();
            }
        };
    }

    private CommandHandler quitCommandHandler() {
        return new LiteralCommandHandler(null, "q", "quit", "exit", "bye") {
            @Override
            protected void executeCommand(String argument) {
                onQuit();
                System.out.println("Bye");
                System.exit(0);
            }
        };
    }
}