com.github.fritaly.dualcommander.UserPreferences.java Source code

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Here is the source code for com.github.fritaly.dualcommander.UserPreferences.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */
package com.github.fritaly.dualcommander;

import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import java.util.prefs.Preferences;

import org.apache.commons.lang.Validate;
import org.apache.log4j.Logger;

public final class UserPreferences {

    private final Logger logger = Logger.getLogger(this.getClass());

    private final PropertyChangeSupport changeSupport = new PropertyChangeSupport(this);

    /**
     * The name associated to the {@link #showHidden} property.
     */
    public static final String PROPERTY_SHOW_HIDDEN = "show.hidden";

    public static final String PROPERTY_EDIT_FILE_COMMAND = "commands.edit.file";

    public static final String PROPERTY_VIEW_FILE_COMMAND = "commands.view.file";

    /**
     * Whether hidden directories and files should be shown.
     */
    private boolean showHidden = false;

    /**
     * The command line for editing a file with an external process.
     */
    private String editFileCommand = "edit";

    /**
     * The command line for viewing a file with an external process.
     */
    private String viewFileCommand = "open";

    /**
     * Whether the object state has been initialized.
     */
    private boolean initialized = false;

    public UserPreferences() {
    }

    // Copy constructor
    public UserPreferences(UserPreferences preferences) {
        Validate.notNull(preferences, "The given user preferences is null");

        this.showHidden = preferences.isShowHidden();
        this.editFileCommand = preferences.getEditFileCommand();
        this.viewFileCommand = preferences.getViewFileCommand();

        // The user preferences can be initialized only once
        this.initialized = true;
    }

    public void apply(UserPreferences preferences) {
        Validate.notNull(preferences, "The given user preferences is null");

        setShowHidden(preferences.isShowHidden());
        setEditFileCommand(preferences.getEditFileCommand());
        setViewFileCommand(preferences.getViewFileCommand());
    }

    private void assertInitialized() {
        if (!isInitialized()) {
            throw new IllegalStateException("The user preferences haven't been initialized");
        }
    }

    private void assertNotInitialized() {
        if (isInitialized()) {
            throw new IllegalStateException("The user preferences have already been initialized");
        }
    }

    private synchronized boolean isInitialized() {
        return this.initialized;
    }

    public void addPropertyChangeListener(PropertyChangeListener listener) {
        this.changeSupport.addPropertyChangeListener(listener);
    }

    public void removePropertyChangeListener(PropertyChangeListener listener) {
        this.changeSupport.removePropertyChangeListener(listener);
    }

    public synchronized void init(Preferences preferences) {
        assertNotInitialized();

        Validate.notNull(preferences, "The given preferences is null");

        this.showHidden = preferences.getBoolean(PROPERTY_SHOW_HIDDEN, false);
        this.editFileCommand = preferences.get(PROPERTY_EDIT_FILE_COMMAND, "edit");
        this.viewFileCommand = preferences.get(PROPERTY_VIEW_FILE_COMMAND, "open");

        // The user preferences can be initialized only once
        this.initialized = true;

        if (logger.isInfoEnabled()) {
            logger.info("Initialized user preferences");
        }
    }

    public void saveState(Preferences preferences) {
        assertInitialized();

        Validate.notNull(preferences, "The given preferences is null");

        preferences.putBoolean(PROPERTY_SHOW_HIDDEN, this.showHidden);
        preferences.put(PROPERTY_EDIT_FILE_COMMAND, this.editFileCommand);
        preferences.put(PROPERTY_VIEW_FILE_COMMAND, this.viewFileCommand);

        if (logger.isInfoEnabled()) {
            logger.info("Saved user preferences");
        }
    }

    public String getEditFileCommand() {
        assertInitialized();

        return editFileCommand;
    }

    public String getViewFileCommand() {
        assertInitialized();

        return viewFileCommand;
    }

    public void setEditFileCommand(String command) {
        Validate.notNull(command, "The given edit file command is null");

        assertInitialized();

        // No need to notify listeners
        this.editFileCommand = command;
    }

    public void setViewFileCommand(String command) {
        Validate.notNull(editFileCommand, "The given view file command is null");

        assertInitialized();

        // No need to notify listeners
        this.viewFileCommand = command;
    }

    public boolean isShowHidden() {
        assertInitialized();

        return showHidden;
    }

    public void setShowHidden(boolean showHidden) {
        assertInitialized();

        final boolean oldValue = this.showHidden;

        this.showHidden = showHidden;

        if (oldValue != showHidden) {
            this.changeSupport.firePropertyChange(PROPERTY_SHOW_HIDDEN, oldValue, showHidden);
        }
    }
}