package org.limewire.setting;

import java.io.File;
import java.util.Properties;


/**
 * A proxy, aka a substitute, for a <code>FileSetting</code> object that returns
 * the value of another file setting as its default value.
 * <p>
 * Create a <code>ProxyFileSetting</code> object with a 
 * {@link SettingsFactory#createProxyFileSetting(String, FileSetting)}.
 * <pre>
        FileSetting genericDownloadFolderSetting = settingsfactory.createFileSetting(
                                                        "genericDownloadFolder", 
                                                        new File("/"));
        ProxyFileSetting audioDownloadFolderSetting = settingsfactory.createProxyFileSetting(
                                                            "audioDownloadFolder", 
                                                     genericDownloadFolderSetting);
        
        // prints the generic setting's value
        System.out.println(audioDownloadFolderSetting.getValue());
        
        audioDownloadFolderSetting.setValue(new File("/audio"));
        
        // audio
        System.out.println(audioDownloadFolderSetting.getValue());
        
        genericDownloadFolderSetting.setValue(new File("/new generic"));
        
        //audio
        System.out.println(audioDownloadFolderSetting.getValue());
        
        audioDownloadFolderSetting.revertToDefault();
        
        ///new generic
        System.out.println(audioDownloadFolderSetting.getValue());
    
        Output:
            C:\
            C:\audio
            C:\audio
            C:\new generic
</pre>
 */
public class ProxyFileSetting extends FileSetting {

	private FileSetting defaultSetting;

	/**
	 * Constructs a new file setting that defaults to a different setting.
	 */
	ProxyFileSetting(Properties defaultProps, Properties props, String key,
					 FileSetting defaultSetting) {
        super(defaultProps, props, key, 
                  new File("impossible-default-limewire-filename3141592"));
        setPrivate(true);
        this.defaultSetting = defaultSetting;
	}

	@Override
    public File get() {
		return isDefault() ? defaultSetting.get() : super.get();
	}
}