CrossPlatform.java

package org.obo.app.util;

import java.io.File;

import javax.swing.JFrame;

/**
 * A collection of static methods providing platform-specific functionality.
 * @author Jim Balhoff
 */
public class CrossPlatform {

    public static enum Platform { MAC, WINDOWS, UNIX; }
    final private static String BULLET = String.format("%c", '\u2022');

    public static Platform getCurrentPlatform() {
        final String name = System.getProperty("os.name");
        if (name.startsWith("Mac")) {
            return Platform.MAC;
        } else if (name.startsWith("Windows")) {
            return Platform.WINDOWS;
        } else {
            return Platform.UNIX;
        }
    }

    /**
     * Don't add "Exit" to the File menu on Mac.
     * Instead there is "Quit" under the automatic app menu.
     */
    public static boolean shouldPutExitInFileMenu() {
        return !getCurrentPlatform().equals(Platform.MAC);
    }

    /**
     * Don't put the application name in the window title on Mac.
     * Instead it is visible in the menubar.
     */
    public static boolean shouldPutAppNameInWindowTitle() {
        return !getCurrentPlatform().equals(Platform.MAC);
    }

    /**
     * Titles this window appropriately to represent the given file, or as untitled 
     * if the file is null.  Also adds a proxy document icon on supported platforms (Mac OS X).
     */
    public static void setTitleOnWindowForFile(JFrame window, File file, String appName) {
        final String docName = file != null ? file.getName() : "Untitled";
        final String windowTitle;
        if (CrossPlatform.shouldPutAppNameInWindowTitle()) {
            windowTitle = docName + " - " + appName;
        } else {
            windowTitle = docName;
        }
        window.setTitle(windowTitle);
        window.getRootPane().putClientProperty("Window.documentFile", file);
    }

    public static void setWindowModified(JFrame window, boolean modified) {
        if (CrossPlatform.getCurrentPlatform().equals(Platform.MAC)) {
            window.getRootPane().putClientProperty("windowModified", modified);
            window.getRootPane().putClientProperty( "Window.documentModified", modified);
        } else {
            final String currentTitle = window.getTitle();
            final boolean currentModified = currentTitle.startsWith(BULLET);
            if (modified == currentModified) {
                return;
            } else {
                if (modified) {
                    window.setTitle(BULLET + " " + currentTitle);
                } else {
                    window.setTitle(currentTitle.substring(2));
                }
            }
        }
    }

    /**
     * Returns a folder suitable for storing per-user application support files.
     * This is unrelated to the storage location for java.util.prefs.
     */
    public static File getUserPreferencesFolder(String name) {
        final String homePath = System.getProperty("user.home");
        switch(getCurrentPlatform()) {
        // it would be much better to find a supported API for obtaining the Application Support folder
        case MAC: return new File(homePath, "Library/Application Support/" + name);
        case WINDOWS: return new File(homePath, name);
        // UNIX behavior is default
        default: return new File(homePath, "." + name.toLowerCase());
        }
    }

}