JMeter example source code file (LoadRecentProject.java)

This example JMeter source code file (LoadRecentProject.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - JMeter tags/keywords

awt, event, file, gui, jmenuitem, jmenuitem, jseparator, linkedlist, linkedlist, non-nls-1, number_of_menu_items, number_of_menu_items, override, preferences, set, string, string, stringbuilder, swing, util

The JMeter LoadRecentProject.java source code

/*
 * 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 org.apache.jmeter.gui.action;

import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.io.File;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Set;
import java.util.prefs.Preferences;

import javax.swing.JComponent;
import javax.swing.JMenuItem;
import javax.swing.JSeparator;

/**
 * Handles the loading of recent files, and also the content and
 * visibility of menu items for loading the recent files
 */
public class LoadRecentProject extends Load {
    /** Prefix for the user preference key */
    private static final String USER_PREFS_KEY = "recent_file_"; //$NON-NLS-1$
    /** The number of menu items used for recent files */
    private static final int NUMBER_OF_MENU_ITEMS = 9;
    private static final Set<String> commands = new HashSet();

    static {
        commands.add(ActionNames.OPEN_RECENT);
    }

    private static final Preferences prefs = Preferences.userNodeForPackage(LoadRecentProject.class);
    // Note: Windows user preferences are stored relative to: HKEY_CURRENT_USER\Software\JavaSoft\Prefs

    public LoadRecentProject() {
        super();
    }

    @Override
    public Set<String> getActionNames() {
        return commands;
    }

    @Override
    public void doAction(ActionEvent e) {
        // We must ask the user if it is ok to close current project
        if (!Close.performAction(e)) {
            return;
        }
        // Load the file for this recent file command
        loadProjectFile(e, getRecentFile(e), false);
    }

    /**
     * Get the recent file for the menu item
     */
    private File getRecentFile(ActionEvent e) {
        JMenuItem menuItem = (JMenuItem)e.getSource();
        // Get the preference for the recent files
        return new File(getRecentFile(Integer.parseInt(menuItem.getName())));
    }

    /**
     * Get the menu items to add to the menu bar, to get recent file functionality
     *
     * @return a List of JMenuItem and a JSeparator, representing recent files
     */
    public static List<JComponent> getRecentFileMenuItems() {
        LinkedList<JComponent> menuItems = new LinkedList();
        // Get the preference for the recent files
        for(int i = 0; i < NUMBER_OF_MENU_ITEMS; i++) {
            // Create the menu item
            JMenuItem recentFile = new JMenuItem();
            // Use the index as the name, used when processing the action
            recentFile.setName(Integer.toString(i));
            recentFile.addActionListener(ActionRouter.getInstance());
            recentFile.setActionCommand(ActionNames.OPEN_RECENT);
            // Set the KeyStroke to use
            int shortKey = getShortcutKey(i);
            if(shortKey >= 0) {
                recentFile.setMnemonic(shortKey);
            }
            // Add the menu item
            menuItems.add(recentFile);
        }
        // Add separator as the last item
        JSeparator separator = new JSeparator();
        separator.setVisible(false);
        menuItems.add(separator);

        // Update menu items to reflect recent files
        updateMenuItems(menuItems);

        return menuItems;
    }

    /**
     * Update the content and visibility of the menu items for recent files
     *
     * @param menuItems the JMenuItem and JSeparator to update
     * @param loadedFileName the file name of the project file that has just
     * been loaded
     */
    public static void updateRecentFileMenuItems(List<JComponent> menuItems, String loadedFileName) {
        // Get the preference for the recent files

        LinkedList<String> newRecentFiles = new LinkedList();
        // Check if the new file is already in the recent list
        boolean alreadyExists = false;
        for(int i = 0; i < NUMBER_OF_MENU_ITEMS; i++) {
            String recentFilePath = getRecentFile(i);
            if(!loadedFileName.equals(recentFilePath)) {
                newRecentFiles.add(recentFilePath);
            }
            else {
                alreadyExists = true;
            }
        }
        // Add the new file at the start of the list
        newRecentFiles.add(0, loadedFileName);
        // Remove the last item from the list if it was a brand new file
        if(!alreadyExists) {
            newRecentFiles.removeLast();
        }
        // Store the recent files
        for(int i = 0; i < NUMBER_OF_MENU_ITEMS; i++) {
            String fileName = newRecentFiles.get(i);
            if(fileName != null) {
                setRecentFile(i, fileName);
            }
        }
        // Update menu items to reflect recent files
        updateMenuItems(menuItems);
    }

    /**
     * Set the content and visibility of menu items and menu separator,
     * based on the recent file stored user preferences.
     */
    private static void updateMenuItems(List<JComponent> menuItems) {
        // Assume no recent files
        boolean someRecentFiles = false;
        // Update the menu items
        for(int i = 0; i < NUMBER_OF_MENU_ITEMS; i++) {
            // Get the menu item
            JMenuItem recentFile = (JMenuItem)menuItems.get(i);

            // Find and set the file for this recent file command
            String recentFilePath = getRecentFile(i);
            if(recentFilePath != null) {
                File file = new File(recentFilePath);
                StringBuilder sb = new StringBuilder(60);
                if (i<9) {
                    sb.append(i+1).append(" "); //$NON-NLS-1$
                }
                sb.append(getMenuItemDisplayName(file));
                recentFile.setText(sb.toString());
                recentFile.setToolTipText(recentFilePath);
                recentFile.setEnabled(true);
                recentFile.setVisible(true);
                // At least one recent file menu item is visible
                someRecentFiles = true;
            }
            else {
                recentFile.setEnabled(false);
                recentFile.setVisible(false);
            }
        }
        // If there are some recent files, we must make the separator visisble
        // The separator is the last item in the list
        JSeparator separator = (JSeparator)menuItems.get(menuItems.size() - 1);
        separator.setVisible(someRecentFiles);
    }

    /**
     * Get the name to display in the menu item, it will chop the file name
     * if it is too long to display in the menu bar
     */
    private static String getMenuItemDisplayName(File file) {
        // Limit the length of the menu text if needed
        final int maxLength = 40;
        String menuText = file.getName();
        if(menuText.length() > maxLength) {
            menuText = "..." + menuText.substring(menuText.length() - maxLength, menuText.length()); //$NON-NLS-1$
        }
        return menuText;
    }

    /**
     * Get the KeyEvent to use as shortcut key for menu item
     */
    private static int getShortcutKey(int index) {
        int shortKey = -1;
        switch(index+1) {
            case 1:
                shortKey = KeyEvent.VK_1;
                break;
            case 2:
                shortKey = KeyEvent.VK_2;
                break;
            case 3:
                shortKey = KeyEvent.VK_3;
                break;
            case 4:
                shortKey = KeyEvent.VK_4;
                break;
            case 5:
                shortKey = KeyEvent.VK_5;
                break;
            case 6:
                shortKey = KeyEvent.VK_6;
                break;
            case 7:
                shortKey = KeyEvent.VK_7;
                break;
            case 8:
                shortKey = KeyEvent.VK_8;
                break;
            case 9:
                shortKey = KeyEvent.VK_9;
                break;
            default:
                break;
        }
        return shortKey;
    }

    /**
     * Get the full path to the recent file where index 0 is the most recent
     */
    public static String getRecentFile(int index) {
        return prefs.get(USER_PREFS_KEY + index, null);
    }

    /**
     * Set the full path to the recent file where index 0 is the most recent
     */
    private static void setRecentFile(int index, String fileName) {
        prefs.put(USER_PREFS_KEY + index, fileName);
    }
}