keybindings.java

这是一个基于java编写的torrent的P2P源码

        final String[] tmpValues = keyBindingValue.split(DELIM_EXP);
        final boolean[] specVisited = new boolean[SPECIAL_KEYS.length]; // flag for speed optimization
        boolean funcVisited = false;

        final StringBuffer displayValue = new StringBuffer(keyBindingValue.length() + 2); // allocate display string
        displayValue.append('\t');

        for (int i = 0; i < tmpValues.length; i++)
        {
            final String value = tmpValues[i];
            boolean matched = false;

             // process special keys first
            for(int j = 0; j < SPECIAL_KEYS.length; j++)
            {
                if(!specVisited[j] && SPECIAL_KEYS[j].equalsIgnoreCase(value))
                {
                    swtAccelerator = swtAccelerator | SPECIAL_VALUES[j];

                    // special-case meta; a generalized solution would be warranted if:
                    // a) additional special modifiers persist or
                    // b) other platforms have special labeling requirements or
                    // c) SWT changes its lower-level API so shortcut labels are no longer custom drawn on Win etc.
                    if(SPECIAL_KEYS[j].equalsIgnoreCase("Meta"))
                        displayValue.append(Constants.isOSX ? "Cmd" : "Ctrl").append(DELIM);
                    else
                        displayValue.append(SPECIAL_KEYS[j]).append(DELIM);

                    // mark flags
                    specVisited[j] = true;
                    matched = true;
                    break;
                }
            }

            if(matched)
                continue;

            // special treatment for function keys
            if(!funcVisited)
            {
                final Matcher funcMatcher = FUNC_EXP.matcher(value);
                if(funcMatcher.find() && funcMatcher.start() == 0 && funcMatcher.end() == value.length())
                {
                    final int funcVal = Integer.parseInt(funcMatcher.group(2));

                    // SWT.F1 is (1 << 24) + 10
                    swtAccelerator = swtAccelerator | ((1 << 24) + (9 + funcVal));
                    displayValue.append(funcMatcher.group(0)).append(DELIM);

                    funcVisited = true;
                    matched = true;
                }
            }

            if(matched)
                continue;

            final Matcher valMatcher = SANCTIONED_EXP.matcher(value);
            if(valMatcher.find() && valMatcher.start() == 0)
            {
                final char c = valMatcher.group().charAt(0);

                // avoid possible duplicates (\t is index 0)
                final int subStrIndex = displayValue.indexOf(c + DELIM);
                if(subStrIndex == 1 || (subStrIndex > 1 && displayValue.substring(subStrIndex - 1, subStrIndex).equals(DELIM)))
                    continue;

                swtAccelerator = swtAccelerator | c;
                displayValue.append(c).append(DELIM);
            }
        }

        if(funcVisited || specVisited[0] || specVisited[1] || specVisited[2] || specVisited[3] || specVisited[4]) // special case - be a bit careful for now
            return new KeyBindingInfo(displayValue.substring(0, displayValue.length() - 1), swtAccelerator);
        else
            return new KeyBindingInfo(null, SWT.NONE);
    }

    /**
     * <p>
     * Removes the keyboard accelerator for a SWT MenuItem
     * </p>
     * @param menu SWT MenuItem
     * @param localizationKey The MenuItem's localization key for the localization resource bundle
     */
    public static void removeAccelerator(final MenuItem menu, String localizationKey)
    {
        setAccelerator(menu, new KeyBindingInfo("", SWT.NONE));
        Messages.setLanguageText(menu, localizationKey);
    }

    /**
     * <p>
     * Sets the keyboard accelerator for a SWT MenuItem.
     * </p>
     * <p>
     * There is a specific order of accelerator setting in consideration with different platforms and localizations. Specifically:<br />
     * <ol>
     * <li>If a localized keybinding value exists for the current locale and platform, it is used</li>
     * <li>If the above is not found, this method looks for a keybinding value for the current locale without platform specificity</li>
     * <li>If the above is not found, this method looks for a keybinding value for the default locale and the currently running platform</li>
     * <li>If the above is not found, this method looks for a keybinding value for the default locale without platform specificity</li>
     * <li>If the above is not found, no accelerator is set for the MenuItem</li>
     * </ol>
     * </p>
     * @param menu SWT MenuItem
     * @param localizationKey The MenuItem's localization key for the localization resource bundle
     */
    public static void setAccelerator(final MenuItem menu, String localizationKey)
    {
        localizationKey += ".keybinding";
        final String platformSpecificKey = localizationKey + getPlatformKeySuffix();

        // first, check for platform-specific, localization-specific binding
        if(MessageText.keyExists(platformSpecificKey))
        {
            setAccelerator(menu, parseKeyBinding(MessageText.getString(platformSpecificKey)));
        }
        else if(MessageText.keyExists(localizationKey)) // platform-independent, localization-specific binding
        {
            setAccelerator(menu, parseKeyBinding(MessageText.getString(localizationKey)));
        }
        else if(!MessageText.isCurrentLocale(MessageText.LOCALE_DEFAULT))
        {
            // default locale

            // platform-specific first
            if(MessageText.keyExistsForDefaultLocale(platformSpecificKey))
            {
                setAccelerator(menu, parseKeyBinding(MessageText.getDefaultLocaleString(platformSpecificKey)));
            }
            else if(MessageText.keyExistsForDefaultLocale(localizationKey))
            {
                 // default locale, platform-independent
                setAccelerator(menu, parseKeyBinding(MessageText.getDefaultLocaleString(localizationKey)));
            }
        }
    }

    /**
     * Helper method to set a keyboard accelerator for a MenuItem. If kbInfo is SWT.NONE, no accelerator will be set.
     * @param menu SWT MenuItem
     * @param kbInfo KeyBindingInfo object, which contains the SWT accelerator value and its display name
     */
    private static void setAccelerator(final MenuItem menu, final KeyBindingInfo kbInfo)
    {
        if(kbInfo.accelerator != SWT.NONE)
        {
            menu.setAccelerator(kbInfo.accelerator);

            // SWT on OS X now uses native drawing
            if(!Constants.isOSX && !menu.getText().endsWith(kbInfo.name))
                menu.setText(menu.getText() + kbInfo.name);
        }
    }

    /**
     * Runs simple tests on KeyBindings keybinding values
     * @param args Command-line arguments; they are not used
     */
    public static void main(final String[] args)
    {
        System.out.println(parseKeyBinding("Ctrl+1").name); // meta+1
        System.out.println(parseKeyBinding("Ctrl+F12").name); // meta+f12
        System.out.println(parseKeyBinding("Ctrl+F4").name); // meta+f4

        System.out.println("Meta+Shift+O");
        System.out.println(parseKeyBinding("Ctrl+Shift+O").accelerator); // meta+shift+o
        System.out.println(parseKeyBinding("Shift+Ctrl+O").accelerator); // meta+shift+o
        System.out.println(SWT.MOD1 | SWT.SHIFT | 'O'); // meta+shift+o

        System.out.println("Meta+Shift+o");
        System.out.println(SWT.MOD1 | SWT.SHIFT | 'o'); // meta+shift+o
    }

    /**
     * <p>
     * A basic bean object containing the SWT accelerator and its display name. This is because on platforms like Windows, vanilla SWT MenuItem must be
     * provided the textual representation (display name) of the accelerator in order for it to be visible to the users (as opposed to having it handled by a higher-
     * level API like JFace or native rendering).
     * </p>
     */
    private static class KeyBindingInfo
    {
        /**
         * The display name of the accelerator
         */
        private final String name;

        /**
         * The SWT keyboard accelerator value
         */
        private final int accelerator;

        /**
         * Constructs a new KeyBindingInfo object with the given accelerator name and accelerator value
         * @param name Display name
         * @param accelerator SWT accelerator value
         */
        private KeyBindingInfo(final String name, final int accelerator)
        {
            this.name = name;
            this.accelerator = accelerator;
        }
    }
}