Pmw.MenuBar

Name

Pmw.MenuBar() - manager megawidget for menu buttons and menus

Inherits

Pmw.MegaWidget

Description

A menu bar is a container megawidget which manages a number of menu buttons and dropdown menus. There are methods to add menu buttons and menus to the menu bar and for adding menu items to the menus. Menu buttons may be added to the left or right of the megawidget. Each menu button and menu item may have help text to be displayed by a Pmw.Balloon. Each menu and cascaded menu (sub-menu) is referenced by name which is supplied on creation.

Options

Options for this megawidget and its base classes are described below.

balloon

Specifies a Pmw.Balloon to display the help text for menu buttons and menu items. If None, no help is displayed. If the balloon has an associated Pmw.MessageBar, the help text will also be displayed there. The default is None.

hotkeys

Initialisation option. If true, keyboard accelerators will be assigned to each menu button and menu item. Keyboard accelerators can be used to access the menus without using the mouse. The accelerator character is always one of the alphanumeric characters in the text label of the menu or menu item and is indicated by an underline.

To select a menu, simultaneously press the <Alt> key and the accelerator character indicated on a menu button. The arrows keys can then be used to select other menus and menu items. To invoke a menu item, press <Return> or press the accelerator character indicated on the menu item.

Each accelerator character will be assigned automatically unless traverseSpec is supplied to the addmenu(), addmenuitem() or addcascademenu() methods. The automatically selected accelerator character for a menu button (or menu item) is the first character in the label text that has not already been used as an accelerator for a menu button (or in the menu containing the menu item).

If traverseSpec is given, it must be either an integer or a character. If an integer, it specifies the index of the character in the label text to use as the accelerator character. If a character, it specifies the character to use as the accelerator character. The default is 1.

padx

Initialisation option. Specifies a padding distance to leave between each menu button in the x direction and also between the menu buttons and the outer edge of the menu bar. The default is 0.

Components

Components created by this megawidget and its base classes are described below.

hull

This acts as the body for the entire megawidget. Other components are created as children of the hull to further specialise this class. By default, this component is a tkinter.Frame.

Dynamic components

Menu button components are created dynamically by the addmenu() method. By default, these are of type tkinter.Menubutton and are created with a component group of Button.

Menu components are created dynamically by the addmenu() and addcascademenu() methods. By default, these are of type tkinter.Menu and are created with a component group of Menu.

Methods

Only methods specific to this megawidget are described below. For a description of its inherited methods, see the manual for its base class Pmw.MegaWidget.

addcascademenu(parentMenuName, menuName, statusHelp = '', traverseSpec = None, **kw)

Add a cascade menu (sub-menu) to the menu parentMenuName. The menuName argument must not be the same as any menu already created using the addmenu() or addcascademenu() methods.

A menu item in the parent menu is created (with the add_cascade() method of the parent menu) using all keyword arguments except tearoff.

If the label keyword argument is not given, the label option of the menu item defaults to menuName. If the underline keyword argument is not given (and the hotkeys megawidget option is true) the underline option is determined as described under hotkeys and is used to specify the keyboard accelerator.

The statusHelp argument is used as the help string for the menu item. This is displayed using the showstatus() method of the balloon.

The tearoff keyword argument, if present, is passed to the constructor of the menu. The menu is created as a component named menuName-menu.

addmenu(menuName, balloonHelp, statusHelp = None, side = 'left', traverseSpec = None, **kw)

Add a menu button and its associated menu to the menu bar. The menuName argument must not be the same as any menu already created using the addmenu() or addcascademenu() methods.

Any keyword arguments present (except tearoff) will be passed to the constructor of the menu button. If the text keyword argument is not given, the text option of the menu button defaults to menuName. If the underline keyword argument is not given (and the hotkeys megawidget option is true) the underline option is determined as described under hotkeys and is used to specify the keyboard accelerator. Each menu button is packed into the menu bar using the given side, which should be either left or right. The menu button is created as a component named menuName-button.

If the balloon option has been defined, balloonHelp and statusHelp are passed to the balloon as the help strings for the menu button. See the bind() method of Pmw.Balloon for how these strings may be displayed.

The tearoff keyword argument, if present, is passed to the constructor of the menu. The menu is created as a component named menuName-menu.

addmenuitem(menuName, itemType, statusHelp = '', traverseSpec = None, **kw)

Add a menu item to the menu menuName. The kind of menu item is given by itemType and may be one of command, separator, checkbutton, radiobutton or cascade (although cascade menus are better added using the addcascademenu() method). Any keyword arguments present will be passed to the menu when creating the menu item. See tkinter.Menu for the valid options for each item type. In addition, a keyboard accelerator may be automatically given to the item, as described under hotkeys.

When the mouse is moved over the menu item, the helpString will be displayed by the balloon's statuscommand.

deletemenu(menuName)

Delete the menu menuName and all its items. The menu may either be a toplevel menu (in which case the corresponding menu button is also deleted) or a cascade menu.

deletemenuitems(menuName, start, end = None)

Delete menu items from the menu menuName. If end is not given, the start item is deleted. Otherwise all items from start to end are deleted.

disableall()

Disable all toplevel menus.

enableall()

Enable all toplevel menus.

Example

The image at the top of this manual is a snapshot of the window (or part of the window) produced by the following code.

class Demo:
    def __init__(self, parent):
        # Create the Balloon.
        self.balloon = Pmw.Balloon(parent)

        # Create and pack the MenuBar.
        menuBar = Pmw.MenuBar(parent,
                hull_relief = 'raised',
                hull_borderwidth = 1,
                balloon = self.balloon)
        menuBar.pack(fill = 'x')
        self.menuBar = menuBar

        # Add some buttons to the MenuBar.
        menuBar.addmenu('File', 'Close this window or exit')
        menuBar.addmenuitem('File', 'command', 'Close this window',
                command = PrintOne('Action: close'),
                label = 'Close')
        menuBar.addmenuitem('File', 'separator')
        menuBar.addmenuitem('File', 'command', 'Exit the application',
                command = PrintOne('Action: exit'),
                label = 'Exit')

        menuBar.addmenu('Edit', 'Cut, copy or paste')
        menuBar.addmenuitem('Edit', 'command', 'Delete the current selection',
                command = PrintOne('Action: delete'),
                label = 'Delete')

        menuBar.addmenu('Options', 'Set user preferences')
        menuBar.addmenuitem('Options', 'command', 'Set general preferences',
                command = PrintOne('Action: general options'),
                label = 'General...')

        # Create a checkbutton menu item.
        self.toggleVar = tkinter.IntVar()
        # Initialise the checkbutton to 1:
        self.toggleVar.set(1)
        menuBar.addmenuitem('Options', 'checkbutton', 'Toggle me on/off',
                label = 'Toggle',
                command = self._toggleMe,
                variable = self.toggleVar)
        self._toggleMe()

        menuBar.addcascademenu('Options', 'Size',
                'Set some other preferences', traverseSpec = 'z', tearoff = 1)
        for size in ('tiny', 'small', 'average', 'big', 'huge'):
            menuBar.addmenuitem('Size', 'command', 'Set size to ' + size,
                    command = PrintOne('Action: size ' + size),
                    label = size)

        menuBar.addmenu('Help', 'User manuals', side = 'right')
        menuBar.addmenuitem('Help', 'command', 'About this application',
                command = PrintOne('Action: about'),
                label = 'About...')

        # Create and pack the main part of the window.
        self.mainPart = tkinter.Label(parent,
                text = 'This is the\nmain part of\nthe window',
                background = 'black',
                foreground = 'white',
                padx = 30,
                pady = 30)
        self.mainPart.pack(fill = 'both', expand = 1)

        # Create and pack the MessageBar.
        self.messageBar = Pmw.MessageBar(parent,
                entry_width = 40,
                entry_relief='groove',
                labelpos = 'w',
                label_text = 'Status:')
        self.messageBar.pack(fill = 'x', padx = 10, pady = 10)
        self.messageBar.message('state', 'OK')

        buttonBox = Pmw.ButtonBox(parent)
        buttonBox.pack(fill = 'x')
        buttonBox.add('Disable\nall', command = menuBar.disableall)
        buttonBox.add('Enable\nall', command = menuBar.enableall)
        buttonBox.add('Create\nmenu', command = self.add)
        buttonBox.add('Delete\nmenu', command = self.delete)
        buttonBox.add('Create\nitem', command = self.additem)
        buttonBox.add('Delete\nitem', command = self.deleteitem)

        # Configure the balloon to displays its status messages in the
        # message bar.
        self.balloon.configure(statuscommand = self.messageBar.helpmessage)

        self.testMenuList = []

    def _toggleMe(self):
        print('Toggle value: ' + str(self.toggleVar.get()))

    def add(self):
        if len(self.testMenuList) == 0:
            num = 0
        else:
            num = self.testMenuList[-1]
        num = num + 1
        name = 'Menu%d' % num
        self.testMenuList.append(num)

        self.menuBar.addmenu(name, 'This is ' + name)

    def delete(self):
        if len(self.testMenuList) == 0:
            self.menuBar.bell()
        else:
            num = self.testMenuList[0]
            name = 'Menu%d' % num
            del self.testMenuList[0]
            self.menuBar.deletemenu(name)

    def additem(self):
        if len(self.testMenuList) == 0:
            self.menuBar.bell()
        else:
            num = self.testMenuList[-1]
            menuName = 'Menu%d' % num
            menu = self.menuBar.component(menuName + '-menu')
            if menu.index('end') is None:
                label = 'item X'
            else:
                label = menu.entrycget('end', 'label') + 'X'
            self.menuBar.addmenuitem(menuName, 'command', 'Help for ' + label,
                    command = PrintOne('Action: ' + menuName + ': ' + label),
                    label = label)

    def deleteitem(self):
        if len(self.testMenuList) == 0:
            self.menuBar.bell()
        else:
            num = self.testMenuList[-1]
            menuName = 'Menu%d' % num
            menu = self.menuBar.component(menuName + '-menu')
            if menu.index('end') is None:
                self.menuBar.bell()
            else:
                self.menuBar.deletemenuitems(menuName, 0)

class PrintOne:
    def __init__(self, text):
        self.text = text

    def __call__(self):
        print(self.text)