在gtk.Menu中放置其他小部件

Question

我想在我的gtk菜单里放一个gtk.ProgressBar（进度条），但菜单只接受gtk.MenuItem和它的子类。于是我做了一个普通的gtk.MenuItem，并尝试把我的进度条作为子元素添加进去。因为gtk.MenuItem是gtk.Bin的子类，所以理论上应该可以放任何小部件。

举个例子：

menu = gtk.Menu()

item = gtk.MenuItem()

button = gtk.ProgressBar()
button.pulse()
button.show()

item.add(button)
item.show()

menu.append(item)

这个代码运行得很好，pygtk也没有抱怨。但是，我的进度条就是不显示：

如果我把进度条换成gtk.Label（标签），那它就能正常显示。

现在我有几个问题：

1. 我怎么知道哪些小部件可以放进去？
2. 我怎么才能让它接受其他小部件呢？

Answer 1

你的示例代码在这里可以正常运行（我通过修改一个pygtk的例子进行了测试，下面会贴出这个例子）。

可能是你其他代码或者主题设置的问题？

#!/usr/bin/env python

# example menu.py

import pygtk
pygtk.require('2.0')
import gtk

class MenuExample:
    def __init__(self):
        # create a new window
        window = gtk.Window(gtk.WINDOW_TOPLEVEL)
        window.set_size_request(200, 100)
        window.set_title("GTK Menu Test")
        window.connect("delete_event", lambda w,e: gtk.main_quit())

        # Init the menu-widget, and remember -- never
        # show() the menu widget!! 
        # This is the menu that holds the menu items, the one that
        # will pop up when you click on the "Root Menu" in the app
        menu = gtk.Menu()

        ### MODIFIED PART!! ###
        item = gtk.MenuItem()

        button = gtk.ProgressBar()
        button.pulse()
        button.show()

        item.add(button)
        item.show()

        menu.append(item)
        #### END MODIFIED PART ####

        # This is the root menu, and will be the label
        # displayed on the menu bar.  There won't be a signal handler attached,
        # as it only pops up the rest of the menu when pressed.
        root_menu = gtk.MenuItem("Root Menu")

        root_menu.show()

        # Now we specify that we want our newly created "menu" to be the
        # menu for the "root menu"
        root_menu.set_submenu(menu)

        # A vbox to put a menu and a button in:
        vbox = gtk.VBox(False, 0)
        window.add(vbox)
        vbox.show()

        # Create a menu-bar to hold the menus and add it to our main window
        menu_bar = gtk.MenuBar()
        vbox.pack_start(menu_bar, False, False, 2)
        menu_bar.show()

        # Create a button to which to attach menu as a popup
        button = gtk.Button("press me")
        button.connect_object("event", self.button_press, menu)
        vbox.pack_end(button, True, True, 2)
        button.show()

        # And finally we append the menu-item to the menu-bar -- this is the
        # "root" menu-item I have been raving about =)
        menu_bar.append (root_menu)

        # always display the window as the last step so it all splashes on
        # the screen at once.
        window.show()

    # Respond to a button-press by posting a menu passed in as widget.
    #
    # Note that the "widget" argument is the menu being posted, NOT
    # the button that was pressed.
    def button_press(self, widget, event):
        if event.type == gtk.gdk.BUTTON_PRESS:
            widget.popup(None, None, None, event.button, event.time)
            # Tell calling code that we have handled this event the buck
            # stops here.
            return True
        # Tell calling code that we have not handled this event pass it on.
        return False

    # Print a string when a menu item is selected
    def menuitem_response(self, widget, string):
        print "%s" % string

def main():
    gtk.main()
    return 0

if __name__ == "__main__":
    MenuExample()
    main()

Answer 2

这是Ubuntu的应用指示器的一个限制，具体可以参考这个在askubuntu上的问题。