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含有章节索引的中文 文章模板
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::-- ehu4ever [<<DateTime(2005-08-08T13:01:32Z)>>]
<<TableOfContents>>
= 小试牛刀 =


下面就是packbox.py的代码，试着运行一下试试。
{{{#!python
#!/usr/bin/env python

# example packbox.py

import pygtk
pygtk.require('2.0')
import gtk
import sys, string

# Helper function that makes a new hbox filled with button-labels. Arguments
# for the variables we're interested are passed in to this function.  We do
# not show the box, but do show everything inside.

def make_box(homogeneous, spacing, expand, fill, padding):

    # Create a new hbox with the appropriate homogeneous
    # and spacing settings
    box = gtk.HBox(homogeneous, spacing)

    # Create a series of buttons with the appropriate settings
    button = gtk.Button("box.pack")
    box.pack_start(button, expand, fill, padding)
    button.show()

    button = gtk.Button("(button,")
    box.pack_start(button, expand, fill, padding)
    button.show()

    # Create a button with the label depending on the value of
    # expand.
    if expand == True:
        button = gtk.Button("True,")
    else:
        button = gtk.Button("False,")

    box.pack_start(button, expand, fill, padding)
    button.show()

    # This is the same as the button creation for "expand"
    # above, but uses the shorthand form.
    button = gtk.Button(("False,", "True,")[fill==True])
    box.pack_start(button, expand, fill, padding)
    button.show()

    padstr = "%d)" % padding

    button = gtk.Button(padstr)
    box.pack_start(button, expand, fill, padding)
    button.show()
    return box

class PackBox1:
    def delete_event(self, widget, event, data=None):
        gtk.main_quit()
        return False

    def __init__(self, which):

        # Create our window
        self.window = gtk.Window(gtk.WINDOW_TOPLEVEL)

        # You should always remember to connect the delete_event signal
        # to the main window. This is very important for proper intuitive
        # behavior
        self.window.connect("delete_event", self.delete_event)
        self.window.set_border_width(10)
    
        # We create a vertical box (vbox) to pack the horizontal boxes into.
        # This allows us to stack the horizontal boxes filled with buttons one
        # on top of the other in this vbox.
        box1 = gtk.VBox(False, 0)
    
        # which example to show. These correspond to the pictures above.
        if which == 1:
            # create a new label.
            label = gtk.Label("HBox(False, 0)")
	
            # Align the label to the left side.  We'll discuss this method
            # and others in the section on Widget Attributes.
            label.set_alignment(0, 0)

            # Pack the label into the vertical box (vbox box1).  Remember that 
            # widgets added to a vbox will be packed one on top of the other in
            # order.
            box1.pack_start(label, False, False, 0)
	
            # Show the label
            label.show()
	
            # Call our make box function - homogeneous = False, spacing = 0,
            # expand = False, fill = False, padding = 0
            box2 = make_box(False, 0, False, False, 0)
            box1.pack_start(box2, False, False, 0)
            box2.show()

            # Call our make box function - homogeneous = False, spacing = 0,
            # expand = True, fill = False, padding = 0
            box2 = make_box(False, 0, True, False, 0)
            box1.pack_start(box2, False, False, 0)
            box2.show()
	
            # Args are: homogeneous, spacing, expand, fill, padding
            box2 = make_box(False, 0, True, True, 0)
            box1.pack_start(box2, False, False, 0)
            box2.show()
	
            # Creates a separator, we'll learn more about these later, 
            # but they are quite simple.
            separator = gtk.HSeparator()
	
            # Pack the separator into the vbox. Remember each of these
            # widgets is being packed into a vbox, so they'll be stacked
            # vertically.
            box1.pack_start(separator, False, True, 5)
            separator.show()
	
            # Create another new label, and show it.
            label = gtk.Label("HBox(True, 0)")
            label.set_alignment(0, 0)
            box1.pack_start(label, False, False, 0)
            label.show()
	
            # Args are: homogeneous, spacing, expand, fill, padding
            box2 = make_box(True, 0, True, False, 0)
            box1.pack_start(box2, False, False, 0)
            box2.show()
	
            # Args are: homogeneous, spacing, expand, fill, padding
            box2 = make_box(True, 0, True, True, 0)
            box1.pack_start(box2, False, False, 0)
            box2.show()
	
            # Another new separator.
            separator = gtk.HSeparator()
            # The last 3 arguments to pack_start are:
            # expand, fill, padding.
            box1.pack_start(separator, False, True, 5)
            separator.show()
        elif which == 2:
            # Create a new label, remember box1 is a vbox as created 
            # near the beginning of __init__()
            label = gtk.Label("HBox(False, 10)")
            label.set_alignment( 0, 0)
            box1.pack_start(label, False, False, 0)
            label.show()
	
            # Args are: homogeneous, spacing, expand, fill, padding
            box2 = make_box(False, 10, True, False, 0)
            box1.pack_start(box2, False, False, 0)
            box2.show()
	
            # Args are: homogeneous, spacing, expand, fill, padding
            box2 = make_box(False, 10, True, True, 0)
            box1.pack_start(box2, False, False, 0)
            box2.show()
	
            separator = gtk.HSeparator()
            # The last 3 arguments to pack_start are:
            # expand, fill, padding.
            box1.pack_start(separator, False, True, 5)
            separator.show()
	
            label = gtk.Label("HBox(False, 0)")
            label.set_alignment(0, 0)
            box1.pack_start(label, False, False, 0)
            label.show()
	
            # Args are: homogeneous, spacing, expand, fill, padding
            box2 = make_box(False, 0, True, False, 10)
            box1.pack_start(box2, False, False, 0)
            box2.show()
	
            # Args are: homogeneous, spacing, expand, fill, padding
            box2 = make_box(False, 0, True, True, 10)
            box1.pack_start(box2, False, False, 0)
            box2.show()
	
            separator = gtk.HSeparator()
            # The last 3 arguments to pack_start are:
            # expand, fill, padding.
            box1.pack_start(separator, False, True, 5)
            separator.show()

        elif which == 3:

            # This demonstrates the ability to use pack_end() to
            # right justify widgets. First, we create a new box as before.
            box2 = make_box(False, 0, False, False, 0)

            # Create the label that will be put at the end.
            label = gtk.Label("end")
            # Pack it using pack_end(), so it is put on the right
            # side of the hbox created in the make_box() call.
            box2.pack_end(label, False, False, 0)
            # Show the label.
            label.show()
	
            # Pack box2 into box1
            box1.pack_start(box2, False, False, 0)
            box2.show()
	
            # A separator for the bottom.
            separator = gtk.HSeparator()
            
            # This explicitly sets the separator to 400 pixels wide by 5
            # pixels high. This is so the hbox we created will also be 400
            # pixels wide, and the "end" label will be separated from the
            # other labels in the hbox. Otherwise, all the widgets in the
            # hbox would be packed as close together as possible.
            separator.set_size_request(400, 5)
            # pack the separator into the vbox (box1) created near the start 
            # of __init__()
            box1.pack_start(separator, False, True, 5)
            separator.show()
    
        # Create another new hbox.. remember we can use as many as we need!
        quitbox = gtk.HBox(False, 0)
    
        # Our quit button.
        button = gtk.Button("Quit")
    
        # Setup the signal to terminate the program when the button is clicked
        button.connect("clicked", lambda w: gtk.main_quit())
        # Pack the button into the quitbox.
        # The last 3 arguments to pack_start are:
        # expand, fill, padding.
        quitbox.pack_start(button, True, False, 0)
        # pack the quitbox into the vbox (box1)
        box1.pack_start(quitbox, False, False, 0)
    
        # Pack the vbox (box1) which now contains all our widgets, into the
        # main window.
        self.window.add(box1)
    
        # And show everything left
        button.show()
        quitbox.show()
    
        box1.show()
        # Showing the window last so everything pops up at once.
        self.window.show()

def main():
    # And of course, our main loop.
    gtk.main()
    # Control returns here when main_quit() is called
    return 0         

if __name__ =="__main__":
##    if len(sys.argv) != 2:
##        sys.stderr.write("usage: packbox.py num, where num is 1, 2, or 3.\n")
##        sys.exit(1)
##    PackBox1(string.atoi(sys.argv[1]))
    PackBox1(string.atoi('3'))
    
    main()

}}}


程序的14到50行定义了一个make_box()，是用来创建一个有gtk.Button在里面的box。它返回一个box的指针。

52到241行定义了类packbox1的初始化__init__()，它用来创建一个主窗口，然后根据不同的命令行传入参数，在主窗口的gtk.VBox中建立三个gtk.HBox。
If a 1 is passed, lines 75-138 create a window displaying the five unique packing arrangements that are available when varying the homogeneous, expand and fill parameters. If a 2 is passed, lines 140-182 create a window displaying the various combinations of fill with spacing and padding. Finally, if a 3 is passed, lines 188-214 create a window displaying the use of the pack_start() method to left justify the buttons and pack_end() method to right justify a label. Lines 215-235 create a horizontal box containing a button that is packed into the vertical box. The button "clicked" signal is connected to the PyGTK main_quit() function to terminate the program.

Lines 250-252 check the command line arguments and exit the program using the sys.exit() function if there isn't exactly one argument. Line 253 creates a PackBox1 instance. Line 254 invokes the main() function to start the GTK event processing loop.

In this example program, the references to the various widgets (except the window) are not saved in the object instance attributes because they are not needed later.