Work a bit more on tkinter demos.

Demo/tkinter/guido/mimeviewer.py

@@ -0,0 +1,159 @@
+#! /usr/bin/env python3
+
+# View a single MIME multipart message.
+# Display each part as a box.
+
+import os
+import sys
+import getopt
+import mailbox
+from tkinter import *
+from tkinter.scrolledtext import ScrolledText
+
+MBOXPATH = os.environ['HOME'] + '/Mail'
+
+class Error(Exception):
+    pass
+
+def getcurrent(self):
+    """Return the current message.  Raise Error when there is none."""
+    seqs = self.get_sequences()
+    try:
+        return max(seqs['cur'])
+    except (ValueError, KeyError):
+        raise Error("no cur message")
+
+
+class MimeViewer:
+    def __init__(self, parent, title, msg):
+        self.title = title
+        self.msg = msg
+        self.frame = Frame(parent, {'relief': 'raised', 'bd': 2})
+        self.frame.packing = {'expand': 0, 'fill': 'both'}
+        self.button = Checkbutton(self.frame,
+                             {'text': title,
+                              'command': self.toggle})
+        self.button.pack({'anchor': 'w'})
+        headertext = []
+        for item in msg.items():
+            headertext.append("%s: %s" % item)
+        headertext = '\n'.join(headertext)
+        height = countlines(headertext, 4)
+        if height:
+            self.htext = ScrolledText(self.frame,
+                              {'height': height,
+                               'width': 80,
+                               'wrap': 'none',
+                               'relief': 'raised',
+                               'bd': 2})
+            self.htext.packing = {'expand': 1, 'fill': 'both',
+                                  'after': self.button}
+            self.htext.insert('end', headertext)
+        else:
+            self.htext = Frame(self.frame,
+                               {'relief': 'raised', 'bd': 2})
+            self.htext.packing = {'side': 'top',
+                                  'ipady': 2,
+                                  'fill': 'x',
+                                  'after': self.button}
+        body = msg.get_payload()
+        if type(body) == str:
+            self.pad = None
+            height = countlines(body, 10)
+            if height:
+                self.btext = ScrolledText(self.frame,
+                                  {'height': height,
+                                   'width': 80,
+                                   'wrap': 'none',
+                                   'relief': 'raised',
+                                   'bd': 2})
+                self.btext.packing = {'expand': 1,
+                                      'fill': 'both'}
+                self.btext.insert('end', body)
+            else:
+                self.btext = None
+            self.parts = None
+        else:
+            self.pad = Frame(self.frame,
+                             {'relief': 'flat', 'bd': 2})
+            self.pad.packing = {'side': 'left', 'ipadx': 10,
+                                'fill': 'y', 'after': self.htext}
+            self.parts = []
+            for i in range(len(body)):
+                p = MimeViewer(self.frame,
+                               '%s.%d' % (title, i+1),
+                               body[i])
+                self.parts.append(p)
+            self.btext = None
+        self.collapsed = 1
+    def pack(self):
+        self.frame.pack(self.frame.packing)
+    def destroy(self):
+        self.frame.destroy()
+    def show(self):
+        if self.collapsed:
+            self.button.invoke()
+    def toggle(self):
+        if self.collapsed:
+            self.explode()
+        else:
+            self.collapse()
+    def collapse(self):
+        self.collapsed = 1
+        for comp in self.htext, self.btext, self.pad:
+            if comp:
+                comp.forget()
+        if self.parts:
+            for part in self.parts:
+                part.frame.forget()
+        self.frame.pack({'expand': 0})
+    def explode(self):
+        self.collapsed = 0
+        for comp in self.htext, self.btext, self.pad:
+            if comp: comp.pack(comp.packing)
+        if self.parts:
+            for part in self.parts:
+                part.pack()
+        self.frame.pack({'expand': 1})
+
+def countlines(str, limit):
+    i = 0
+    n = 0
+    while  n < limit:
+        i = str.find('\n', i)
+        if i < 0: break
+        n = n+1
+        i = i+1
+    return n
+
+def main():
+    opts, args = getopt.getopt(sys.argv[1:], '')
+    for o, a in opts:
+        pass
+    message = None
+    folder = 'inbox'
+    for arg in args:
+        if arg[:1] == '+':
+            folder = arg[1:]
+        else:
+            message = int(arg)
+
+    mh = mailbox.MH(MBOXPATH)
+    f = mh.get_folder(folder)
+    if message is None:
+        message = getcurrent(f)
+    m = mailbox.MHMessage(f.get(message))
+
+    root = Tk()
+    tk = root.tk
+
+    top = MimeViewer(root, '+%s/%d' % (folder, message), m)
+    top.pack()
+    top.show()
+
+    root.minsize(1, 1)
+
+    tk.mainloop()
+
+if __name__ == '__main__':
+    main()