Show how to do switchable panels.

Demo/tkinter/guido/switch.py

@@ -0,0 +1,54 @@
+# Show how to do switchable panels.
+
+from Tkinter import *
+
+class App:
+
+    def __init__(self, top=None, master=None):
+        if top is None:
+            if master is None:
+                top = Tk()
+            else:
+                top = Toplevel(master)
+        self.top = top
+        self.buttonframe = Frame(top)
+        self.buttonframe.pack()
+        self.panelframe = Frame(top,  borderwidth=2, relief=GROOVE)
+        self.panelframe.pack(expand=1, fill=BOTH)
+        self.panels = {}
+        self.curpanel = None
+
+    def addpanel(self, name, klass):
+        button = Button(self.buttonframe, text=name,
+                        command=lambda self=self, name=name: self.show(name))
+        button.pack(side=LEFT)
+        frame = Frame(self.panelframe)
+        instance = klass(frame)
+        self.panels[name] = (button, frame, instance)
+        if self.curpanel is None:
+            self.show(name)
+
+    def show(self, name):
+        (button, frame, instance) = self.panels[name]
+        if self.curpanel:
+            self.curpanel.pack_forget()
+        self.curpanel = frame
+        frame.pack(expand=1, fill="both")
+
+class LabelPanel:
+    def __init__(self, frame):
+        self.label = Label(frame, text="Hello world")
+        self.label.pack()
+
+class ButtonPanel:
+    def __init__(self, frame):
+        self.button = Button(frame, text="Press me")
+        self.button.pack()
+
+def main():
+    app = App()
+    app.addpanel("label", LabelPanel)
+    app.addpanel("button", ButtonPanel)
+
+if __name__ == '__main__':
+    main()