Demos for ttk added.

Demo/tkinter/ttk/combo_themes.py

@@ -0,0 +1,46 @@
+"""Ttk Theme Selector.
+
+Although it is a theme selector, you won't notice many changes since
+there is only a combobox and a frame around.
+"""
+import ttk
+
+class App(ttk.Frame):
+    def __init__(self):
+        ttk.Frame.__init__(self)
+
+        self.style = ttk.Style()
+        self._setup_widgets()
+
+    def _change_theme(self, event):
+        if event.widget.current(): # value #0 is not a theme
+            newtheme = event.widget.get()
+            # change to the new theme and refresh all the widgets
+            self.style.theme_use(newtheme)
+
+    def _setup_widgets(self):
+        themes = list(self.style.theme_names())
+        themes.insert(0, "Pick a theme")
+        # Create a readonly Combobox which will display 4 values at max,
+        # which will cause it to create a scrollbar if there are more
+        # than 4 values in total.
+        themes_combo = ttk.Combobox(self, values=themes, state="readonly",
+                                    height=4)
+        themes_combo.set(themes[0]) # sets the combobox value to "Pick a theme"
+        # Combobox widget generates a <<ComboboxSelected>> virtual event
+        # when the user selects an element. This event is generated after
+        # the listbox is unposted (after you select an item, the combobox's
+        # listbox disappears, then it is said that listbox is now unposted).
+        themes_combo.bind("<<ComboboxSelected>>", self._change_theme)
+        themes_combo.pack(fill='x')
+
+        self.pack(fill='both', expand=1)
+
+
+def main():
+    app = App()
+    app.master.title("Ttk Combobox")
+    app.mainloop()
+
+if __name__ == "__main__":
+    main()