combo_themes.py 文件源码

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)