Group selection icons in CliMultiMenu API

The select/unselect icons of a CliMultiMenu will in nearly all cases be
changed together, therefore it makes sense to let the API be less
verbose for this case.

This is an API breaking change for CliMultiMenu

clintermission/climenu.py

@@ -311,18 +311,15 @@ class CliMenu:
 
 
 class CliMultiMenu(CliMenu):
-    default_selected_icon = '[x]'
+    default_selection_icons = ('[x]', '[ ]')
-    default_unselected_icon = '[ ]'
 
     @classmethod
-    def set_default_selector_icons(cls, selected_icon, unselected_icon):
+    def set_default_selector_icons(cls, selection_icons):
-        cls.default_selected_icon = selected_icon
+        cls.default_selection_icons = selection_icons
-        cls.default_unselected_icon = unselected_icon
 
-    def __init__(self, *args, selected_icon=None, unselected_icon=None, **kwargs):
+    def __init__(self, *args, selection_icons=None, **kwargs):
         self._multi_selected = []
-        self._selected_icon = selected_icon if selected_icon is not None else self.default_selected_icon
+        self._selection_icons = selection_icons if selection_icons is not None else self.default_selection_icons
-        self._unselected_icon = unselected_icon if unselected_icon is not None else self.default_unselected_icon
         super().__init__(*args, **kwargs)
 
     def add_option(self, text, item=None, selected=False):
@@ -360,9 +357,9 @@ class CliMultiMenu(CliMenu):
     def _transform_prefix(self, item, lineno, prefix):
         if item.focusable:
             if lineno in self._multi_selected:
-                icon = self._selected_icon
+                icon = self._selection_icons[0]
             else:
-                icon = self._unselected_icon
+                icon = self._selection_icons[1]
             return "{}{} ".format(prefix, icon)
         else:
             return prefix

examples/multiselect.py

@@ -10,7 +10,7 @@ q = [
     "Option 4"
 ]
 m = CliMultiMenu(q, "Make your choice (<space> selects, <return> accepts):\n", cursor=CliMenuCursor.ASCII_ARROW,
-                 unselected_icon="✖", selected_icon="✔")
+                 selection_icons=("✔", "✖"))
 
 print("You selected", m.get_selection())
 print("You selected num:", m.get_selection_num())