add callback for filter_list choice change

Author: badranX

src/inquirer/questions.py

@@ -192,11 +192,13 @@ def __init__(
         other=False,
         autocomplete=None,
         filter_func=None,
+        choice_callback=None,
     ):
         super().__init__(name, message, choices, default, ignore, validate, hints=hints, other=other)
         self.carousel = carousel
         self.autocomplete = autocomplete
         self.filter_func = filter_func
+        self.choice_callback = choice_callback
 
 
 class Checkbox(Question):

src/inquirer/render/console/_filter_list.py

@@ -70,7 +70,22 @@ def get_options(self):
                 symbol = " " if choice == GLOBAL_OTHER_CHOICE else " " * len(self.theme.List.selection_cursor)
             yield choice, symbol, color
 
+    def _get_current_choice(self):
+        return self.question.choices[self.current]
+
     def process_input(self, pressed):
+        prev_choice = self._get_current_choice()
+
+        self._process_control_input(pressed)
+
+        self._process_text_input(pressed)
+
+        current_choice = self._get_current_choice()
+        if prev_choice != current_choice:
+            if self.question.choice_callback:
+                self.question.choice_callback(current_choice)
+
+    def _process_control_input(self, pressed):
         question = self.question
         if pressed == key.UP:
             if question.carousel and self.current == 0:
@@ -85,7 +100,7 @@ def process_input(self, pressed):
                 self.current = min(len(self.question.choices) - 1, self.current + 1)
             return
         if pressed == key.ENTER:
-            value = self.question.choices[self.current]
+            value = self._get_current_choice()
 
             if value == GLOBAL_OTHER_CHOICE:
                 value = self.other_input()
@@ -99,10 +114,7 @@ def process_input(self, pressed):
         if pressed == key.CTRL_C:
             raise KeyboardInterrupt()
 
-        # Add text processing
-        self._process_text(pressed)
-
-    def _process_text(self, pressed):
+    def _process_text_input(self, pressed):
         prev_text = self.current_text
 
         if pressed == key.TAB and self.question.autocomplete: