Tweaked the meaning of topmost in apply_formatting to also extend to …

…all settings leading up to the start index

src/ansi_string/ansi_string.py

@@ -33,7 +33,7 @@
 )
 from .ansi_parsing import ParsedAnsiControlSequenceString, parse_graphic_sequence, settings_to_dict
 
-__version__ = '1.1.7'
+__version__ = '1.1.8'
 PACKAGE_NAME = 'ansi_string'
 
 # Constant: all characters considered to be whitespaces - this is used in strip functionality
@@ -315,8 +315,7 @@ def apply_formatting(
             settings - setting or list of settings to apply
             start - The string start index where setting(s) are to be applied
             end - The string index where the setting(s) should be removed
-            topmost - When true, the settings placed at the end of the set for the given
-                      start_index, meaning it takes precedent over others; the opposite when False
+            topmost - When False, all other existing settings in this range will take precedent
         '''
         start = self._slice_val_to_idx(start, 0)
         end = self._slice_val_to_idx(end, len(self._s))
@@ -336,6 +335,17 @@ def apply_formatting(
             self._fmts[start] = _AnsiSettingPoint()
         self._fmts[start].insert_settings(True, ansi_settings, topmost)
 
+        # When not topmost, do a remove and re-add of any settings that lead up to the start index
+        if not topmost:
+            remove_and_add_settings = []
+            settings_at_start = self.ansi_settings_at(start)
+            for setting in settings_at_start:
+                if setting not in self._fmts[start].add:
+                    remove_and_add_settings.append(setting)
+            if remove_and_add_settings:
+                self._fmts[start].insert_settings(False, remove_and_add_settings)
+                self._fmts[start].insert_settings(True, remove_and_add_settings)
+
         # Remove settings
         if end not in self._fmts:
             self._fmts[end] = _AnsiSettingPoint()

tests/test_ansi_string.py

@@ -475,6 +475,29 @@ def test_rpartition_not_found(self):
         )
         self.assertIs(s, s_orig)
 
+    def test_apply_formatting_topmost(self):
+        s = AnsiString.join('This ', AnsiString('string', AnsiFormat.BOLD))
+        s += AnsiString(' contains ') + AnsiString('multiple', AnsiFormat.BG_BLUE)
+        s += ' color settings across different ranges'
+        s.apply_formatting([AnsiFormat.FG_ORANGE, AnsiFormat.ITALIC], 21, 35)
+        s.apply_formatting(AnsiFormat.FG_BLUE, 21, 44)
+        self.assertEqual(str(s), 'This \x1b[1mstring\x1b[m contains \x1b[44;34;3mmultiple\x1b[49m color\x1b[23m settings\x1b[m across different ranges')
+
+    def test_apply_formatting_not_topmost(self):
+        s = AnsiString.join('This ', AnsiString('string', AnsiFormat.BOLD))
+        s += AnsiString(' contains ') + AnsiString('multiple', AnsiFormat.BG_BLUE)
+        s += ' color settings across different ranges'
+        s.apply_formatting([AnsiFormat.FG_ORANGE, AnsiFormat.ITALIC], 21, 35)
+        s.apply_formatting(AnsiFormat.FG_BLUE, 21, 44, topmost=False) # Should be ignored until index 35
+        self.assertEqual(str(s), 'This \x1b[1mstring\x1b[m contains \x1b[38;5;214;44;3mmultiple\x1b[49m color\x1b[0;34m settings\x1b[m across different ranges')
+
+    def test_apply_formatting_not_topmost2(self):
+        s = AnsiString.join('This ', AnsiString('string', AnsiFormat.BOLD))
+        s += AnsiString(' contains ') + AnsiString('multiple', AnsiFormat.BG_BLUE)
+        s += ' color settings across different ranges'
+        s.apply_formatting([AnsiFormat.FG_ORANGE, AnsiFormat.ITALIC], 21, 35)
+        s.apply_formatting(AnsiFormat.FG_BLUE, 30, 35, topmost=False) # Should be ignored
+        self.assertEqual(str(s), 'This \x1b[1mstring\x1b[m contains \x1b[44;38;5;214;3mmultiple\x1b[49m color\x1b[m settings across different ranges')
 
     def test_get_item_edge_case(self):
         # There used to be a bug where if a single character was retrieved right before the index where a new format was