bpo-37903: IDLE: Shell sidebar with prompts (GH-22682)

The first followup will change shell indents to spaces.
More are expected.

Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>

Lib/idlelib/editor.py

@@ -60,7 +60,6 @@ class EditorWindow:
     from idlelib.sidebar import LineNumbers
     from idlelib.format import FormatParagraph, FormatRegion, Indents, Rstrip
     from idlelib.parenmatch import ParenMatch
-    from idlelib.squeezer import Squeezer
     from idlelib.zoomheight import ZoomHeight
 
     filesystemencoding = sys.getfilesystemencoding()  # for file names
@@ -68,6 +67,7 @@ class EditorWindow:
 
     allow_code_context = True
     allow_line_numbers = True
+    user_input_insert_tags = None
 
     def __init__(self, flist=None, filename=None, key=None, root=None):
         # Delay import: runscript imports pyshell imports EditorWindow.
@@ -784,9 +784,7 @@ class EditorWindow:
             self.color = self.ColorDelegator()
         # can add more colorizers here...
         if self.color:
-            self.per.removefilter(self.undo)
-            self.per.insertfilter(self.color)
-            self.per.insertfilter(self.undo)
+            self.per.insertfilterafter(filter=self.color, after=self.undo)
 
     def _rmcolorizer(self):
         if not self.color:
@@ -1303,8 +1301,6 @@ class EditorWindow:
         # Debug prompt is multilined....
         ncharsdeleted = 0
         while 1:
-            if chars == self.prompt_last_line:  # '' unless PyShell
-                break
             chars = chars[:-1]
             ncharsdeleted = ncharsdeleted + 1
             have = len(chars.expandtabs(tabwidth))
@@ -1313,7 +1309,8 @@ class EditorWindow:
         text.undo_block_start()
         text.delete("insert-%dc" % ncharsdeleted, "insert")
         if have < want:
-            text.insert("insert", ' ' * (want - have))
+            text.insert("insert", ' ' * (want - have),
+                        self.user_input_insert_tags)
         text.undo_block_stop()
         return "break"
 
@@ -1346,7 +1343,7 @@ class EditorWindow:
                     effective = len(prefix.expandtabs(self.tabwidth))
                     n = self.indentwidth
                     pad = ' ' * (n - effective % n)
-                text.insert("insert", pad)
+                text.insert("insert", pad, self.user_input_insert_tags)
             text.see("insert")
             return "break"
         finally:
@@ -1377,13 +1374,14 @@ class EditorWindow:
             if i == n:
                 # The cursor is in or at leading indentation in a continuation
                 # line; just inject an empty line at the start.
-                text.insert("insert linestart", '\n')
+                text.insert("insert linestart", '\n',
+                            self.user_input_insert_tags)
                 return "break"
             indent = line[:i]
 
             # Strip whitespace before insert point unless it's in the prompt.
             i = 0
-            while line and line[-1] in " \t" and line != self.prompt_last_line:
+            while line and line[-1] in " \t":
                 line = line[:-1]
                 i += 1
             if i:
@@ -1394,7 +1392,7 @@ class EditorWindow:
                 text.delete("insert")
 
             # Insert new line.
-            text.insert("insert", '\n')
+            text.insert("insert", '\n', self.user_input_insert_tags)
 
             # Adjust indentation for continuations and block open/close.
             # First need to find the last statement.
@@ -1430,7 +1428,7 @@ class EditorWindow:
                 elif c == pyparse.C_STRING_NEXT_LINES:
                     # Inside a string which started before this line;
                     # just mimic the current indent.
-                    text.insert("insert", indent)
+                    text.insert("insert", indent, self.user_input_insert_tags)
                 elif c == pyparse.C_BRACKET:
                     # Line up with the first (if any) element of the
                     # last open bracket structure; else indent one
@@ -1444,7 +1442,8 @@ class EditorWindow:
                     # beyond leftmost =; else to beyond first chunk of
                     # non-whitespace on initial line.
                     if y.get_num_lines_in_stmt() > 1:
-                        text.insert("insert", indent)
+                        text.insert("insert", indent,
+                                    self.user_input_insert_tags)
                     else:
                         self.reindent_to(y.compute_backslash_indent())
                 else:
@@ -1455,7 +1454,7 @@ class EditorWindow:
             # indentation of initial line of closest preceding
             # interesting statement.
             indent = y.get_base_indent_string()
-            text.insert("insert", indent)
+            text.insert("insert", indent, self.user_input_insert_tags)
             if y.is_block_opener():
                 self.smart_indent_event(event)
             elif indent and y.is_block_closer():
@@ -1502,7 +1501,8 @@ class EditorWindow:
         if text.compare("insert linestart", "!=", "insert"):
             text.delete("insert linestart", "insert")
         if column:
-            text.insert("insert", self._make_blanks(column))
+            text.insert("insert", self._make_blanks(column),
+                        self.user_input_insert_tags)
         text.undo_block_stop()
 
     # Guess indentwidth from text content.