1 files changed, 55 insertions, 37 deletions

diff --git a/Lib/idlelib/IdleHistory.py b/Lib/idlelib/IdleHistory.py
index 983a140..d6cb162 100644
--- a/Lib/idlelib/IdleHistory.py
+++ b/Lib/idlelib/IdleHistory.py
@@ -1,81 +1,93 @@
+"Implement Idle Shell history mechanism with History class"
+
 from idlelib.configHandler import idleConf
 
 class History:
+    ''' Implement Idle Shell history mechanism.
+
+    store - Store source statement (called from PyShell.resetoutput).
+    fetch - Fetch stored statement matching prefix already entered.
+    history_next - Bound to <<history-next>> event (default Alt-N).
+    history_prev - Bound to <<history-prev>> event (default Alt-P).
+    '''
+    def __init__(self, text):
+        '''Initialize data attributes and bind event methods.
 
-    def __init__(self, text, output_sep = "\n"):
+        .text - Idle wrapper of tk Text widget, with .bell().
+        .history - source statements, possibly with multiple lines.
+        .prefix - source already entered at prompt; filters history list.
+        .pointer - index into history.
+        .cyclic - wrap around history list (or not).
+        '''
         self.text = text
         self.history = []
-        self.history_prefix = None
-        self.history_pointer = None
-        self.output_sep = output_sep
+        self.prefix = None
+        self.pointer = None
         self.cyclic = idleConf.GetOption("main", "History", "cyclic", 1, "bool")
         text.bind("<<history-previous>>", self.history_prev)
         text.bind("<<history-next>>", self.history_next)
 
     def history_next(self, event):
-        self.history_do(0)
+        "Fetch later statement; start with ealiest if cyclic."
+        self.fetch(reverse=False)
         return "break"
 
     def history_prev(self, event):
-        self.history_do(1)
+        "Fetch earlier statement; start with most recent."
+        self.fetch(reverse=True)
         return "break"
 
-    def _get_source(self, start, end):
-        # Get source code from start index to end index.  Lines in the
-        # text control may be separated by sys.ps2 .
-        lines = self.text.get(start, end).split(self.output_sep)
-        return "\n".join(lines)
+    def fetch(self, reverse):
+        '''Fetch statememt and replace current line in text widget.
 
-    def _put_source(self, where, source):
-        output = self.output_sep.join(source.split("\n"))
-        self.text.insert(where, output)
-
-    def history_do(self, reverse):
+        Set prefix and pointer as needed for successive fetches.
+        Reset them to None, None when returning to the start line.
+        Sound bell when return to start line or cannot leave a line
+        because cyclic is False.
+        '''
         nhist = len(self.history)
-        pointer = self.history_pointer
-        prefix = self.history_prefix
+        pointer = self.pointer
+        prefix = self.prefix
         if pointer is not None and prefix is not None:
             if self.text.compare("insert", "!=", "end-1c") or \
-               self._get_source("iomark", "end-1c") != self.history[pointer]:
+                    self.text.get("iomark", "end-1c") != self.history[pointer]:
                 pointer = prefix = None
+                self.text.mark_set("insert", "end-1c")  # != after cursor move
         if pointer is None or prefix is None:
-            prefix = self._get_source("iomark", "end-1c")
+            prefix = self.text.get("iomark", "end-1c")
             if reverse:
-                pointer = nhist
+                pointer = nhist  # will be decremented
             else:
                 if self.cyclic:
-                    pointer = -1
-                else:
+                    pointer = -1  # will be incremented
+                else:  # abort history_next
                     self.text.bell()
                     return
         nprefix = len(prefix)
         while 1:
-            if reverse:
-                pointer = pointer - 1
-            else:
-                pointer = pointer + 1
+            pointer += -1 if reverse else 1
             if pointer < 0 or pointer >= nhist:
                 self.text.bell()
-                if not self.cyclic and pointer < 0:
+                if not self.cyclic and pointer < 0:  # abort history_prev
                     return
                 else:
-                    if self._get_source("iomark", "end-1c") != prefix:
+                    if self.text.get("iomark", "end-1c") != prefix:
                         self.text.delete("iomark", "end-1c")
-                        self._put_source("iomark", prefix)
+                        self.text.insert("iomark", prefix)
                     pointer = prefix = None
                 break
             item = self.history[pointer]
             if item[:nprefix] == prefix and len(item) > nprefix:
                 self.text.delete("iomark", "end-1c")
-                self._put_source("iomark", item)
+                self.text.insert("iomark", item)
                 break
-        self.text.mark_set("insert", "end-1c")
         self.text.see("insert")
         self.text.tag_remove("sel", "1.0", "end")
-        self.history_pointer = pointer
-        self.history_prefix = prefix
+        self.pointer = pointer
+        self.prefix = prefix
 
-    def history_store(self, source):
+    def store(self, source):
+        "Store Shell input statement into history list."
         source = source.strip()
         if len(source) > 2:
             # avoid duplicates
@@ -84,5 +96,11 @@ class History:
             except ValueError:
                 pass
             self.history.append(source)
-        self.history_pointer = None
-        self.history_prefix = None
+        self.pointer = None
+        self.prefix = None
+
+if __name__ == "__main__":
+    from test import support
+    support.use_resources = ['gui']
+    from unittest import main
+    main('idlelib.idle_test.test_idlehistory', verbosity=2, exit=False)