| "Implement Idle Shell history mechanism with History class" |
| |
| from idlelib.config 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. |
| |
| .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.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): |
| "Fetch later statement; start with earliest if cyclic." |
| self.fetch(reverse=False) |
| return "break" |
| |
| def history_prev(self, event): |
| "Fetch earlier statement; start with most recent." |
| self.fetch(reverse=True) |
| return "break" |
| |
| def fetch(self, reverse): |
| '''Fetch statement and replace current line in text widget. |
| |
| 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.pointer |
| prefix = self.prefix |
| if pointer is not None and prefix is not None: |
| if self.text.compare("insert", "!=", "end-1c") or \ |
| 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.text.get("iomark", "end-1c") |
| if reverse: |
| pointer = nhist # will be decremented |
| else: |
| if self.cyclic: |
| pointer = -1 # will be incremented |
| else: # abort history_next |
| self.text.bell() |
| return |
| nprefix = len(prefix) |
| while 1: |
| pointer += -1 if reverse else 1 |
| if pointer < 0 or pointer >= nhist: |
| self.text.bell() |
| if not self.cyclic and pointer < 0: # abort history_prev |
| return |
| else: |
| if self.text.get("iomark", "end-1c") != prefix: |
| self.text.delete("iomark", "end-1c") |
| self.text.insert("iomark", prefix, "stdin") |
| pointer = prefix = None |
| break |
| item = self.history[pointer] |
| if item[:nprefix] == prefix and len(item) > nprefix: |
| self.text.delete("iomark", "end-1c") |
| self.text.insert("iomark", item, "stdin") |
| break |
| self.text.see("insert") |
| self.text.tag_remove("sel", "1.0", "end") |
| self.pointer = pointer |
| self.prefix = prefix |
| |
| def store(self, source): |
| "Store Shell input statement into history list." |
| source = source.strip() |
| if len(source) > 2: |
| # avoid duplicates |
| try: |
| self.history.remove(source) |
| except ValueError: |
| pass |
| self.history.append(source) |
| self.pointer = None |
| self.prefix = None |
| |
| |
| if __name__ == "__main__": |
| from unittest import main |
| main('idlelib.idle_test.test_history', verbosity=2, exit=False) |
