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| "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 ealiest 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 True: | |
| 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) | |