Start work on a path completion implementation

kittens/tui/path_completer.py

@@ -0,0 +1,130 @@
+#!/usr/bin/env python
+# vim:fileencoding=utf-8
+# License: GPLv3 Copyright: 2020, Kovid Goyal <kovid at kovidgoyal.net>
+
+
+import os
+from typing import Any, Dict, Generator, Optional, Sequence, Tuple
+
+from kitty.fast_data_types import wcswidth
+from kitty.utils import ScreenSize, screen_size_function
+
+from .operations import styled
+
+
+def directory_completions(path: str, qpath: str, prefix: str = '') -> Generator[str, None, None]:
+    try:
+        entries = os.scandir(qpath)
+    except OSError:
+        return
+    for x in entries:
+        try:
+            is_dir = x.is_dir()
+        except OSError:
+            is_dir = False
+        name = x.name + (os.sep if is_dir else '')
+        if not prefix or name.startswith(prefix):
+            if path:
+                yield os.path.join(path, name)
+            else:
+                yield name
+
+
+def expand_path(path: str) -> str:
+    return os.path.abspath(os.path.expandvars(os.path.expanduser(path)))
+
+
+def find_completions(path: str) -> Generator[str, None, None]:
+    qpath = expand_path(path)
+    if not path or path.endswith(os.sep):
+        yield from directory_completions(path, qpath)
+    else:
+        yield from directory_completions(os.path.dirname(path), os.path.dirname(qpath), os.path.basename(qpath))
+
+
+def print_table(items: Sequence[str], screen_size: ScreenSize) -> None:
+    max_width = 0
+    item_widths = {}
+    for item in items:
+        item_widths[item] = w = wcswidth(item)
+        max_width = max(w, max_width)
+    col_width = max_width + 2
+    num_of_cols = max(1, screen_size.cols // col_width)
+    cr = 0
+    at_start = False
+    for item in items:
+        w = item_widths[item]
+        left = col_width - w
+        print(item, ' ' * left, sep='', end='')
+        at_start = False
+        cr = (cr + 1) % num_of_cols
+        if not cr:
+            print()
+            at_start = True
+    if not at_start:
+        print()
+
+
+class PathCompleter:
+
+    def __init__(self, prompt: str = '> '):
+        self.prompt = prompt
+
+    def __enter__(self) -> 'PathCompleter':
+        import readline
+        if 'libedit' in readline.__doc__:
+            readline.parse_and_bind("bind -e")
+            readline.parse_and_bind("bind '\t' rl_complete")
+        else:
+            readline.parse_and_bind('tab: complete')
+            readline.parse_and_bind('set colored-stats on')
+            readline.set_completer_delims(' \t\n`!@#$%^&*()-=+[{]}\\|;:\'",<>?')
+        readline.set_completion_display_matches_hook(self.format_completions)
+        self.original_completer = readline.get_completer()
+        readline.set_completer(self)
+        self.cache: Dict[str, Tuple[str, ...]] = {}
+        return self
+
+    def format_completions(self, substitution: str, matches: Sequence[str], longest_match_length: int) -> None:
+        import readline
+        print()
+        files, dirs = [], []
+        for m in matches:
+            if m.endswith('/'):
+                if len(m) > 1:
+                    m = m[:-1]
+                dirs.append(m)
+            else:
+                files.append(m)
+
+        ss = screen_size_function()()
+        if dirs:
+            print(styled('Directories', bold=True, fg_intense=True))
+            print_table(dirs, ss)
+        if files:
+            print(styled('Files', bold=True, fg_intense=True))
+            print_table(files, ss)
+
+        print(self.prompt, readline.get_line_buffer(), sep='', end='', flush=True)
+
+    def __call__(self, text: str, state: int) -> Optional[str]:
+        options = self.cache.get(text)
+        if options is None:
+            options = self.cache[text] = tuple(find_completions(text))
+        if options and state < len(options):
+            return options[state]
+
+    def __exit__(self, *a: Any) -> bool:
+        import readline
+        del self.cache
+        readline.set_completer(self.original_completer)
+        readline.set_completion_display_matches_hook()
+        return True
+
+    def input(self) -> str:
+        with self:
+            return input(self.prompt)
+
+
+def develop() -> None:
+    PathCompleter().input()