Changed code to support older Python versions

venv/lib/python3.11/site-packages/rich_toolkit/_input_handler.py

@@ -0,0 +1,132 @@
+"""Unified input handler for all platforms."""
+
+import sys
+import unicodedata
+
+
+class TextInputHandler:
+    """Input handler with platform-specific key code support."""
+
+    # Platform-specific key codes
+    if sys.platform == "win32":
+        # Windows uses \xe0 prefix for special keys when using msvcrt.getwch
+        DOWN_KEY = "\xe0P"  # Down arrow
+        UP_KEY = "\xe0H"  # Up arrow
+        LEFT_KEY = "\xe0K"  # Left arrow
+        RIGHT_KEY = "\xe0M"  # Right arrow
+        DELETE_KEY = "\xe0S"  # Delete key
+        BACKSPACE_KEY = "\x08"  # Backspace
+        TAB_KEY = "\t"
+        SHIFT_TAB_KEY = "\x00\x0f"  # Shift+Tab
+        ENTER_KEY = "\r"
+
+        # Alternative codes that might be sent
+        ALT_BACKSPACE = "\x7f"
+        ALT_DELETE = "\x00S"
+    else:
+        # Unix/Linux key codes (ANSI escape sequences)
+        DOWN_KEY = "\x1b[B"
+        UP_KEY = "\x1b[A"
+        LEFT_KEY = "\x1b[D"
+        RIGHT_KEY = "\x1b[C"
+        BACKSPACE_KEY = "\x7f"
+        DELETE_KEY = "\x1b[3~"
+        TAB_KEY = "\t"
+        SHIFT_TAB_KEY = "\x1b[Z"
+        ENTER_KEY = "\r"
+
+        # Alternative codes
+        ALT_BACKSPACE = "\x08"
+        ALT_DELETE = None
+
+    def __init__(self):
+        self.text = ""
+        self._cursor_index = 0  # Character index in the text string
+
+    @property
+    def cursor_left(self) -> int:
+        """Visual cursor position in display columns."""
+        return self._get_text_width(self.text[: self._cursor_index])
+
+    @staticmethod
+    def _get_char_width(char: str) -> int:
+        """Get the display width of a character (1 for normal, 2 for CJK/fullwidth)."""
+        if not char:
+            return 0
+
+        # Check East Asian Width property
+        east_asian_width = unicodedata.east_asian_width(char)
+        # F (Fullwidth) and W (Wide) characters take 2 columns
+        if east_asian_width in ("F", "W"):
+            return 2
+        # A (Ambiguous) characters are typically 2 columns in CJK contexts
+        # but for simplicity we'll treat them as 1 (can be made configurable)
+        return 1
+
+    def _get_text_width(self, text: str) -> int:
+        """Get the total display width of a text string."""
+        return sum(self._get_char_width(char) for char in text)
+
+    def _move_cursor_left(self) -> None:
+        self._cursor_index = max(0, self._cursor_index - 1)
+
+    def _move_cursor_right(self) -> None:
+        self._cursor_index = min(len(self.text), self._cursor_index + 1)
+
+    def _insert_char(self, char: str) -> None:
+        self.text = (
+            self.text[: self._cursor_index] + char + self.text[self._cursor_index :]
+        )
+        self._cursor_index += 1
+
+    def _delete_char(self) -> None:
+        """Delete character before cursor (backspace)."""
+        if self._cursor_index == 0:
+            return
+
+        self.text = (
+            self.text[: self._cursor_index - 1] + self.text[self._cursor_index :]
+        )
+        self._cursor_index -= 1
+
+    def _delete_forward(self) -> None:
+        """Delete character at cursor (delete key)."""
+        if self._cursor_index >= len(self.text):
+            return
+
+        self.text = (
+            self.text[: self._cursor_index] + self.text[self._cursor_index + 1 :]
+        )
+
+    def handle_key(self, key: str) -> None:
+        # Handle backspace (both possible codes)
+        if key == self.BACKSPACE_KEY or (
+            self.ALT_BACKSPACE and key == self.ALT_BACKSPACE
+        ):
+            self._delete_char()
+        # Handle delete key
+        elif key == self.DELETE_KEY or (self.ALT_DELETE and key == self.ALT_DELETE):
+            self._delete_forward()
+        elif key == self.LEFT_KEY:
+            self._move_cursor_left()
+        elif key == self.RIGHT_KEY:
+            self._move_cursor_right()
+        elif key in (
+            self.UP_KEY,
+            self.DOWN_KEY,
+            self.ENTER_KEY,
+            self.SHIFT_TAB_KEY,
+            self.TAB_KEY,
+        ):
+            pass
+        else:
+            # Handle regular text input
+            # Special keys on Windows start with \x00 or \xe0
+            if sys.platform == "win32" and key and key[0] in ("\x00", "\xe0"):
+                # Skip special key sequences
+                return
+
+            # Even if we call this handle_key, in some cases we might receive
+            # multiple keys at once (e.g., during paste operations)
+            for char in key:
+                self._insert_char(char)