adding text editor project

Author: FoamyGuy

CircuitPython_Text_Editor/adafruit_editor/__init__.py

@@ -0,0 +1,123 @@
+# SPDX-FileCopyrightText: 2023 Jeff Epler for Adafruit Industries
+#
+# SPDX-License-Identifier: MIT
+
+import select
+import sys
+
+try:
+    import termios
+
+    _orig_attr = None  # pylint: disable=invalid-name
+
+    def _nonblocking():
+        global _orig_attr  # pylint: disable=global-statement
+        _orig_attr = termios.tcgetattr(sys.stdin)
+        attr = termios.tcgetattr(sys.stdin)
+        attr[3] &= ~(termios.ECHO | termios.ICANON)
+        attr[6][termios.VMIN] = 1
+        attr[6][termios.VTIME] = 0
+        termios.tcsetattr(sys.stdin, termios.TCSADRAIN, attr)
+
+    def _blocking():
+        if _orig_attr is not None:
+            termios.tcsetattr(sys.stdin, termios.TCSADRAIN, _orig_attr)
+
+except ImportError:
+
+    def _nonblocking():
+        pass
+
+    def _blocking():
+        pass
+
+
+LINES = 24
+COLS = 80
+
+special_keys = {
+    "\x1b": ...,  # all prefixes of special keys must be entered as Ellipsis
+    "\x1b[": ...,
+    "\x1b[5": ...,
+    "\x1b[6": ...,
+    "\x1b[A": "KEY_UP",
+    "\x1b[B": "KEY_DOWN",
+    "\x1b[C": "KEY_RIGHT",
+    "\x1b[D": "KEY_LEFT",
+    "\x1b[H": "KEY_HOME",
+    "\x1b[F": "KEY_END",
+    "\x1b[5~": "KEY_PGUP",
+    "\x1b[6~": "KEY_PGDN",
+    "\x1b[3~": "KEY_DELETE",
+}
+
+
+class Screen:
+    def __init__(self):
+        self._poll = select.poll()
+        self._poll.register(sys.stdin, select.POLLIN)
+        self._pending = ""
+
+    def _sys_stdin_readable(self):
+        return hasattr(sys.stdin, "readable") and sys.stdin.readable()
+
+    def _sys_stdout_flush(self):
+        if hasattr(sys.stdout, "flush"):
+            sys.stdout.flush()
+
+    def _terminal_read_blocking(self):
+        return sys.stdin.read(1)
+
+    def _terminal_read_timeout(self, timeout):
+        if self._sys_stdin_readable() or self._poll.poll(timeout):
+            r = sys.stdin.read(1)
+            return r
+        return None
+
+    def move(self, y, x):
+        print(end=f"\033[{y+1};{x+1}H")
+
+    def erase(self):
+        print(end="\033H\033[2J")
+
+    def addstr(self, y, x, text):
+        self.move(y, x)
+        print(end=text)
+
+    def getkey(self):
+        self._sys_stdout_flush()
+        pending = self._pending
+        if pending and (code := special_keys.get(pending)) is None:
+            self._pending = pending[1:]
+            return pending[0]
+
+        while True:
+            if pending:
+                c = self._terminal_read_timeout(50)
+                if c is None:
+                    self._pending = pending[1:]
+                    return pending[0]
+            else:
+                c = self._terminal_read_blocking()
+            c = pending + c
+
+            code = special_keys.get(c)
+
+            if code is None:
+                self._pending = c[1:]
+                return c[0]
+            if code is not Ellipsis:
+                return code
+
+            pending = c
+
+
+def wrapper(func, *args, **kwds):
+    stdscr = Screen()
+    try:
+        _nonblocking()
+        return func(stdscr, *args, **kwds)
+    finally:
+        _blocking()
+        stdscr.move(LINES - 1, 0)
+        print("\n")