Basic unicode input works

kittens/unicode_input/main.py

@@ -4,15 +4,73 @@
 
 import sys
 
+from kitty.fast_data_types import wcswidth
+from kitty.key_encoding import backspace_key, enter_key, ESCAPE
+
 from ..tui.handler import Handler
 from ..tui.loop import Loop
+from ..tui.operations import (
+    clear_screen, colored, set_line_wrapping, set_window_title
+)
 
 
 class UnicodeInput(Handler):
 
+    def __init__(self):
+        self.current_input = ''
+        self.current_char = None
+        self.prompt_template = '{}> '
+        self.update_prompt()
+
+    def update_current_char(self):
+        try:
+            code = int(self.current_input, 16)
+            if code <= 32 or code == 127 or 128 <= code <= 159:
+                self.current_char = None
+            else:
+                self.current_char = chr(code)
+        except Exception:
+            self.current_char = None
+
+    def update_prompt(self):
+        self.update_current_char()
+        if self.current_char is None:
+            c, color = '??', 'red'
+        else:
+            c, color = self.current_char, 'green'
+        w = wcswidth(c)
+        self.prompt = self.prompt_template.format(colored(c, color))
+        self.promt_len = w + len(self.prompt_template) - 2
+
     def initialize(self, *args):
         Handler.initialize(self, *args)
-        self.write('Testing 123...')
+        self.write(set_line_wrapping(False))
+        self.write(set_window_title('Unicode input'))
+        self.draw_screen()
+
+    def draw_screen(self):
+        self.write(clear_screen())
+        self.print('Enter the hex code for the unicode character')
+        self.write(self.prompt)
+        self.write(self.current_input)
+
+    def refresh(self):
+        self.update_prompt()
+        self.draw_screen()
+
+    def on_text(self, text, in_bracketed_paste):
+        self.current_input += text
+        self.refresh()
+
+    def on_key(self, key_event):
+        if key_event is backspace_key:
+            self.current_input = self.current_input[:-1]
+            self.refresh()
+        elif key_event is enter_key:
+            self.quit_loop(0)
+        else:
+            if key_event.key is ESCAPE:
+                self.quit_loop(1)
 
     def on_interrupt(self):
         self.quit_loop(1)
@@ -20,8 +78,15 @@ class UnicodeInput(Handler):
     def on_eot(self):
         self.quit_loop(1)
 
+    def on_resize(self, new_size):
+        Handler.on_resize(self, new_size)
+        self.draw_screen()
+
 
 def main(args=sys.argv):
     loop = Loop()
     handler = UnicodeInput()
     loop.loop(handler)
+    if handler.current_char and loop.return_code == 0:
+        print(hex(ord(handler.current_char))[2:])
+    raise SystemExit(loop.return_code)