Implement using Ctrl+Shift+u to input unicode

Fixes #302

README.asciidoc

@@ -11,6 +11,7 @@
 :sc_first_window: pass:quotes[`ctrl+shift+1`]
 :sc_fourth_window: pass:quotes[`ctrl+shift+4`]
 :sc_increase_font_size: pass:quotes[`ctrl+shift+equal`]
+:sc_input_unicode_character: pass:quotes[`ctrl+shift+u`]
 :sc_move_tab_backward: pass:quotes[`ctrl+shift+,`]
 :sc_move_tab_forward: pass:quotes[`ctrl+shift+.`]
 :sc_move_window_backward: pass:quotes[`ctrl+shift+b`]
@@ -226,6 +227,7 @@ windows are:
 |Decrease font size   | {sc_decrease_font_size}
 |Restore font size    | {sc_restore_font_size}
 |Toggle fullscreen    | {sc_toggle_fullscreen}
+|Input unicode character | {sc_input_unicode_character}
 |Pass current selection to program | {sc_pass_selection_to_program}
 |===
 

kittens/unicode_input/main.py

@@ -88,5 +88,5 @@ def main(args=sys.argv):
     handler = UnicodeInput()
     loop.loop(handler)
     if handler.current_char and loop.return_code == 0:
-        print(hex(ord(handler.current_char))[2:])
+        print('OK:', hex(ord(handler.current_char))[2:])
     raise SystemExit(loop.return_code)

kitty/boss.py

@@ -3,6 +3,7 @@
 # License: GPL v3 Copyright: 2016, Kovid Goyal <kovid at kovidgoyal.net>
 
 import re
+from functools import partial
 from gettext import gettext as _
 from weakref import WeakValueDictionary
 
@@ -196,6 +197,12 @@ def on_child_death(self, window_id):
         window = self.window_id_map.pop(window_id, None)
         if window is None:
             return
+        if window.action_on_close:
+            try:
+                window.action_on_close(window)
+            except Exception:
+                import traceback
+                traceback.print_exc()
         os_window_id = window.os_window_id
         window.destroy()
         tm = self.os_window_map.get(os_window_id)
@@ -366,6 +373,29 @@ def display_scrollback(self, window, data):
                 SpecialWindow(
                     self.opts.scrollback_pager, data, _('History'), overlay_for=window.id))
 
+    def input_unicode_character(self):
+        w = self.active_window
+        tab = self.active_tab
+        if w is not None and tab is not None and w.overlay_for is None:
+            overlay_window = tab.new_special_window(
+                SpecialWindow(
+                    ['kitty', '+runpy', 'from kittens.unicode_input.main import main; main()'],
+                    overlay_for=w.id))
+            overlay_window.action_on_close = partial(self.send_unicode_character, w.id)
+
+    def send_unicode_character(self, target_window_id, source_window):
+        w = self.window_id_map.get(target_window_id)
+        if w is not None:
+            output = str(source_window.screen.linebuf.line(0))
+            if output.startswith('OK: '):
+                try:
+                    text = chr(int(output.partition(' ')[2], 16))
+                except Exception:
+                    import traceback
+                    traceback.print_exc()
+                else:
+                    w.paste(text)
+
     def switch_focus_to(self, window_idx):
         tab = self.active_tab
         tab.set_active_window_idx(window_idx)
@@ -491,6 +521,8 @@ def new_window(self, *args):
 
     def new_window_with_cwd(self, *args):
         w = self.active_window
+        if w is None:
+            return self.new_window(*args)
         cwd_from = w.child.pid if w is not None else None
         self._new_window(args, cwd_from=cwd_from)
 

kitty/kitty.conf

@@ -328,6 +328,7 @@ map ctrl+shift+equal    increase_font_size
 map ctrl+shift+minus    decrease_font_size
 map ctrl+shift+backspace restore_font_size
 map ctrl+shift+f11      toggle_fullscreen
+map ctrl+shift+u        input_unicode_character
 
 # Sending arbitrary text on shortcut key presses
 # You can tell kitty to send arbitrary (UTF-8) encoded text to

kitty/window.py

@@ -87,6 +87,7 @@ def setup_colors(screen, opts):
 class Window:
 
     def __init__(self, tab, child, opts, args, override_title=None):
+        self.action_on_close = None
         self.override_title = override_title
         self.overlay_window_id = None
         self.overlay_for = None