From 96326280e5d6e49b511bc1e5cd1579a6d2a4864e Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Wed, 4 Aug 2021 22:06:05 +0530
Subject: [PATCH] Use a pending update when drawing the screen

---
 kittens/themes/main.py    | 13 +++++++------
 kittens/tui/handler.py    |  9 +++++++--
 kittens/tui/operations.py |  8 ++++++++
 3 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/kittens/themes/main.py b/kittens/themes/main.py
index fdc57c4c0..d3c6df808 100644
--- a/kittens/themes/main.py
+++ b/kittens/themes/main.py
@@ -278,12 +278,13 @@ class ThemesHandler(Handler):
             self.on_browsing_key_event(key_event, in_bracketed_paste)
 
     def draw_screen(self) -> None:
-        self.cmd.clear_screen()
-        self.enforce_cursor_state()
-        if self.state is State.fetching:
-            self.draw_fetching_screen()
-        elif self.state is State.browsing:
-            self.draw_browsing_screen()
+        with self.pending_update():
+            self.cmd.clear_screen()
+            self.enforce_cursor_state()
+            if self.state is State.fetching:
+                self.draw_fetching_screen()
+            elif self.state is State.browsing:
+                self.draw_browsing_screen()
 
     def on_resize(self, screen_size: ScreenSize) -> None:
         self.screen_size = screen_size
diff --git a/kittens/tui/handler.py b/kittens/tui/handler.py
index b3794e804..68a7260cb 100644
--- a/kittens/tui/handler.py
+++ b/kittens/tui/handler.py
@@ -10,10 +10,12 @@ from typing import (
 
 from kitty.types import ParsedShortcut
 from kitty.typing import (
-    AbstractEventLoop, BossType, Debug, ImageManagerType, KeyEventType,
-    KeyActionType, LoopType, MouseEvent, ScreenSize, TermManagerType
+    AbstractEventLoop, BossType, Debug, ImageManagerType, KeyActionType,
+    KeyEventType, LoopType, MouseEvent, ScreenSize, TermManagerType
 )
 
+from .operations import pending_update
+
 
 class Handler:
 
@@ -134,6 +136,9 @@ class Handler:
     def suspend(self) -> ContextManager[TermManagerType]:
         return self._term_manager.suspend()
 
+    def pending_update(self) -> ContextManager[None]:
+        return pending_update(self.write)
+
 
 class HandleResult:
 
diff --git a/kittens/tui/operations.py b/kittens/tui/operations.py
index 8a1a8cf06..8e41daea1 100644
--- a/kittens/tui/operations.py
+++ b/kittens/tui/operations.py
@@ -40,6 +40,7 @@ MODES = dict(
     MOUSE_URXVT_MODE=(1015, '?'),
     ALTERNATE_SCREEN=(1049, '?'),
     BRACKETED_PASTE=(2004, '?'),
+    PENDING_UPDATE=(2026, '?'),
 )
 
 F = TypeVar('F')
@@ -290,6 +291,13 @@ def reset_state(normal_screen: bool = True) -> str:
     return ans
 
 
+@contextmanager
+def pending_update(write: Callable[[str], None]) -> Generator[None, None, None]:
+    write(set_mode('PENDING_UPDATE'))
+    yield
+    write(reset_mode('PENDING_UPDATE'))
+
+
 @contextmanager
 def cursor(write: Callable[[str], None]) -> Generator[None, None, None]:
     write(SAVE_CURSOR)