From b4d6a7cd8973c779ee26caad85d7b60c01aef3bc Mon Sep 17 00:00:00 2001
From: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
Date: Wed, 5 Jun 2024 12:17:08 +0200
Subject: [PATCH] `Grid`: set the `sizing_pass` flag during the initial sizing
 pass (#4612)

* Part of https://github.com/emilk/egui/issues/4535

This should improve the auto-sizing of columns when nesting expanding
widgets (e.g. `Separator`), or centered or justified layouts.
---
 crates/egui/src/grid.rs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/crates/egui/src/grid.rs b/crates/egui/src/grid.rs
index b888f756b5e..2466c41e9b7 100644
--- a/crates/egui/src/grid.rs
+++ b/crates/egui/src/grid.rs
@@ -426,7 +426,10 @@ impl Grid {
         // which we do here:
         let max_rect = ui.cursor().intersect(ui.max_rect());
         ui.allocate_ui_at_rect(max_rect, |ui| {
-            ui.set_visible(prev_state.is_some()); // Avoid visible first-frame jitter
+            if prev_state.is_none() {
+                // Hide the ui this frame, and make things as narrow as possible.
+                ui.set_sizing_pass();
+            }
             ui.horizontal(|ui| {
                 let is_color = color_picker.is_some();
                 let mut grid = GridLayout {