From e0a8e8f36a45b2db6a12308a4932b62cde68d733 Mon Sep 17 00:00:00 2001
From: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
Date: Mon, 8 Nov 2021 23:24:48 +0100
Subject: [PATCH] Add multipass option and checkbox

---
 egui/src/memory.rs                 | 5 +++++
 egui_demo_lib/src/backend_panel.rs | 7 +++++++
 2 files changed, 12 insertions(+)

diff --git a/egui/src/memory.rs b/egui/src/memory.rs
index f8d615ed..8aa9a48a 100644
--- a/egui/src/memory.rs
+++ b/egui/src/memory.rs
@@ -100,6 +100,11 @@ pub struct Options {
     /// but is a signal to any backend that we want the [`crate::Output::events`] read out loud.
     /// Screen readers is an experimental feature of egui, and not supported on all platforms.
     pub screen_reader: bool,
+
+    /// Enable experimental two-pass layout.
+    ///
+    /// See https://github.com/emilk/egui/issues/843
+    pub multi_pass: bool,
 }
 
 // ----------------------------------------------------------------------------
diff --git a/egui_demo_lib/src/backend_panel.rs b/egui_demo_lib/src/backend_panel.rs
index 170d7081..7049db61 100644
--- a/egui_demo_lib/src/backend_panel.rs
+++ b/egui_demo_lib/src/backend_panel.rs
@@ -132,6 +132,13 @@ impl BackendPanel {
             ui.ctx().memory().options.screen_reader = screen_reader;
         }
 
+        {
+            let mut multi_pass = ui.ctx().memory().options.multi_pass;
+            ui.checkbox(&mut multi_pass, "☯ Multipass (experimental)")
+                .on_hover_text("Experimental two-pass layout");
+            ui.ctx().memory().options.multi_pass = multi_pass;
+        }
+
         if !frame.is_web() {
             ui.separator();
             if ui.button("Quit").clicked() {