From 040cc4d4c3eb9d968e5accbe4672a1120d67a737 Mon Sep 17 00:00:00 2001
From: Antonio Scandurra <me@as-cii.com>
Date: Wed, 3 May 2023 19:25:00 +0200
Subject: [PATCH] Allow notifying views when the ancestry of another view is
 outdated

---
 crates/gpui/src/app.rs        |  5 +++--
 crates/gpui/src/app/window.rs | 21 ++++++++++++++++++++-
 crates/gpui/src/elements.rs   |  7 ++++---
 3 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/crates/gpui/src/app.rs b/crates/gpui/src/app.rs
index 355e8215e7..0b618d8e6d 100644
--- a/crates/gpui/src/app.rs
+++ b/crates/gpui/src/app.rs
@@ -25,6 +25,7 @@ use std::{
 use anyhow::{anyhow, Context, Result};
 use parking_lot::Mutex;
 use postage::oneshot;
+use smallvec::SmallVec;
 use smol::prelude::*;
 use util::ResultExt;
 use uuid::Uuid;
@@ -3198,7 +3199,7 @@ impl<V> BorrowWindowContext for ViewContext<'_, '_, V> {
 pub struct LayoutContext<'a, 'b, 'c, V: View> {
     view_context: &'c mut ViewContext<'a, 'b, V>,
     new_parents: &'c mut HashMap<usize, usize>,
-    views_to_notify_if_ancestors_change: &'c mut HashSet<usize>,
+    views_to_notify_if_ancestors_change: &'c mut HashMap<usize, SmallVec<[usize; 2]>>,
     pub refreshing: bool,
 }
 
@@ -3206,7 +3207,7 @@ impl<'a, 'b, 'c, V: View> LayoutContext<'a, 'b, 'c, V> {
     pub fn new(
         view_context: &'c mut ViewContext<'a, 'b, V>,
         new_parents: &'c mut HashMap<usize, usize>,
-        views_to_notify_if_ancestors_change: &'c mut HashSet<usize>,
+        views_to_notify_if_ancestors_change: &'c mut HashMap<usize, SmallVec<[usize; 2]>>,
         refreshing: bool,
     ) -> Self {
         Self {
diff --git a/crates/gpui/src/app/window.rs b/crates/gpui/src/app/window.rs
index 606cfc9a24..a96d937b1b 100644
--- a/crates/gpui/src/app/window.rs
+++ b/crates/gpui/src/app/window.rs
@@ -933,7 +933,7 @@ impl<'a> WindowContext<'a> {
         let root_view_id = self.window.root_view().id();
         let mut rendered_root = self.window.rendered_views.remove(&root_view_id).unwrap();
         let mut new_parents = HashMap::default();
-        let mut views_to_notify_if_ancestors_change = HashSet::default();
+        let mut views_to_notify_if_ancestors_change = HashMap::default();
         rendered_root.layout(
             SizeConstraint::strict(window_size),
             &mut new_parents,
@@ -942,6 +942,25 @@ impl<'a> WindowContext<'a> {
             self,
         )?;
 
+        for (view_id, view_ids_to_notify) in views_to_notify_if_ancestors_change {
+            let mut current_view_id = view_id;
+            loop {
+                let old_parent_id = self.window.parents.get(&current_view_id);
+                let new_parent_id = new_parents.get(&current_view_id);
+                if old_parent_id.is_none() && new_parent_id.is_none() {
+                    break;
+                } else if old_parent_id == new_parent_id {
+                    current_view_id = *old_parent_id.unwrap();
+                } else {
+                    let window_id = self.window_id;
+                    for view_id_to_notify in view_ids_to_notify {
+                        self.notify_view(window_id, view_id_to_notify);
+                    }
+                    break;
+                }
+            }
+        }
+
         self.window.parents = new_parents;
         self.window
             .rendered_views
diff --git a/crates/gpui/src/elements.rs b/crates/gpui/src/elements.rs
index 073d12c329..e2c4af143c 100644
--- a/crates/gpui/src/elements.rs
+++ b/crates/gpui/src/elements.rs
@@ -37,9 +37,10 @@ use crate::{
     WindowContext,
 };
 use anyhow::{anyhow, Result};
-use collections::{HashMap, HashSet};
+use collections::HashMap;
 use core::panic;
 use json::ToJson;
+use smallvec::SmallVec;
 use std::{
     any::Any,
     borrow::Cow,
@@ -648,7 +649,7 @@ pub trait AnyRootElement {
         &mut self,
         constraint: SizeConstraint,
         new_parents: &mut HashMap<usize, usize>,
-        views_to_notify_if_ancestors_change: &mut HashSet<usize>,
+        views_to_notify_if_ancestors_change: &mut HashMap<usize, SmallVec<[usize; 2]>>,
         refreshing: bool,
         cx: &mut WindowContext,
     ) -> Result<Vector2F>;
@@ -673,7 +674,7 @@ impl<V: View> AnyRootElement for RootElement<V> {
         &mut self,
         constraint: SizeConstraint,
         new_parents: &mut HashMap<usize, usize>,
-        views_to_notify_if_ancestors_change: &mut HashSet<usize>,
+        views_to_notify_if_ancestors_change: &mut HashMap<usize, SmallVec<[usize; 2]>>,
         refreshing: bool,
         cx: &mut WindowContext,
     ) -> Result<Vector2F> {