From 25415458292a42a52910f1728334d212ce34906e Mon Sep 17 00:00:00 2001
From: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
Date: Mon, 5 Sep 2022 18:26:18 +0200
Subject: [PATCH 1/2] Add opt-in serde feature to enable serialization of Tree

Allows users to persist the `Tree` layout
---
 CHANGELOG.md | 4 ++++
 Cargo.toml   | 8 ++++++++
 src/tree.rs  | 4 ++++
 3 files changed, 16 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6f123d9..09111e4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Added
+- Added opt-in `serde` feature to enable serialization of `Tree`.
+
+
 ## 0.2.0 - 2022-09-04
 
 ### Added
diff --git a/Cargo.toml b/Cargo.toml
index fb6de6f..c09a83c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -10,8 +10,16 @@ readme = "README.md"
 repository = "https://github.com/Adanos020/egui_dock"
 categories = ["gui", "game-development"]
 
+[features]
+default = []
+
+# Enable serialization of `Tree`.
+serde = ["dep:serde", "egui/serde"]
+
+
 [dependencies]
 egui = "0.19"
+serde = { version = "1", optional = true, features = ["derive"] }
 
 [dev-dependencies]
 eframe = "0.19"
diff --git a/src/tree.rs b/src/tree.rs
index b5508e7..a937558 100644
--- a/src/tree.rs
+++ b/src/tree.rs
@@ -2,6 +2,7 @@ use egui::*;
 
 /// Identifies a tab within a [`Node`].
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, Ord, PartialOrd)]
+#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
 pub struct TabIndex(pub usize);
 
 impl From<usize> for TabIndex {
@@ -14,6 +15,7 @@ impl From<usize> for TabIndex {
 // ----------------------------------------------------------------------------
 
 /// Represents an abstract node of a `Tree`.
+#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
 pub enum Node<Tab> {
     /// Empty node
     Empty,
@@ -154,6 +156,7 @@ impl<Tab> Node<Tab> {
 
 /// Wrapper around indices to the collection of nodes inside a `Tree`.
 #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
 pub struct NodeIndex(pub usize);
 
 impl From<usize> for NodeIndex {
@@ -239,6 +242,7 @@ pub enum Split {
 // ----------------------------------------------------------------------------
 
 /// Binary tree representing the relationships between `Node`s.
+#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
 pub struct Tree<Tab> {
     tree: Vec<Node<Tab>>,
     focused_node: Option<NodeIndex>,

From e9044607d84de013a562bc8c5ef376e7246c0205 Mon Sep 17 00:00:00 2001
From: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
Date: Mon, 5 Sep 2022 18:31:19 +0200
Subject: [PATCH 2/2] Fix: Tree::push_to_first_leaf no longer panics when used
 on empty Tree

---
 CHANGELOG.md | 3 +++
 src/tree.rs  | 4 +++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 09111e4..f63c514 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,9 @@
 ### Added
 - Added opt-in `serde` feature to enable serialization of `Tree`.
 
+### Fixed
+* `Tree::push_to_first_leaf` no longer panics when used on an empty `Tree`
+
 
 ## 0.2.0 - 2022-09-04
 
diff --git a/src/tree.rs b/src/tree.rs
index a937558..73362b9 100644
--- a/src/tree.rs
+++ b/src/tree.rs
@@ -574,7 +574,9 @@ impl<Tab> Tree<Tab> {
                 _ => {}
             }
         }
-        panic!();
+        assert!(self.tree.is_empty());
+        self.tree.push(Node::leaf_with(vec![tab]));
+        self.focused_node = Some(NodeIndex(0));
     }
 
     /// Currently focused leaf.