From 61b5049186afabcbea08bf972c0d6ec3666400c4 Mon Sep 17 00:00:00 2001
From: Dawid Gliwka <dawid.gliwka@gmail.com>
Date: Tue, 10 Nov 2020 17:21:10 +0100
Subject: [PATCH] Add keyboard navigation history similar to ranger

---
 src/App.tsx      | 23 +++++++++++++++++------
 src/core/tree.ts |  2 ++
 2 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/src/App.tsx b/src/App.tsx
index 8c39042..13a7b7b 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -87,9 +87,16 @@ export default class App extends Component<{
 
     selectNode = (node_id: NodeID) =>
     {
-        this.setState({
-            chosenNode: node_id,
-        });
+        const root = this.state.ourTree.root
+        const node = this.state.ourTree._selectNodeById(node_id)
+        if (node !== root)
+        {
+            const parent = root.getParent(node, root)
+            parent.lastSelectedChild = node_id
+            this.setState({
+                chosenNode: node_id,
+            });
+        }
     }
 
     selectParentNode = () =>
@@ -99,7 +106,7 @@ export default class App extends Component<{
         if (node !== root)
         {
             const parent = root.getParent(node, root)
-        
+            parent.lastSelectedChild = node.id
             this.setState({
                 chosenNode: parent.id
             })
@@ -114,7 +121,7 @@ export default class App extends Component<{
             const child = node.children[0]
         
             this.setState({
-                chosenNode: child.id
+                chosenNode: node.lastSelectedChild || child.id
             })
         }
     }
@@ -129,7 +136,9 @@ export default class App extends Component<{
             const indexOfNode = parent.children.indexOf(node)
             const indexOfNextChild = Math.min(indexOfNode+1, parent.children.length-1)
             const nextChild = parent.children[indexOfNextChild]
-            
+
+            parent.lastSelectedChild = nextChild.id
+
             this.setState({
                 chosenNode: nextChild.id
             })
@@ -147,6 +156,8 @@ export default class App extends Component<{
             const indexOfPrevChild = Math.max(indexOfNode-1, 0)
             const prevChild = parent.children[indexOfPrevChild]
             
+            parent.lastSelectedChild = prevChild.id
+            
             this.setState({
                 chosenNode: prevChild.id
             })
diff --git a/src/core/tree.ts b/src/core/tree.ts
index 49282bc..6e9a565 100644
--- a/src/core/tree.ts
+++ b/src/core/tree.ts
@@ -196,12 +196,14 @@ export class TreeNode<T>
     // TODO: how about children being Sets?
     children: TreeNode<T>[];
     data: T;
+    lastSelectedChild: NodeID | null;
 
     constructor(id: NodeID, data: T, children: TreeNode<T>[] = [])
     {
         this.data = data;
         this.id = id;
         this.children = children;
+        this.lastSelectedChild = null
     }
 
     _append(node: TreeNode<T>)