From 0b54691f07771a737f6efa3aaf26a84f8a2dcf99 Mon Sep 17 00:00:00 2001
From: stefnotch <brandmairstefan@gmail.com>
Date: Wed, 17 Feb 2021 22:36:11 +0100
Subject: [PATCH] Basic Visject box arrow key navigation

---
 Source/Editor/Surface/SurfaceNode.cs          | 19 ++--
 Source/Editor/Surface/VisjectSurface.Input.cs | 95 +++++++++++++++++++
 2 files changed, 106 insertions(+), 8 deletions(-)

diff --git a/Source/Editor/Surface/SurfaceNode.cs b/Source/Editor/Surface/SurfaceNode.cs
index bdce94513..303324870 100644
--- a/Source/Editor/Surface/SurfaceNode.cs
+++ b/Source/Editor/Surface/SurfaceNode.cs
@@ -553,19 +553,22 @@ namespace FlaxEditor.Surface
 
         internal Box GetNextBox(Box box)
         {
-            int i = 0;
-            for (; i < Elements.Count; i++)
+            // Get the one after it
+            for (int i = box.IndexInParent + 1; i < Elements.Count; i++)
             {
-                if (Elements[i] == box)
+                if (Elements[i] is Box b)
                 {
-                    // We found the box
-                    break;
+                    return b;
                 }
             }
 
-            // Get the one after it
-            i++;
-            for (; i < Elements.Count; i++)
+            return null;
+        }
+
+        internal Box GetPreviousBox(Box box)
+        {
+            // Get the one before it
+            for (int i = box.IndexInParent - 1; i >= 0; i--)
             {
                 if (Elements[i] is Box b)
                 {
diff --git a/Source/Editor/Surface/VisjectSurface.Input.cs b/Source/Editor/Surface/VisjectSurface.Input.cs
index dec89e143..28cff42b8 100644
--- a/Source/Editor/Surface/VisjectSurface.Input.cs
+++ b/Source/Editor/Surface/VisjectSurface.Input.cs
@@ -527,6 +527,101 @@ namespace FlaxEditor.Surface
                     }
                     return true;
                 }
+
+                if (key == KeyboardKeys.ArrowUp)
+                {
+                    Box selectedBox = GetSelectedBox(SelectedNodes);
+                    Box toSelect = selectedBox?.ParentNode.GetPreviousBox(selectedBox);
+
+                    if (toSelect != null)
+                    {
+                        if (toSelect.Connections.Count > 1)
+                        {
+                            // Box has multiple connections
+                        }
+
+                        if (toSelect.IsOutput != selectedBox.IsOutput)
+                        {
+                            // Jump up (nodes)
+                        }
+                        else
+                        {
+                            Select(toSelect.ParentNode);
+                            toSelect.ParentNode.SelectBox(toSelect);
+                        }
+                    }
+
+                    return true;
+                }
+                if (key == KeyboardKeys.ArrowDown)
+                {
+                    Box selectedBox = GetSelectedBox(SelectedNodes);
+                    Box toSelect = selectedBox?.ParentNode.GetNextBox(selectedBox);
+
+                    if (toSelect != null)
+                    {
+                        if (toSelect.Connections.Count > 1)
+                        {
+                            // Box has multiple connections
+                        }
+
+                        if (toSelect.IsOutput != selectedBox.IsOutput)
+                        {
+                            // Jump down (nodes)
+                        }
+                        else
+                        {
+                            Select(toSelect.ParentNode);
+                            toSelect.ParentNode.SelectBox(toSelect);
+                        }
+                    }
+
+                    return true;
+                }
+
+                if (key == KeyboardKeys.ArrowRight || key == KeyboardKeys.ArrowLeft)
+                {
+                    Box selectedBox = GetSelectedBox(SelectedNodes);
+                    if (selectedBox == null) return false;
+
+                    Box toSelect = null;
+
+                    if (key == KeyboardKeys.ArrowRight && selectedBox.IsOutput || key == KeyboardKeys.ArrowLeft && !selectedBox.IsOutput)
+                    {
+                        if (selectedBox.Connections.Count > 1)
+                        {
+                            // Box has multiple connections
+                        }
+                        else if (selectedBox.Connections.Count == 1)
+                        {
+                            toSelect = selectedBox.Connections[0];
+                        }
+                    }
+                    else
+                    {
+                        // Use the node with the closest Y-level
+                        // Since there are cases like 3 nodes on one side and only 1 node on the other side
+
+                        var elements = selectedBox?.ParentNode.Elements;
+                        float distance = float.PositiveInfinity;
+                        for (int i = 0; i < elements.Count; i++)
+                        {
+                            if (elements[i] is Box box && box.IsOutput != selectedBox.IsOutput && Mathf.Abs(box.Y - selectedBox.Y) < distance)
+                            {
+                                toSelect = box;
+                                distance = Mathf.Abs(box.Y - selectedBox.Y);
+                            }
+                        }
+                    }
+
+                    if (toSelect != null)
+                    {
+                        Select(toSelect.ParentNode);
+                        toSelect.ParentNode.SelectBox(toSelect);
+
+                    }
+                    return true;
+                }
             }
 
             return false;