From 41d6e0f647bc4eae9d0c29856f014da930db2f96 Mon Sep 17 00:00:00 2001
From: jlewin <lewin76@gmail.com>
Date: Fri, 7 Jun 2019 13:54:11 -0700
Subject: [PATCH] Add keyboard support for nudging selected scene items

- Issue MatterHackers/MCCentral#5655
[Feature Request] Move objects with keyboard
---
 .../ApplicationView/ApplicationController.cs  | 79 +++++++++++++++++--
 1 file changed, 73 insertions(+), 6 deletions(-)

diff --git a/MatterControlLib/ApplicationView/ApplicationController.cs b/MatterControlLib/ApplicationView/ApplicationController.cs
index 897a97e6c..82593c0c2 100644
--- a/MatterControlLib/ApplicationView/ApplicationController.cs
+++ b/MatterControlLib/ApplicationView/ApplicationController.cs
@@ -3441,8 +3441,15 @@ Support and tutorials:
 							}
 							else
 							{
-								// move or rotate view left
-								Offset3DView(view3D, new Vector2(-offsetDist, 0), arrowKeyOperation);
+								if (view3D.sceneContext.Scene.SelectedItem is IObject3D object3D)
+								{
+									NudgeItem(view3D, object3D, ArrowDirection.Left, keyEvent);
+								}
+								else
+								{
+									// move or rotate view left
+									Offset3DView(view3D, new Vector2(-offsetDist, 0), arrowKeyOperation);
+								}
 							}
 
 							keyEvent.Handled = true;
@@ -3459,8 +3466,15 @@ Support and tutorials:
 							}
 							else
 							{
-								// move or rotate view right
-								Offset3DView(view3D, new Vector2(offsetDist, 0), arrowKeyOperation);
+								if (view3D.sceneContext.Scene.SelectedItem is IObject3D object3D)
+								{
+									NudgeItem(view3D, object3D, ArrowDirection.Right, keyEvent);
+								}
+								else
+								{
+									// move or rotate view right
+									Offset3DView(view3D, new Vector2(offsetDist, 0), arrowKeyOperation);
+								}
 							}
 
 							keyEvent.Handled = true;
@@ -3476,7 +3490,14 @@ Support and tutorials:
 							}
 							else
 							{
-								Offset3DView(view3D, new Vector2(0, offsetDist), arrowKeyOperation);
+								if (view3D.sceneContext.Scene.SelectedItem is IObject3D object3D)
+								{
+									NudgeItem(view3D, object3D, ArrowDirection.Up, keyEvent);
+								}
+								else
+								{
+									Offset3DView(view3D, new Vector2(0, offsetDist), arrowKeyOperation);
+								}
 							}
 
 							keyEvent.Handled = true;
@@ -3492,7 +3513,14 @@ Support and tutorials:
 							}
 							else
 							{
-								Offset3DView(view3D, new Vector2(0, -offsetDist), arrowKeyOperation);
+								if (view3D.sceneContext.Scene.SelectedItem is IObject3D object3D)
+								{
+									NudgeItem(view3D, object3D, ArrowDirection.Down, keyEvent);
+								}
+								else
+								{
+									Offset3DView(view3D, new Vector2(0, -offsetDist), arrowKeyOperation);
+								}
 							}
 
 							keyEvent.Handled = true;
@@ -3597,6 +3625,45 @@ Support and tutorials:
 			return systemWindow;
 		}
 
+		private static void NudgeItem(View3DWidget view3D, IObject3D object3D, ArrowDirection arrowDirection, KeyEventArgs keyEvent)
+		{
+			// TODO: analyze the view and adjust movements to be relative to the current perspective
+			//
+			// Naive movements in Identity space
+			switch (arrowDirection)
+			{
+				case ArrowDirection.Left:
+					object3D.Translate(-view3D.InteractionLayer.SnapGridDistance, 0);
+					break;
+
+				case ArrowDirection.Right:
+					object3D.Translate(view3D.InteractionLayer.SnapGridDistance, 0);
+					break;
+
+				case ArrowDirection.Up:
+					if (keyEvent.Control)
+					{
+						object3D.Translate(0, 0, view3D.InteractionLayer.SnapGridDistance);
+					}
+					else
+					{
+						object3D.Translate(0, view3D.InteractionLayer.SnapGridDistance);
+					}
+					break;
+
+				case ArrowDirection.Down:
+					if (keyEvent.Control)
+					{
+						object3D.Translate(0, 0, -view3D.InteractionLayer.SnapGridDistance);
+					}
+					else
+					{
+						object3D.Translate(0, -view3D.InteractionLayer.SnapGridDistance);
+					}
+					break;
+			}
+		}
+
 		private static void Offset3DView(View3DWidget view3D, Vector2 offset, TrackBallTransformType operation)
 		{
 			var center = view3D.TrackballTumbleWidget.LocalBounds.Center;