refactor: replace floating tool window with docked side panel

- Add general-purpose ShowSidePanel/HideSidePanel to EditNestForm
- CuttingPanel uses Dock.Top layout so collapsible panels reflow
- Add loop selection step: click contour to lock before placing lead-in
- Stay on selected part after placing a lead-in
- Delete unused LeadInToolWindow

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

OpenNest/Actions/ActionLeadIn.cs

@@ -31,10 +31,12 @@ namespace OpenNest.Actions
         private bool hasSnap;
         private SnapType activeSnapType;
         private ShapeInfo hoveredContour;
+        private ShapeInfo lockedContour;
         private ContextMenuStrip contextMenu;
-        private LeadInToolWindow toolWindow;
+        private CuttingPanel cuttingPanel;
         private static readonly Brush grayOverlay = new SolidBrush(Color.FromArgb(160, 180, 180, 180));
         private static readonly Pen highlightPen = new Pen(Color.Cyan, 2.5f);
+        private static readonly Pen lockedPen = new Pen(Color.Yellow, 3.0f);
 
         public ActionLeadIn(PlateView plateView)
             : base(plateView)
@@ -48,7 +50,7 @@ namespace OpenNest.Actions
             plateView.MouseDown += OnMouseDown;
             plateView.KeyDown += OnKeyDown;
             plateView.Paint += OnPaint;
-            ShowToolWindow();
+            ShowSidePanel();
         }
 
         public override void DisconnectEvents()
@@ -58,7 +60,7 @@ namespace OpenNest.Actions
             plateView.KeyDown -= OnKeyDown;
             plateView.Paint -= OnPaint;
 
-            HideToolWindow();
+            HideSidePanel();
 
             contextMenu?.Dispose();
             contextMenu = null;
@@ -77,18 +79,20 @@ namespace OpenNest.Actions
 
         public override bool IsBusy() => selectedPart != null;
 
-        private void ShowToolWindow()
+        private void ShowSidePanel()
         {
-            if (toolWindow == null)
+            var form = plateView.FindForm() as EditNestForm;
-            {
+            if (form == null)
-                toolWindow = new LeadInToolWindow();
+                return;
-                toolWindow.AutoAssignClicked += OnAutoAssignClicked;
+
-            }
+            cuttingPanel = new CuttingPanel { ShowAutoAssign = true };
+            cuttingPanel.AutoAssignClicked += OnAutoAssignClicked;
+            cuttingPanel.ParametersChanged += OnToolParametersChanged;
 
             // Load current parameters or defaults
             var plate = plateView.Plate;
             if (plate?.CuttingParameters != null)
-                toolWindow.LoadFromParameters(plate.CuttingParameters);
+                cuttingPanel.LoadFromParameters(plate.CuttingParameters);
             else
             {
                 var json = Properties.Settings.Default.CuttingParametersJson;
@@ -97,46 +101,42 @@ namespace OpenNest.Actions
                     try
                     {
                         var saved = CuttingParametersSerializer.Deserialize(json);
-                        toolWindow.LoadFromParameters(saved);
+                        cuttingPanel.LoadFromParameters(saved);
                     }
                     catch { /* use defaults */ }
                 }
             }
 
-            toolWindow.ParametersChanged += OnToolParametersChanged;
+            form.ShowSidePanel(cuttingPanel);
-
-            var mainForm = plateView.FindForm();
-            if (mainForm != null)
-                toolWindow.Owner = mainForm;
-
-            toolWindow.Show();
         }
 
-        private void HideToolWindow()
+        private void HideSidePanel()
         {
-            if (toolWindow == null)
+            if (cuttingPanel == null)
                 return;
 
             SaveParameters();
 
-            toolWindow.ParametersChanged -= OnToolParametersChanged;
+            cuttingPanel.ParametersChanged -= OnToolParametersChanged;
-            toolWindow.AutoAssignClicked -= OnAutoAssignClicked;
+            cuttingPanel.AutoAssignClicked -= OnAutoAssignClicked;
-            toolWindow.Close();
+
-            toolWindow.Dispose();
+            var form = plateView.FindForm() as EditNestForm;
-            toolWindow = null;
+            form?.HideSidePanel();
+
+            cuttingPanel = null;
         }
 
         private CuttingParameters GetCurrentParameters()
         {
-            return toolWindow?.BuildParameters() ?? plateView.Plate?.CuttingParameters ?? new CuttingParameters();
+            return cuttingPanel?.BuildParameters() ?? plateView.Plate?.CuttingParameters ?? new CuttingParameters();
         }
 
         private void SaveParameters()
         {
-            if (toolWindow == null)
+            if (cuttingPanel == null)
                 return;
 
-            var parameters = toolWindow.BuildParameters();
+            var parameters = cuttingPanel.BuildParameters();
             var json = CuttingParametersSerializer.Serialize(parameters);
             Properties.Settings.Default.CuttingParametersJson = json;
             Properties.Settings.Default.Save();
@@ -169,7 +169,12 @@ namespace OpenNest.Actions
             activeSnapType = SnapType.None;
             hoveredContour = null;
 
-            foreach (var info in contours)
+            // When a contour is locked, only snap within that contour
+            var searchContours = lockedContour != null
+                ? new List<ShapeInfo> { lockedContour }
+                : contours;
+
+            foreach (var info in searchContours)
             {
                 var closest = info.Shape.ClosestPointTo(localPt, out var entity);
                 var dist = closest.DistanceTo(localPt);
@@ -191,9 +196,9 @@ namespace OpenNest.Actions
             {
                 TrySnapToEntityPoints(localPt);
 
-                // Auto-switch tool window tab
+                // Auto-switch tool window tab only when no contour is locked
-                if (toolWindow != null)
+                if (cuttingPanel != null && lockedContour == null)
-                    toolWindow.ActiveContourType = snapContourType;
+                    cuttingPanel.ActiveContourType = snapContourType;
             }
 
             plateView.Invalidate();
@@ -208,15 +213,22 @@ namespace OpenNest.Actions
                     // First click: select a part
                     SelectPartAtCursor();
                 }
-                else if (hasSnap)
+                else if (lockedContour == null && hasSnap)
                 {
-                    // Second click: commit lead-in at snap point
+                    // Second click: lock the hovered contour
+                    LockContour(hoveredContour);
+                }
+                else if (lockedContour != null && hasSnap)
+                {
+                    // Third click: commit lead-in at snap point on locked contour
                     CommitLeadIn();
                 }
             }
             else if (e.Button == MouseButtons.Right)
             {
-                if (selectedPart != null && selectedPart.HasManualLeadIns)
+                if (lockedContour != null)
+                    UnlockContour();
+                else if (selectedPart != null && selectedPart.HasManualLeadIns)
                     ShowContextMenu(e.Location);
                 else
                     DeselectPart();
@@ -227,7 +239,9 @@ namespace OpenNest.Actions
         {
             if (e.KeyCode == Keys.Escape)
             {
-                if (selectedPart != null)
+                if (lockedContour != null)
+                    UnlockContour();
+                else if (selectedPart != null)
                     DeselectPart();
                 else
                     plateView.SetAction(typeof(ActionSelect));
@@ -243,6 +257,23 @@ namespace OpenNest.Actions
             DrawLeadInPreview(g);
         }
 
+        private void LockContour(ShapeInfo contour)
+        {
+            lockedContour = contour;
+
+            // Lock the tab to this contour type
+            if (cuttingPanel != null)
+                cuttingPanel.ActiveContourType = contour.ContourType;
+
+            plateView.Invalidate();
+        }
+
+        private void UnlockContour()
+        {
+            lockedContour = null;
+            plateView.Invalidate();
+        }
+
         private void DrawOverlay(Graphics g)
         {
             foreach (var lp in plateView.LayoutParts)
@@ -254,10 +285,24 @@ namespace OpenNest.Actions
 
         private void DrawHoveredContour(Graphics g)
         {
-            if (hoveredContour == null || selectedPart == null)
+            if (selectedPart == null)
                 return;
 
-            using var contourPath = hoveredContour.Shape.GetGraphicsPath();
+            // Draw locked contour with distinct pen
+            if (lockedContour != null)
+            {
+                DrawContourHighlight(g, lockedContour.Shape, lockedPen);
+                return;
+            }
+
+            // Draw hovered contour
+            if (hoveredContour != null)
+                DrawContourHighlight(g, hoveredContour.Shape, highlightPen);
+        }
+
+        private void DrawContourHighlight(Graphics g, Shape shape, Pen pen)
+        {
+            using var contourPath = shape.GetGraphicsPath();
             using var contourMatrix = new Matrix();
             contourMatrix.Translate((float)selectedPart.Location.X, (float)selectedPart.Location.Y);
             contourMatrix.Multiply(plateView.Matrix, MatrixOrder.Append);
@@ -265,7 +310,7 @@ namespace OpenNest.Actions
 
             var prevSmooth = g.SmoothingMode;
             g.SmoothingMode = SmoothingMode.AntiAlias;
-            g.DrawPath(highlightPen, contourPath);
+            g.DrawPath(pen, contourPath);
             g.SmoothingMode = prevSmooth;
         }
 
@@ -468,7 +513,7 @@ namespace OpenNest.Actions
             selectedPart.LeadInsLocked = true;
 
             selectedLayoutPart.IsDirty = true;
-            DeselectPart();
+            UnlockContour();
             plateView.Invalidate();
         }
 
@@ -488,7 +533,7 @@ namespace OpenNest.Actions
             selectedPart.LeadInsLocked = true;
 
             selectedLayoutPart.IsDirty = true;
-            DeselectPart();
+            UnlockContour();
             plateView.Invalidate();
         }
 
@@ -515,6 +560,7 @@ namespace OpenNest.Actions
             selectedPart = null;
             profile = null;
             contours = null;
+            lockedContour = null;
             hasSnap = false;
             activeSnapType = SnapType.None;
             hoveredContour = null;

OpenNest/Controls/CuttingPanel.cs

@@ -76,14 +76,10 @@ namespace OpenNest.Controls
             AutoScroll = true;
             BackColor = Color.White;
 
-            var y = 0;
+            // Tab control for contour types — wrapped in a fixed-height panel for Dock.Top
-
-            // Tab control for contour types
             tabControl = new TabControl
             {
-                Location = new Point(4, y),
+                Dock = DockStyle.Fill
-                Size = new Size(372, 340),
-                Anchor = AnchorStyles.Top | AnchorStyles.Left | AnchorStyles.Right
             };
 
             var tabExternal = new TabPage("External") { Padding = new Padding(4) };
@@ -101,18 +97,20 @@ namespace OpenNest.Controls
             tabControl.Controls.Add(tabInternal);
             tabControl.Controls.Add(tabArcCircle);
 
-            Controls.Add(tabControl);
+            var tabWrapper = new Panel
-            y += tabControl.Height + 4;
+            {
+                Dock = DockStyle.Top,
+                Height = 340
+            };
+            tabWrapper.Controls.Add(tabControl);
 
             // Tabs section
             var tabsPanel = new CollapsiblePanel
             {
                 HeaderText = "Tabs",
-                Location = new Point(0, y),
+                Dock = DockStyle.Top,
-                Size = new Size(380, 120),
                 ExpandedHeight = 120,
-                IsExpanded = true,
+                IsExpanded = false
-                Anchor = AnchorStyles.Top | AnchorStyles.Left | AnchorStyles.Right
             };
 
             chkTabsEnabled = new CheckBox
@@ -159,18 +157,13 @@ namespace OpenNest.Controls
             nudAutoTabMax = CreateNumeric(140, 55, 0, 0.0625);
             tabsPanel.ContentPanel.Controls.Add(nudAutoTabMax);
 
-            Controls.Add(tabsPanel);
-            y += tabsPanel.Height + 4;
-
             // Pierce section
             var piercePanel = new CollapsiblePanel
             {
                 HeaderText = "Pierce",
-                Location = new Point(0, y),
+                Dock = DockStyle.Top,
-                Size = new Size(380, 60),
                 ExpandedHeight = 60,
-                IsExpanded = true,
+                IsExpanded = true
-                Anchor = AnchorStyles.Top | AnchorStyles.Left | AnchorStyles.Right
             };
 
             piercePanel.ContentPanel.Controls.Add(new Label
@@ -183,20 +176,29 @@ namespace OpenNest.Controls
             nudPierceClearance = CreateNumeric(130, 3, 0.0625, 0.0625);
             piercePanel.ContentPanel.Controls.Add(nudPierceClearance);
 
-            Controls.Add(piercePanel);
+            // Auto-Assign button — wrapped in a panel for Dock.Top with padding
-            y += piercePanel.Height + 4;
-
-            // Auto-Assign button
             btnAutoAssign = new Button
             {
                 Text = "Auto-Assign Lead-ins",
-                Location = new Point(4, y),
+                Dock = DockStyle.Top,
-                Size = new Size(372, 32),
+                Height = 32,
-                Anchor = AnchorStyles.Top | AnchorStyles.Left | AnchorStyles.Right,
                 Visible = false
             };
             btnAutoAssign.Click += (s, e) => AutoAssignClicked?.Invoke(this, EventArgs.Empty);
-            Controls.Add(btnAutoAssign);
+
+            var btnWrapper = new Panel
+            {
+                Dock = DockStyle.Top,
+                Height = 36,
+                Padding = new Padding(4, 2, 4, 2)
+            };
+            btnWrapper.Controls.Add(btnAutoAssign);
+
+            // Add in reverse order — Dock.Top stacks top-down
+            Controls.Add(btnWrapper);
+            Controls.Add(piercePanel);
+            Controls.Add(tabsPanel);
+            Controls.Add(tabWrapper);
 
             // Wire up change events
             PopulateDropdowns();

OpenNest/Forms/EditNestForm.cs

@@ -37,6 +37,9 @@ namespace OpenNest.Forms
         private Button btnNextPlate;
         private Button btnLastPlate;
 
+        private SplitContainer viewSplitContainer;
+        private Panel sidePanel;
+
         /// <summary>
         /// Used to distinguish between single/double click on drawing within drawinglistbox.
         /// If double click, this is set to false so the single click action won't be triggered.
@@ -53,8 +56,9 @@ namespace OpenNest.Forms
 
             InitializeComponent();
             CreatePlateHeader();
+            CreateSidePanel();
 
-            splitContainer.Panel2.Controls.Add(PlateView);
+            splitContainer.Panel2.Controls.Add(viewSplitContainer);
             splitContainer.Panel2.Controls.Add(plateHeaderPanel);
 
             var renderer = new ToolStripRenderer(ToolbarTheme.Toolbar);
@@ -146,6 +150,43 @@ namespace OpenNest.Forms
             navPanel.Top = (plateHeaderPanel.Height - navPanel.Height) / 2;
         }
 
+        private void CreateSidePanel()
+        {
+            sidePanel = new Panel
+            {
+                Dock = DockStyle.Fill,
+                AutoScroll = true,
+                BackColor = Color.White
+            };
+
+            viewSplitContainer = new SplitContainer
+            {
+                Dock = DockStyle.Fill,
+                Orientation = Orientation.Vertical,
+                FixedPanel = FixedPanel.Panel2,
+                Panel2MinSize = 0
+            };
+
+            viewSplitContainer.Panel1.Controls.Add(PlateView);
+            viewSplitContainer.Panel2.Controls.Add(sidePanel);
+            viewSplitContainer.Panel2Collapsed = true;
+        }
+
+        public void ShowSidePanel(Control content, int width = 390)
+        {
+            sidePanel.Controls.Clear();
+            content.Dock = DockStyle.Fill;
+            sidePanel.Controls.Add(content);
+            viewSplitContainer.SplitterDistance = viewSplitContainer.Width - width;
+            viewSplitContainer.Panel2Collapsed = false;
+        }
+
+        public void HideSidePanel()
+        {
+            viewSplitContainer.Panel2Collapsed = true;
+            sidePanel.Controls.Clear();
+        }
+
         private static Button CreateNavButton(System.Drawing.Image image)
         {
             return new Button

OpenNest/Forms/LeadInToolWindow.cs

@@ -1,110 +0,0 @@
-using OpenNest.CNC.CuttingStrategy;
-using OpenNest.Controls;
-using System;
-using System.Drawing;
-using System.Windows.Forms;
-
-namespace OpenNest.Forms
-{
-    public class LeadInToolWindow : Form
-    {
-        private readonly CuttingPanel cuttingPanel;
-
-        public CuttingPanel CuttingPanel => cuttingPanel;
-
-        public event EventHandler ParametersChanged
-        {
-            add => cuttingPanel.ParametersChanged += value;
-            remove => cuttingPanel.ParametersChanged -= value;
-        }
-
-        public event EventHandler AutoAssignClicked
-        {
-            add => cuttingPanel.AutoAssignClicked += value;
-            remove => cuttingPanel.AutoAssignClicked -= value;
-        }
-
-        public LeadInToolWindow()
-        {
-            Text = "Lead-In Properties";
-            FormBorderStyle = FormBorderStyle.SizableToolWindow;
-            ShowInTaskbar = false;
-            StartPosition = FormStartPosition.Manual;
-            MinimumSize = new Size(300, 400);
-            Size = new Size(400, 580);
-
-            cuttingPanel = new CuttingPanel
-            {
-                Dock = DockStyle.Fill,
-                ShowAutoAssign = true
-            };
-            Controls.Add(cuttingPanel);
-
-            RestorePosition();
-        }
-
-        public CuttingParameters BuildParameters() => cuttingPanel.BuildParameters();
-
-        public void LoadFromParameters(CuttingParameters p) => cuttingPanel.LoadFromParameters(p);
-
-        public ContourType? ActiveContourType
-        {
-            get => cuttingPanel.ActiveContourType;
-            set => cuttingPanel.ActiveContourType = value;
-        }
-
-        protected override void OnFormClosing(FormClosingEventArgs e)
-        {
-            if (e.CloseReason == CloseReason.UserClosing)
-            {
-                e.Cancel = true;
-                Hide();
-            }
-
-            SavePosition();
-            base.OnFormClosing(e);
-        }
-
-        protected override void OnMove(EventArgs e)
-        {
-            base.OnMove(e);
-            if (WindowState == FormWindowState.Normal)
-                SavePosition();
-        }
-
-        protected override void OnResize(EventArgs e)
-        {
-            base.OnResize(e);
-            if (WindowState == FormWindowState.Normal)
-                SavePosition();
-        }
-
-        private void SavePosition()
-        {
-            if (WindowState != FormWindowState.Normal)
-                return;
-
-            Properties.Settings.Default.LeadInToolWindowLocation = Location;
-            Properties.Settings.Default.LeadInToolWindowSize = Size;
-            Properties.Settings.Default.Save();
-        }
-
-        private void RestorePosition()
-        {
-            var savedLocation = Properties.Settings.Default.LeadInToolWindowLocation;
-            var savedSize = Properties.Settings.Default.LeadInToolWindowSize;
-
-            if (savedSize.Width > 0 && savedSize.Height > 0)
-                Size = savedSize;
-
-            if (savedLocation.X != 0 || savedLocation.Y != 0)
-            {
-                var screen = Screen.FromPoint(savedLocation);
-                if (screen.WorkingArea.Contains(savedLocation))
-                    Location = savedLocation;
-                else
-                    CenterToParent();
-            }
-        }
-    }
-}

OpenNest/Properties/Settings.Designer.cs

@@ -238,29 +238,5 @@ namespace OpenNest.Properties {
                 this["CuttingParametersJson"] = value;
             }
         }
-
-        [global::System.Configuration.UserScopedSettingAttribute()]
-        [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
-        [global::System.Configuration.DefaultSettingValueAttribute("0, 0")]
-        public global::System.Drawing.Point LeadInToolWindowLocation {
-            get {
-                return ((global::System.Drawing.Point)(this["LeadInToolWindowLocation"]));
-            }
-            set {
-                this["LeadInToolWindowLocation"] = value;
-            }
-        }
-
-        [global::System.Configuration.UserScopedSettingAttribute()]
-        [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
-        [global::System.Configuration.DefaultSettingValueAttribute("0, 0")]
-        public global::System.Drawing.Size LeadInToolWindowSize {
-            get {
-                return ((global::System.Drawing.Size)(this["LeadInToolWindowSize"]));
-            }
-            set {
-                this["LeadInToolWindowSize"] = value;
-            }
-        }
     }
 }

OpenNest/Properties/Settings.settings

@@ -56,11 +56,5 @@
     <Setting Name="CuttingParametersJson" Type="System.String" Scope="User">
       <Value Profile="(Default)" />
     </Setting>
-    <Setting Name="LeadInToolWindowLocation" Type="System.Drawing.Point" Scope="User">
-      <Value Profile="(Default)">0, 0</Value>
-    </Setting>
-    <Setting Name="LeadInToolWindowSize" Type="System.Drawing.Size" Scope="User">
-      <Value Profile="(Default)">0, 0</Value>
-    </Setting>
   </Settings>
 </SettingsFile>