Disable toolbar buttons that cannot be used

Plate commands need an open nest and no running job; Trim/Extend Cut-Off
needs a cut-off on the plate and Sequence by Path needs two parts. The
Plate menu's Trim/Extend item follows the same rule.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

OpenNest.WinForms.Tests/Forms/MainFormCharacterizationTests.cs

@@ -1,4 +1,5 @@
 using System.Reflection;
+using System.Windows.Forms;
 using OpenNest.Controls;
 using OpenNest.Forms;
 using OpenNest.Geometry;
@@ -77,6 +78,65 @@ public class MainFormCharacterizationTests
         Assert.Equal(new Guards(false, true, false, false), Read(host, editor, views));
     }, TimeSpan.FromMinutes(1), "The STA test did not complete.");
 
+    [Fact]
+    public void ToolbarFollowsTheActiveDocumentAndItsPlate() => UndoTestEnv.Run(env =>
+    {
+        var host = env.Host;
+        bool Enabled(string button) => Field<ToolStripItem>(typeof(MainForm), host, button).Enabled;
+        void AddCutOff()
+        {
+            using var change = env.View.BeginChange("Add Cut-Off");
+            change.MarkChanged();
+            env.View.Plate.CutOffs.Add(new CutOff(new Vector(50, 0), CutOffAxis.Vertical));
+            env.View.Plate.RegenerateCutOffs(env.View.CutOffSettings);
+            change.Complete();
+        }
+
+        // The first plate holds two parts and no cut-offs.
+        env.Editor.PlateManager.LoadAt(0);
+        Assert.True(Enabled("btnCutOff"));
+        Assert.True(Enabled("btnSequenceByPath"));
+        Assert.False(Enabled("btnTrimExtendCutOff"));
+        Assert.False(UndoTestEnv.MenuItem(host, "mnuPlateTrimExtendCutOff").Enabled);
+
+        AddCutOff();
+        Assert.True(Enabled("btnTrimExtendCutOff"));
+        Assert.True(UndoTestEnv.MenuItem(host, "mnuPlateTrimExtendCutOff").Enabled);
+
+        Assert.True(host.TryUndo(env.Editor));
+        Assert.False(Enabled("btnTrimExtendCutOff"));
+        Assert.True(host.TryRedo(env.Editor));
+        Assert.True(Enabled("btnTrimExtendCutOff"));
+
+        // Another plate has its own cut-offs; the third one is empty.
+        env.Editor.PlateManager.LoadAt(2);
+        Assert.False(Enabled("btnTrimExtendCutOff"));
+        Assert.False(Enabled("btnSequenceByPath"));
+        env.View.Plate.Parts.Add(new Part(env.Nest.Drawings.First(), new Vector(5, 5)));
+        env.View.Plate.Parts.Add(new Part(env.Nest.Drawings.First(), new Vector(25, 5)));
+        Assert.True(Enabled("btnSequenceByPath"));
+
+        // A running job locks the plate commands, as it does the Nest and Plate menus.
+        Invoke(host, "SetNestingLockout", true);
+        Assert.False(Enabled("btnAutoNest"));
+        Assert.False(Enabled("btnCutOff"));
+        Assert.False(Enabled("postButton"));
+        Invoke(host, "SetNestingLockout", false);
+        Assert.True(Enabled("btnAutoNest"));
+
+        env.Editor.Close();
+        foreach (var button in ToolbarPlateCommands)
+            Assert.False(Enabled(button), button);
+        Assert.True(Enabled("btnNew"));
+        Assert.True(Enabled("btnOpen"));
+    });
+
+    private static readonly string[] ToolbarPlateCommands =
+    {
+        "btnSave", "btnSaveAs", "btnAutoNest", "btnShowRemnants", "btnCutOff", "btnTrimExtendCutOff",
+        "btnCutPlanner", "btnSimulateCutting", "btnSequenceByPath", "postButton",
+    };
+
     private sealed record Guards(bool ExpandSpacing, bool CuttingPlan, bool Clamps, bool NestJob);
 
     private static Guards Read(MainForm host, EditNestForm editor, PlateView[] views) => new(

OpenNest/Forms/MainForm.Status.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Windows.Forms;
+using OpenNest.Collections;
 
 namespace OpenNest.Forms
 {
@@ -8,6 +9,7 @@ namespace OpenNest.Forms
         private void EnableCheck()
         {
             NavigationEnableCheck();
+            ToolbarEnableCheck();
 
             var hasValue = activeForm != null;
 
@@ -45,6 +47,31 @@ namespace OpenNest.Forms
             mnuNestLastPlate.Enabled = hasPlates && !plates.IsLast;
         }
 
+        // The plate commands need a plate to act on and, like the Nest and Plate menus, no
+        // running job. Trim/Extend works on existing cut-offs; Sequence by Path needs two parts.
+        private void ToolbarEnableCheck()
+        {
+            var plate = nestingInProgress ? null : activeForm?.PlateView?.Plate;
+            var hasPlate = plate != null;
+            var hasCutOffs = plate?.CutOffs.Count > 0;
+
+            btnAutoNest.Enabled = hasPlate;
+            btnShowRemnants.Enabled = hasPlate;
+            btnCutOff.Enabled = hasPlate;
+            btnTrimExtendCutOff.Enabled = hasCutOffs;
+            mnuPlateTrimExtendCutOff.Enabled = hasCutOffs;
+            btnCutPlanner.Enabled = hasPlate;
+            btnSimulateCutting.Enabled = hasPlate;
+            btnSequenceByPath.Enabled = plate?.Parts.Count >= 2;
+            postButton.Enabled = hasPlate;
+        }
+
+        private void EditForm_PlateChanged(object sender, EventArgs e) => ToolbarEnableCheck();
+
+        private void PlateView_PartAdded(object sender, ItemAddedEventArgs<Part> e) => ToolbarEnableCheck();
+
+        private void PlateView_PartRemoved(object sender, ItemRemovedEventArgs<Part> e) => ToolbarEnableCheck();
+
         private void SetNestingLockout(bool locked)
         {
             nestingInProgress = locked;
@@ -53,6 +80,7 @@ namespace OpenNest.Forms
             mnuNest.Enabled = !locked;
             mnuPlate.Enabled = !locked;
             NavigationEnableCheck(locked);
+            ToolbarEnableCheck();
         }
 
         private void EngineComboBox_SelectedIndexChanged(object sender, EventArgs e)

OpenNest/Forms/MainForm.Undo.cs

@@ -105,7 +105,12 @@ namespace OpenNest.Forms
             UpdateUndoMenu();
         }
 
-        private void History_Changed(object sender, EventArgs e) => UpdateUndoMenu();
+        // Every recorded edit lands here, including those that add or remove a cut-off.
+        private void History_Changed(object sender, EventArgs e)
+        {
+            UpdateUndoMenu();
+            ToolbarEnableCheck();
+        }
 
         internal void UpdateUndoMenu()
         {

OpenNest/Forms/MainForm.cs

@@ -25,6 +25,9 @@ namespace OpenNest.Forms
         private readonly NestStorageController storage;
         private readonly ToolStripMenuItem storageModeMenu = new("Storage Mode...");
         private readonly ToolStripMenuItem exportNestMenu = new("Export .nest...");
+        private readonly ToolStripButton btnCutPlanner;
+        private readonly ToolStripButton btnSimulateCutting;
+        private readonly ToolStripButton btnSequenceByPath;
         private readonly ToolStripDropDownButton postButton = new()
         {
             Name = "btnPost",
@@ -124,12 +127,15 @@ namespace OpenNest.Forms
             statusStripToolTips = new StatusStripToolTips(statusStrip1); // The hold list lives in the ledger label's tooltip.
             statusBar = new MainStatusBar(statusLabel1, locationStatusLabel, selectionStatusLabel,
                 machineStatusLabel, materialStatusLabel, plateUtilStatusLabel, ledgerStatusLabel);
-            toolStrip1.Items.Add(CreateActionButton("btnCutPlanner", "Plan Cutting",
-                Resources.cut_planner, ToolbarPlanCutting_Click));
-            toolStrip1.Items.Add(CreateActionButton("btnSimulateCutting", "Simulate Cutting",
-                Resources.cut_simulate, SimulateCutting_Click));
-            toolStrip1.Items.Add(CreateActionButton("btnSequenceByPath", "Sequence by Path",
-                Resources.manual_sequence, SequenceByPath_Click));
+            btnCutPlanner = CreateActionButton("btnCutPlanner", "Plan Cutting",
+                Resources.cut_planner, ToolbarPlanCutting_Click);
+            btnSimulateCutting = CreateActionButton("btnSimulateCutting", "Simulate Cutting",
+                Resources.cut_simulate, SimulateCutting_Click);
+            btnSequenceByPath = CreateActionButton("btnSequenceByPath", "Sequence by Path",
+                Resources.manual_sequence, SequenceByPath_Click);
+            toolStrip1.Items.Add(btnCutPlanner);
+            toolStrip1.Items.Add(btnSimulateCutting);
+            toolStrip1.Items.Add(btnSequenceByPath);
             toolStrip1.Items.Add(postButton);
             storageModeMenu.Click += StorageMode_Click;
             exportNestMenu.Click += ExportNest_Click;
@@ -262,7 +268,12 @@ namespace OpenNest.Forms
 
             statusBar.Unbind();
             if (activeForm != null)
+            {
+                activeForm.PlateChanged -= EditForm_PlateChanged;
                 activeForm.PlateView.OverlapStateChanged -= OverlapStateChanged;
+                activeForm.PlateView.PartAdded -= PlateView_PartAdded;
+                activeForm.PlateView.PartRemoved -= PlateView_PartRemoved;
+            }
 
             // If nesting is in progress and the active form changed, cancel nesting
             if (nestingInProgress && nestingCts != null)
@@ -280,7 +291,10 @@ namespace OpenNest.Forms
             if (activeForm == null)
                 return;
 
+            activeForm.PlateChanged += EditForm_PlateChanged;
             activeForm.PlateView.OverlapStateChanged += OverlapStateChanged;
+            activeForm.PlateView.PartAdded += PlateView_PartAdded;
+            activeForm.PlateView.PartRemoved += PlateView_PartRemoved;
             var activeNest = activeForm.Nest;
             activeForm.PlateView.CanEditClamps = () => !ClampsInUse(activeNest);
             mnuViewDrawRapids.Checked = activeForm.PlateView.DrawRapid;