Handle handle leaks on dragdrop cursor icon

Also pass the tooltips to the components container so that they dispose of anything if needed too.
A user had a long-running script/session that drag-dropped a few thousand times, which exhausted the Windows GDI handle limit (10,000 per process).

PKHeX.Drawing/ImageUtil.cs

@@ -136,7 +136,7 @@ public int GetAverageColor()
         }
     }
 
-    private static Span<byte> GetSpan(IntPtr ptr, int length)
+    private static Span<byte> GetSpan(nint ptr, int length)
         => MemoryMarshal.CreateSpan(ref Unsafe.AddByteOffset(ref Unsafe.NullRef<byte>(), ptr), length);
 
     public static Bitmap LayerImage(Bitmap baseLayer, Bitmap overLayer, int x, int y, double transparency)

PKHeX.WinForms/Controls/SAV Editor/SAVEditor.cs

@@ -86,6 +86,7 @@ public SAVEditor()
 
         SL_Extra.ViewIndex = -2;
         menu = new ContextMenuSAV { Manager = M };
+        components!.Add(menu);
         InitializeEvents();
     }
 
@@ -1497,7 +1498,8 @@ private async void TabMouseMove(object sender, MouseEventArgs e)
             {
                 using var img = new Bitmap(Box.Width, Box.Height);
                 Box.DrawToBitmap(img, new Rectangle(0, 0, Box.Width, Box.Height));
-                using var cursor = Cursor = new Cursor(img.GetHicon());
+                using var dragCursor = new BitmapCursor(img);
+                Cursor = dragCursor.Cursor;
                 await File.WriteAllBytesAsync(newFile, bin).ConfigureAwait(true);
                 DoDragDrop(new DataObject(DataFormats.FileDrop, new[] { newFile }), DragDropEffects.Copy);
             }

PKHeX.WinForms/Controls/SAV Editor/SlotChangeManager.cs

@@ -85,7 +85,7 @@ public void QueryContinueDrag(object? sender, QueryContinueDragEventArgs e)
 
     public void DragEnter(object? sender, DragEventArgs e)
     {
-        if (sender is null)
+        if (sender is not Control c)
             return;
         if ((e.AllowedEffect & DragDropEffects.Copy) != 0) // external file
             e.Effect = DragDropEffects.Copy;
@@ -93,7 +93,7 @@ public void DragEnter(object? sender, DragEventArgs e)
             e.Effect = DragDropEffects.Move;
 
         if (Drag.Info.IsDragDropInProgress)
-            Drag.SetCursor(((Control)sender).FindForm(), Drag.Info.Cursor);
+            Drag.SetCursor(c, Drag.Info.Cursor);
     }
 
     private static SlotViewInfo<T> GetSlotInfo<T>(T pb) where T : Control
@@ -156,7 +156,7 @@ private void HandleMovePKM(PictureBox pb, bool encrypt)
         // drop finished, clean up
         Drag.Info.Source = null;
         Drag.Reset();
-        Drag.ResetCursor(pb.FindForm());
+        Drag.ResetCursor(pb);
 
         // Browser apps need time to load data since the file isn't moved to a location on the user's local storage.
         // Tested 10ms -> too quick, 100ms was fine. 500ms should be safe?
@@ -210,7 +210,7 @@ private bool TryMakeDragDropPKM(PictureBox pb, ReadOnlySpan<byte> data, string n
         ArgumentNullException.ThrowIfNull(img);
         File.WriteAllBytes(newfile, data);
 
-        Drag.SetCursor(pb.FindForm(), new Cursor(img.GetHicon()));
+        Drag.SetOwnedCursor(pb, img);
         Hover.Stop();
         pb.Image = null;
         pb.BackgroundImage = SpriteUtil.Spriter.Drag;
@@ -223,7 +223,7 @@ private bool TryMakeDragDropPKM(PictureBox pb, ReadOnlySpan<byte> data, string n
         {
             pb.Image = img;
             pb.BackgroundImage = LastSlot.OriginalBackground;
-            Drag.ResetCursor(pb.FindForm());
+            Drag.ResetCursor(pb);
             return external;
         }
 
@@ -347,7 +347,7 @@ private bool TrySetPKMDestination(PictureBox pb, DropModifier mod)
         // Copy from temp to destination slot.
         var type = info.IsDragSwap ? SlotTouchType.Swap : SlotTouchType.Set;
         Env.Slots.Set(info.Destination!.Slot, pk, type);
-        Drag.ResetCursor(pb.FindForm());
+        Drag.ResetCursor(pb);
         return true;
     }
 
@@ -381,6 +381,7 @@ public void SwapBoxes(int index, int other, SaveFile SAV)
 
     public void Dispose()
     {
+        Drag.Dispose();
         Hover.Dispose();
         SE.Dispose();
         LastSlot.OriginalBackground?.Dispose();

PKHeX.WinForms/Controls/Slots/BitmapCursor.cs

@@ -0,0 +1,38 @@
+using System;
+using System.Drawing;
+using System.Runtime.InteropServices;
+using System.Windows.Forms;
+
+namespace PKHeX.WinForms.Controls;
+
+/// <summary>
+/// Managed <see cref="Cursor"/> implementation that acquires the cursor appearance from a <see cref="Bitmap"/> and properly disposes of the underlying icon handle when done.
+/// </summary>
+public sealed class BitmapCursor : IDisposable
+{
+    public Cursor Cursor { get; }
+    private nint IconHandle;
+
+    public BitmapCursor(Bitmap bitmap)
+    {
+        IconHandle = bitmap.GetHicon(); // creates a handle we need to dispose of.
+        Cursor = new Cursor(IconHandle);
+    }
+
+    // Need to use DestroyIcon as Cursor does not take ownership of the icon handle and will not destroy it when disposed.
+
+    #pragma warning disable SYSLIB1054
+    [DllImport("user32.dll", SetLastError = true)]
+    [return: MarshalAs(UnmanagedType.Bool)]
+    private static extern bool DestroyIcon(nint hIcon);
+    #pragma warning restore SYSLIB1054
+
+    public void Dispose()
+    {
+        Cursor.Dispose();
+        if (IconHandle == nint.Zero)
+            return;
+        _ = DestroyIcon(IconHandle);
+        IconHandle = nint.Zero;
+    }
+}

PKHeX.WinForms/Controls/Slots/DragManager.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Drawing;
 using System.Windows.Forms;
 
@@ -6,7 +7,7 @@ namespace PKHeX.WinForms.Controls;
 /// <summary>
 /// Manages drag-and-drop operations for slot controls.
 /// </summary>
-public sealed class DragManager
+public sealed class DragManager : IDisposable
 {
     /// <summary>
     /// Gets the current slot change information for drag-and-drop operations.
@@ -17,6 +18,7 @@ public sealed class DragManager
     /// Occurs when an external drag-and-drop operation is requested.
     /// </summary>
     public event DragEventHandler? RequestExternalDragDrop;
+    private BitmapCursor? OwnedCursor;
 
     /// <summary>
     /// Requests a drag-and-drop operation.
@@ -30,17 +32,26 @@ public sealed class DragManager
     /// </summary>
     /// <param name="f">The form to set the cursor for.</param>
     /// <param name="z">The cursor to set.</param>
-    public void SetCursor(Form? f, Cursor? z)
+    public void SetCursor(Control f, Cursor? z)
     {
-        f?.Cursor = z;
+        if (OwnedCursor is not null && !ReferenceEquals(OwnedCursor.Cursor, z))
+            DisposeOwnedCursor();
+        f.Cursor = z;
         Info.Cursor = z;
     }
 
+    public void SetOwnedCursor(Control f, Bitmap bitmap)
+    {
+        DisposeOwnedCursor();
+        OwnedCursor = new BitmapCursor(bitmap);
+        SetCursor(f, OwnedCursor.Cursor);
+    }
+
     /// <summary>
     /// Resets the cursor for the specified form to the default cursor.
     /// </summary>
     /// <param name="sender">The form to reset the cursor for.</param>
-    public void ResetCursor(Form? sender)
+    public void ResetCursor(Control sender)
     {
         SetCursor(sender, Cursors.Default);
     }
@@ -50,13 +61,28 @@ public void ResetCursor(Form? sender)
     /// </summary>
     public void Initialize()
     {
+        DisposeOwnedCursor();
         Info = new SlotChangeInfo<Cursor, PictureBox>();
     }
 
     /// <summary>
     /// Resets the drag manager's slot change info.
     /// </summary>
-    public void Reset() => Info.Reset();
+    public void Reset()
+    {
+        DisposeOwnedCursor();
+        Info.Reset();
+    }
+
+    private void DisposeOwnedCursor()
+    {
+        if (OwnedCursor is null)
+            return;
+        OwnedCursor.Dispose();
+        OwnedCursor = null;
+    }
+
+    public void Dispose() => DisposeOwnedCursor();
 
     /// <summary>
     /// Gets or sets the mouse down position for drag detection.

PKHeX.WinForms/MainWindow/Main.cs

@@ -106,6 +106,7 @@ private void FormLoadAddEvents()
         mnu.RequestEditorSaveAs += MainMenuSave;
         dragout.ContextMenuStrip = mnu.mnuL;
         C_SAV.menu.RequestEditorLegality = DisplayLegalityReport;
+        components.Add(mnu);
     }
 
     public void LoadInitialFiles(StartupArguments args)
@@ -1239,7 +1240,7 @@ private async void Dragout_MouseDown(object sender, MouseEventArgs e)
 
                 var pb = (PictureBox)sender;
                 if (pb.Image is Bitmap img)
-                    C_SAV.M.Drag.Info.Cursor = Cursor = new Cursor(img.GetHicon());
+                    C_SAV.M.Drag.SetOwnedCursor(pb, img);
 
                 DoDragDrop(new DataObject(DataFormats.FileDrop, new[] { newfile }), DragDropEffects.Copy);
             }

PKHeX.WinForms/Subforms/PKM Editors/Text.Designer.cs

@@ -28,6 +28,8 @@ protected override void Dispose(bool disposing)
         /// </summary>
         private void InitializeComponent()
         {
+            components = new System.ComponentModel.Container();
+            Tip = new System.Windows.Forms.ToolTip(components);
             TB_Text = new System.Windows.Forms.TextBox();
             CB_Species = new System.Windows.Forms.ComboBox();
             B_Cancel = new System.Windows.Forms.Button();
@@ -47,6 +49,12 @@ private void InitializeComponent()
             ((System.ComponentModel.ISupportInitialize)NUD_Generation).BeginInit();
             SuspendLayout();
             // 
+            // Tip
+            // 
+            Tip.AutoPopDelay = 32767;
+            Tip.InitialDelay = 200;
+            Tip.IsBalloon = false;
+            // 
             // TB_Text
             // 
             TB_Text.Location = new System.Drawing.Point(114, 14);
@@ -262,5 +270,6 @@ private void InitializeComponent()
         private System.Windows.Forms.Label L_Generation;
         private System.Windows.Forms.Button B_ClearTrash;
         private System.Windows.Forms.Label L_String;
+        private System.Windows.Forms.ToolTip Tip;
     }
 }

PKHeX.WinForms/Subforms/PKM Editors/Text.cs

@@ -10,7 +10,6 @@ namespace PKHeX.WinForms;
 public partial class TrashEditor : Form
 {
     private readonly IStringConverter Converter;
-    private readonly ToolTip Tip = new() { InitialDelay = 200, IsBalloon = false, AutoPopDelay = 32_767 };
     private readonly List<NumericUpDown> Bytes = [];
     public string FinalString { get; private set; }
     public byte[] FinalBytes { get; private set; }
@@ -93,8 +92,7 @@ private void AddCharEditing(Font f, EntityContext context)
             l.Size = new Size(20, 20);
             l.Click += (_, _) => { if (TB_Text.Text.Length < TB_Text.MaxLength) TB_Text.AppendText(l.Text); };
             FLP_Characters.Controls.Add(l);
-            var tt = new ToolTip();
-            tt.SetToolTip(l, $"Insert {l.Text} (0x{c:X4})");
+            Tip.SetToolTip(l, $"Insert {l.Text} (0x{c:X4})");
         }
     }
 

PKHeX.WinForms/Subforms/ReportGrid.cs

@@ -52,6 +52,8 @@ private void GetContextMenu()
         ContextMenuStrip mnu = new();
         mnu.Items.Add(mnuHide);
         mnu.Items.Add(mnuRestore);
+        components ??= new System.ComponentModel.Container();
+        components.Add(mnu);
 
         dgData.ContextMenuStrip = mnu;
     }

PKHeX.WinForms/Subforms/SAV_FolderList.cs

@@ -31,6 +31,7 @@ public SAV_FolderList(Action<SaveFile> openSaveFile)
         var drives = Environment.GetLogicalDrives();
         Paths = GetPathList(drives, backups);
 
+        components ??= new System.ComponentModel.Container();
         dgDataRecent.ContextMenuStrip = GetContextMenu(dgDataRecent);
         dgDataBackup.ContextMenuStrip = GetContextMenu(dgDataBackup);
         dgDataRecent.Sorted += (_, _) => GetFilterText(dgDataRecent);
@@ -111,7 +112,7 @@ private void AddButton(string name, string path)
         };
         FLP_Buttons.Controls.Add(button);
 
-        var hover = new ToolTip {AutoPopDelay = 30_000};
+        var hover = new ToolTip(components) {AutoPopDelay = 30_000};
         button.MouseHover += (_, _) => hover.Show(path, button);
     }
 
@@ -202,6 +203,7 @@ private ContextMenuStrip GetContextMenu(DataGridView dgv)
         mnu.Items.Add(mnuOpen);
         mnu.Items.Add(mnuBrowseAt);
         mnu.Items.Add(mnuDelete);
+        components.Add(mnu);
         return mnu;
     }
 

PKHeX.WinForms/Subforms/Save Editors/Gen8/SAV_FlagWork8b.cs

@@ -290,7 +290,7 @@ private static void ApplyWorkFilter(TableLayoutPanel panel, IReadOnlyList<(strin
         panel.ResumeLayout();
     }
 
-    private TextBox CreateSearchBox(Action<string> applyFilter)
+    private static TextBox CreateSearchBox(Action<string> applyFilter)
     {
         var box = new TextBox
         {

PKHeX.WinForms/Subforms/Save Editors/SAV_EventFlags.cs

@@ -332,7 +332,7 @@ private static void ApplyConstFilter(TableLayoutPanel panel, IReadOnlyList<(stri
         panel.ResumeLayout();
     }
 
-    private TextBox CreateSearchBox(Action<string> applyFilter)
+    private static TextBox CreateSearchBox(Action<string> applyFilter)
     {
         var box = new TextBox
         {

PKHeX.WinForms/Subforms/Save Editors/SAV_EventFlags2.cs

@@ -334,7 +334,7 @@ private static void ApplyConstFilter(TableLayoutPanel panel, IReadOnlyList<(stri
         panel.ResumeLayout();
     }
 
-    private TextBox CreateSearchBox(Action<string> applyFilter)
+    private static TextBox CreateSearchBox(Action<string> applyFilter)
     {
         var box = new TextBox
         {

PKHeX.WinForms/Subforms/Save Editors/SAV_EventWork.cs

@@ -250,7 +250,7 @@ private static void ApplyWorkFilter(TableLayoutPanel panel, IReadOnlyList<(strin
         panel.ResumeLayout();
     }
 
-    private TextBox CreateSearchBox(Action<string> applyFilter)
+    private static TextBox CreateSearchBox(Action<string> applyFilter)
     {
         var box = new TextBox
         {