added Checked, CheckState for ToolStripButton;

added timeout between AcceptButtons.PerformClick in 'Form' class in case 'Enter' key were pressed and not released (MessageBox is also affected);
fixed ToolStripSeparator width in Horizontal mode and also it's painting;
fixed ToolStripItem background painting;
fixed removing nodes from TreeNodeCollection;

Author: Meragon

System/Windows/Forms/Form.cs

@@ -29,6 +29,8 @@ public class Form : ContainerControl, IResizableControl
         private static readonly Padding defaultFormPadding = new Padding(32, 0, 32, 0);
         private static readonly Color defaultFormShadowColor = Color.FromArgb(12, 64, 64, 64);
         private static Point nextLocation = new Point(156, 156);
+        private static Form lastAcceptForm;
+        private static Timer lastAcceptFormTimer;
 
         private Color backColor = SystemColors.Control;
         private formSystemButton closeButton;
@@ -490,10 +492,31 @@ protected override void OnKeyDown(KeyEventArgs e)
         {
             base.OnKeyDown(e);
 
-            if (e.KeyCode == Keys.Enter && AcceptButton != null)
+            if (e.KeyCode == Keys.Enter && AcceptButton != null && lastAcceptForm == null)
+            {
+                lastAcceptForm = this;
+                
+                // Start timer that will reset the last form with the accept button.
+                if (lastAcceptFormTimer != null)
+                    lastAcceptFormTimer.Dispose();
+                
+                lastAcceptFormTimer = new Timer();
+                lastAcceptFormTimer.Interval = 1000; // Interval between the accepting forms.
+                lastAcceptFormTimer.Tick += (sender, args) =>
+                {
+                    lastAcceptForm = null;
+                    lastAcceptFormTimer.Dispose();
+                    lastAcceptFormTimer = null;
+                };
+                lastAcceptFormTimer.Start();
+
                 AcceptButton.PerformClick();
+            }
+
             if (e.KeyCode == Keys.Escape && CancelButton != null)
+            {
                 CancelButton.PerformClick();
+            }
         }
         protected override void OnMouseDown(MouseEventArgs e)
         {

System/Windows/Forms/MessageBox.cs

@@ -71,6 +71,7 @@ public static DialogResult Show(string text, string caption, Font textFont)
             form.AcceptButton = buttonOk;
             form.Controls.Add(buttonOk);
             form.ShowDialog();
+            form.Focus(); // Disable button focus to prevent invoking Click event from the OnKeyDown event.
 
             Last = form;
 

System/Windows/Forms/ToolStrip.cs

@@ -113,17 +113,6 @@ internal ToolStripItem ItemAt(Point position)
 
             return null;
         }
-        internal void MakeShadow()
-        {
-            uwfShadowHandler = (g) =>
-            {
-                var loc = PointToScreen(Point.Empty);
-                var color = Color.FromArgb(12, 64, 64, 64);
-                g.Graphics.uwfFillRectangle(color, loc.X - 3, loc.Y, Width + 6, Height + 3);
-                g.Graphics.uwfFillRectangle(color, loc.X - 2, loc.Y, Width + 4, Height + 2);
-                g.Graphics.uwfFillRectangle(color, loc.X - 1, loc.Y, Width + 2, Height + 1);
-            };
-        }
         internal void NotifySelectionChange(ToolStripItem item)
         {
             throw new NotImplementedException();
@@ -348,11 +337,16 @@ protected override void OnPaint(PaintEventArgs e)
                 if (item.AutoSize && item.boundsChanged) // Check if item size need to be updated.
                 {
                     var itemTextWidth = item.GetEstimatedWidth(graphics);
-                    var itemWidth = itemTextWidth + item.Padding.Horizontal + 4;
-                    if (orientation == Orientation.Horizontal)
-                        item.Width = itemWidth;
+                    if (itemTextWidth > 0)
+                    {
+                        var itemWidth = itemTextWidth + item.Padding.Horizontal + 4;
+                        if (orientation == Orientation.Horizontal)
+                            item.Width = itemWidth;
+                        
+                        maxWidth = Math.Max(maxWidth, itemWidth);
+                    }
+
                     item.boundsChanged = false;
-                    maxWidth = Math.Max(maxWidth, itemWidth);
                 }
 
                 totalWidth += item.Width;

System/Windows/Forms/ToolStripButton.cs

@@ -2,10 +2,12 @@ namespace System.Windows.Forms
 {
     using System.Drawing;
 
+    //// Default size is 23, 22.
     public class ToolStripButton : ToolStripItem
     {
-        //// Default size is 23, 22.
-
+        private CheckState checkState = CheckState.Unchecked;
+        private bool checkOnClick;
+        
         public ToolStripButton()
         {
         }
@@ -25,10 +27,41 @@ public ToolStripButton(string text, Image image, EventHandler onClick, string na
         {
         }
 
+        public event EventHandler CheckedChanged;
+        public event EventHandler CheckStateChanged;
+
         public override bool CanSelect
         {
             get { return true; }
         }
+        public bool Checked
+        {
+            get { return checkState != CheckState.Unchecked; }
+            set
+            {
+                if (value == Checked)
+                    return;
+
+                CheckState = value ? CheckState.Checked : CheckState.Unchecked;
+            }
+        }
+        public CheckState CheckState
+        {
+            get { return checkState; }
+            set
+            {
+                if (value == checkState)
+                    return;
+
+                checkState = value;
+                OnCheckedChanged(EventArgs.Empty);
+                OnCheckStateChanged(EventArgs.Empty);
+            }
+        }
+        public bool CheckOnClick {
+            get { return checkOnClick; }
+            set { checkOnClick = value; }
+        }
 
         protected internal override void SetBounds(Rectangle nbounds)
         {
@@ -37,5 +70,31 @@ protected internal override void SetBounds(Rectangle nbounds)
 
             base.SetBounds(nbounds);
         }
+
+        protected override void OnClick(EventArgs e)
+        {
+            if (checkOnClick)
+                Checked = !Checked;
+            
+            base.OnClick(e);
+        }
+        protected virtual void OnCheckedChanged(EventArgs e) {
+            var handler = CheckedChanged;
+            if (handler != null) 
+                handler(this,e);
+        }
+        protected virtual void OnCheckStateChanged(EventArgs e)
+        {
+            var handler = CheckStateChanged;
+            if (handler != null) 
+                handler(this,e);
+        }
+        protected override void OnPaint(PaintEventArgs e)
+        {
+            base.OnPaint(e);
+            
+            if (Checked)
+                e.Graphics.DrawRectangle(selectPen, Bounds);
+        }
     }
 }

System/Windows/Forms/ToolStripItem.cs

@@ -399,6 +399,10 @@ protected internal virtual void DrawImage(Graphics graphics)
         }
         protected internal virtual int GetEstimatedWidth(Graphics graphics) // OnPaint only.
         {
+            // ToolStripSeparator?
+            if (string.IsNullOrEmpty(Text))
+                return 0; 
+            
             return (int)graphics.MeasureString(Text, Font).Width;
         }
         protected internal virtual void SetBounds(Rectangle nbounds)
@@ -483,7 +487,10 @@ protected virtual void OnPaint(PaintEventArgs e)
                 leftOffset = Owner.Padding.Left;
 
             // Paint back + backImage.
-            ControlPaint.DrawBackgroundImage(graphics, BackgroundImage, localBackColor, BackgroundImageLayout, rect, rect);
+            if (BackgroundImage != null)
+                ControlPaint.DrawBackgroundImage(graphics, BackgroundImage, localBackColor, BackgroundImageLayout, rect, rect);
+            else
+                e.Graphics.uwfFillRectangle(localBackColor, rect);
 
             // Draw border for selected state.
             if (stateSelected && Enabled)

System/Windows/Forms/ToolStripSeparator.cs

@@ -4,8 +4,8 @@ namespace System.Windows.Forms
 
     public class ToolStripSeparator : ToolStripItem
     {
-        protected Pen borderColor = new Pen(defaultSeparatorBorderColor);
-        protected Pen borderColor2 = new Pen(Color.White);
+        protected readonly Pen borderColor = new Pen(defaultSeparatorBorderColor);
+        protected readonly Pen borderColor2 = new Pen(Color.White);
 
         private const int WINBAR_SEPARATORTHICKNESS = 6;
         private static readonly Color defaultSeparatorBorderColor = Color.FromArgb(189, 189, 189);
@@ -24,18 +24,41 @@ protected override void OnPaint(PaintEventArgs e)
         {
             base.OnPaint(e);
 
+            if (Owner == null)
+                return;
+
             var g = e.Graphics;
             var bounds = Bounds;
-            var ex = bounds.X;
-            var ey = bounds.Y + Height / 2 - 1;
-            var ex2 = bounds.X + bounds.Width - 8;
-            var ey2 = ey + 1;
-
-            if (Owner != null && Owner.Orientation == Orientation.Vertical)
+            
+            if (Owner.Orientation == Orientation.Vertical)
+            {
+                var ex = bounds.X;
+                var ey = bounds.Y + Height / 2 - 1;
+                var ex2 = bounds.X + bounds.Width - 8;
+                var ey2 = ey + 1;
+                
                 ex += Owner.Padding.Left;
 
-            g.DrawLine(borderColor, ex, ey, ex2, ey);
-            g.DrawLine(borderColor2, ex, ey2, ex2, ey2);
+                g.DrawLine(borderColor, ex, ey, ex2, ey);
+                g.DrawLine(borderColor2, ex, ey2, ex2, ey2);
+            }
+            else
+            {
+                var ex = bounds.X + Width / 2 -1;
+                var ey = Owner.Padding.Top;
+                var ex2 = ex + 1;
+                var ey2 = Owner.Height - Owner.Padding.Vertical + 1;
+                
+                g.DrawLine(borderColor, ex, ey, ex, ey2);
+                g.DrawLine(borderColor2, ex2, ey, ex2, ey2);
+            }
+        }
+
+        protected internal override void SetBounds(Rectangle nbounds)
+        {
+            //UnityEngine.Debug.Log(nbounds.Width);
+            
+            base.SetBounds(nbounds);
         }
     }
 }

System/Windows/Forms/TreeNode.cs

@@ -208,9 +208,6 @@ internal int GetYIndex()
         }
         internal void Remove(bool notify)
         {
-            for (int i = 0; i < Nodes.Count; i++)
-                Nodes[i].Remove(false);
-
             if (parent != null)
             {
                 parent.Nodes.RemoveAt(index);