SplitButton.cs

using System;
using System.ComponentModel;
using System.Drawing;
using System.Windows.Forms;
using System.Windows.Forms.VisualStyles;


//Get the latest version of SplitButton at: http://wyday.com/splitbutton/


namespace wyDay.Controls
{
    public class SplitButton : Button
    {
        private PushButtonState _state;
        private bool separateDropdownButton = true;

        private const int SplitSectionWidth = 18;

        private static int BorderSize = SystemInformation.Border3DSize.Width * 2;
        private bool skipNextOpen = false;
        private Rectangle dropDownRectangle = new Rectangle();
        private bool showSplit = false;

        private bool isSplitMenuVisible = false;


        private ContextMenuStrip m_SplitMenuStrip = null;
        private ContextMenu m_SplitMenu = null;

        TextFormatFlags textFormatFlags = TextFormatFlags.Default;

        public SplitButton()
        {
            this.AutoSize = true;
        }

        #region Properties

        /// <summary>
        /// Determines whether or not the dropdown
        /// button is considered a separate button.
        /// If this is set to false, the main button
        /// area will also trigger the context menu and
        /// not have any function on its own.
        /// </summary>
        [DefaultValue(true)]
        public bool SeparateDropdownButton
        {
            get { return separateDropdownButton; }
            set { separateDropdownButton = value; }
        }

        [Browsable(false)]
        public override ContextMenuStrip ContextMenuStrip
        {
            get
            {
                return m_SplitMenuStrip;
            }
            set
            {
                m_SplitMenuStrip = value;
            }
        }

        [DefaultValue(null)]
        public ContextMenu SplitMenu
        {
            get { return m_SplitMenu; }
            set
            {
                //remove the event handlers for the old SplitMenu
                if (m_SplitMenu != null)
                {
                    m_SplitMenu.Popup -= new EventHandler(SplitMenu_Popup);
                    m_SplitMenu.Collapse -= new EventHandler(value_Collapse);
                }

                //add the event handlers for the new SplitMenu
                if (value != null)
                {
                    ShowSplit = true;
                    value.Popup += new EventHandler(SplitMenu_Popup);
                    value.Collapse += new EventHandler(value_Collapse);
                }
                else
                    ShowSplit = false;

                m_SplitMenu = value;
            }
        }

        [DefaultValue(null)]
        public ContextMenuStrip SplitMenuStrip
        {
            get
            {
                return m_SplitMenuStrip;
            }
            set
            {
                //remove the event handlers for the old SplitMenuStrip
                if (m_SplitMenuStrip != null)
                {
                    m_SplitMenuStrip.Closing -= new ToolStripDropDownClosingEventHandler(SplitMenuStrip_Closing);
                    m_SplitMenuStrip.Opening -= new CancelEventHandler(SplitMenuStrip_Opening);
                }

                //add the event handlers for the new SplitMenuStrip
                if (value != null)
                {
                    ShowSplit = true;
                    value.Closing += new ToolStripDropDownClosingEventHandler(SplitMenuStrip_Closing);
                    value.Opening += new CancelEventHandler(SplitMenuStrip_Opening);
                }
                else
                    ShowSplit = false;


                m_SplitMenuStrip = value;
            }
        }

        [DefaultValue(false)]
        public bool ShowSplit
        {
            set
            {
                if (value != showSplit)
                {
                    showSplit = value;
                    Invalidate();
                    if (this.Parent != null)
                    {
                        this.Parent.PerformLayout();
                    }
                }
            }
        }

        private PushButtonState State
        {
            get
            {
                return _state;
            }
            set
            {
                if (!_state.Equals(value))
                {
                    _state = value;
                    Invalidate();
                }
            }
        }

        #endregion Properties

        protected override bool IsInputKey(Keys keyData)
        {
            if (keyData.Equals(Keys.Down) && showSplit)
            {
                return true;
            }

            else
            {
                return base.IsInputKey(keyData);
            }
        }

        protected override void OnGotFocus(EventArgs e)
        {
            if (!showSplit)
            {
                base.OnGotFocus(e);
                return;
            }

            if (!State.Equals(PushButtonState.Pressed) && !State.Equals(PushButtonState.Disabled))
            {
                State = PushButtonState.Default;
            }
        }

        protected override void OnKeyDown(KeyEventArgs kevent)
        {
            if (showSplit)
            {
                if (kevent.KeyCode.Equals(Keys.Down) && !isSplitMenuVisible)
                {
                    ShowContextMenuStrip();
                }

                else if (kevent.KeyCode.Equals(Keys.Space) && kevent.Modifiers == Keys.None)
                {
                    State = PushButtonState.Pressed;
                }
            }

            base.OnKeyDown(kevent);
        }

        protected override void OnKeyUp(KeyEventArgs kevent)
        {
            if (kevent.KeyCode.Equals(Keys.Space))
            {
                if (Control.MouseButtons == MouseButtons.None)
                {
                    State = PushButtonState.Normal;
                }
            }
            else if (kevent.KeyCode.Equals(Keys.Apps))
            {
                if (Control.MouseButtons == MouseButtons.None && !isSplitMenuVisible)
                {
                    ShowContextMenuStrip();
                }
            }

            base.OnKeyUp(kevent);
        }

        protected override void OnEnabledChanged(EventArgs e)
        {
            if (Enabled)
                State = PushButtonState.Normal;
            else
                State = PushButtonState.Disabled;

            base.OnEnabledChanged(e);
        }

        protected override void OnLostFocus(EventArgs e)
        {
            if (!showSplit)
            {
                base.OnLostFocus(e);
                return;
            }

            if (!State.Equals(PushButtonState.Pressed) && !State.Equals(PushButtonState.Disabled))
            {
                State = PushButtonState.Normal;
            }
        }

        bool isMouseEntered = false;

        protected override void OnMouseEnter(EventArgs e)
        {
            if (!showSplit)
            {
                base.OnMouseEnter(e);
                return;
            }

            isMouseEntered = true;

            if (!State.Equals(PushButtonState.Pressed) && !State.Equals(PushButtonState.Disabled))
            {
                State = PushButtonState.Hot;
            }
               
        }

        protected override void OnMouseLeave(EventArgs e)
        {
            if (!showSplit)
            {
                base.OnMouseLeave(e);
                return;
            }

            isMouseEntered = false;

            if (!State.Equals(PushButtonState.Pressed) && !State.Equals(PushButtonState.Disabled))
            {
                if (Focused)
                {
                    State = PushButtonState.Default;
                }

                else
                {
                    State = PushButtonState.Normal;
                }
            }
        }

        protected override void OnMouseDown(MouseEventArgs e)
        {
            if (!showSplit)
            {
                base.OnMouseDown(e);
                return;
            }

            //handle ContextMenu re-clicking the drop-down region to close the menu
            if (m_SplitMenu != null && e.Button == MouseButtons.Left && !isMouseEntered)
                skipNextOpen = true;

            if ((!separateDropdownButton || dropDownRectangle.Contains(e.Location)) && !isSplitMenuVisible && e.Button == MouseButtons.Left)
            {
                ShowContextMenuStrip();
            }
            else
            {
                State = PushButtonState.Pressed;
            }
        }

        protected override void OnMouseUp(MouseEventArgs mevent)
        {
            if (!showSplit)
            {
                base.OnMouseUp(mevent);
                return;
            }

            // if the right button was released inside the button
            if (mevent.Button == MouseButtons.Right && ClientRectangle.Contains(mevent.Location) && !isSplitMenuVisible)
            {
                ShowContextMenuStrip();
            }
            else if (m_SplitMenuStrip == null && m_SplitMenu == null || !isSplitMenuVisible)
            {
                SetButtonDrawState();

                if (ClientRectangle.Contains(mevent.Location) && !dropDownRectangle.Contains(mevent.Location))
                {
                    OnClick(new EventArgs());
                }
            }
        }

        protected override void OnPaint(PaintEventArgs pevent)
        {
            base.OnPaint(pevent);

            if (!showSplit)
                return;

            Graphics g = pevent.Graphics;
            Rectangle bounds = this.ClientRectangle;

            // draw the button background as according to the current state.
            if (State != PushButtonState.Pressed && IsDefault && !Application.RenderWithVisualStyles)
            {
                Rectangle backgroundBounds = bounds;
                backgroundBounds.Inflate(-1, -1);
                ButtonRenderer.DrawButton(g, backgroundBounds, State);

                // button renderer doesnt draw the black frame when themes are off
                g.DrawRectangle(SystemPens.WindowFrame, 0, 0, bounds.Width - 1, bounds.Height - 1);
            }
            else
            {
                ButtonRenderer.DrawButton(g, bounds, State);
            }

            // calculate the current dropdown rectangle.
            dropDownRectangle = new Rectangle(bounds.Right - SplitSectionWidth, 0, SplitSectionWidth, bounds.Height);

            int internalBorder = BorderSize;
            Rectangle focusRect =
                new Rectangle(internalBorder - 1,
                              internalBorder - 1,
                              bounds.Width - dropDownRectangle.Width - internalBorder,
                              bounds.Height - (internalBorder * 2) + 2);

            bool drawSplitLine = (State == PushButtonState.Hot || State == PushButtonState.Pressed || !Application.RenderWithVisualStyles);


            if (RightToLeft == RightToLeft.Yes)
            {
                dropDownRectangle.X = bounds.Left + 1;
                focusRect.X = dropDownRectangle.Right;

                if (drawSplitLine)
                {
                    // draw two lines at the edge of the dropdown button
                    g.DrawLine(SystemPens.ButtonShadow, bounds.Left + SplitSectionWidth, BorderSize, bounds.Left + SplitSectionWidth, bounds.Bottom - BorderSize);
                    g.DrawLine(SystemPens.ButtonFace, bounds.Left + SplitSectionWidth + 1, BorderSize, bounds.Left + SplitSectionWidth + 1, bounds.Bottom - BorderSize);
                }
            }
            else
            {
                if (drawSplitLine)
                {
                    // draw two lines at the edge of the dropdown button
                    g.DrawLine(SystemPens.ButtonShadow, bounds.Right - SplitSectionWidth, BorderSize, bounds.Right - SplitSectionWidth, bounds.Bottom - BorderSize);
                    g.DrawLine(SystemPens.ButtonFace, bounds.Right - SplitSectionWidth - 1, BorderSize, bounds.Right - SplitSectionWidth - 1, bounds.Bottom - BorderSize);
                }
            }

            // Draw an arrow in the correct location
            PaintArrow(g, dropDownRectangle);

            //paint the image and text in the "button" part of the splitButton
            PaintTextandImage(g, new Rectangle(0, 0, ClientRectangle.Width - SplitSectionWidth, ClientRectangle.Height));

            // draw the focus rectangle.
            if (State != PushButtonState.Pressed && Focused && ShowFocusCues)
            {
                ControlPaint.DrawFocusRectangle(g, focusRect);
            }
        }

        private void PaintTextandImage(Graphics g, Rectangle bounds)
        {
            // Figure out where our text and image should go
            Rectangle text_rectangle;
            Rectangle image_rectangle;

            CalculateButtonTextAndImageLayout(ref bounds, out text_rectangle, out image_rectangle);

            //draw the image
            if (Image != null)
            {
                if (Enabled)
                    g.DrawImage(Image, image_rectangle.X, image_rectangle.Y, Image.Width, Image.Height);
                else
                    ControlPaint.DrawImageDisabled(g, Image, image_rectangle.X, image_rectangle.Y, BackColor);
            }

            // If we dont' use mnemonic, set formatFlag to NoPrefix as this will show ampersand.
            if (!UseMnemonic)
                textFormatFlags = textFormatFlags | TextFormatFlags.NoPrefix;
            else if (!ShowKeyboardCues)
                textFormatFlags = textFormatFlags | TextFormatFlags.HidePrefix;

            //draw the text
            if (!string.IsNullOrEmpty(this.Text))
            {
                if (Enabled)
                    TextRenderer.DrawText(g, Text, Font, text_rectangle, SystemColors.ControlText, textFormatFlags);
                else
                    ControlPaint.DrawStringDisabled(g, Text, Font, BackColor, text_rectangle, textFormatFlags);
            }
        }

        private void PaintArrow(Graphics g, Rectangle dropDownRect)
        {
            Point middle = new Point(Convert.ToInt32(dropDownRect.Left + dropDownRect.Width / 2), Convert.ToInt32(dropDownRect.Top + dropDownRect.Height / 2));

            //if the width is odd - favor pushing it over one pixel right.
            middle.X += (dropDownRect.Width % 2);

            Point[] arrow = new Point[] { new Point(middle.X - 2, middle.Y - 1), new Point(middle.X + 3, middle.Y - 1), new Point(middle.X, middle.Y + 2) };

            if (Enabled)
                g.FillPolygon(SystemBrushes.ControlText, arrow);
            else
                g.FillPolygon(SystemBrushes.ButtonShadow, arrow);
        }

        public override Size GetPreferredSize(Size proposedSize)
        {
            Size preferredSize = base.GetPreferredSize(proposedSize);

            //autosize correctly for splitbuttons
            if (showSplit)
            {
                if (AutoSize)
                    return CalculateButtonAutoSize();
                else if (!string.IsNullOrEmpty(Text) && TextRenderer.MeasureText(Text, Font).Width + SplitSectionWidth > preferredSize.Width)
                    return preferredSize + new Size(SplitSectionWidth + BorderSize * 2, 0);
            }

            return preferredSize;
        }

        private Size CalculateButtonAutoSize()
        {
            Size ret_size = Size.Empty;
            Size text_size = TextRenderer.MeasureText(Text, Font);
            Size image_size = Image == null ? Size.Empty : Image.Size;

            // Pad the text size
            if (Text.Length != 0)
            {
                text_size.Height += 4;
                text_size.Width += 4;
            }

            switch (TextImageRelation)
            {
                case TextImageRelation.Overlay:
                    ret_size.Height = Math.Max(Text.Length == 0 ? 0 : text_size.Height, image_size.Height);
                    ret_size.Width = Math.Max(text_size.Width, image_size.Width);
                    break;
                case TextImageRelation.ImageAboveText:
                case TextImageRelation.TextAboveImage:
                    ret_size.Height = text_size.Height + image_size.Height;
                    ret_size.Width = Math.Max(text_size.Width, image_size.Width);
                    break;
                case TextImageRelation.ImageBeforeText:
                case TextImageRelation.TextBeforeImage:
                    ret_size.Height = Math.Max(text_size.Height, image_size.Height);
                    ret_size.Width = text_size.Width + image_size.Width;
                    break;
            }

            // Pad the result
            ret_size.Height += (Padding.Vertical + 6);
            ret_size.Width += (Padding.Horizontal + 6);

            //pad the splitButton arrow region
            if (showSplit)
                ret_size.Width += SplitSectionWidth;

            return ret_size;
        }

        #region Button Layout Calculations

        //The following layout functions were taken from Mono's Windows.Forms 
        //implementation, specifically "ThemeWin32Classic.cs", 
        //then modified to fit the context of this splitButton

        private void CalculateButtonTextAndImageLayout(ref Rectangle content_rect, out Rectangle textRectangle, out Rectangle imageRectangle)
        {
            Size text_size = TextRenderer.MeasureText(Text, Font, content_rect.Size, textFormatFlags);
            Size image_size = Image == null ? Size.Empty : Image.Size;

            textRectangle = Rectangle.Empty;
            imageRectangle = Rectangle.Empty;

            switch (TextImageRelation)
            {
                case TextImageRelation.Overlay:
                    // Overlay is easy, text always goes here
                    textRectangle = OverlayObjectRect(ref content_rect, ref text_size, TextAlign); // Rectangle.Inflate(content_rect, -4, -4);

                    //Offset on Windows 98 style when button is pressed
                    if (_state == PushButtonState.Pressed && !Application.RenderWithVisualStyles)
                        textRectangle.Offset(1, 1);

                    // Image is dependent on ImageAlign
                    if (Image != null)
                        imageRectangle = OverlayObjectRect(ref content_rect, ref image_size, ImageAlign);

                    break;
                case TextImageRelation.ImageAboveText:
                    content_rect.Inflate(-4, -4);
                    LayoutTextAboveOrBelowImage(content_rect, false, text_size, image_size, out textRectangle, out imageRectangle);
                    break;
                case TextImageRelation.TextAboveImage:
                    content_rect.Inflate(-4, -4);
                    LayoutTextAboveOrBelowImage(content_rect, true, text_size, image_size, out textRectangle, out imageRectangle);
                    break;
                case TextImageRelation.ImageBeforeText:
                    content_rect.Inflate(-4, -4);
                    LayoutTextBeforeOrAfterImage(content_rect, false, text_size, image_size, out textRectangle, out imageRectangle);
                    break;
                case TextImageRelation.TextBeforeImage:
                    content_rect.Inflate(-4, -4);
                    LayoutTextBeforeOrAfterImage(content_rect, true, text_size, image_size, out textRectangle, out imageRectangle);
                    break;
            }
        }

        private Rectangle OverlayObjectRect(ref Rectangle container, ref Size sizeOfObject, System.Drawing.ContentAlignment alignment)
        {
            int x, y;

            switch (alignment)
            {
                case System.Drawing.ContentAlignment.TopLeft:
                    x = 4;
                    y = 4;
                    break;
                case System.Drawing.ContentAlignment.TopCenter:
                    x = (container.Width - sizeOfObject.Width) / 2;
                    y = 4;
                    break;
                case System.Drawing.ContentAlignment.TopRight:
                    x = container.Width - sizeOfObject.Width - 4;
                    y = 4;
                    break;
                case System.Drawing.ContentAlignment.MiddleLeft:
                    x = 4;
                    y = (container.Height - sizeOfObject.Height) / 2;
                    break;
                case System.Drawing.ContentAlignment.MiddleCenter:
                    x = (container.Width - sizeOfObject.Width) / 2;
                    y = (container.Height - sizeOfObject.Height) / 2;
                    break;
                case System.Drawing.ContentAlignment.MiddleRight:
                    x = container.Width - sizeOfObject.Width - 4;
                    y = (container.Height - sizeOfObject.Height) / 2;
                    break;
                case System.Drawing.ContentAlignment.BottomLeft:
                    x = 4;
                    y = container.Height - sizeOfObject.Height - 4;
                    break;
                case System.Drawing.ContentAlignment.BottomCenter:
                    x = (container.Width - sizeOfObject.Width) / 2;
                    y = container.Height - sizeOfObject.Height - 4;
                    break;
                case System.Drawing.ContentAlignment.BottomRight:
                    x = container.Width - sizeOfObject.Width - 4;
                    y = container.Height - sizeOfObject.Height - 4;
                    break;
                default:
                    x = 4;
                    y = 4;
                    break;
            }

            return new Rectangle(x, y, sizeOfObject.Width, sizeOfObject.Height);
        }

        private void LayoutTextBeforeOrAfterImage(Rectangle totalArea, bool textFirst, Size textSize, Size imageSize, out Rectangle textRect, out Rectangle imageRect)
        {
            int element_spacing = 0;	// Spacing between the Text and the Image
            int total_width = textSize.Width + element_spacing + imageSize.Width;

            if (!textFirst)
                element_spacing += 2;

            // If the text is too big, chop it down to the size we have available to it
            if (total_width > totalArea.Width)
            {
                textSize.Width = totalArea.Width - element_spacing - imageSize.Width;
                total_width = totalArea.Width;
            }

            int excess_width = totalArea.Width - total_width;
            int offset = 0;

            Rectangle final_text_rect;
            Rectangle final_image_rect;

            HorizontalAlignment h_text = GetHorizontalAlignment(TextAlign);
            HorizontalAlignment h_image = GetHorizontalAlignment(ImageAlign);

            if (h_image == HorizontalAlignment.Left)
                offset = 0;
            else if (h_image == HorizontalAlignment.Right && h_text == HorizontalAlignment.Right)
                offset = excess_width;
            else if (h_image == HorizontalAlignment.Center && (h_text == HorizontalAlignment.Left || h_text == HorizontalAlignment.Center))
                offset += (int)(excess_width / 3);
            else
                offset += (int)(2 * (excess_width / 3));

            if (textFirst)
            {
                final_text_rect = new Rectangle(totalArea.Left + offset, AlignInRectangle(totalArea, textSize, TextAlign).Top, textSize.Width, textSize.Height);
                final_image_rect = new Rectangle(final_text_rect.Right + element_spacing, AlignInRectangle(totalArea, imageSize, ImageAlign).Top, imageSize.Width, imageSize.Height);
            }
            else
            {
                final_image_rect = new Rectangle(totalArea.Left + offset, AlignInRectangle(totalArea, imageSize, ImageAlign).Top, imageSize.Width, imageSize.Height);
                final_text_rect = new Rectangle(final_image_rect.Right + element_spacing, AlignInRectangle(totalArea, textSize, TextAlign).Top, textSize.Width, textSize.Height);
            }

            textRect = final_text_rect;
            imageRect = final_image_rect;
        }

        private void LayoutTextAboveOrBelowImage(Rectangle totalArea, bool textFirst, Size textSize, Size imageSize, out Rectangle textRect, out Rectangle imageRect)
        {
            int element_spacing = 0;	// Spacing between the Text and the Image
            int total_height = textSize.Height + element_spacing + imageSize.Height;

            if (textFirst)
                element_spacing += 2;

            if (textSize.Width > totalArea.Width)
                textSize.Width = totalArea.Width;

            // If the there isn't enough room and we're text first, cut out the image
            if (total_height > totalArea.Height && textFirst)
            {
                imageSize = Size.Empty;
                total_height = totalArea.Height;
            }

            int excess_height = totalArea.Height - total_height;
            int offset = 0;

            Rectangle final_text_rect;
            Rectangle final_image_rect;

            VerticalAlignment v_text = GetVerticalAlignment(TextAlign);
            VerticalAlignment v_image = GetVerticalAlignment(ImageAlign);

            if (v_image == VerticalAlignment.Top)
                offset = 0;
            else if (v_image == VerticalAlignment.Bottom && v_text == VerticalAlignment.Bottom)
                offset = excess_height;
            else if (v_image == VerticalAlignment.Center && (v_text == VerticalAlignment.Top || v_text == VerticalAlignment.Center))
                offset += (int)(excess_height / 3);
            else
                offset += (int)(2 * (excess_height / 3));

            if (textFirst)
            {
                final_text_rect = new Rectangle(AlignInRectangle(totalArea, textSize, TextAlign).Left, totalArea.Top + offset, textSize.Width, textSize.Height);
                final_image_rect = new Rectangle(AlignInRectangle(totalArea, imageSize, ImageAlign).Left, final_text_rect.Bottom + element_spacing, imageSize.Width, imageSize.Height);
            }
            else
            {
                final_image_rect = new Rectangle(AlignInRectangle(totalArea, imageSize, ImageAlign).Left, totalArea.Top + offset, imageSize.Width, imageSize.Height);
                final_text_rect = new Rectangle(AlignInRectangle(totalArea, textSize, TextAlign).Left, final_image_rect.Bottom + element_spacing, textSize.Width, textSize.Height);

                if (final_text_rect.Bottom > totalArea.Bottom)
                    final_text_rect.Y = totalArea.Top;
            }

            textRect = final_text_rect;
            imageRect = final_image_rect;
        }

        private HorizontalAlignment GetHorizontalAlignment(System.Drawing.ContentAlignment align)
        {
            switch (align)
            {
                case System.Drawing.ContentAlignment.BottomLeft:
                case System.Drawing.ContentAlignment.MiddleLeft:
                case System.Drawing.ContentAlignment.TopLeft:
                    return HorizontalAlignment.Left;
                case System.Drawing.ContentAlignment.BottomCenter:
                case System.Drawing.ContentAlignment.MiddleCenter:
                case System.Drawing.ContentAlignment.TopCenter:
                    return HorizontalAlignment.Center;
                case System.Drawing.ContentAlignment.BottomRight:
                case System.Drawing.ContentAlignment.MiddleRight:
                case System.Drawing.ContentAlignment.TopRight:
                    return HorizontalAlignment.Right;
            }

            return HorizontalAlignment.Left;
        }

        private VerticalAlignment GetVerticalAlignment(System.Drawing.ContentAlignment align)
        {
            switch (align)
            {
                case System.Drawing.ContentAlignment.TopLeft:
                case System.Drawing.ContentAlignment.TopCenter:
                case System.Drawing.ContentAlignment.TopRight:
                    return VerticalAlignment.Top;
                case System.Drawing.ContentAlignment.MiddleLeft:
                case System.Drawing.ContentAlignment.MiddleCenter:
                case System.Drawing.ContentAlignment.MiddleRight:
                    return VerticalAlignment.Center;
                case System.Drawing.ContentAlignment.BottomLeft:
                case System.Drawing.ContentAlignment.BottomCenter:
                case System.Drawing.ContentAlignment.BottomRight:
                    return VerticalAlignment.Bottom;
            }

            return VerticalAlignment.Top;
        }

        internal Rectangle AlignInRectangle(Rectangle outer, Size inner, System.Drawing.ContentAlignment align)
        {
            int x = 0;
            int y = 0;

            if (align == System.Drawing.ContentAlignment.BottomLeft || align == System.Drawing.ContentAlignment.MiddleLeft || align == System.Drawing.ContentAlignment.TopLeft)
                x = outer.X;
            else if (align == System.Drawing.ContentAlignment.BottomCenter || align == System.Drawing.ContentAlignment.MiddleCenter || align == System.Drawing.ContentAlignment.TopCenter)
                x = Math.Max(outer.X + ((outer.Width - inner.Width) / 2), outer.Left);
            else if (align == System.Drawing.ContentAlignment.BottomRight || align == System.Drawing.ContentAlignment.MiddleRight || align == System.Drawing.ContentAlignment.TopRight)
                x = outer.Right - inner.Width;
            if (align == System.Drawing.ContentAlignment.TopCenter || align == System.Drawing.ContentAlignment.TopLeft || align == System.Drawing.ContentAlignment.TopRight)
                y = outer.Y;
            else if (align == System.Drawing.ContentAlignment.MiddleCenter || align == System.Drawing.ContentAlignment.MiddleLeft || align == System.Drawing.ContentAlignment.MiddleRight)
                y = outer.Y + (outer.Height - inner.Height) / 2;
            else if (align == System.Drawing.ContentAlignment.BottomCenter || align == System.Drawing.ContentAlignment.BottomRight || align == System.Drawing.ContentAlignment.BottomLeft)
                y = outer.Bottom - inner.Height;

            return new Rectangle(x, y, Math.Min(inner.Width, outer.Width), Math.Min(inner.Height, outer.Height));
        }

        #endregion Button Layout Calculations


        private void ShowContextMenuStrip()
        {
            if (skipNextOpen)
            {
                // we were called because we're closing the context menu strip
                // when clicking the dropdown button.
                skipNextOpen = false;
                return;
            }

            State = PushButtonState.Pressed;

            if (m_SplitMenu != null)
            {
                m_SplitMenu.Show(this, new Point(0, Height));
            }
            else if (m_SplitMenuStrip != null)
            {
                m_SplitMenuStrip.Show(this, new Point(0, Height), ToolStripDropDownDirection.BelowRight);
            }
        }

        void SplitMenuStrip_Opening(object sender, CancelEventArgs e)
        {
            isSplitMenuVisible = true;
        }

        void SplitMenuStrip_Closing(object sender, ToolStripDropDownClosingEventArgs e)
        {
            isSplitMenuVisible = false;

            SetButtonDrawState();

            if (e.CloseReason == ToolStripDropDownCloseReason.AppClicked)
            {
                skipNextOpen = (dropDownRectangle.Contains(this.PointToClient(Cursor.Position))) && Control.MouseButtons == MouseButtons.Left;
            }
        }

        void SplitMenu_Popup(object sender, EventArgs e)
        {
            isSplitMenuVisible = true;
        }

        void value_Collapse(object sender, EventArgs e)
        {
            isSplitMenuVisible = false;
        }

        protected override void WndProc(ref Message m)
        {
            //0x0212 == WM_EXITMENULOOP
            if (m.Msg == 0x0212)
            {
                //this message is only sent when a ContextMenu is closed (not a ContextMenuStrip)
                isSplitMenuVisible = false;
                SetButtonDrawState();
            }

            base.WndProc(ref m);
        }

        private void SetButtonDrawState()
        {
            if (Bounds.Contains(Parent.PointToClient(Cursor.Position)))
            {
                State = PushButtonState.Hot;
            }
            else if (Focused)
            {
                State = PushButtonState.Default;
            }
            else if (!Enabled)
            {
                State = PushButtonState.Disabled;
            }
            else
            {
                State = PushButtonState.Normal;
            }
        }
    }
}