System.Windows.Forms.Form.GetPreferredSizeCore C# (CSharp) Method

		internal override Size GetPreferredSizeCore (Size proposedSize)
		{
			Size retsize = Size.Empty;
			
			foreach (Control child in Controls) {
				Size child_preferred_size;
				if (child.AutoSize)
					child_preferred_size = child.PreferredSize;
				else
					child_preferred_size = child.ExplicitBounds.Size;
				int child_right = child.Bounds.X + child_preferred_size.Width;
				int child_bottom = child.Bounds.Y + child_preferred_size.Height;

				if (child.Dock == DockStyle.Fill) {
					if (child_right > retsize.Width)
						retsize.Width = child_right;
				} 
				else if (child.Dock != DockStyle.Top && child.Dock != DockStyle.Bottom && child_right > retsize.Width)
					retsize.Width = child_right + child.Margin.Right;

				if (child.Dock == DockStyle.Fill) {
					if (child_bottom > retsize.Height)
						retsize.Height = child_bottom;
				}
				else if (child.Dock != DockStyle.Left && child.Dock != DockStyle.Right && child_bottom > retsize.Height)
					retsize.Height = child_bottom + child.Margin.Bottom;
			}

			if (retsize == Size.Empty) { // no child controls
				retsize.Height += this.Padding.Top;
				retsize.Width += this.Padding.Left;
			}
			retsize.Height += this.Padding.Bottom;
			retsize.Width += this.Padding.Right;

			return SizeFromClientSize (retsize);
		}