// Copyright (c) 2007-2012  Michael Chapman
// http://ipaddresscontrollib.googlecode.com

// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:

// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.


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


namespace IPAddressControlLib
{
   internal class DotControl : Control
   {
      #region Public Properties

      public override Size MinimumSize
      {
         get
         {
            using ( Graphics g = Graphics.FromHwnd( Handle ) )
            {
               _sizeText = g.MeasureString( Text, Font, -1, _stringFormat );
            }

            // MeasureString() cuts off the bottom pixel for descenders no matter
            // which StringFormatFlags are chosen.  This doesn't matter for '.' but
            // it's here in case someone wants to modify the text.
            //
            _sizeText.Height += 1F;

            return _sizeText.ToSize();
         }
      }

      public bool ReadOnly
      {
         get
         {
            return _readOnly;
         }
         set
         {
            _readOnly = value;
            Invalidate();
         }
      }

      #endregion // Public Properties

      #region Public Methods

      public override string ToString()
      {
         return Text;
      }

      #endregion // Public Methods

      #region Constructors

      public DotControl()
      {
         Text = Properties.Resources.FieldSeparator;

         _stringFormat = StringFormat.GenericTypographic;
         _stringFormat.FormatFlags = StringFormatFlags.MeasureTrailingSpaces;

         BackColor = SystemColors.Window;
         Size = MinimumSize;
         TabStop = false;

         SetStyle( ControlStyles.AllPaintingInWmPaint, true );
         SetStyle( ControlStyles.OptimizedDoubleBuffer, true );
         SetStyle( ControlStyles.ResizeRedraw, true );
         SetStyle( ControlStyles.UserPaint, true );

         SetStyle( ControlStyles.FixedHeight, true );
         SetStyle( ControlStyles.FixedWidth, true );
      }

      #endregion // Constructors

      #region Protected Methods

      protected override void OnFontChanged( EventArgs e )
      {
         base.OnFontChanged( e );
         Size = MinimumSize;
      }

      protected override void OnPaint( PaintEventArgs e )
      {
         if ( null == e ) { throw new ArgumentNullException( "e" ); }

         base.OnPaint( e );

         Color backColor = BackColor;

         if ( !_backColorChanged )
         {
            if ( !Enabled || ReadOnly )
            {
               backColor = SystemColors.Control;
            }
         }

         Color textColor = ForeColor;

         if ( !Enabled )
         {
            textColor = SystemColors.GrayText;
         }
         else if ( ReadOnly )
         {
            if ( !_backColorChanged )
            {
               textColor = SystemColors.WindowText;
            }
         }

         using ( SolidBrush backgroundBrush = new SolidBrush( backColor ) )
         {
            e.Graphics.FillRectangle( backgroundBrush, ClientRectangle );
         }

         using ( SolidBrush foreBrush = new SolidBrush( textColor ) )
         {
            float x = (float)ClientRectangle.Width / 2F - _sizeText.Width / 2F;
            e.Graphics.DrawString( Text, Font, foreBrush,
               new RectangleF( x, 0F, _sizeText.Width, _sizeText.Height ), _stringFormat );
         }
      }

      protected override void OnParentBackColorChanged( EventArgs e )
      {
         base.OnParentBackColorChanged( e );
         BackColor = Parent.BackColor;
         _backColorChanged = true;
      }

      protected override void OnParentForeColorChanged( EventArgs e )
      {
         base.OnParentForeColorChanged( e );
         ForeColor = Parent.ForeColor;
      }

      protected override void OnSizeChanged( EventArgs e )
      {
         base.OnSizeChanged( e );
         base.Size = MinimumSize;
      }

      #endregion // Protected Methods

      #region Private Data

      private bool _backColorChanged;
      private bool _readOnly;

      private StringFormat _stringFormat;
      private SizeF _sizeText;

      #endregion // Private Data
   }
}