using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Diagnostics;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;
namespace AMT_SW_GUI
{

//Parts of this file taken from codeproject
    public enum LineSpacingRule
    {
        Single, //single line
        Normal, // 1.5 line
        Double, // double line
    }

    public partial class AMT_RichTextbox : RichTextBox
    {
        private bool labelMode = true;
        public AMT_RichTextbox()
        {
            InitializeComponent();
            this.TextChanged += new EventHandler(AMT_RichTextbox_TextChanged);
        }

        public AMT_RichTextbox(IContainer container)
        {
            container.Add(this);

            InitializeComponent();
            this.TextChanged+=new EventHandler(AMT_RichTextbox_TextChanged);
        }

        [StructLayout(LayoutKind.Sequential)]
        private class PARAFORMAT2
        {
            public int cbSize;
            public int dwMask;
            public short wNumbering;
            public short wReserved;
            public int dxStartIndent;
            public int dxRightIndent;
            public int dxOffset;
            public short wAlignment;
            public short cTabCount;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 0x20)]
            public int[] rgxTabs;

            public int dySpaceBefore; // Vertical spacing before para
            public int dySpaceAfter; // Vertical spacing after para
            public int dyLineSpacing; // Line spacing depending on Rule
            public short sStyle; // Style handle
            public byte bLineSpacingRule; // Rule for line spacing (see tom.doc)
            public byte bOutlineLevel; // Outline Level
            public short wShadingWeight; // Shading in hundredths of a per cent
            public short wShadingStyle; // Byte 0: style, nib 2: cfpat, 3: cbpat
            public short wNumberingStart; // Starting value for numbering
            public short wNumberingStyle; // Alignment, Roman/Arabic, (), ), ., etc.
            public short wNumberingTab; // Space bet 1st indent and 1st-line text
            public short wBorderSpace; // Border-text spaces (nbl/bdr in pts)
            public short wBorderWidth; // Pen widths (nbl/bdr in half twips)
            public short wBorders; // Border styles (nibble/border)

            public PARAFORMAT2()
            {
                this.cbSize = Marshal.SizeOf(typeof(PARAFORMAT2));
            }
        }

        #region PARAFORMAT MASK VALUES
        // PARAFORMAT mask values
        private const uint PFM_STARTINDENT = 0x00000001;
        private const uint PFM_RIGHTINDENT = 0x00000002;
        private const uint PFM_OFFSET = 0x00000004;
        private const uint PFM_ALIGNMENT = 0x00000008;
        private const uint PFM_TABSTOPS = 0x00000010;
        private const uint PFM_NUMBERING = 0x00000020;
        private const uint PFM_OFFSETINDENT = 0x80000000;

        // PARAFORMAT 2.0 masks and effects
        private const uint PFM_SPACEBEFORE = 0x00000040;
        private const uint PFM_SPACEAFTER = 0x00000080;
        private const uint PFM_LINESPACING = 0x00000100;
        private const uint PFM_STYLE = 0x00000400;
        private const uint PFM_BORDER = 0x00000800; // (*)
        private const uint PFM_SHADING = 0x00001000; // (*)
        private const uint PFM_NUMBERINGSTYLE = 0x00002000; // RE 3.0
        private const uint PFM_NUMBERINGTAB = 0x00004000; // RE 3.0
        private const uint PFM_NUMBERINGSTART = 0x00008000; // RE 3.0

        private const uint PFM_RTLPARA = 0x00010000;
        private const uint PFM_KEEP = 0x00020000; // (*)
        private const uint PFM_KEEPNEXT = 0x00040000; // (*)
        private const uint PFM_PAGEBREAKBEFORE = 0x00080000; // (*)
        private const uint PFM_NOLINENUMBER = 0x00100000; // (*)
        private const uint PFM_NOWIDOWCONTROL = 0x00200000; // (*)
        private const uint PFM_DONOTHYPHEN = 0x00400000; // (*)
        private const uint PFM_SIDEBYSIDE = 0x00800000; // (*)
        private const uint PFM_TABLE = 0x40000000; // RE 3.0
        private const uint PFM_TEXTWRAPPINGBREAK = 0x20000000; // RE 3.0
        private const uint PFM_TABLEROWDELIMITER = 0x10000000; // RE 4.0

        // The following three properties are read only
        private const uint PFM_COLLAPSED = 0x01000000; // RE 3.0
        private const uint PFM_OUTLINELEVEL = 0x02000000; // RE 3.0
        private const uint PFM_BOX = 0x04000000; // RE 3.0
        private const uint PFM_RESERVED2 = 0x08000000; // RE 4.0

        #endregion

        [DllImport("user32.dll", CharSet = System.Runtime.InteropServices.CharSet.Auto)]
        private static extern IntPtr SendMessage(HandleRef hWnd, int msg, int wParam,
           [In, Out, MarshalAs(UnmanagedType.LPStruct)] PARAFORMAT2 lParam);


        #region AutoSize
        private bool autoSize = false;

        public void SetAutoSize(bool turnOn)
        {
            autoSize = turnOn;
        }
        #endregion

        #region Line Spacing

        public void SetLineSpacingRule(byte rule)
        {
            PARAFORMAT2 pf = new PARAFORMAT2();
            pf.dwMask = (int)(PFM_LINESPACING);
            pf.bLineSpacingRule = rule;
            SendMessage(new System.Runtime.InteropServices.HandleRef(this, this.Handle),
                0x447, 0, pf);
        }

        

        private double lineSpacingRule = 0;

        private LineSpacingRule lineSpacing = LineSpacingRule.Single;

        public LineSpacingRule LineSpacing
        {
            get { return lineSpacing; }
            set
            {
                lineSpacing = value;
                switch (value)
                {
                    case LineSpacingRule.Single:
                        {
                            lineSpacingRule = 1;
                            SetLineSpacingRule(0); break;
                        }
                    case LineSpacingRule.Normal:
                        {
                            lineSpacingRule = 1.5;
                            SetLineSpacingRule(1); break;
                        }
                    case LineSpacingRule.Double:
                        {
                            lineSpacingRule = 2;
                            SetLineSpacingRule(2); break;
                        }
                }
            }
        }

        #endregion 

        protected override void WndProc(ref Message m)
        {
            const int WM_SETFOCUS = 0x0007;
            if (labelMode == true)
            {
                //this code prevents from the user to edit/get focus the rich text box
                if (m.Msg == WM_SETFOCUS)
                {
                    m.Result = IntPtr.Zero;
                }
                else
                    base.WndProc(ref m);
            }
            else
            {
                base.WndProc(ref m);
            }
        }

        public bool LabelMode
        {
            get
            {
                return labelMode;
            }
            set 
            {
                labelMode = value;
                if (labelMode == true)
                {
                    // for label mode , the control is readonly
                    this.ReadOnly = true;
                }                 
            }
        }

        void AMT_RichTextbox_TextChanged(object sender, EventArgs e)
        {
            if (autoSize == true)
            {
                LineSpacing = lineSpacing;
                this.Height = Convert.ToInt32((((this.GetLineFromCharIndex(this.Text.Length) + 1) * this.Font.Height + 1 + this.Margin.Vertical) * lineSpacingRule)) + 2;
                this.SelectionStart = 0;
            }
            this.SelectionStart = this.Text.Length;
            this.ScrollToCaret();
        }

    }
}