'/*
' *	CodeEditor - RTFBox for SyntaxHighlighting
' *
' *	(c) 2009 Christian Ivicevic
' *
' */

Public Class CodeEditor
    Inherits System.Windows.Forms.RichTextBox

    Private Declare Function SendMessage _
		Lib "user32" Alias "SendMessageA" _
		(ByVal hWnd As IntPtr, _
		 ByVal wMsg As Integer, _
		 ByVal wParam As Integer, _
		 ByVal lParam As Integer) As Integer
    Private Declare Function LockWindowUpdate _
		Lib "user32" _
		(ByVal hWnd As Integer) As Integer

    Private _CaseSensitive As Boolean = True
    Private _Language As CodeLanguages = CodeLanguages.Plain
    Friend Words As New DataTable

    Private Enum EditMessages
        LineIndex = 187
        LineFromChar = 201
        GetFirstVisibleLine = 206
        CharFromPos = 215
        PosFromChar = 1062
    End Enum

    Public Enum CodeLanguages
        Plain = 0
        MyLang1 = 1
		MyLang2 = 1
    End Enum

    Protected Overrides Sub OnTextChanged(ByVal e As System.EventArgs)
        MyBase.OnTextChanged(e)
        ColorVisibleLines()
    End Sub

    Public Sub New()
        AcceptsTab = True
        InitSyntax()
    End Sub

    Function InitSyntax()
        ClearSyntaxWords()
        'AddSyntaxWord("\b()\b", Color.Blue)
		If CodeLanguage = CodeLanguages.Plain Then
			' No Syntax
		ElseIf CodeLanguage = CodeLanguage.MyLang1 Then
			AddSyntaxWord("\b(double|float|int|void)\b", Color.Blue)
			AddSyntaxWord("\b(main|dllmain|winmain)\b", Color.Green)
		ElseIf CodeLanguage = CodeLanguage.MyLang2 Then
			AddSyntaxWord("\b(double|float|int|void)\b", Color.Pink)
			AddSyntaxWord("\b(main|dllmain|winmain)\b", Color.Red)
		Else
			' No Syntax
		End If
        Return True
    End Function

    Public Function ClearSyntaxWords()
        Words = New DataTable()
        Words.Columns.Add("Word")
        Words.PrimaryKey = New DataColumn() {Words.Columns(0)}
        Words.Columns.Add("Color")
        Return True
    End Function

    Public Function AddSyntaxWord(ByVal strWord As String, ByVal clrColor As Color)
        Dim MyRow As DataRow
        MyRow = Words.NewRow()
        MyRow("Word") = strWord
        MyRow("Color") = clrColor.Name
        Words.Rows.Add(MyRow)
        Return True
    End Function

    Public Sub ColorRtb()
        Dim FirstVisibleChar As Integer
        Dim i As Integer = 0
        While i < Me.Lines.Length
            FirstVisibleChar = GetCharFromLineIndex(i)
            ColorLineNumber(i, FirstVisibleChar)
            i += 1
        End While
    End Sub

    Public Sub ColorVisibleLines()
        Dim FirstLine As Integer = FirstVisibleLine()
        Dim LastLine As Integer = LastVisibleLine()
        Dim FirstVisibleChar As Integer
        If (FirstLine = 0) And (LastLine = 0) Then
            Exit Sub
        Else
            While FirstLine < LastLine
                FirstVisibleChar = GetCharFromLineIndex(FirstLine)
                ColorLineNumber(FirstLine, FirstVisibleChar)
                FirstLine += 1
            End While
        End If
    End Sub

    Public Sub ColorLineNumber(ByVal LineIndex As Integer, ByVal lStart As Integer)
        Dim i As Integer = 0
        Dim SelectionAt As Integer = SelectionStart
        Dim MyRow As DataRow
        Dim MyI As Integer

        LockWindowUpdate(Handle.ToInt32)

        MyI = lStart

        SelectionStart = MyI
        SelectionLength = Lines(LineIndex).Length
        SelectionColor = Color.Black

        Dim rm As System.Text.RegularExpressions.MatchCollection
        Dim m As System.Text.RegularExpressions.Match

        Dim TextA As String = ""
        If CaseSensitive = False Then
            TextA = Text.ToLower
        Else
            TextA = Text
        End If
        For Each MyRow In Words.Rows
            rm = System.Text.RegularExpressions.Regex.Matches(TextA, MyRow("Word"))
            For Each m In rm
                SelectionStart = m.Index
                SelectionLength = m.Length
                SelectionColor = Color.FromName(MyRow("color"))
            Next
        Next

        SelectionStart = SelectionAt
        SelectionLength = 0
        SelectionColor = Color.Black

        LockWindowUpdate(0)
    End Sub

    Public Function GetCharFromLineIndex(ByVal LineIndex As Integer) As Integer
        Return SendMessage(Handle, EditMessages.LineIndex, LineIndex, 0)
    End Function

    Public Function FirstVisibleLine() As Integer
        Return SendMessage(Handle, EditMessages.GetFirstVisibleLine, 0, 0)
    End Function

    Public Function LastVisibleLine() As Integer
        Dim LastLine As Integer = FirstVisibleLine() + (Height / Font.Height)

        If LastLine > Lines.Length Or LastLine = 0 Then
            LastLine = Lines.Length
        End If

        Return LastLine
    End Function

    Public Property CaseSensitive() As Boolean
        Get
            Return _CaseSensitive
        End Get
        Set(ByVal Value As Boolean)
            _CaseSensitive = Value
        End Set
    End Property

    Public Property CodeLanguage() As CodeLanguages
        Get
            Return _Language
        End Get
        Set(ByVal value As CodeLanguages)
			_Language = value
			InitSyntax()
        End Set
    End Property
End Class