Basic calc

'creator : ibennz
'TODO : handle multiples operations with multi levels array , handle overflows and some errors
Option Strict On
Public Class Form1
    Sub New()

        ' This call is required by the designer.
        InitializeComponent()
        AddHandler MouseDown, AddressOf MouseDownHandling
        MouseDownSetting(Me)
        ' Add any initialization after the InitializeComponent() call.

    End Sub
    Private Sub MouseDownSetting(ByVal parentCtr As Control)
        Dim ctr As Control
        For Each ctr In parentCtr.Controls
            If TypeOf ctr Is Button Then
                AddHandler ctr.MouseDown, AddressOf MouseDownHandling
                MouseDownSetting(ctr)

            End If
        Next
    End Sub
    'cleaner than fkn with each buttons
    Private IsDoingOtherTask As Integer = 0
    Private OldInput As Double = 0
    Private Answer As Double = 0
    Private Sub MouseDownHandling(ByVal sender As Object, ByVal e As MouseEventArgs)
        'direcast the sender object with his original type (control)
        Dim MainNumbers As String = DirectCast(sender, Control).Text


        Select Case IsDoingOtherTask
            Case Tasks.Additioning
                MainNumbers = MainNumbers.Insert(0, "+")
            Case Tasks.finishing
                MainNumbers = MainNumbers.Insert(0, "f")
            Case Tasks.Substracting
                MainNumbers = MainNumbers.Insert(0, "-")
            Case Tasks.Multiplying
                MainNumbers = MainNumbers.Insert(0, "x")
            Case Tasks.Dividing
                MainNumbers = MainNumbers.Insert(0, "/")
        End Select

        If MainNumbers.Contains("c") Then
            MainNumbers = "other"
        End If

        Select Case MainNumbers
            Case "-"
                IsDoingOtherTask = Tasks.Substracting
                OldInput = CDbl(TextBox1.Text)
            Case "+"
                IsDoingOtherTask = Tasks.Additioning
                OldInput = CDbl(TextBox1.Text)

            Case "*"
                IsDoingOtherTask = Tasks.Multiplying
                OldInput = CDbl(TextBox1.Text)

            Case "/"
                IsDoingOtherTask = Tasks.Dividing
                OldInput = CDbl(TextBox1.Text)

            Case "0"
                If TextBox1.Text = "0" Then
                    TextBox1.Text = "0"
                    Exit Select
                End If
                TextBox1.Text &= "0"
                OldInput = 0
            Case "1"
                TextBox1.Text &= "1"
                OldInput = 1
            Case "2"
                TextBox1.Text &= "2"
                OldInput = 2
            Case "3"
                TextBox1.Text &= "3"
                OldInput = 3
            Case "4"
                TextBox1.Text &= "4"
                OldInput = 4
            Case "5"
                TextBox1.Text &= "5"
                OldInput = 5
            Case "6"
                TextBox1.Text &= "6"
                OldInput = 6
            Case "7"
                TextBox1.Text &= "7"
                OldInput = 7
            Case "8"
                TextBox1.Text &= "8"
                OldInput = 8
            Case "9"
                TextBox1.Text &= "9"
                OldInput = 9
            Case ","
                If TextBox1.Text.Contains(",") Then Exit Select
                If TextBox1.Text.Length >= 1 Then
                    OldInput = CDbl(TextBox1.Text)
                    TextBox1.Text &= ","
                End If
            Case "+" & DirectCast(sender, Control).Text
                If Not (IsNumeric(DirectCast(sender, Control).Text)) Then
                    Exit Select
                End If
                TextBox1.Text = DirectCast(sender, Control).Text
                Answer = CDbl(DirectCast(sender, Control).Text) + OldInput
                OldInput = 0
                IsDoingOtherTask = Tasks.finishing
            Case "-" & DirectCast(sender, Control).Text
                If Not (IsNumeric(DirectCast(sender, Control).Text)) Then
                    Exit Select
                End If
                TextBox1.Text = DirectCast(sender, Control).Text
                Answer = OldInput - CDbl(DirectCast(sender, Control).Text)
                OldInput = 0
                IsDoingOtherTask = Tasks.finishing
            Case "/" & DirectCast(sender, Control).Text
                If Not (IsNumeric(DirectCast(sender, Control).Text)) Then
                    Exit Select
                End If
                TextBox1.Text = DirectCast(sender, Control).Text
                Answer = OldInput / CDbl(DirectCast(sender, Control).Text)
                OldInput = 0
                IsDoingOtherTask = Tasks.finishing
            Case "x" & DirectCast(sender, Control).Text
                If Not (IsNumeric(DirectCast(sender, Control).Text)) Then
                    Exit Select
                End If
                TextBox1.Text = DirectCast(sender, Control).Text
                Answer = OldInput * CDbl(DirectCast(sender, Control).Text)
                OldInput = 0
                IsDoingOtherTask = Tasks.finishing
            Case "f" & DirectCast(sender, Control).Text
                If "f" & DirectCast(sender, Control).Text = "f=" Then
                    TextBox1.Text = CStr(Answer)
                    IsDoingOtherTask = Tasks.finishing
                    Exit Sub
                End If
                If Not IsNumeric(DirectCast(sender, Control).Text) Then
                    IsDoingOtherTask = Tasks.idle
                    Exit Select
                End If
                TextBox1.Text = DirectCast(sender, Control).Text
                IsDoingOtherTask = Tasks.idle

            Case Else
                'magestically handle the errors
                TextBox1.Text = "0"
                OldInput = 0
                Answer = 0
                IsDoingOtherTask = Tasks.idle
        End Select

        'carret scroll
        If TextBox1.Text(0) = "0" And TextBox1.Text.Length > 1 And Not (TextBox1.Text.Contains(",")) Then
            TextBox1.Text = TextBox1.Text.Remove(0, 1)
        End If
        TextBox1.Select(0, TextBox1.Text.Length)
    End Sub
    Private Structure Tasks
        Const idle As Integer = 0
        Const Additioning As Integer = 1
        Const finishing As Integer = 2
        Const Substracting As Integer = 3
        Const Multiplying As Integer = 4
        Const Dividing As Integer = 5
    End Structure
End Class