Mathemathics Framework

Imports BV.Controls
Imports System.Drawing
Imports System.Windows.Forms
Imports System.ComponentModel

<CLSCompliant(True), DesignTimeVisible(True)> _
Public Class VScrollBar


    Public Shadows Property Width() As Integer
        Get
            Return MyBase.Width
        End Get
        Set(ByVal value As Integer)
            If value <= 50 Then
                If value >= 20 Then
                    MyBase.Width = value
                Else
                    MyBase.Width = 20
                End If
            Else
                MyBase.Width = 50
            End If
        End Set
    End Property

    Private Sub VScrollBar_Click(ByVal sender As System.Object, ByVal e As MouseEventArgs) Handles MyBase.MouseDown
        If e.Y > Me.btnMiddle.Location.Y Then
            Me.Increment()
        Else
            Me.Decrement()
        End If
        SetMidButtonLocation()
    End Sub

    Private Sub btnUp_Click(ByVal sender As System.Object, ByVal e As EventArgs) Handles btnUp.Click
        Me.SmallDecrement()
        SetMidButtonLocation()
    End Sub

    Private intMidBtnLoc As Point

    Private Sub btnMiddle_Down(ByVal sender As System.Object, ByVal e As MouseEventArgs) Handles btnMiddle.MouseDown
        If e.Button = Windows.Forms.MouseButtons.Left Then
            intMidBtnLoc.Y = e.Y
            intMidBtnLoc.X = e.X
        End If
    End Sub

    Private Sub btnMiddle_Move(ByVal sender As System.Object, ByVal e As MouseEventArgs) Handles btnMiddle.MouseMove
        If e.Button = Windows.Forms.MouseButtons.Left Then
            Dim y, p As Integer
            p = Me.intValue

            If (Me.btnMiddle.Location.Y + (e.Y - Me.intMidBtnLoc.Y)) < (Me.ScrollAreaRange) Then
                If (Me.btnMiddle.Location.Y + (e.Y - Me.intMidBtnLoc.Y)) > Me.btnUp.Height Then
                    y = Me.btnMiddle.Location.Y + (e.Y - Me.intMidBtnLoc.Y)
                Else
                    y = Me.btnUp.Height
                End If
            Else
                y = Me.ScrollAreaRange
            End If

            Me.btnMiddle.Location = New Point(0, y)
            Me.intValue = Me.intMax * (y - Me.btnUp.Height) / (Me.Height - Me.btnUp.Height - Me.btnDown.Height)
            If y = Me.intMin Then
                MyBase.OnScroll(New ScrollEventArgs(ScrollEventType.First, Me.intValue, p, ScrollOrientation.VerticalScroll))
            ElseIf y = Me.intMax Then
                MyBase.OnScroll(New ScrollEventArgs(ScrollEventType.Last, Me.intValue, p, ScrollOrientation.VerticalScroll))
            ElseIf Me.intValue > p Then
                MyBase.OnScroll(New ScrollEventArgs(ScrollEventType.LargeIncrement, Me.intValue, p, ScrollOrientation.VerticalScroll))
            Else
                MyBase.OnScroll(New ScrollEventArgs(ScrollEventType.LargeDecrement, Me.intValue, p, ScrollOrientation.VerticalScroll))
            End If
            ' SetMidButtonLocation()
        End If
    End Sub

    Private Sub btnDown_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDown.Click
        Me.SmallIncrement()
        SetMidButtonLocation()
    End Sub

    Protected Overrides ReadOnly Property ScrollAreaRange() As Integer
        Get
            Return (Me.Height - Me.btnUp.Height - Me.btnDown.Height)
        End Get
    End Property

    Protected Overrides Sub SetMidButtonLocation()
        Dim y As Integer

        y = Me.btnUp.Height + Me.intValue * (Me.ScrollAreaRange - Me.btnMiddle.Height) / Me.intMax
        Me.btnMiddle.Location = New Point(0, y)
    End Sub

End Class