Imports System
Imports System.Text
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Windows.Forms
Imports System.Collections.Generic


Public Class ShadowPanelasas
    Inherits Windows.Forms.Form

    Private _panelColor As Color






    Public Property PanelColor() As Color
        Get
            Return _panelColor
        End Get
        Set(ByVal value As Color)
            _panelColor = value
        End Set
    End Property

    Private _borderColor As Color
    Public Property BorderColor() As Color
        Get
            Return _borderColor
        End Get
        Set(ByVal value As Color)
            _borderColor = value
        End Set
    End Property

    Private shadowSize As Integer = 5
    Private shadowMargin As Integer = 2

    ' static for good perfomance 
    Shared shadowDownRight As Image = New Bitmap(GetType(ShadowPanel), "tshadowdownright.png")
    Shared shadowDownLeft As Image = New Bitmap(GetType(ShadowPanel), "tshadowdownleft.png")
    Shared shadowDown As Image = New Bitmap(GetType(ShadowPanel), "tshadowdown.png")
    Shared shadowRight As Image = New Bitmap(GetType(ShadowPanel), "tshadowright.png")
    Shared shadowTopRight As Image = New Bitmap(GetType(ShadowPanel), "tshadowtopright.png")


    Public Sub New()
    End Sub

    Protected Overloads Overrides Sub OnPaint(ByVal e As PaintEventArgs)
        MyBase.OnPaint(e)

        ' Get the graphics object. We need something to draw with ;-)
        Dim g As Graphics = e.Graphics
        ' Create tiled brushes for the shadow on the right and at the bottom.
        Dim shadowRightBrush As New TextureBrush(shadowRight, WrapMode.Tile)
        Dim shadowDownBrush As New TextureBrush(shadowDown, WrapMode.Tile)


        ' Translate (move) the brushes so the top or left of the image matches the top or left of the
        ' area where it's drawed. If you don't understand why this is necessary, comment it out. 
        ' Hint: The tiling would start at 0,0 of the control, so the shadows will be offset a little.

        shadowDownBrush.TranslateTransform(0, Height - shadowSize)
        shadowRightBrush.TranslateTransform(Width - shadowSize, 0)

        ' Define the rectangles that will be filled with the brush.
        ' (where the shadow is drawn)
        ' X
        ' Y
        ' width (stretches)
        ' height


        Dim shadowDownRectangle As New Rectangle(shadowSize + shadowMargin, Height - shadowSize, _
        Width - (shadowSize * 2 + shadowMargin), shadowSize)

        ' X
        ' Y
        ' width
        ' height (stretches)


        Dim shadowRightRectangle As New Rectangle(Width - shadowSize, shadowSize + shadowMargin, _
        shadowSize, Height - (shadowSize * 2 + shadowMargin))

        ' And draw the shadow on the right and at the bottom.
        g.FillRectangle(shadowDownBrush, shadowDownRectangle)
        g.FillRectangle(shadowRightBrush, shadowRightRectangle)

        ' Now for the corners, draw the 3 5x5 pixel images.
        g.DrawImage(shadowTopRight, New Rectangle(Width - shadowSize, _
        shadowMargin, shadowSize, shadowSize))

        g.DrawImage(shadowDownRight, New Rectangle(Width - shadowSize, _
        Height - shadowSize, shadowSize, shadowSize))

        g.DrawImage(shadowDownLeft, New Rectangle(shadowMargin, _
        Height - shadowSize, shadowSize, shadowSize))

        ' Fill the area inside with the color in the PanelColor property.
        ' 1 pixel is added to everything to make the rectangle smaller. 
        ' This is because the 1 pixel border is actually drawn outside the rectangle.
        ' X
        ' Y
        ' Width
        ' Height

        Dim fullRectangle As New Rectangle(1, 1, Width - (shadowSize + 2), Height - (shadowSize + 2))

        If Not PanelColor = Nothing Then
            Dim bgBrush As New SolidBrush(_panelColor)
            g.FillRectangle(bgBrush, fullRectangle)
        End If

        ' Draw a nice 1 pixel border it a BorderColor is specified

        If Not BorderColor = Nothing Then
            Dim borderPen As New Pen(BorderColor)
            g.DrawRectangle(borderPen, fullRectangle)
        End If

        ' Memory efficiency
        shadowDownBrush.Dispose()
        shadowRightBrush.Dispose()
        shadowDownBrush = Nothing
        shadowRightBrush = Nothing

    End Sub


    ' Correct resizing
    Protected Overloads Overrides Sub OnResize(ByVal e As EventArgs)
        MyBase.Invalidate()
        MyBase.OnResize(e)
    End Sub

End Class