Imports System.Drawing
Imports System.Drawing.Drawing2D

Public Class DisplayHelp

    Public Shared Sub FillRectangle(ByVal g As Graphics, ByVal bounds As Rectangle, ByVal color1 As Color)
        FillRectangle(g, bounds, color1, Color.Empty, 90)
    End Sub

    Public Shared Sub FillRectangle(ByVal g As Graphics, ByVal bounds As Rectangle, ByVal color1 As Color, ByVal color2 As Color)
        FillRectangle(g, bounds, color1, color2, 90)
    End Sub

    Public Shared Sub FillRectangle(ByVal g As Graphics, ByVal r As Rectangle, ByVal color1 As Color, ByVal color2 As Color, ByVal gradientAngle As Integer)
        If r.Width = 0 OrElse r.Height = 0 Then Return

        If color2.IsEmpty Then

            If Not color1.IsEmpty Then
                Dim sm As SmoothingMode = g.SmoothingMode
                g.SmoothingMode = SmoothingMode.None

                Using brush As SolidBrush = New SolidBrush(color1)
                    g.FillRectangle(brush, r)
                End Using

                g.SmoothingMode = sm
            End If
        Else

            Using brush As LinearGradientBrush = CreateLinearGradientBrush(r, color1, color2, gradientAngle)
                g.FillRectangle(brush, r)
            End Using
        End If
    End Sub

    Public Shared Sub FillRectangle(ByVal g As Graphics, ByVal r As Rectangle, ByVal color1 As Color, ByVal color2 As Color, ByVal gradientAngle As Integer, ByVal factors As Single(), ByVal positions As Single())
        If r.Width = 0 OrElse r.Height = 0 Then Return

        If color2.IsEmpty Then

            If Not color1.IsEmpty Then
                Dim sm As SmoothingMode = g.SmoothingMode
                g.SmoothingMode = SmoothingMode.None

                Using brush As SolidBrush = New SolidBrush(color1)
                    g.FillRectangle(brush, r)
                End Using

                g.SmoothingMode = sm
            End If
        Else

            Using brush As LinearGradientBrush = CreateLinearGradientBrush(r, color1, color2, gradientAngle)
                Dim blend As Blend = New Blend(factors.Length)
                blend.Factors = factors
                blend.Positions = positions
                brush.Blend = blend
                g.FillRectangle(brush, r)
            End Using
        End If
    End Sub

    Public Shared Sub FillRoundedRectangle(ByVal g As Graphics, ByVal bounds As Rectangle, ByVal cornerSize As Integer, ByVal color1 As Color, ByVal color2 As Color, ByVal gradientAngle As Integer)
        If color2.IsEmpty Then

            If Not color1.IsEmpty Then

                Using brush As SolidBrush = New SolidBrush(color1)
                    FillRoundedRectangle(g, brush, bounds, cornerSize)
                End Using
            End If
        Else

            Using brush As LinearGradientBrush = CreateLinearGradientBrush(bounds, color1, color2, gradientAngle)
                FillRoundedRectangle(g, brush, bounds, cornerSize)
            End Using
        End If
    End Sub

    Public Shared Sub FillRoundedRectangle(ByVal g As Graphics, ByVal bounds As Rectangle, ByVal cornerSize As Integer, ByVal color1 As Color, ByVal color2 As Color)
        FillRoundedRectangle(g, bounds, cornerSize, color1, color2, 90)
    End Sub

    Public Shared Sub FillRoundedRectangle(ByVal g As Graphics, ByVal bounds As Rectangle, ByVal cornerSize As Integer, ByVal color1 As Color)
        Using brush As SolidBrush = New SolidBrush(color1)
            FillRoundedRectangle(g, brush, bounds, cornerSize)
        End Using
    End Sub

    Public Shared Sub FillRoundedRectangle(ByVal g As Graphics, ByVal brush As Brush, ByVal bounds As Rectangle, ByVal cornerSize As Integer)
        If cornerSize <= 0 Then
            Dim sm As SmoothingMode = g.SmoothingMode
            g.SmoothingMode = SmoothingMode.None
            g.FillRectangle(brush, bounds)
            g.SmoothingMode = sm
        Else
            bounds.Width -= 1
            bounds.Height -= 1

            Using path As GraphicsPath = GetRoundedRectanglePath(bounds, cornerSize)
                g.FillPath(brush, path)
            End Using
        End If
    End Sub

    Public Shared Sub DrawRectangle(ByVal g As System.Drawing.Graphics, ByVal color As Color, ByVal x As Integer, ByVal y As Integer, ByVal width As Integer, ByVal height As Integer)
        Using pen As Pen = New Pen(color, 1)
            DrawRectangle(g, pen, x, y, width, height)
        End Using
    End Sub

    Public Shared Sub DrawRectangle(ByVal g As System.Drawing.Graphics, ByVal color As Color, ByVal r As System.Drawing.Rectangle)
        DrawRectangle(g, color, r.X, r.Y, r.Width, r.Height)
    End Sub

    Public Shared Sub DrawRectangle(ByVal g As System.Drawing.Graphics, ByVal pen As System.Drawing.Pen, ByVal x As Integer, ByVal y As Integer, ByVal width As Integer, ByVal height As Integer)
        width -= 1
        height -= 1
        g.DrawRectangle(pen, x, y, width, height)
    End Sub

    Public Shared Sub DrawRoundedRectangle(ByVal g As System.Drawing.Graphics, ByVal color As Color, ByVal bounds As Rectangle, ByVal cornerSize As Integer)
        If Not color.IsEmpty Then

            Using pen As Pen = New Pen(color)
                DrawRoundedRectangle(g, pen, bounds.X, bounds.Y, bounds.Width, bounds.Height, cornerSize)
            End Using
        End If
    End Sub

    Public Shared Sub DrawRoundedRectangle(ByVal g As System.Drawing.Graphics, ByVal pen As System.Drawing.Pen, ByVal x As Integer, ByVal y As Integer, ByVal width As Integer, ByVal height As Integer, ByVal cornerSize As Integer)
        DrawRoundedRectangle(g, pen, Nothing, x, y, width, height, cornerSize)
    End Sub

    Public Shared Sub DrawRoundedRectangle(ByVal g As System.Drawing.Graphics, ByVal pen As System.Drawing.Pen, ByVal fill As Brush, ByVal x As Integer, ByVal y As Integer, ByVal width As Integer, ByVal height As Integer, ByVal cornerSize As Integer)
        width -= 1
        height -= 1
        Dim r As Rectangle = New Rectangle(x, y, width, height)

        Using path As GraphicsPath = GetRoundedRectanglePath(r, cornerSize)
            If fill IsNot Nothing Then g.FillPath(fill, path)
            g.DrawPath(pen, path)
        End Using
    End Sub

    Public Shared Function GetRoundedRectanglePath(ByVal r As Rectangle, ByVal cornerSize As Integer) As GraphicsPath
        Dim path As GraphicsPath = New GraphicsPath()

        If cornerSize = 0 Then
            path.AddRectangle(r)
        End If

        Return path
    End Function

    Public Shared Function CreateLinearGradientBrush(ByVal r As Rectangle, ByVal color1 As Color, ByVal color2 As Color, ByVal gradientAngle As Single) As LinearGradientBrush
        If r.Width <= 0 Then r.Width = 1
        If r.Height <= 0 Then r.Height = 1
        Return New LinearGradientBrush(New Rectangle(r.X, r.Y - 1, r.Width, r.Height + 1), color1, color2, gradientAngle)
    End Function

End Class