Public Class square

    '''''''''''''''''''''''''''''''''''''''''''''''''''''''
    ' declare instance variables of square
    '''''''''''''''''''''''''''''''''''''''''''''''''''''''
    Private side As Integer
    Private Xloc As Integer
    Private Yloc As Integer
    Private name As String      ' text inside square
    Private bcolor As Color     ' background color
    Private fcolor As Color     ' foreground (text) color
    Private sqDisplay As System.Windows.Forms.Button  ' button that will be the visual display of the square

    Const adjustAmount As Integer = 10     ' distance a move of "1" is in pixels
    Const titleBarSize As Integer = 34

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    ' declare interface to properties
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    ' length of a side
    Public Property sideLen() As Integer
        Get
            Return side
        End Get
        Set(ByVal Value As Integer)
            If Value > 0 Then
                side = Value
            End If     ' don't change if invalid
        End Set
    End Property

    ' horizontal location
    Public Property xLocation() As Integer
        Get
            Return Xloc
        End Get
        Set(ByVal Value As Integer)
            If Value >= 0 Then
                Xloc = Value
            End If   ' if invalid don't change
        End Set
    End Property

    ' vertical location
    Public Property yLocation() As Integer
        Get
            Return Yloc
        End Get
        Set(ByVal Value As Integer)
            If Value >= 0 Then
                Yloc = Value
            End If   ' if invalid don't change
        End Set
    End Property

    ' text inside the square
    Public Property sqName() As String
        Get
            Return name
        End Get
        Set(ByVal Value As String)
            ' don't need to validate
            name = Value
        End Set
    End Property

    ' background color
    Public Property backgroundColor() As Color
        Get
            Return bcolor
        End Get
        Set(ByVal Value As Color)
            If Value.IsKnownColor Then  ' color known to VB
                bcolor = Value
            End If     ' don't change if invalid
        End Set
    End Property

    ' text color
    Public Property foregroundColor() As Color
        Get
            Return fcolor
        End Get
        Set(ByVal Value As Color)
            If Value.IsKnownColor Then ' color known to VB
                fcolor = Value
            End If     ' don't change if invalid
        End Set
    End Property

    ' button to use to display the square
    Public Property squareDisplay() As System.Windows.Forms.Button
        Get
            Return sqDisplay
        End Get
        Set(ByVal Value As System.Windows.Forms.Button)
            If Not Value Is Nothing Then  ' check if the button exists
                sqDisplay = Value
            End If     ' don't change if invalid
        End Set
    End Property

    '''''''''''''''''''''''''''''''''''''''''''''''''''''''
    '' constructors
    '''''''''''''''''''''''''''''''''''''''''''''''''''''''
    ' no default constructor - because at minimun we need that button that we
    ' will use as the display of the square
    Public Sub New(ByRef sq As System.Windows.Forms.Button)
        sqDisplay = sq
        ' use values from the default button for all other instance variables
        side = sq.Height
        Xloc = sq.Left
        Yloc = sq.Top
        name = sq.Text
        bcolor = sq.BackColor
        fcolor = sq.ForeColor
    End Sub

    ' constructor using just a button and side length
    Public Sub New(ByRef sq As System.Windows.Forms.Button, ByVal len As Integer)
        sqDisplay = sq
        side = len
        ' use values from the default button for all other instance variables
        Xloc = sq.Left
        Yloc = sq.Top
        name = sq.Text
        bcolor = sq.BackColor
        fcolor = sq.ForeColor
    End Sub

    ' constructor using just button, side length and text
    Public Sub New(ByRef sq As System.Windows.Forms.Button, ByVal len As Integer, ByVal nam As String)
        sqDisplay = sq
        side = len
        name = nam
        ' use values from the default button for all other instance variables
        Xloc = sq.Left
        Yloc = sq.Top
        bcolor = sq.BackColor
        fcolor = sq.ForeColor
    End Sub

    ' constructor using just button, side length, location and text
    Public Sub New(ByRef sq As System.Windows.Forms.Button, ByVal len As Integer, ByVal x As Integer, ByVal y As Integer, ByVal nam As String)
        sqDisplay = sq
        side = len
        Xloc = x
        Yloc = y
        name = nam
        ' use values from the default button for all other instance variables
        bcolor = sq.BackColor
        fcolor = sq.ForeColor
    End Sub

    ' constructor passed values for all instance variables
    Public Sub New(ByRef sq As System.Windows.Forms.Button, ByVal len As Integer, ByVal x As Integer, ByVal y As Integer, ByVal nam As String, ByVal back As Color, ByVal fore As Color)
        sqDisplay = sq
        side = len
        Xloc = x
        Yloc = y
        name = nam
        bcolor = back
        fcolor = fore
    End Sub

    '''''''''''''''''''''''''''''''''''''''''''''''''''''''
    ' some useful functions
    '''''''''''''''''''''''''''''''''''''''''''''''''''''''

    ' calculate area of the square
    Public Function calcArea() As Integer
        Return side * side
    End Function

    ' calculate perimeter of the square
    Public Function calcPerim() As Integer
        Return side * 4
    End Function

    ' move the square up by given amount of space - but make sure it doesn't go out of sight
    Public Sub moveUp(ByVal amt As Double)
        Yloc = Yloc - (amt * adjustAmount)
        If (Yloc < 0) Then
            Yloc = 0
        End If
        ' adjust display to reflect changed position
        adjustSquare()
    End Sub

    ' move the square down by given amount of space 
    Public Sub moveDown(ByVal amt As Double)
        Yloc = Yloc + (amt * adjustAmount)
        ' square doesn't know how big window can be - so will let it just go off
        ' adjust display to reflect changed position
        adjustSquare()
    End Sub

    ' move the square left by given amount of space - but make sure it doesn't go out of sight
    Public Sub moveLeft(ByVal amt As Double)
        Xloc = Xloc - (amt * adjustAmount)
        ' make sure don't go off left edge
        If Xloc < 0 Then
            Xloc = 0
        End If
        ' adjust display to reflect changed position
        adjustSquare()
    End Sub

    ' move the square right by given amount of space 
    Public Sub moveRight(ByVal amt As Double)
        Xloc = Xloc + (amt * adjustAmount)
        ' square doesn't know how big window can be - so will let it just go off
        ' adjust display to reflect changed position
        adjustSquare()
    End Sub

    ' adjust display so that it reflects instance variables
    Public Sub adjustSquare()
        sqDisplay.Height = side
        sqDisplay.Width = side
        sqDisplay.Top = Yloc
        sqDisplay.Left = Xloc
        sqDisplay.BackColor = bcolor
        sqDisplay.ForeColor = fcolor
        sqDisplay.Text = name
    End Sub
End Class