' and push the rest of the
' blocks up one column.
For row As Integer = matrix.GetLength(0) – 1 To 1 Step -1
matrix(row, column) = matrix(row – 1, column)
Next
matrix(0, column) = newBlock
Next
End Sub
'''
''' Draw the grid of blocks
'''
'''
'''
'''
Public Sub Draw(ByVal graphics As Graphics, _
ByVal backColor As Color)
graphics.Clear(backColor)
Dim row As Integer
Dim column As Integer
Dim theBlock As Block
For row = 0 To matrix.GetLength(0) – 1
For column = 0 To matrix.GetLength(1) – 1
theBlock = matrix(row, column)
If Not theBlock Is Nothing Then
Dim pointA As New Point( _
column * Block.BlockSize, _
row * Block.BlockSize)
matrix(row, column).Draw(graphics, pointA)
End If
Next
Next
End Sub
'''
''' This method responds to a click event in the UI.
'''
'''
'''
'''
Public Function Click(ByVal point As Point) As Integer
' Figure out row and column.
Dim total As Integer
Dim transPt As Point = PointTranslator.TranslateToTL(point)
Dim selectedRow As Integer = transPt.Y \ Block.BlockSize
Dim selectedColumn As Integer = transPt.X \ Block.BlockSize
Dim selectedBlock As Block = matrix(selectedRow, _
selectedColumn)
If Not selectedBlock Is Nothing Then
selectedBlock.MarkedForDeletion = True
' Determine if any of the neighboring blocks are
' the same color.
FindSameColorNeighbors(selectedRow, selectedColumn)
' Determine how many blocks would be eliminated.
total = Me.CalculateScore
If total > 1 Then
Me.CollapseBlocks
Else
Me.ClearMarkedForDeletion
End If
End If
Return total
End Function
Private Sub ClearMarkedForDeletion
Dim row As Integer
Dim column As Integer
For column = matrix.GetLength(1) – 1 To 0 Step -1
' If column is completely empty, then move everthing
' down one.
For row = 0 To matrix.GetLength(0) – 1
If Not matrix(row, column) Is Nothing Then
matrix(row, column).MarkedForDeletion = False
End If
Next
Next
End Sub
'''
''' Find out how many blocks will be eliminated.
'''
'''
'''
Private Function CalculateScore As Integer
Dim row As Integer
Dim column As Integer
Dim total As Integer = 0
For column = matrix.GetLength(1) – 1 To 0 Step -1
' If column is completely empty, then move everthing
' down one.
For row = 0 To matrix.GetLength(0) – 1
If Not matrix(row, column) Is Nothing Then
If matrix(row, column).MarkedForDeletion Then
total += 1
End If
End If
Next
Next
Return total
End Function
'''
''' After the blocks are removed from the columns, there may be
''' columns that are empty. Move columns from right to left to
''' fill in the empty columns.
'''
'''
Public Sub CollapseColumns
Dim row As Integer
Dim column As Integer
For column = matrix.GetLength(1) – 1 To 0 Step -1
' If column is completely empty, then all the columns
' over one.
Dim noBlocks As Boolean = True
For row = 0 To matrix.GetLength(0) – 1
If Not matrix(row, column) Is Nothing Then
noBlocks = False
End If
Next
If noBlocks Then
Dim newcol As Integer
For newcol = column To matrix.GetLength(1) – 2
For row = 0 To matrix.GetLength(0) – 1
matrix(row, newcol) = matrix(row, newcol + 1)
Next
Next
newcol = matrix.GetLength(1) – 1
For row = 0 To matrix.GetLength(0) – 1
matrix(row, newcol) = Nothing
Next
End If
Next
End Sub
'''
''' Remove all the blocks from the grid.
'''
'''
Public Sub CollapseBlocks
Dim theBlock As Block
Dim column As Integer
Dim row As Integer
Dim aRow As Integer
' First remove the blocks from each column.
For column = 0 To matrix.GetLength(1) – 1
For row = matrix.GetLength(0) – 1 To 0 Step -1
theBlock = matrix(row, column)
If (Not theBlock Is Nothing) Then
If theBlock.MarkedForDeletion Then
For aRow = row To matrix.GetLength(0) – 2
matrix(aRow, column) = _
matrix(aRow + 1, column)
Next
matrix(matrix.GetLength(0) – 1, _
column) = Nothing
End If
End If
Next
Next
' Reset the MarkedForDeletion flags.
For row = 0 To matrix.GetLength(0) – 1
For column = 0 To matrix.GetLength(1) – 1
theBlock = matrix(row, column)
If Not theBlock Is Nothing Then
theBlock.MarkedForDeletion = False
End If
Next
Next
' Remove any columns that are now empty.
CollapseColumns
End Sub
'''
''' Provides access into the grid.
'''
'''
'''
'''
'''
Default Public Property Item(ByVal row As Integer, _
ByVal column As Integer) As Block
Get
Return matrix(row, column)
End Get
Set(ByVal Value As Block)
matrix(row, column) = Value
End Set
End Property
Private blocksToExamine As ArrayList
'''
''' Set MarkedForDeletion to True for each neighboring block
''' of the same color.
'''
'''
'''
'''
Private Sub FindSameColorNeighbors(ByVal row As Integer, _
ByVal column As Integer)
Dim color As Color = matrix(row, column).Color
blocksToExamine = New ArrayList
blocksToExamine.Add(New Point(row, column))
matrix(row, column).MarkedForDeletion = True
' Each time you find a neighbor, mark it for deletion, and
' add it to the list of blocks to look for neighbors.
' After you
' examine it, remove it from the list. Keep doing this
' until there are no more blocks to look at.
While blocksToExamine.Count > 0
FindNeighbors
End While
End Sub
'''
''' Look to the blocks on each side.
'''
'''
Private Sub FindNeighbors
' Take the first block out of the arraylist and examine it.