Conditional format cell borders based on adjacent cells

In LibreOffice Calc (, Windows), I can use Conditional Formatting to set the background of cells depending on their content:

Conditional formatting background of cells

However, I can’t seem to find a way to conditionally set borders based on adjacent cell values being equal or not to each cell’s content.

What I would like is to get a result like the following, without having to set the borders by hand:

Desired conditional formatting result

This is certainly possible, but time consuming. You would have to create 16 styles for each of the possible values. Conditional formatting in this case it seems to me inappropriate. I think that simple macro that went through to all the cells in the selected range and painted them in the right color will be easier to implement.

You can use this simple code additionally to your conditional formatting

Sub paintBrdrs
Dim oSheet As Variant
Dim oStatInd As Variant
Dim oCursor As Variant
Dim aData As Variant
Dim oCell As Variant
Dim i&, j&
	oSheet = ThisComponent.getCurrentController().getActiveSheet()
	oCursor = oSheet.createCursor()
	aData = oCursor.getDataArray()
	oStatInd = ThisComponent.getCurrentController().getFrame().createStatusIndicator()
	oStatInd.start("Please wait...", (UBound(aData)+1))
	For i = LBound(aData) To UBound(aData)
		For j = LBound(aData(0)) To UBound(aData(0))
			oCell = oSheet.getCellByPosition(j, i)
			'oCell.TopBorder = newBorder(aData, i, j, i-1, j) ' there is no need
			oCell.RightBorder = newBorder(aData, i, j, i, j+1)
			oCell.BottomBorder = newBorder(aData, i, j, i+1, j)
			'oCell.LeftBorder = newBorder(aData, i, j, i, j-1) ' there is no need
		Next j
	Next i
End Sub

Function newBorder(oData As Variant, currentY, currentX, testY, testX) As
Dim aBorder As New
  aBorder.OuterLineWidth = 0
  If (testY >= 0) And (testX >= 0) And (testY <= UBound(oData)) And (testX <= UBound(oData(0))) Then
    If (oData(currentY)(currentX)<>oData(testY)(testX)) Then aBorder.OuterLineWidth = 26
  newBorder = aBorder
End Function