Getting position of top and bottom of text

I have an add-in which inserts images between lines of text. To make space for the images I increase the line spacing in the text. The problem is I haven't found a way which can consistently and accurately work out where the top and bottom of the text ends up after changing the line spacing.

For example, if you increase the space using SpaceWithin (or manually), space is actually added above and below the lines of text (more above than below), except for the last line where space is only added above. Any BoundTop and BoundHeight values that I can find refer to the line and not to the characters within it.

How can I find the top and height measurements for characters within the lines?

This demonstrates the issue:

Code:

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Public Sub PositionTest()
  Dim shTextBox As Shape
  Dim i As Long
 
  With ActivePresentation.Slides(1)
    Set shTextBox = .Shapes.AddTextbox(Orientation:=msoTextOrientationHorizontal, _
                        Left:=300, Top:=100, Width:=300, Height:=100)
  End With
   
  With shTextBox.TextFrame.TextRange
      .Text = "Line number: 1" & vbCrLf & "Line number: 2" & vbCrLf & "Line number: 3"
  End With
 
  With shTextBox.TextFrame.TextRange
  For i = 1 To .Lines.Count
    With .Lines(i, 1)
      Debug.Print .Text & " Top: " & .BoundTop & " Height: " & .BoundHeight
    End With
  Next i
  End With
     
  Debug.Print "New spacing"
  With shTextBox.TextFrame.TextRange
    .Lines.ParagraphFormat.LineRuleWithin = msoTrue
    .Lines.ParagraphFormat.SpaceWithin = 3
  End With
   
  With shTextBox.TextFrame.TextRange
  For i = 1 To .Lines.Count
    With .Lines(i, 1)
      Debug.Print .Text & " Top: " & .BoundTop & " Height: " & .BoundHeight
    End With
  Next i
  End With

End Sub

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And this is the output that that produces:

Code:

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Line number: 1
 Top: 103.6 Height: 21.6
Line number: 2
 Top: 125.2 Height: 21.6
Line number: 3 Top: 146.8 Height: 21.6
New spacing
Line number: 1
 Top: 103.6 Height: 64.8
Line number: 2
 Top: 168.4 Height: 64.8
Line number: 3 Top: 233.2 Height: 53.35

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If I try to refer to any individual characters - e.g. .Characters(n).BoundTop - the output is the same as for the line in which that character is in.

The solution I have come up with involves creating a temporary test textbox for each line in the input textbox, and then inspecting the heights of this new textbox before and after applying the paragraph formatting used in the input textbox:

Code:

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Option Explicit

' lngLine - the index of the line to compute TextTop and TextHeight for.
' shTextBox - the text box containing the line.
' dblTextTop - returned value for the top of the text.
' dblTextHeight - returned value for the height of the text.
Public Sub TextPosition(ByVal lngLine As Long, _
                        ByRef shTextBox As Shape, _
                        ByRef dblTextTop As Double, _
                        ByRef dblTextHeight As Double)

  Dim shTestTextBox As Shape
  Dim dblMaxCharHeight As Double
 
  Dim trLine As TextRange
  Set trLine = shTextBox.TextFrame.TextRange.Lines(lngLine)
 
  ' The height of the derived textbox before manipulation:
  Dim dblBaseBoundHeight As Double

  dblMaxCharHeight = MaxCharHeight(trLine)
 
  Dim lngSlideIndex As Long
  lngSlideIndex = shTextBox.Parent.SlideIndex
 
  With shTextBox.Parent.Parent.Slides(lngSlideIndex)
 
    ' Create a one line high text box from the original text box.
    ' The height of this before and after paragraph formatting is used to
    ' compute where the text will be in relation to the bounding box of the
    ' line.
    Set shTestTextBox = .Shapes.AddTextbox(Orientation:=msoTextOrientationHorizontal, _
                                          Left:=shTextBox.Left, _
                                          Top:=trLine.BoundTop, _
                                          Width:=shTextBox.Width, _
                                          Height:=trLine.BoundHeight)
  End With
                                       
  shTestTextBox.TextFrame.WordWrap = msoFalse
   
  With shTestTextBox.TextFrame.TextRange
     
    ' Any returns at the end of lines (i.e. new paragraphs) must be removed to
    ' ensure that the test textbox contains only one line.
    .Text = Replace(trLine.Text, Chr(13), "")
    .Characters(1, .Characters.Count).Font.Size = dblMaxCharHeight
     
    ' Record the bound height of the text box before copying over the
    ' paragraph formatting.
    dblBaseBoundHeight = .BoundHeight
     
    .ParagraphFormat.LineRuleAfter = trLine.ParagraphFormat.LineRuleAfter
    .ParagraphFormat.SpaceAfter = trLine.ParagraphFormat.SpaceAfter
     
    .ParagraphFormat.LineRuleBefore = trLine.ParagraphFormat.LineRuleBefore
    .ParagraphFormat.SpaceBefore = trLine.ParagraphFormat.SpaceBefore
     
    .ParagraphFormat.LineRuleWithin = trLine.ParagraphFormat.LineRuleWithin
    .ParagraphFormat.SpaceWithin = trLine.ParagraphFormat.SpaceWithin
     
  End With
   
  dblTextHeight = dblBaseBoundHeight
  If lngLine = shTextBox.TextFrame.TextRange.Lines.Count Then
    ' Space is never added after the last line in a textbox, so the top of the
    ' text is the bottom of the original bound box less the bound height of
    ' the (one line high) test textbox.
    dblTextTop = (trLine.BoundTop + trLine.BoundHeight) - _
                dblBaseBoundHeight
  Else
    ' For the other lines, also allow for the extra space that is inserted
    ' below a line with paragraph formatting.
    dblTextTop = (trLine.BoundTop + trLine.BoundHeight) - _
                dblBaseBoundHeight - _
                (trLine.BoundHeight - shTestTextBox.TextFrame.TextRange.BoundHeight)
  End If
 
  shTestTextBox.Delete
 
End Sub

Public Function MaxCharHeight(ByRef trLine As TextRange) As Double

  Dim i As Long
  Dim dblMaxHeight As Double
 
  For i = 1 To trLine.Characters.Count
    If trLine.Characters(i, 1).Font.Size > dblMaxHeight Then
      dblMaxHeight = trLine.Characters(i, 1).Font.Size
    End If
  Next i

  MaxCharHeight = dblMaxHeight

End Function

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I've posted an updated version of this question on StackOverflow - https://stackoverflow.com/questions/...ted-paragraphs