Autosize. No, not the control, the text.

Originally posted to SOAPitStop, Nov 16, 2008.

It’s nice that .NET controls have an auto-size property so you don’t have to worry about overflow and all.  But what about cases where you have a fixed layout?  Well, that’s simple, you turn autosize off and fix the control to the size you need.

That’s half the story.  What about the text that’s inside it?  Now you know I’m talking to marketing people when I say that there are times you want the text to be as big as possible within that control.  But you can’t just set the font to a huge size, because sometimes you’ll have more text to display and the font size must regrettably be reduced.

To accommodate this, I made a quick method that brute-forces the correct font size in the control.  basically, stepping down the size of the font until it fits.  I know loops like this are cheap, poor programming, and I did give consideration to doing some hard math to calculate the proper font size based on the initial size, but sometimes not getting hung up on performance can be liberating.

    Private Sub ResizeText(ByVal c As Control)
        Dim currentSize As Size
        Dim currentFont As Font

        currentFont = c.Font

            currentSize = TextRenderer.MeasureText(c.Text, currentFont, _
                c.Size, TextFormatFlags.WordBreak)

            If currentSize.Width > (c.Width - c.Margin.Horizontal) _
                OrElse currentSize.Height > (c.Height - c.Margin.Vertical) Then

                currentFont = New Font(currentFont.FontFamily, _
                    CSng(currentFont.Size - 0.5), currentFont.Style, currentFont.Unit)
                Exit Do

            End If

        Loop While currentFont.Size >= 1

        c.Font = currentFont

    End Sub