[reportlab-users] vertically centered text

[Robin Becker]

Aaron Spike wrote:

> I am able to center text horizontally with the drawCenteredString() 

> function that the api provides. I haven't been able to find any way to 

> center text vertically (or both vertically and horizontally at the same 

> time). Is there any font metric I can access to adjust the vertical 

> placement of text so that I can center it on a point?

> 

> Aaron Spike

.......
The y coordinate of a drawString type operation ends up as being the 
baseline of the text. Typically text is not vertically symmetric so is 
not visually centered. A good rule of thumb is that the part below the 
base line is 20% of the point size ie the vertical middle of the text is 
40% of the pointsize above the normal base line. However, these 
assumptions are clearly dependent on exactly which glyphs are being 
used. I know this is not a decent answer, but you can obtain the curves 
being used for a particular string using 
reportlab.graphics.charts.textlabels._text2path

def _text2Path(text, x=0, y=0, fontName='Times-Roman', fontSize=1000,
				anchor='start', truncate=1, pathReverse=0):


the returned path can then be used to obtain a bounding box ie

 >>> from reportlab.graphics.charts.textlabels import _text2Path
 >>> p=_text2Path('a min')
 >>> p.getBounds()
(34, -14, 2246, 694)
 >>> p=_text2Path('A min')
 >>> p.getBounds()
(10, 0, 2524, 694)
 >>>

so you can see that A is taller than a
-- 
Robin Becker