implement vertical baseline alignment for text

1 files changed, 24 insertions, 10 deletions

diff --git a/fpdf.go b/fpdf.go
index 6eae426..fd0c91f 100644
--- a/fpdf.go
+++ b/fpdf.go
@@ -1376,6 +1376,16 @@ func (f *Fpdf) AddFont(familyStr, styleStr, fileStr string) {
 	f.AddFontFromReader(familyStr, styleStr, file)
 }
 
+// getFontKey is used by AddFontFromReader and GetFontDesc
+func getFontKey(familyStr, styleStr string) string {
+	familyStr = strings.ToLower(familyStr)
+	styleStr = strings.ToUpper(styleStr)
+	if styleStr == "IB" {
+		styleStr = "BI"
+	}
+	return familyStr + styleStr
+}
+
 // AddFontFromReader imports a TrueType, OpenType or Type1 font and makes it
 // available using a reader that satisifies the io.Reader interface. See
 // AddFont for details about familyStr and styleStr.
@@ -1385,12 +1395,7 @@ func (f *Fpdf) AddFontFromReader(familyStr, styleStr string, r io.Reader) {
 	}
 	// dbg("Adding family [%s], style [%s]", familyStr, styleStr)
 	var ok bool
-	familyStr = strings.ToLower(familyStr)
-	styleStr = strings.ToUpper(styleStr)
-	if styleStr == "IB" {
-		styleStr = "BI"
-	}
-	fontkey := familyStr + styleStr
+	fontkey := getFontKey(familyStr, styleStr)
 	_, ok = f.fonts[fontkey]
 	if ok {
 		return
@@ -1434,8 +1439,7 @@ func (f *Fpdf) AddFontFromReader(familyStr, styleStr string, r io.Reader) {
 // documentation about the font descriptor.
 // See AddFont for details about familyStr and styleStr.
 func (f *Fpdf) GetFontDesc(familyStr, styleStr string) FontDescType {
-	fontkey := familyStr + styleStr // see AddFontFromReader
-	return f.fonts[fontkey].Desc
+	return f.fonts[getFontKey(familyStr, styleStr)].Desc
 }
 
 // SetFont sets the font used to print character strings. It is mandatory to
@@ -1686,8 +1690,8 @@ func (f *Fpdf) SetAcceptPageBreakFunc(fnc func() bool) {
 // alignStr specifies how the text is to be positionined within the cell.
 // Horizontal alignment is controlled by including "L", "C" or "R" (left,
 // center, right) in alignStr. Vertical alignment is controlled by including
-// "T", "M" or "B" (top, middle, bottom) in alignStr. The default alignment is
-// left middle.
+// "T", "M", "B" or "A" (top, middle, bottom, baseline) in alignStr. The default
+// alignment is left middle.
 //
 // fill is true to paint the cell background or false to leave it transparent.
 //
@@ -1778,6 +1782,16 @@ func (f *Fpdf) CellFormat(w, h float64, txtStr string, borderStr string, ln int,
 			dy = (f.fontSize - h) / 2.0
 		} else if strings.Index(alignStr, "B") != -1 {
 			dy = (h - f.fontSize) / 2.0
+		} else if strings.Index(alignStr, "A") != -1 {
+			var descent float64
+			d := f.currentFont.Desc
+			if d.Descent == 0 {
+				// not defined (standard font?), use average of 19%
+				descent = -0.19 * f.fontSize
+			} else {
+				descent = float64(d.Descent) * f.fontSize / float64(d.Ascent-d.Descent)
+			}
+			dy = (h-f.fontSize)/2.0 - descent
 		} else {
 			dy = 0
 		}