Example of Claudio Felber's generalized font loaing implementation

2 files changed, 38 insertions, 4 deletions

diff --git a/fpdf.go b/fpdf.go
index f4d7bdc..08f0fb3 100644
--- a/fpdf.go
+++ b/fpdf.go
@@ -313,10 +313,13 @@ func (f *Fpdf) SetFontLocation(fontDirStr string) {
 	f.fontpath = fontDirStr
 }
 
-// SetFontLoader sets a loader used to load font files (.json and .z) from
-// arbitrary locations. If a font loader has been specified, Fpdf first tries
-// to load files using the font loader. If the loading files Fpdf tries to
-// load the font from the configured fonts directory (see SetFontLocation).
+// SetFontLoader sets a loader used to read font files (.json and .z) from an
+// arbitrary source. If a font loader has been specified, it is used to load
+// the named font resources when AddFont() is called. If this operation fails,
+// an attempt is made to load the resources from the configured font directory
+// (see SetFontLocation()).
+//
+// See tutorial 29 for an example of this method.
 func (f *Fpdf) SetFontLoader(loader FontLoader) {
 	f.fontLoader = loader
 }
diff --git a/fpdf_test.go b/fpdf_test.go
index bb69569..3439f91 100644
--- a/fpdf_test.go
+++ b/fpdf_test.go
@@ -18,8 +18,10 @@ package gofpdf_test
 
 import (
 	"bufio"
+	"bytes"
 	"fmt"
 	"github.com/jung-kurt/gofpdf"
+	"io"
 	"io/ioutil"
 	"math"
 	"net/http"
@@ -101,6 +103,19 @@ func textFile(fileStr string) string {
 	return filepath.Join(cnTextDir, fileStr)
 }
 
+type fontResourceType struct {
+}
+
+func (f fontResourceType) Open(name string) (rdr io.Reader, err error) {
+	var buf []byte
+	buf, err = ioutil.ReadFile(fontFile(name))
+	if err == nil {
+		rdr = bytes.NewReader(buf)
+		fmt.Printf("Generalized font loader reading %s\n", name)
+	}
+	return
+}
+
 // Convert 'ABCDEFG' to, for example, 'A,BCD,EFG'
 func strDelimit(str string, sepstr string, sepcount int) string {
 	pos := len(str) - sepcount
@@ -1427,3 +1442,19 @@ func ExampleFpdf_tutorial28() {
 	// Successfully generated pdf/tutorial28.pdf
 
 }
+
+// Non-standard font using generalized font loader
+func ExampleFpdf_tutorial29() {
+	var fr fontResourceType
+	pdf := gofpdf.New("P", "mm", "A4", cnFontDir)
+	pdf.SetFontLoader(fr)
+	pdf.AddFont("Calligrapher", "", "calligra.json")
+	pdf.AddPage()
+	pdf.SetFont("Calligrapher", "", 35)
+	pdf.Cell(0, 10, "Enjoy new fonts with FPDF!")
+	pdf.OutputAndClose(docWriter(pdf, 29))
+	// Output:
+	// Generalized font loader reading calligra.json
+	// Generalized font loader reading calligra.z
+	// Successfully generated pdf/tutorial29.pdf
+}