Merge branch 'aloidev-LastPageIndicator'

3 files changed, 92 insertions, 6 deletions

diff --git a/def.go b/def.go
index c80eb37..552415f 100644
--- a/def.go
+++ b/def.go
@@ -221,6 +221,7 @@ type Fpdf struct {
 	headerFnc        func()                    // function provided by app and called to write header
 	inFooter         bool                      // flag set when processing footer
 	footerFnc        func()                    // function provided by app and called to write footer
+	footerFncLpi     func(bool)                // function provided by app and called to write footer with last page flag
 	zoomMode         string                    // zoom display mode
 	layoutMode       string                    // layout display mode
 	title            string                    // title
diff --git a/fpdf.go b/fpdf.go
index 9587e55..a8656dd 100644
--- a/fpdf.go
+++ b/fpdf.go
@@ -363,11 +363,27 @@ func (f *Fpdf) SetHeaderFunc(fnc func()) {
 // Close() and should not be called directly by the application. The
 // implementation in Fpdf is empty, so you have to provide an appropriate
 // function if you want page footers. fnc will typically be a closure that has
-// access to the Fpdf instance and other document generation variables.
+// access to the Fpdf instance and other document generation variables. See
+// SetFooterFuncLpi for a similar function that passes a last page indicator.
 //
 // This method is demonstrated in the example for AddPage().
 func (f *Fpdf) SetFooterFunc(fnc func()) {
 	f.footerFnc = fnc
+	f.footerFncLpi = nil
+}
+
+// SetFooterFuncLpi sets the function that lets the application render the page
+// footer. The specified function is automatically called by AddPage() and
+// Close() and should not be called directly by the application. It is passed a
+// boolean that is true if the last page of the document is being rendered. The
+// implementation in Fpdf is empty, so you have to provide an appropriate
+// function if you want page footers. fnc will typically be a closure that has
+// access to the Fpdf instance and other document generation variables.
+//
+// This method is demonstrated in the example for AddPage().
+func (f *Fpdf) SetFooterFuncLpi(fnc func(lastPage bool)) {
+	f.footerFncLpi = fnc
+	f.footerFnc = nil
 }
 
 // SetTopMargin defines the top margin. The method can be called before
@@ -538,11 +554,14 @@ func (f *Fpdf) Close() {
 		}
 	}
 	// Page footer
+	f.inFooter = true
 	if f.footerFnc != nil {
-		f.inFooter = true
 		f.footerFnc()
-		f.inFooter = false
+	} else if f.footerFncLpi != nil {
+		f.footerFncLpi(true)
 	}
+	f.inFooter = false
+
 	// Close page
 	f.endpage()
 	// Close document
@@ -592,12 +611,15 @@ func (f *Fpdf) AddPageFormat(orientationStr string, size SizeType) {
 	tc := f.color.text
 	cf := f.colorFlag
 	if f.page > 0 {
-		// Page footer
+		f.inFooter = true
+		// Page footer avoid double call on footer.
 		if f.footerFnc != nil {
-			f.inFooter = true
 			f.footerFnc()
-			f.inFooter = false
+
+		} else if f.footerFncLpi != nil {
+			f.footerFncLpi(false) // not last page.
 		}
+		f.inFooter = false
 		// Close page
 		f.endpage()
 	}
diff --git a/fpdf_test.go b/fpdf_test.go
index 7da45aa..9b45486 100644
--- a/fpdf_test.go
+++ b/fpdf_test.go
@@ -75,7 +75,70 @@ func TestIssue0116(t *testing.T) {
 	if pdf.Error() == nil {
 		t.Fatalf("expecting error when rendering text without having set font")
 	}
+}
+
+// Test to make sure the footer is not call twice and SetFooterFuncLpi can work
+// without SetFooterFunc.
+func TestFooterFuncLpi(t *testing.T) {
+	pdf := gofpdf.New("P", "mm", "A4", "")
+	var (
+		oldFooterFnc  = "oldFooterFnc"
+		bothPages     = "bothPages"
+		firstPageOnly = "firstPageOnly"
+		lastPageOnly  = "lastPageOnly"
+	)
 
+	// This set just for testing, only set SetFooterFuncLpi.
+	pdf.SetFooterFunc(func() {
+		pdf.SetY(-15)
+		pdf.SetFont("Arial", "I", 8)
+		pdf.CellFormat(0, 10, oldFooterFnc,
+			"", 0, "C", false, 0, "")
+	})
+	pdf.SetFooterFuncLpi(func(lastPage bool) {
+		pdf.SetY(-15)
+		pdf.SetFont("Arial", "I", 8)
+		pdf.CellFormat(0, 10, bothPages, "", 0, "L", false, 0, "")
+		if !lastPage {
+			pdf.CellFormat(0, 10, firstPageOnly, "", 0, "C", false, 0, "")
+		} else {
+			pdf.CellFormat(0, 10, lastPageOnly, "", 0, "C", false, 0, "")
+		}
+	})
+	pdf.AddPage()
+	pdf.SetFont("Arial", "B", 16)
+	for j := 1; j <= 40; j++ {
+		pdf.CellFormat(0, 10, fmt.Sprintf("Printing line number %d", j),
+			"", 1, "", false, 0, "")
+	}
+	if pdf.Error() != nil {
+		t.Fatalf("not expecting error when rendering text")
+	}
+	w := &bytes.Buffer{}
+	if err := pdf.Output(w); err != nil {
+		t.Errorf("unexpected err: %s", err)
+	}
+	b := w.Bytes()
+	if bytes.Contains(b, []byte(oldFooterFnc)) {
+		t.Errorf("not expecting %s render on pdf when FooterFncLpi is set", oldFooterFnc)
+	}
+	got := bytes.Count(b, []byte("bothPages"))
+	if got != 2 {
+		t.Errorf("footer %s should render on two page got:%d", bothPages, got)
+	}
+	got = bytes.Count(b, []byte(firstPageOnly))
+	if got != 1 {
+		t.Errorf("footer %s should render only on first page got: %d", firstPageOnly, got)
+	}
+	got = bytes.Count(b, []byte(lastPageOnly))
+	if got != 1 {
+		t.Errorf("footer %s should render only on first page got: %d", lastPageOnly, got)
+	}
+	f := bytes.Index(b, []byte(firstPageOnly))
+	l := bytes.Index(b, []byte(lastPageOnly))
+	if f > l {
+		t.Errorf("index %d (%s) should less than index %d (%s)", f, firstPageOnly, l, lastPageOnly)
+	}
 }
 
 type fontResourceType struct {