Tidy up, make main a cmd/

cmd/main.go

@@ -0,0 +1,79 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+
+	"code.ppl.town/justin/qr_labels/qr_labels"
+)
+
+var flagLabel string
+var flagQRCode string
+var flagQRSize float64
+var flagRows, flagCols uint
+var flagFontSize float64
+var flagFont string
+var flagFontStyle string
+var flagBorders bool = true
+var flagFilename string
+var flagCodeIsLabel bool
+
+func main() {
+
+	flag.StringVar(&flagLabel, "label", "", "label (printed above QR code)")
+	flag.StringVar(&flagQRCode, "code", "", "string to turn into a QR code (URL, text etc)")
+	flag.Float64Var(&flagQRSize, "size", 50.0, "size of the QR code")
+
+	flag.UintVar(&flagRows, "rows", 4, "number of rows on the page")
+	flag.UintVar(&flagCols, "cols", 3, "number of columns on the page")
+	flag.StringVar(&flagFont, "font", "Helvetica", "name of the font")
+	flag.Float64Var(&flagFontSize, "font-size", 24.0, "font-size, in pts")
+	flag.StringVar(&flagFontStyle, "font-style", "", "font style, combine 'B', 'U', 'S', 'I' characters")
+	flag.BoolVar(&flagBorders, "borders", false, "print borders between labels")
+	flag.StringVar(&flagFilename, "output", "", "filename to write the PDF")
+
+	flag.BoolVar(&flagCodeIsLabel, "code-is-label", false, "use the -code as the -label")
+
+	flag.Parse()
+
+	if flagFilename == "" {
+		fmt.Println("you need to supply an -output filename")
+		os.Exit(1)
+	}
+
+	if flagQRCode == "" {
+		fmt.Println("you need to supply a QR -code string")
+		os.Exit(1)
+	}
+
+	if flagCodeIsLabel && flagLabel != "" {
+		fmt.Println("you cannot use both -code-is-label and -label")
+		os.Exit(1)
+	}
+
+	if flagCodeIsLabel {
+		flagLabel = flagQRCode
+	}
+
+	f, err := os.Create(flagFilename)
+	if err != nil {
+		fmt.Printf("failed to create output file: %s\n", err.Error())
+		os.Exit(1)
+	}
+
+	err = qr_labels.GeneratePage(f,
+		flagQRCode,
+		flagLabel,
+		qr_labels.WithQRSize(flagQRSize),
+		qr_labels.WithFont(flagFont, flagFontSize, flagFontStyle),
+		qr_labels.WithBorders(flagBorders),
+		qr_labels.WithGrid(int(flagRows), int(flagCols)),
+	)
+
+	if err != nil {
+		fmt.Printf("could not generate pdf: %s\n", err.Error())
+		os.Exit(1)
+	}
+
+}

main.go

@@ -1,38 +0,0 @@
-package main
-
-import (
-	"log/slog"
-	"os"
-
-	"code.ppl.town/justin/qr_labels/qr_labels"
-)
-
-func main() {
-	f, _ := os.Create("hello.pdf")
-	err := qr_labels.GeneratePage(f,
-		`https://signal.me/#eu/tardisx.81`,
-		"Wow Nic is cool :-)",
-		qr_labels.WithQRSize(55),
-		// qr_labels.WithFont("Helvetica", 16, ""),
-		// qr_labels.WithBorders(false),
-		// qr_labels.WithGrid(4, 3),
-	)
-	// err := qr_labels.GeneratePage(f, qr_labels.PageOptions{
-	// 	// qrURL:   "geo:-34.9285,138.6007",
-	// 	qrURL:   `https://signal.me/#eu/tardisx.81`,
-	// 	qrLabel: "Á[Hjqy]|",
-	// 	qrSize:  54,
-
-	// 	font:      "Helvetica",
-	// 	fontStyle: "B",
-	// 	fontSize:  34.0,
-	// 	rows:      4,
-	// 	cols:      3,
-	// 	borders:   true,
-	// })
-	if err != nil {
-		slog.Error("could not generate pdf", "error", err)
-		os.Exit(1)
-	}
-
-}

qr_labels/qr_labels.go

@@ -3,7 +3,6 @@ package qr_labels
 import (
 	"fmt"
 	"io"
-	"log/slog"
 
 	"codeberg.org/go-pdf/fpdf"
 	"github.com/yeqown/go-qrcode/v2"
@@ -117,20 +116,15 @@ func GeneratePage(w io.Writer, url, label string, opts ...Option) error {
 	cellWidth := po.qrSize
 
 	if cellHeight > rowHeight-requiredCellPadding {
-		slog.Warn("qr is too big for row", "cell_height", cellHeight, "row_height", rowHeight)
-		return fmt.Errorf("qr is too big for row size")
+		return fmt.Errorf("qr is too big for row size - reduce number of rows or QR size")
 	}
 
-	//	slog.Info("check width", "cell_width", cellWidth, "col_width", colWidth)
-
 	if cellWidth > colWidth-requiredCellPadding {
-		slog.Warn("qr is too big for column", "cell_width", cellWidth, "col_width", colWidth)
-		return fmt.Errorf("qr is too big for col size")
+		return fmt.Errorf("QR is too big for col size - reduce number of columns or QR size")
 	}
 
 	if textWidth > colWidth {
-		slog.Warn("text probably too wide")
-		return fmt.Errorf("text is too wide for col size")
+		return fmt.Errorf("text is too wide for col size - reduce label length or reduce font size")
 	}
 
 	for rowIdx := range po.rows {