package main import ( "errors" "html/template" "image" "image/color" "image/draw" "image/png" "log" "net/http" "os" "strconv" "github.com/boombuler/barcode" "github.com/boombuler/barcode/qr" "janouch.name/sklad/bdf" "janouch.name/sklad/ql" ) // scaler is a scaling image.Image wrapper. type scaler struct { image image.Image scale int } // ColorModel implements image.Image. func (s *scaler) ColorModel() color.Model { return s.image.ColorModel() } // Bounds implements image.Image. func (s *scaler) Bounds() image.Rectangle { r := s.image.Bounds() return image.Rect(r.Min.X*s.scale, r.Min.Y*s.scale, r.Max.X*s.scale, r.Max.Y*s.scale) } // At implements image.Image. func (s *scaler) At(x, y int) color.Color { if x < 0 { x = x - s.scale + 1 } if y < 0 { y = y - s.scale + 1 } return s.image.At(x/s.scale, y/s.scale) } // leftRotate is a 90 degree rotating image.Image wrapper. type leftRotate struct { image image.Image } // ColorModel implements image.Image. func (lr *leftRotate) ColorModel() color.Model { return lr.image.ColorModel() } // Bounds implements image.Image. func (lr *leftRotate) Bounds() image.Rectangle { r := lr.image.Bounds() // Min is inclusive, Max is exclusive. return image.Rect(r.Min.Y, -(r.Max.X - 1), r.Max.Y, -(r.Min.X - 1)) } // At implements image.Image. func (lr *leftRotate) At(x, y int) color.Color { return lr.image.At(-y, x) } // ----------------------------------------------------------------------------- var font *bdf.Font func genLabelForHeight(text string, height, scale int) image.Image { // Create a scaled bitmap of the text label. textRect, _ := font.BoundString(text) textImg := image.NewRGBA(textRect) draw.Draw(textImg, textRect, image.White, image.ZP, draw.Src) font.DrawString(textImg, image.ZP, text) scaledTextImg := scaler{image: textImg, scale: scale} scaledTextRect := scaledTextImg.Bounds() remains := height - scaledTextRect.Dy() - 20 width := scaledTextRect.Dx() if remains > width { width = remains } // Create a scaled bitmap of the QR code. qrImg, _ := qr.Encode(text, qr.H, qr.Auto) qrImg, _ = barcode.Scale(qrImg, remains, remains) qrRect := qrImg.Bounds() // Combine. combinedRect := image.Rect(0, 0, width, height) combinedImg := image.NewRGBA(combinedRect) draw.Draw(combinedImg, combinedRect, image.White, image.ZP, draw.Src) draw.Draw(combinedImg, combinedRect.Add(image.Point{X: (width - qrRect.Dx()) / 2, Y: 0}), qrImg, image.ZP, draw.Src) target := image.Rect( (width-scaledTextRect.Dx())/2, qrRect.Dy()+20, combinedRect.Max.X, combinedRect.Max.Y) draw.Draw(combinedImg, target, &scaledTextImg, scaledTextRect.Min, draw.Src) return combinedImg } var tmpl = template.Must(template.New("form").Parse(`

PT-CBP label printing tool

Printer: {{ .Printer.Manufacturer }} {{ .Printer.Model }}

Tape: {{ if .Printer.LastStatus }} {{ .Printer.LastStatus.MediaWidthMM }} mm × {{ .Printer.LastStatus.MediaLengthMM }} mm {{ if .MediaInfo }} (offset: {{ .MediaInfo.SideMarginPins }} pt, print area: {{ .MediaInfo.PrintAreaPins }} pt) {{ else }} (unknown media) {{ end }} {{ if .Printer.LastStatus.Errors }} {{ range .Printer.LastStatus.Errors }}

Error: {{ . }} {{ end }} {{ end }} {{ end }} {{ if .InitErr }} {{ .InitErr }} {{ end }} {{ else }}

Error: {{ .PrinterErr }} {{ end }}

`)) func getPrinter() (*ql.Printer, error) { printer, err := ql.Open() if err != nil { return nil, err } if printer == nil { return nil, errors.New("no suitable printer found") } return printer, nil } func getStatus(printer *ql.Printer) error { if err := printer.Initialize(); err != nil { return err } if err := printer.UpdateStatus(); err != nil { return err } log.Printf("status\n%s", printer.LastStatus) return nil } func handle(w http.ResponseWriter, r *http.Request) { if err := r.ParseForm(); err != nil { http.Error(w, err.Error(), 500) return } var initErr error printer, printerErr := getPrinter() if printerErr == nil { defer printer.Close() initErr = getStatus(printer) } var mediaInfo *ql.MediaInfo if printer.LastStatus != nil { mediaInfo = ql.GetMediaInfo(printer.LastStatus.MediaWidthMM(), printer.LastStatus.MediaLengthMM()) } var params = struct { Printer *ql.Printer PrinterErr error InitErr error MediaInfo *ql.MediaInfo Text string Scale int }{ Printer: printer, PrinterErr: printerErr, InitErr: initErr, MediaInfo: mediaInfo, Text: r.FormValue("text"), } var err error params.Scale, err = strconv.Atoi(r.FormValue("scale")) if err != nil { params.Scale = 3 } var label image.Image if mediaInfo != nil { label = &leftRotate{image: genLabelForHeight( params.Text, mediaInfo.PrintAreaPins, params.Scale)} if r.FormValue("print") != "" { if err := printer.Print(label); err != nil { log.Println("print error:", err) } } } if _, ok := r.Form["img"]; !ok { w.Header().Set("Content-Type", "text/html") tmpl.Execute(w, ¶ms) return } if mediaInfo == nil { http.Error(w, "unknown media", 500) return } w.Header().Set("Content-Type", "image/png") if err := png.Encode(w, label); err != nil { http.Error(w, err.Error(), 500) return } } func main() { var err error fi, err := os.Open("../../ucs-fonts-75dpi100dpi/100dpi/luBS24.bdf") if err != nil { log.Fatalln(err) } font, err = bdf.NewFromBDF(fi) if err != nil { log.Fatalln(err) } if err := fi.Close(); err != nil { log.Fatalln(err) } log.Println("Starting server") http.HandleFunc("/", handle) log.Fatal(http.ListenAndServe(":8080", nil)) }