sklad/label-exp/main.go

276 lines
6.1 KiB
Go

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(`
<!DOCTYPE html>
<html><body>
<h1>PT-CBP label printing tool</h1>
<table><tr>
<td valign=top>
<img border=1 src='?img&amp;scale={{.Scale}}&amp;text={{.Text}}'>
</td>
<td valign=top>
<fieldset>
{{ if .Printer }}
<p>Printer: {{ .Printer.Manufacturer }} {{ .Printer.Model }}
<p>Tape:
{{ if .Printer.LastStatus }}
{{ .Printer.LastStatus.MediaWidthMM }} mm &times;
{{ .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 }}
<p>Error: {{ . }}
{{ end }}
{{ end }}
{{ end }}
{{ if .InitErr }}
{{ .InitErr }}
{{ end }}
{{ else }}
<p>Error: {{ .PrinterErr }}
{{ end }}
</fieldset>
<form><fieldset>
<p><label for=text>Text:</label>
<input id=text name=text value='{{.Text}}'>
<label for=scale>Scale:</label>
<input id=scale name=scale value='{{.Scale}}' size=1>
<p><input type=submit value='Update'>
<input type=submit name=print value='Update and Print'>
</fieldset></form>
</td>
</tr></table>
</body></html>
`))
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, &params)
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))
}