Fix die-cut label printing

My QL-800 refuses to print black only on a red/black tape.

I really don't like the added `rb` function parameter.
It would be best to be able to recognize such tapes, however
nothing of the sort is documented in official Brother documentation.

makeBitmapData{,RB} also look like they could be simplified further.

LICENSE

@@ -0,0 +1,12 @@
+Copyright (c) 2019 - 2021, Přemysl Eric Janouch <p@janouch.name>
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

README.adoc

@@ -9,6 +9,8 @@ The project also contains reusable Go packages with a Brother QL-series USB
 printer driver and a simple BDF bitmap font renderer, as well as a few related
 utilities for previewing, printing and debugging.
 
+image::sklad.png[align="center"]
+
 Building and Running
 --------------------
 Build dependencies: Go +
@@ -17,6 +19,7 @@ Runtime dependencies: Linux, a Brother QL label printer connected over USB
  $ go get -u https://janouch.name/sklad/cmd/sklad
 
 You will need to bootstrap the database by writing a minimal 'db.json':
+
 ....
 {
 	"Password": "login-password",

bdf/bdf.go

@@ -49,6 +49,8 @@ func (g *glyph) At(x, y int) color.Color {
 // Font represents a particular bitmap font.
 type Font struct {
 	Name     string
+	Ascent   int // needn't be present in the font
+	Descent  int // needn't be present in the font
 	glyphs   map[rune]glyph
 	fallback glyph
 }
@@ -64,11 +66,13 @@ func (f *Font) FindGlyph(r rune) (glyph, bool) {
 
 // DrawString draws the specified text string onto dst horizontally along
 // the baseline starting at dp, using black color.
-func (f *Font) DrawString(dst draw.Image, dp image.Point, s string) {
+func (f *Font) DrawString(dst draw.Image, dp image.Point,
+	color color.Color, s string) {
+	src := image.NewUniform(color)
 	for _, r := range s {
 		g, _ := f.FindGlyph(r)
 		draw.DrawMask(dst, g.bounds.Add(dp),
-			image.Black, image.ZP, &g, g.bounds.Min, draw.Over)
+			src, image.ZP, &g, g.bounds.Min, draw.Over)
 		dp.X += g.advance
 	}
 }
@@ -192,17 +196,23 @@ func (p *bdfParser) readLine() bool {
 	return true
 }
 
-func (p *bdfParser) readCharEncoding() int {
+func (p *bdfParser) readIntegerArgument() int {
 	if len(p.tokens) < 2 {
 		panic("insufficient arguments")
 	}
 	if i, err := strconv.Atoi(p.tokens[1]); err != nil {
 		panic(err)
 	} else {
-		return i // Some fonts even use -1 for things outside the encoding.
+		return i
 	}
 }
 
+// Some fonts even use -1 for things outside the encoding.
+func (p *bdfParser) readCharEncoding() int { return p.readIntegerArgument() }
+
+// XXX: Ignoring vertical advance since we only expect purely horizontal fonts.
+func (p *bdfParser) readDwidth() int { return p.readIntegerArgument() }
+
 func (p *bdfParser) parseProperties() {
 	// The wording in the specification suggests that the argument
 	// with the number of properties to follow isn't reliable.
@@ -210,22 +220,14 @@ func (p *bdfParser) parseProperties() {
 		switch p.tokens[0] {
 		case "DEFAULT_CHAR":
 			p.defaultChar = p.readCharEncoding()
+		case "FONT_ASCENT":
+			p.font.Ascent = p.readIntegerArgument()
+		case "FONT_DESCENT":
+			p.font.Descent = p.readIntegerArgument()
 		}
 	}
 }
 
-// XXX: Ignoring vertical advance since we only expect purely horizontal fonts.
-func (p *bdfParser) readDwidth() int {
-	if len(p.tokens) < 2 {
-		panic("insufficient arguments")
-	}
-	if i, err := strconv.Atoi(p.tokens[1]); err != nil {
-		panic(err)
-	} else {
-		return i
-	}
-}
-
 func (p *bdfParser) readBBX() image.Rectangle {
 	if len(p.tokens) < 5 {
 		panic("insufficient arguments")

cmd/bdf-preview/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"html/template"
 	"image"
+	"image/color"
 	"image/draw"
 	"image/png"
 	"log"
@@ -27,12 +28,12 @@ var tmpl = template.Must(template.New("list").Parse(`
 		<th>Name</th>
 		<th>Preview</th>
 	<tr>
-{{range $k, $v := . }}
+	{{- range $k, $v := . }}
 	<tr>
 		<td>{{ $k }}</td>
 		<td><img src='?name={{ $k }}'></td>
 	</tr>
-{{end}}
+	{{- end }}
 </table>
 </body></html>
 `))
@@ -82,12 +83,12 @@ func main() {
 
 		img := image.NewRGBA(super)
 		draw.Draw(img, super, image.White, image.ZP, draw.Src)
-		font.DrawString(img, image.ZP, font.Name)
+		font.DrawString(img, image.ZP, color.Black, font.Name)
 
 		fonts[filename] = fontItem{Font: font, Preview: img}
 	}
 
-	log.Println("Starting server")
+	log.Println("starting server")
 	http.HandleFunc("/", handle)
 	log.Fatal(http.ListenAndServe(":8080", nil))
 }

cmd/bdf-sample/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"image"
+	"image/color"
 	"image/draw"
 	"image/png"
 	"log"
@@ -26,7 +27,7 @@ func main() {
 
 	img := image.NewRGBA(super)
 	draw.Draw(img, super, image.White, image.ZP, draw.Src)
-	font.DrawString(img, image.ZP, font.Name)
+	font.DrawString(img, image.ZP, color.Black, font.Name)
 
 	fo, err := os.Create("out.png")
 	if err != nil {

cmd/label-tool/main.go

@@ -4,6 +4,8 @@ import (
 	"errors"
 	"html/template"
 	"image"
+	"image/color"
+	"image/draw"
 	"image/png"
 	"log"
 	"net/http"
@@ -16,17 +18,28 @@ import (
 	"janouch.name/sklad/ql"
 )
 
-var font *bdf.Font
+var tmplFont = template.Must(template.New("font").Parse(`
+<!DOCTYPE html>
+<html><body>
+<h1>PT-CBP label printing tool</h1>
+<h2>Choose font</h2>
+{{ range $i, $f := . }}
+<p><a href='?font={{ $i }}'>
+<img src='?font={{ $i }}&amp;preview' title='{{ $f.Path }}'></a>
+{{ end }}
+</body></html>
+`))
 
-var tmpl = template.Must(template.New("form").Parse(`
+var tmplForm = 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}}'>
+	<img border=1 src='?font={{ .FontIndex }}&amp;scale={{ .Scale }}{{/*
+	*/}}&amp;text={{ .Text }}&amp;render'>
 </td>
-<td valign=top>
+<td valign=top><form>
 	<fieldset>
 		{{ if .Printer }}
 
@@ -59,21 +72,38 @@ var tmpl = template.Must(template.New("form").Parse(`
 		{{ end }}
 	</fieldset>
 	<fieldset>
-		<p>Font: {{ .Font.Name }}
+		<legend>Font</legend>
-	</fieldset>
+		<p>{{ .Font.Name }} <a href='?'>Change</a>
-	<form><fieldset>
+			<input type=hidden name=font value='{{ .FontIndex }}'>
-		<p><label for=text>Text:</label>
+		<p><label for=scale>Scale:</label>
-			<input id=text name=text value='{{.Text}}'>
-			<label for=scale>Scale:</label>
 			<input id=scale name=scale value='{{.Scale}}' size=1>
+	</fieldset>
+	<fieldset>
+		<legend>Label</legend>
+		<p><textarea name=text>{{.Text}}</textarea>
+		<p>Kind:
+			<input type=radio id=kind-text name=kind value=text
+				{{ if eq .Kind "text" }} checked{{ end }}>
+			<label for=kind-text>plain text (horizontal)</label>
+			<input type=radio id=kind-qr name=kind value=qr
+				{{ if eq .Kind "qr" }} checked{{ end }}>
+			<label for=kind-qr>QR code (vertical)</label>
 		<p><input type=submit value='Update'>
 			<input type=submit name=print value='Update and Print'>
-	</fieldset></form>
+	</fieldset>
-</td>
+</form></td>
 </tr></table>
 </body></html>
 `))
 
+type fontItem struct {
+	Path    string
+	Font    *bdf.Font
+	Preview image.Image
+}
+
+var fonts = []*fontItem{}
+
 func getPrinter() (*ql.Printer, error) {
 	printer, err := ql.Open()
 	if err != nil {
@@ -96,8 +126,30 @@ func getStatus(printer *ql.Printer) error {
 }
 
 func handle(w http.ResponseWriter, r *http.Request) {
-	if err := r.ParseForm(); err != nil {
+	if r.Method == http.MethodGet {
+		w.Header().Set("Cache-Control", "no-store")
+	}
+
+	var (
+		font      *fontItem
+		fontIndex int
+		err       error
+	)
+	if fontIndex, err = strconv.Atoi(r.FormValue("font")); err == nil {
+		font = fonts[fontIndex]
+	} else {
+		w.Header().Set("Content-Type", "text/html; charset=utf-8")
+		if err := tmplFont.Execute(w, fonts); err != nil {
 			http.Error(w, err.Error(), 500)
+		}
+		return
+	}
+
+	if _, ok := r.Form["preview"]; ok {
+		w.Header().Set("Content-Type", "image/png")
+		if err := png.Encode(w, font.Preview); err != nil {
+			http.Error(w, err.Error(), 500)
+		}
 		return
 	}
 
@@ -126,37 +178,50 @@ func handle(w http.ResponseWriter, r *http.Request) {
 		InitErr    error
 		MediaInfo  *ql.MediaInfo
 		Font       *bdf.Font
+		FontIndex  int
 		Text       string
 		Scale      int
+		Kind       string
 	}{
 		Printer:    printer,
 		PrinterErr: printerErr,
 		InitErr:    initErr,
 		MediaInfo:  mediaInfo,
-		Font:       font,
+		Font:       font.Font,
+		FontIndex:  fontIndex,
 		Text:       r.FormValue("text"),
+		Kind:       r.FormValue("kind"),
 	}
 
-	var err error
 	params.Scale, err = strconv.Atoi(r.FormValue("scale"))
 	if err != nil {
 		params.Scale = 3
 	}
+	if params.Kind == "" {
+		params.Kind = "text"
+	}
 
 	var img image.Image
 	if mediaInfo != nil {
+		if params.Kind == "qr" {
 			img = &imgutil.LeftRotate{Image: label.GenLabelForHeight(
-			font, params.Text, mediaInfo.PrintAreaPins, params.Scale)}
+				font.Font, params.Text, mediaInfo.PrintAreaPins, params.Scale)}
+		} else {
+			img = label.GenLabelForWidth(
+				font.Font, params.Text, mediaInfo.PrintAreaPins, params.Scale)
+		}
 		if r.FormValue("print") != "" {
-			if err := printer.Print(img); err != nil {
+			if err := printer.Print(img, false); err != nil {
 				log.Println("print error:", err)
 			}
 		}
 	}
 
-	if _, ok := r.Form["img"]; !ok {
+	if _, ok := r.Form["render"]; !ok {
-		w.Header().Set("Content-Type", "text/html")
+		w.Header().Set("Content-Type", "text/html; charset=utf-8")
-		tmpl.Execute(w, &params)
+		if err := tmplForm.Execute(w, &params); err != nil {
+			http.Error(w, err.Error(), 500)
+		}
 		return
 	}
 
@@ -173,24 +238,32 @@ func handle(w http.ResponseWriter, r *http.Request) {
 }
 
 func main() {
-	if len(os.Args) != 3 {
+	if len(os.Args) < 3 {
-		log.Fatalf("usage: %s ADDRESS BDF-FILE\n", os.Args[0])
+		log.Fatalf("usage: %s ADDRESS BDF-FILE...\n", os.Args[0])
 	}
 
-	address, bdfPath := os.Args[1], os.Args[2]
+	address, bdfPaths := os.Args[1], os.Args[2:]
-
+	for _, path := range bdfPaths {
-	var err error
+		fi, err := os.Open(path)
-	fi, err := os.Open(bdfPath)
 		if err != nil {
 			log.Fatalln(err)
 		}
-
+		font, err := bdf.NewFromBDF(fi)
-	font, err = bdf.NewFromBDF(fi)
+		if err != nil {
+			log.Fatalf("%s: %s\n", path, err)
+		}
 		if err := fi.Close(); err != nil {
 			log.Fatalln(err)
 		}
-	if err != nil {
+
-		log.Fatalln(err)
+		r, _ := font.BoundString(font.Name)
+		super := r.Inset(-3)
+
+		img := image.NewRGBA(super)
+		draw.Draw(img, super, image.White, image.ZP, draw.Src)
+		font.DrawString(img, image.ZP, color.Black, font.Name)
+
+		fonts = append(fonts, &fontItem{Path: path, Font: font, Preview: img})
 	}
 
 	log.Println("starting server")

cmd/ql-print/main.go

@@ -17,6 +17,7 @@ import (
 
 var scale = flag.Int("scale", 1, "integer upscaling")
 var rotate = flag.Bool("rotate", false, "print sideways")
+var redblack = flag.Bool("redblack", false, "red and black print")
 
 func main() {
 	flag.Usage = func() {
@@ -82,7 +83,7 @@ func main() {
 		log.Fatalln("the image is too high,", dy, ">", mi.PrintAreaLength, "pt")
 	}
 
-	if err := p.Print(img); err != nil {
+	if err := p.Print(img, *redblack); err != nil {
 		log.Fatalln(err)
 	}
 }

cmd/sklad/base.tmpl

@@ -49,14 +49,14 @@
 	<h1>sklad</h1>
 
 {{ block "HeaderControls" . }}
-	<a href=/>Obaly</a>
+	<a href="container">Obaly</a>
-	<a href=/series>Řady</a>
+	<a href="series">Řady</a>
 
-	<form method=get action=/search>
+	<form method=get action="search">
 	<input type=text name=q autofocus><input type=submit value="Hledat">
 	</form>
 
-	<form method=post action=/logout>
+	<form method=post action="logout">
 	<input type=submit value="Odhlásit">
 	</form>
 {{ end }}

cmd/sklad/container.tmpl

@@ -12,6 +12,8 @@
 <p>Chyba: Řadu u neprázdných obalů nelze měnit.
 {{ else if .ErrorCannotChangeNumber }}
 <p>Chyba: Číslo obalu v řadě nelze měnit.
+{{ else if .ErrorWouldContainItself }}
+<p>Chyba: Obal by obsahoval sám sebe.
 {{ else if .ErrorContainerInUse }}
 <p>Chyba: Obal se používá.
 {{ else if .Error }}
@@ -19,36 +21,42 @@
 {{ end }}
 
 {{ if .Container }}
-
 <section>
 	<header>
-	<h2>{{ .Container.Id }}</h2>
+		<h2><a href="container?id={{ .Container.Id }}">{{ .Container.Id }}</a>
-	<form method=post action="/label?id={{ .Container.Id }}">
+		{{- range .Container.Path }}
+		<small>&laquo; <a href="container?id={{ . }}">{{ . }}</a></small>
+		{{- end }}
+		</h2>
+		<form method=post action="label?id={{ .Container.Id }}" target=_blank>
 			<input type=submit value="Vytisknout štítek">
 		</form>
-	<form method=post action="/?id={{ .Container.Id }}&amp;remove">
+		<form method=post action="container?id={{ .Container.Id }}&amp;remove">
 			<input type=submit value="Odstranit">
 		</form>
 	</header>
-
+	<form method=post action="container?id={{ .Container.Id }}">
-<form method=post action="/?id={{ .Container.Id }}">
+		{{- $description := or .NewDescription .Container.Description }}
-<textarea name=description rows=5>
+		<textarea name=description rows="{{ max 5 (lines $description) }}"
-{{ .Container.Description }}
+			placeholder="Popis obalu nebo jeho obsahu">
+			{{- $description -}}
 		</textarea>
 		<footer>
 			<div>
 				<label for=series>Řada:</label>
 				<select name=series id=series>
-{{ range $prefix, $desc := .AllSeries }}
+				{{- $preselect := or .NewSeries .Container.Series }}
+				{{- range $prefix, $desc := .AllSeries }}
 					<option value="{{ $prefix }}"
-				{{ if eq $prefix $.Container.Series }}selected{{ end }}
+						{{ if eq $prefix $preselect }}selected{{ end -}}
 						>{{ $prefix }} &mdash; {{ $desc }}</option>
-{{ end }}
+				{{- end }}
 				</select>
 			</div>
 			<div>
 				<label for=parent>Nadobal:</label>
-		<input type=text name=parent id=parent value="{{ .Container.Parent }}">
+				<input type=text name=parent id=parent
+					value="{{ or .NewParent .Container.Parent }}">
 			</div>
 			<input type=submit value="Uložit">
 		</footer>
@@ -56,28 +64,33 @@
 </section>
 
 <h2>Podobaly</h3>
-
 {{ else }}
 <section>
 	<header>
 		<h2>Nový obal</h2>
 	</header>
-<form method=post action="/">
+	<form method=post action="container">
-<textarea name=description rows=5
+		{{- $description := or .NewDescription "" }}
-	placeholder="Popis obalu nebo jeho obsahu"></textarea>
+		<textarea name=description rows="{{ max 5 (lines $description) }}"
+			placeholder="Popis obalu nebo jeho obsahu">
+			{{- $description -}}
+		</textarea>
 		<footer>
 			<div>
 				<label for=series>Řada:</label>
 				<select name=series id=series>
-{{ range $prefix, $desc := .AllSeries }}
+				{{- $preselect := or .NewSeries "" }}
+				{{- range $prefix, $desc := .AllSeries }}
 					<option value="{{ $prefix }}"
+						{{ if eq $prefix $preselect }}selected{{ end -}}
 						>{{ $prefix }} &mdash; {{ $desc }}</option>
-{{ end }}
+				{{- end }}
 				</select>
 			</div>
 			<div>
 				<label for=parent>Nadobal:</label>
-		<input type=text name=parent id=parent value="">
+				<input type=text name=parent id=parent
+					value="{{ or .NewParent "" }}">
 			</div>
 			<input type=submit value="Uložit">
 		</footer>
@@ -90,23 +103,35 @@
 {{ range .Children }}
 <section>
 	<header>
-	<h3><a href="/?id={{ .Id }}">{{ .Id }}</a></h3>
+		<h3><a href="container?id={{ .Id }}">{{ .Id }}</a>
-	<form method=post action="/label?id={{ .Id }}">
+		{{- range .Path }}
+		<small>&laquo; <a href="container?id={{ . }}">{{ . }}</a></small>
+		{{- end }}
+		</h3>
+		<form method=post action="label?id={{ .Id }}" target=_blank>
+			{{- if $.Container }}
+			<input type=hidden name=context value="{{ $.Container.Id }}">
+			{{- end }}
 			<input type=submit value="Vytisknout štítek">
 		</form>
-	<form method=post action="/?id={{ .Id }}&amp;remove">
+		<form method=post action="container?id={{ .Id }}&amp;remove">
+			{{- if $.Container }}
+			<input type=hidden name=context value="{{ $.Container.Id }}">
+			{{- end }}
 			<input type=submit value="Odstranit">
 		</form>
 	</header>
-{{ if .Description }}
+
+	{{- if .Description }}
 	<p>{{ .Description }}
-{{ end }}
+	{{- end }}
-{{ if .Children }}
+
+	{{- if .Children }}
 	<p>
-{{ range .Children }}
+	{{- range .Children }}
-<a href="/?id={{ .Id }}">{{ .Id }}</a>
+	<a href="container?id={{ .Id }}">{{ .Id }}</a>
-{{ end }}
+	{{- end }}
-{{ end }}
+	{{- end }}
 </section>
 {{ else }}
 <p>Obal je prázdný.

cmd/sklad/db.go

@@ -163,6 +163,7 @@ var errNoSuchContainer = errors.New("no such container")
 var errCannotChangeSeriesNotEmpty = errors.New(
 	"cannot change the series of a non-empty container")
 var errCannotChangeNumber = errors.New("cannot change the number")
+var errWouldContainItself = errors.New("container would contain itself")
 var errContainerInUse = errors.New("container is in use")
 
 // Find and filter out the container in O(n).
@@ -204,19 +205,34 @@ func dbContainerCreate(c *Container) error {
 }
 
 func dbContainerUpdate(c *Container, updated Container) error {
-	newId := updated.Id()
+	if _, ok := indexSeries[updated.Series]; !ok {
+		return errNoSuchSeries
+	}
+	if updated.Parent != "" && indexContainer[updated.Parent] == nil {
+		return errNoSuchContainer
+	}
+
+	newID := updated.Id()
 	if updated.Series != c.Series && len(c.Children()) > 0 {
 		return errCannotChangeSeriesNotEmpty
 	}
 	if updated.Number != c.Number {
 		return errCannotChangeNumber
 	}
-	if _, ok := indexContainer[newId]; ok && newId != c.Id() {
+	if _, ok := indexContainer[newID]; ok && newID != c.Id() {
 		return errContainerAlreadyExists
 	}
 	if updated.Parent != c.Parent {
+		// Relying on the invariant that we can't change the ID
+		// of a non-empty container.
+		for pv := &updated; pv.Parent != ""; pv = indexContainer[pv.Parent] {
+			if pv.Parent == updated.Id() {
+				return errWouldContainItself
+			}
+		}
+
 		indexChildren[c.Parent] = filterContainer(indexChildren[c.Parent], c)
-		indexChildren[newId] = append(indexChildren[newId], c)
+		indexChildren[updated.Parent] = append(indexChildren[updated.Parent], c)
 	}
 	*c = updated
 	return dbCommit()
@@ -282,6 +298,7 @@ func loadDatabase() error {
 	if err != nil {
 		return err
 	}
+	defer dbFile.Close()
 	if err := json.NewDecoder(dbFile).Decode(&db); err != nil {
 		return err
 	}

cmd/sklad/label.tmpl

@@ -1,6 +1,7 @@
 {{ define "Title" }}Tisk štítku{{ end }}
 {{ define "Content" }}
-<h2>Tisk štítku pro {{ .Id }}</h2>
+
+<h2>Tisk štítku pro <a href="container?id={{ .Id }}">{{ .Id }}</a></h2>
 
 {{ if .UnknownId }}
 <p>Neznámý obal.

cmd/sklad/main.go

@@ -1,7 +1,9 @@
 package main
 
 import (
+	"context"
 	"errors"
+	"html"
 	"html/template"
 	"io"
 	"log"
@@ -9,7 +11,13 @@ import (
 	"net/http"
 	"net/url"
 	"os"
+	"os/signal"
+	"path"
 	"path/filepath"
+	"regexp"
+	"strings"
+	"sync"
+	"syscall"
 	"time"
 
 	"janouch.name/sklad/imgutil"
@@ -25,24 +33,10 @@ func executeTemplate(name string, w io.Writer, data interface{}) {
 	}
 }
 
-func wrap(inner func(http.ResponseWriter, *http.Request)) func(
-	http.ResponseWriter, *http.Request) {
-	return func(w http.ResponseWriter, r *http.Request) {
-		if err := r.ParseForm(); err != nil {
-			http.Error(w, err.Error(), http.StatusInternalServerError)
-			return
-		}
-		if r.Method == http.MethodGet {
-			w.Header().Set("Cache-Control", "no-store")
-		}
-		inner(w, r)
-	}
-}
-
 func handleLogin(w http.ResponseWriter, r *http.Request) {
 	redirect := r.FormValue("redirect")
 	if redirect == "" {
-		redirect = "/"
+		redirect = "container"
 	}
 
 	session := sessionGet(w, r)
@@ -81,14 +75,14 @@ func handleLogout(w http.ResponseWriter, r *http.Request) {
 
 	session := r.Context().Value(sessionContextKey{}).(*Session)
 	session.LoggedIn = false
-	http.Redirect(w, r, "/", http.StatusSeeOther)
+	http.Redirect(w, r, "login", http.StatusSeeOther)
 }
 
 func handleContainerPost(r *http.Request) error {
 	id := ContainerId(r.FormValue("id"))
-	description := r.FormValue("description")
+	description := strings.TrimSpace(r.FormValue("description"))
 	series := r.FormValue("series")
-	parent := ContainerId(r.FormValue("parent"))
+	parent := ContainerId(strings.TrimSpace(r.FormValue("parent")))
 	_, remove := r.Form["remove"]
 
 	if container, ok := indexContainer[id]; ok {
@@ -98,6 +92,7 @@ func handleContainerPost(r *http.Request) error {
 			c := *container
 			c.Description = description
 			c.Series = series
+			c.Parent = parent
 			return dbContainerUpdate(container, c)
 		}
 	} else if remove {
@@ -112,11 +107,22 @@ func handleContainerPost(r *http.Request) error {
 }
 
 func handleContainer(w http.ResponseWriter, r *http.Request) {
+	// When deleting, do not try to show the deleted entry but the context.
+	shownId := r.FormValue("context")
+	if shownId == "" {
+		shownId = r.FormValue("id")
+	}
+
 	var err error
 	if r.Method == http.MethodPost {
-		err = handleContainerPost(r)
+		if err = handleContainerPost(r); err == nil {
-		// XXX: This is rather ugly. When removing, we want to keep
+			redirect := r.URL.EscapedPath()
-		// the context id, in addition to the id being changed.
+			if shownId != "" {
+				redirect += "?id=" + url.QueryEscape(shownId)
+			}
+			http.Redirect(w, r, redirect, http.StatusSeeOther)
+			return
+		}
 	} else if r.Method != http.MethodGet {
 		w.WriteHeader(http.StatusMethodNotAllowed)
 		return
@@ -127,14 +133,6 @@ func handleContainer(w http.ResponseWriter, r *http.Request) {
 		allSeries[s.Prefix] = s.Description
 	}
 
-	var container *Container
-	children := indexChildren[""]
-
-	if c, ok := indexContainer[ContainerId(r.FormValue("id"))]; ok {
-		children = c.Children()
-		container = c
-	}
-
 	params := struct {
 		Error                           error
 		ErrorNoSuchSeries               bool
@@ -142,8 +140,12 @@ func handleContainer(w http.ResponseWriter, r *http.Request) {
 		ErrorNoSuchContainer            bool
 		ErrorCannotChangeSeriesNotEmpty bool
 		ErrorCannotChangeNumber         bool
+		ErrorWouldContainItself         bool
 		ErrorContainerInUse             bool
 		Container                       *Container
+		NewDescription                  *string
+		NewSeries                       string
+		NewParent                       *string
 		Children                        []*Container
 		AllSeries                       map[string]string
 	}{
@@ -153,18 +155,33 @@ func handleContainer(w http.ResponseWriter, r *http.Request) {
 		ErrorNoSuchContainer:            err == errNoSuchContainer,
 		ErrorCannotChangeSeriesNotEmpty: err == errCannotChangeSeriesNotEmpty,
 		ErrorCannotChangeNumber:         err == errCannotChangeNumber,
+		ErrorWouldContainItself:         err == errWouldContainItself,
 		ErrorContainerInUse:             err == errContainerInUse,
-		Container:                       container,
+		Children:                        indexChildren[""],
-		Children:                        children,
 		AllSeries:                       allSeries,
 	}
+	if c, ok := indexContainer[ContainerId(shownId)]; ok {
+		params.Children = c.Children()
+		params.Container = c
+	}
+	if description, ok := r.Form["description"]; ok {
+		params.NewDescription = &description[0]
+	}
+	if series, ok := r.Form["series"]; ok {
+		// It seems impossible to dereference strings in text/template so that
+		// `eq` can be used, and we don't actually need a null value here.
+		params.NewSeries = series[0]
+	}
+	if parent, ok := r.Form["parent"]; ok {
+		params.NewParent = &parent[0]
+	}
 
 	executeTemplate("container.tmpl", w, &params)
 }
 
 func handleSeriesPost(r *http.Request) error {
-	prefix := r.FormValue("prefix")
+	prefix := strings.TrimSpace(r.FormValue("prefix"))
-	description := r.FormValue("description")
+	description := strings.TrimSpace(r.FormValue("description"))
 	_, remove := r.Form["remove"]
 
 	if series, ok := indexSeries[prefix]; ok {
@@ -188,7 +205,10 @@ func handleSeriesPost(r *http.Request) error {
 func handleSeries(w http.ResponseWriter, r *http.Request) {
 	var err error
 	if r.Method == http.MethodPost {
-		err = handleSeriesPost(r)
+		if err = handleSeriesPost(r); err == nil {
+			http.Redirect(w, r, r.URL.EscapedPath(), http.StatusSeeOther)
+			return
+		}
 		// XXX: This is rather ugly.
 		r.Form = url.Values{}
 	} else if r.Method != http.MethodGet {
@@ -289,7 +309,7 @@ func printLabel(id string) error {
 	}
 
 	return printer.Print(&imgutil.LeftRotate{Image: label.GenLabelForHeight(
-		labelFont, id, mediaInfo.PrintAreaPins, db.BDFScale)})
+		labelFont, id, mediaInfo.PrintAreaPins, db.BDFScale)}, false)
 }
 
 func handleLabel(w http.ResponseWriter, r *http.Request) {
@@ -315,6 +335,67 @@ func handleLabel(w http.ResponseWriter, r *http.Request) {
 	executeTemplate("label.tmpl", w, &params)
 }
 
+var mutex sync.Mutex
+
+func handle(w http.ResponseWriter, r *http.Request) {
+	if err := r.ParseForm(); err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	if r.Method == http.MethodGet {
+		w.Header().Set("Cache-Control", "no-store")
+	}
+
+	mutex.Lock()
+	defer mutex.Unlock()
+
+	switch _, base := path.Split(r.URL.Path); base {
+	case "login":
+		handleLogin(w, r)
+	case "logout":
+		sessionWrap(handleLogout)(w, r)
+
+	case "container":
+		sessionWrap(handleContainer)(w, r)
+	case "series":
+		sessionWrap(handleSeries)(w, r)
+	case "search":
+		sessionWrap(handleSearch)(w, r)
+	case "label":
+		sessionWrap(handleLabel)(w, r)
+
+	case "":
+		http.Redirect(w, r, "container", http.StatusSeeOther)
+	default:
+		http.NotFound(w, r)
+	}
+}
+
+var funcMap = template.FuncMap{
+	"max": func(i, j int) int {
+		if i > j {
+			return i
+		}
+		return j
+	},
+	"lines": func(s string) int {
+		return strings.Count(s, "\n") + 1
+	},
+	"highlight": func(highlight, s string) template.HTML {
+		b, last := strings.Builder{}, 0
+		for _, m := range regexp.MustCompile(
+			`(?i:`+regexp.QuoteMeta(highlight)+`)`).FindAllStringIndex(s, -1) {
+			b.WriteString(html.EscapeString(s[last:m[0]]))
+			b.WriteString(`<mark>`)
+			b.WriteString(html.EscapeString(s[m[0]:m[1]]))
+			b.WriteString(`</mark>`)
+			last = m[1]
+		}
+		b.WriteString(html.EscapeString(s[last:]))
+		return template.HTML(b.String())
+	},
+}
+
 func main() {
 	// Randomize the RNG for session string generation.
 	rand.Seed(time.Now().UnixNano())
@@ -337,16 +418,27 @@ func main() {
 		log.Fatalln(err)
 	}
 	for _, name := range m {
-		templates[name] = template.Must(template.ParseFiles("base.tmpl", name))
+		templates[name] = template.Must(template.New("base.tmpl").
+			Funcs(funcMap).ParseFiles("base.tmpl", name))
 	}
 
-	http.HandleFunc("/login", wrap(handleLogin))
+	http.HandleFunc("/", handle)
-	http.HandleFunc("/logout", sessionWrap(wrap(handleLogout)))
+	server := &http.Server{Addr: address}
 
-	http.HandleFunc("/", sessionWrap(wrap(handleContainer)))
+	sigs := make(chan os.Signal, 1)
-	http.HandleFunc("/series", sessionWrap(wrap(handleSeries)))
+	errs := make(chan error, 1)
-	http.HandleFunc("/search", sessionWrap(wrap(handleSearch)))
+	signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM, syscall.SIGHUP)
-	http.HandleFunc("/label", sessionWrap(wrap(handleLabel)))
+	go func() { errs <- server.ListenAndServe() }()
 
-	log.Fatalln(http.ListenAndServe(address, nil))
+	select {
+	case <-sigs:
+	case err := <-errs:
+		log.Println(err)
+	}
+
+	// Wait for all HTTP goroutines to finish so that not even the database
+	// log gets corrupted by an interrupted update.
+	if err := server.Shutdown(context.Background()); err != nil {
+		log.Fatalln(err)
+	}
 }

cmd/sklad/search.tmpl

@@ -1,15 +1,15 @@
 {{ define "Title" }}„{{ .Query }}“ — Vyhledávání{{ end }}
 {{ define "Content" }}
 
-<h2>Vyhledávání: &bdquo;{{ .Query }}&ldquo;<h2>
+<h2>Vyhledávání: &bdquo;{{ .Query }}&ldquo;</h2>
 
 <h3>Řady</h3>
 
 {{ range .Series }}
 <section>
 	<header>
-	<h3><a href="/series?prefix={{ .Prefix }}">{{ .Prefix }}</a></h3>
+		<h3><a href="series?prefix={{ .Prefix }}">{{ .Prefix }}</a></h3>
-	<p>{{ .Description }}
+		<p>{{ .Description | highlight $.Query }}
 	</header>
 </section>
 {{ else }}
@@ -21,15 +21,15 @@
 {{ range .Containers }}
 <section>
 	<header>
-	<h3><a href="/?id={{ .Id }}">{{ .Id }}</a>
+		<h3><a href="container?id={{ .Id }}">{{ .Id }}</a>
-{{ range .Path }}
+		{{- range .Path }}
-	<small>&laquo; <a href="/?id={{ . }}">{{ . }}</a></small>
+		<small>&laquo; <a href="container?id={{ . }}">{{ . }}</a></small>
-{{ end }}
+		{{- end }}
 		</h3>
 	</header>
-{{ if .Description }}
+	{{- if .Description }}
-<p>{{ .Description }}
+	<p>{{ .Description | highlight $.Query }}
-{{ end }}
+	{{- end }}
 </section>
 {{ else }}
 <p>Neodpovídají žádné obaly.

cmd/sklad/series.tmpl

@@ -22,15 +22,13 @@
 <p>{{ .Description }}
 {{ end }}
 {{ else }}
-
 <section>
-<form method=post action="/series">
+	<form method=post action="series">
 		<header>
 			<h3>Nová řada</h3>
 			<input type=text name=prefix placeholder="Prefix řady">
 			<input type=text name=description placeholder="Popis řady"
 			><input type=submit value="Uložit">
-	</form>
 		</header>
 	</form>
 </section>
@@ -38,21 +36,21 @@
 {{ range .AllSeries }}
 <section>
 	<header>
-	<h3><a href="/series?prefix={{ .Prefix }}">{{ .Prefix }}</a></h3>
+		<h3><a href="series?prefix={{ .Prefix }}">{{ .Prefix }}</a></h3>
-{{ with $count := len .Containers }}
+		{{- with $count := len .Containers }}
-{{ if eq $count 1 }}
+		{{- if eq $count 1 }}
 		<p>{{ $count }} obal
-{{ else if and (ge $count 2) (le $count 4) }}
+		{{- else if and (ge $count 2) (le $count 4) }}
 		<p>{{ $count }} obaly
-{{ else if gt $count 0 }}
+		{{- else if gt $count 0 }}
 		<p>{{ $count }} obalů
-{{ end }}
+		{{- end }}
-{{ end }}
+		{{- end }}
-	<form method=post action="/series?prefix={{ .Prefix }}">
+		<form method=post action="series?prefix={{ .Prefix }}">
 			<input type=text name=description value="{{ .Description }}"
 			><input type=submit value="Uložit">
 		</form>
-	<form method=post action="/series?prefix={{ .Prefix }}&amp;remove">
+		<form method=post action="series?prefix={{ .Prefix }}&amp;remove">
 			<input type=submit value="Odstranit">
 		</form>
 	</header>
@@ -60,7 +58,6 @@
 {{ else }}
 <p>Nejsou žádné řady.
 {{ end }}
-
 {{ end }}
 
 {{ end }}

cmd/sklad/session.go

@@ -50,7 +50,7 @@ func sessionWrap(inner func(http.ResponseWriter, *http.Request)) func(
 		// though I don't expect any substantial improvements of anything.
 		w.Header().Set("Cache-Control", "no-store")
 
-		redirect := "/login"
+		redirect := "login"
 		if r.RequestURI != "/" && r.Method == http.MethodGet {
 			redirect += "?redirect=" + url.QueryEscape(r.RequestURI)
 		}

go.mod

@@ -1,28 +1,5 @@
 module janouch.name/sklad
 
-go 1.12
+go 1.17
 
-require (
+require github.com/boombuler/barcode v1.0.1
-	github.com/boombuler/barcode v1.0.0
-	github.com/cosiner/argv v0.0.1 // indirect
-	github.com/cpuguy83/go-md2man v1.0.10 // indirect
-	github.com/go-delve/delve v1.2.0 // indirect
-	github.com/konsorten/go-windows-terminal-sequences v1.0.2 // indirect
-	github.com/mattn/go-colorable v0.1.1 // indirect
-	github.com/mattn/go-isatty v0.0.7 // indirect
-	github.com/mattn/go-runewidth v0.0.4 // indirect
-	github.com/peterh/liner v1.1.0 // indirect
-	github.com/pkg/profile v1.3.0 // indirect
-	github.com/russross/blackfriday v2.0.0+incompatible // indirect
-	github.com/sirupsen/logrus v1.4.1 // indirect
-	github.com/spf13/cobra v0.0.3 // indirect
-	github.com/spf13/pflag v1.0.3 // indirect
-	github.com/stretchr/objx v0.2.0 // indirect
-	golang.org/x/arch v0.0.0-20190312162104-788fe5ffcd8c // indirect
-	golang.org/x/crypto v0.0.0-20190411191339-88737f569e3a // indirect
-	golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3 // indirect
-	golang.org/x/sys v0.0.0-20190411185658-b44545bcd369 // indirect
-	golang.org/x/tools v0.0.0-20190411180116-681f9ce8ac52 // indirect
-	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect
-	gopkg.in/yaml.v2 v2.2.2 // indirect
-)

go.sum

@@ -1,70 +1,2 @@
-github.com/boombuler/barcode v1.0.0 h1:s1TvRnXwL2xJRaccrdcBQMZxq6X7DvsMogtmJeHDdrc=
+github.com/boombuler/barcode v1.0.1 h1:NDBbPmhS+EqABEs5Kg3n/5ZNjy73Pz7SIV+KCeqyXcs=
-github.com/boombuler/barcode v1.0.0/go.mod h1:paBWMcWSl3LHKBqUq+rly7CNSldXjb2rDl3JlRe0mD8=
+github.com/boombuler/barcode v1.0.1/go.mod h1:paBWMcWSl3LHKBqUq+rly7CNSldXjb2rDl3JlRe0mD8=
-github.com/cosiner/argv v0.0.0-20170225145430-13bacc38a0a5/go.mod h1:p/NrK5tF6ICIly4qwEDsf6VDirFiWWz0FenfYBwJaKQ=
-github.com/cosiner/argv v0.0.1 h1:2iAFN+sWPktbZ4tvxm33Ei8VY66FPCxdOxpncUGpAXE=
-github.com/cosiner/argv v0.0.1/go.mod h1:p/NrK5tF6ICIly4qwEDsf6VDirFiWWz0FenfYBwJaKQ=
-github.com/cpuguy83/go-md2man v1.0.8/go.mod h1:N6JayAiVKtlHSnuTCeuLSQVs75hb8q+dYQLjr7cDsKY=
-github.com/cpuguy83/go-md2man v1.0.10/go.mod h1:SmD6nW6nTyfqj6ABTjUi3V3JVMnlJmwcJI5acqYI6dE=
-github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/go-delve/delve v1.2.0 h1:uwGyfYO0WsWqbnDWvxCBKOr2qFLpii3tLxwM+fTJs70=
-github.com/go-delve/delve v1.2.0/go.mod h1:yP+LD36s/ud5nm4lsQY0TwNhYu2PAwk6xItz+442j74=
-github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANytuPF1OarO4DADm73n8=
-github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
-github.com/konsorten/go-windows-terminal-sequences v1.0.2/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
-github.com/mattn/go-colorable v0.0.0-20170327083344-ded68f7a9561/go.mod h1:9vuHe8Xs5qXnSaW/c/ABM9alt+Vo+STaOChaDxuIBZU=
-github.com/mattn/go-colorable v0.1.1/go.mod h1:FuOcm+DKB9mbwrcAfNl7/TZVBZ6rcnceauSikq3lYCQ=
-github.com/mattn/go-isatty v0.0.3/go.mod h1:M+lRXTBqGeGNdLjl/ufCoiOlB5xdOkqRJdNxMWT7Zi4=
-github.com/mattn/go-isatty v0.0.5/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hdxcsrc5s=
-github.com/mattn/go-isatty v0.0.7 h1:UvyT9uN+3r7yLEYSlJsbQGdsaB/a0DlgWP3pql6iwOc=
-github.com/mattn/go-isatty v0.0.7/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hdxcsrc5s=
-github.com/mattn/go-runewidth v0.0.3/go.mod h1:LwmH8dsx7+W8Uxz3IHJYH5QSwggIsqBzpuz5H//U1FU=
-github.com/mattn/go-runewidth v0.0.4 h1:2BvfKmzob6Bmd4YsL0zygOqfdFnK7GR4QL06Do4/p7Y=
-github.com/mattn/go-runewidth v0.0.4/go.mod h1:LwmH8dsx7+W8Uxz3IHJYH5QSwggIsqBzpuz5H//U1FU=
-github.com/peterh/liner v0.0.0-20170317030525-88609521dc4b/go.mod h1:xIteQHvHuaLYG9IFj6mSxM0fCKrs34IrEQUhOYuGPHc=
-github.com/peterh/liner v1.1.0 h1:f+aAedNJA6uk7+6rXsYBnhdo4Xux7ESLe+kcuVUF5os=
-github.com/peterh/liner v1.1.0/go.mod h1:CRroGNssyjTd/qIG2FyxByd2S8JEAZXBl4qUrZf8GS0=
-github.com/pkg/profile v0.0.0-20170413231811-06b906832ed0/go.mod h1:hJw3o1OdXxsrSjjVksARp5W95eeEaEfptyVZyv6JUPA=
-github.com/pkg/profile v1.3.0/go.mod h1:hJw3o1OdXxsrSjjVksARp5W95eeEaEfptyVZyv6JUPA=
-github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/russross/blackfriday v0.0.0-20180428102519-11635eb403ff/go.mod h1:JO/DiYxRf+HjHt06OyowR9PTA263kcR/rfWxYHBV53g=
-github.com/russross/blackfriday v1.5.2/go.mod h1:JO/DiYxRf+HjHt06OyowR9PTA263kcR/rfWxYHBV53g=
-github.com/russross/blackfriday v2.0.0+incompatible/go.mod h1:JO/DiYxRf+HjHt06OyowR9PTA263kcR/rfWxYHBV53g=
-github.com/sirupsen/logrus v0.0.0-20180523074243-ea8897e79973/go.mod h1:pMByvHTf9Beacp5x1UXfOR9xyW/9antXMhjMPG0dEzc=
-github.com/sirupsen/logrus v1.4.1 h1:GL2rEmy6nsikmW0r8opw9JIRScdMF5hA8cOYLH7In1k=
-github.com/sirupsen/logrus v1.4.1/go.mod h1:ni0Sbl8bgC9z8RoU9G6nDWqqs/fq4eDPysMBDgk/93Q=
-github.com/spf13/cobra v0.0.0-20170417170307-b6cb39589372/go.mod h1:1l0Ry5zgKvJasoi3XT1TypsSe7PqH0Sj9dhYf7v3XqQ=
-github.com/spf13/cobra v0.0.3 h1:ZlrZ4XsMRm04Fr5pSFxBgfND2EBVa1nLpiy1stUsX/8=
-github.com/spf13/cobra v0.0.3/go.mod h1:1l0Ry5zgKvJasoi3XT1TypsSe7PqH0Sj9dhYf7v3XqQ=
-github.com/spf13/pflag v0.0.0-20170417173400-9e4c21054fa1/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
-github.com/spf13/pflag v1.0.3 h1:zPAT6CGy6wXeQ7NtTnaTerfKOsV6V6F8agHXFiazDkg=
-github.com/spf13/pflag v1.0.3/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
-github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/objx v0.2.0/go.mod h1:qt09Ya8vawLte6SNmTgCsAVtYtaKzEcn8ATUoHMkEqE=
-github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
-github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
-golang.org/x/arch v0.0.0-20171004143515-077ac972c2e4/go.mod h1:cYlCBUl1MsqxdiKgmc4uh7TxZfWSFLOGSRR090WDxt8=
-golang.org/x/arch v0.0.0-20190312162104-788fe5ffcd8c h1:Rx/HTKi09myZ25t1SOlDHmHOy/mKxNAcu0hP1oPX9qM=
-golang.org/x/arch v0.0.0-20190312162104-788fe5ffcd8c/go.mod h1:flIaEI6LNU6xOCD5PaJvn9wGP0agmIOqjrtsKGRguv4=
-golang.org/x/crypto v0.0.0-20180614174826-fd5f17ee7299/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
-golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/crypto v0.0.0-20190411191339-88737f569e3a/go.mod h1:WFFai1msRO1wXaEeE5yQxYXgSfI8pQAWXbQop6sCtWE=
-golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
-golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
-golang.org/x/sys v0.0.0-20180614134839-8883426083c0/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/sys v0.0.0-20190403152447-81d4e9dc473e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20190411185658-b44545bcd369 h1:aBlRBZoCuZNRDClvfkDoklQqdLzBaA3uViASg2z2p24=
-golang.org/x/sys v0.0.0-20190411185658-b44545bcd369/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
-golang.org/x/tools v0.0.0-20181120060634-fc4f04983f62/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
-golang.org/x/tools v0.0.0-20190411180116-681f9ce8ac52/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v2 v2.0.0-20170407172122-cd8b52f8269e/go.mod h1:JAlM8MvJe8wmxCU4Bli9HhUf9+ttbYbLASfIpnQbh74=
-gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
-gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-rsc.io/pdf v0.1.1/go.mod h1:n8OzWcQ6Sp37PL01nO98y4iUCRdTGarVfzxY20ICaU4=

label/label.go

@@ -0,0 +1,108 @@
+package label
+
+import (
+	"image"
+	"image/color"
+	"image/draw"
+	"strings"
+
+	"janouch.name/sklad/bdf"
+	"janouch.name/sklad/imgutil"
+
+	"github.com/boombuler/barcode"
+	"github.com/boombuler/barcode/qr"
+)
+
+// TODO: Rename to GenQRLabelForHeight.
+func GenLabelForHeight(font *bdf.Font,
+	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, color.Black, text)
+
+	scaledTextImg := imgutil.Scale{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
+}
+
+func max(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+func GenLabelForWidth(font *bdf.Font,
+	text string, width, scale int) image.Image {
+	var lines []string
+	for _, line := range strings.Split(text, "\n") {
+		lines = append(lines, strings.TrimSuffix(line, "\r"))
+	}
+
+	// Respect font ascent and descent so that there are gaps between lines.
+	rects := make([]image.Rectangle, len(lines))
+	jumps := make([]int, len(lines))
+	for i, line := range lines {
+		r, _ := font.BoundString(line)
+		rects[i] = r
+
+		if i > 0 {
+			deficitD := font.Descent - rects[i-1].Max.Y
+			jumps[i] += max(0, deficitD)
+			deficitA := font.Ascent - (-r.Min.Y)
+			jumps[i] += max(0, deficitA)
+		}
+	}
+
+	height := 0
+	for i := range lines {
+		height += jumps[i] + rects[i].Dy()
+	}
+
+	imgRect := image.Rect(0, 0, width, height*scale)
+	img := image.NewRGBA(imgRect)
+	draw.Draw(img, imgRect, image.White, image.ZP, draw.Src)
+
+	y := 0
+	for i, line := range lines {
+		textImg := image.NewRGBA(rects[i])
+		draw.Draw(textImg, rects[i], image.White, image.ZP, draw.Src)
+		font.DrawString(textImg, image.ZP, color.Black, line)
+
+		scaledImg := imgutil.Scale{Image: textImg, Scale: scale}
+		scaledRect := scaledImg.Bounds()
+
+		y += jumps[i]
+		target := image.Rect(0, y*scale, imgRect.Max.X, imgRect.Max.Y)
+		draw.Draw(img, target, &scaledImg, scaledRect.Min, draw.Src)
+		y += rects[i].Dy()
+	}
+	return img
+}

ql/ql.go

@@ -120,9 +120,67 @@ const (
 	printPins  = printBytes * 8
 )
 
+// pack packs a bool array into a byte array for the printer to print out.
+func pack(data [printPins]bool, out *[]byte) {
+	for i := 0; i < printBytes; i++ {
+		var b byte
+		for j := 0; j < 8; j++ {
+			b <<= 1
+			if data[i*8+j] {
+				b |= 1
+			}
+		}
+		*out = append(*out, b)
+	}
+}
+
+// makeBitmapDataRB converts an image to the printer's red-black raster format.
+func makeBitmapDataRB(src image.Image, margin, length int) []byte {
+	data, bounds := []byte{}, src.Bounds()
+	if bounds.Dy() > length {
+		bounds.Max.Y = bounds.Min.Y + length
+	}
+	if bounds.Dx() > printPins-margin {
+		bounds.Max.X = bounds.Min.X + printPins
+	}
+
+	redcells, blackcells := [printPins]bool{}, [printPins]bool{}
+	for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
+		length--
+
+		// The graphics needs to be inverted horizontally, iterating backwards.
+		offset := margin
+		for x := bounds.Max.X - 1; x >= bounds.Min.X; x-- {
+			r, g, b, a := src.At(x, y).RGBA()
+			redcells[offset] = r >= 0xc000 && g < 0x4000 && b < 0x4000 &&
+				a >= 0x8000
+			blackcells[offset] = r < 0x4000 && g < 0x4000 && b < 0x4000 &&
+				a >= 0x8000
+			offset++
+		}
+
+		data = append(data, 'w', 0x01, printBytes)
+		pack(blackcells, &data)
+		data = append(data, 'w', 0x02, printBytes)
+		pack(redcells, &data)
+	}
+	for ; length > 0; length-- {
+		data = append(data, 'w', 0x01, printBytes)
+		data = append(data, make([]byte, printBytes)...)
+		data = append(data, 'w', 0x02, printBytes)
+		data = append(data, make([]byte, printBytes)...)
+	}
+	return data
+}
+
 // makeBitmapData converts an image to the printer's raster format.
-func makeBitmapData(src image.Image, margin, length int) (data []byte) {
+func makeBitmapData(src image.Image, rb bool, margin, length int) []byte {
-	bounds := src.Bounds()
+	// It's a necessary nuisance, so just copy and paste.
+	if rb {
+		return makeBitmapDataRB(src, margin, length)
+	}
+
+	data, bounds := []byte{}, src.Bounds()
 	if bounds.Dy() > length {
 		bounds.Max.Y = bounds.Min.Y + length
 	}
@@ -138,30 +196,24 @@ func makeBitmapData(src image.Image, margin, length int) (data []byte) {
 		offset := margin
 		for x := bounds.Max.X - 1; x >= bounds.Min.X; x-- {
 			r, g, b, a := src.At(x, y).RGBA()
-			pixels[offset] = r == 0 && g == 0 && b == 0 && a >= 0x8000
+			pixels[offset] = r < 0x4000 && g < 0x4000 && b < 0x4000 &&
+				a >= 0x8000
 			offset++
 		}
 
 		data = append(data, 'g', 0x00, printBytes)
-		for i := 0; i < printBytes; i++ {
+		pack(pixels, &data)
-			var b byte
-			for j := 0; j < 8; j++ {
-				b <<= 1
-				if pixels[i*8+j] {
-					b |= 1
-				}
-			}
-			data = append(data, b)
-		}
 	}
 	for ; length > 0; length-- {
 		data = append(data, 'g', 0x00, printBytes)
 		data = append(data, make([]byte, printBytes)...)
 	}
-	return
+	return data
 }
 
-func makePrintData(status *Status, image image.Image) (data []byte) {
+// XXX: It would be preferrable to know for certain if this is a red-black tape,
+// because the printer refuses to print on a mismatch.
+func makePrintData(status *Status, image image.Image, rb bool) (data []byte) {
 	mediaInfo := GetMediaInfo(
 		status.MediaWidthMM(),
 		status.MediaLengthMM(),
@@ -188,8 +240,17 @@ func makePrintData(status *Status, image image.Image) (data []byte) {
 		mediaType = byte(0x0b)
 	}
 
-	data = append(data, 0x1b, 0x69, 0x7a, 0x02|0x04|0x40|0x80, mediaType,
+	const (
-		byte(status.MediaWidthMM()), byte(status.MediaLengthMM()),
+		flagValidMediaType    = 0x02
+		flagValidMediaWidth   = 0x04
+		flagValidMediaLength  = 0x08
+		flagPriorityToQuality = 0x40
+		flagRecoveryAlwaysOn  = 0x80
+	)
+	data = append(data, 0x1b, 0x69, 0x7a, flagValidMediaType|
+		flagValidMediaWidth|flagValidMediaLength|
+		flagPriorityToQuality|flagRecoveryAlwaysOn,
+		mediaType, byte(status.MediaWidthMM()), byte(status.MediaLengthMM()),
 		byte(dy), byte(dy>>8), byte(dy>>16), byte(dy>>24), 0, 0x00)
 
 	// Auto cut, each 1 label.
@@ -198,9 +259,13 @@ func makePrintData(status *Status, image image.Image) (data []byte) {
 
 	// Cut at end (though it's the default).
 	// Not sure what it means, doesn't seem to have any effect to turn it off.
+	if rb {
+		data = append(data, 0x1b, 0x69, 0x4b, 0x08|0x01)
+	} else {
 		data = append(data, 0x1b, 0x69, 0x4b, 0x08)
+	}
 
-	if status.MediaLengthMM() != 0 {
+	if status.MediaLengthMM() == 0 {
 		// 3mm margins along the direction of feed. 0x23 = 35 dots, the minimum.
 		data = append(data, 0x1b, 0x69, 0x64, 0x23, 0x00)
 	} else {
@@ -213,7 +278,8 @@ func makePrintData(status *Status, image image.Image) (data []byte) {
 	data = append(data, 0x4d, 0x00)
 
 	// The graphics data itself.
-	data = append(data, makeBitmapData(image, mediaInfo.SideMarginPins, dy)...)
+	bitmapData := makeBitmapData(image, rb, mediaInfo.SideMarginPins, dy)
+	data = append(data, bitmapData...)
 
 	// Print command with feeding.
 	return append(data, 0x1a)

ql/ql_linux.go

@@ -172,8 +172,8 @@ var errErrorOccurred = errors.New("error occurred")
 var errUnexpectedStatus = errors.New("unexpected status")
 var errUnknownMedia = errors.New("unknown media")
 
-func (p *Printer) Print(image image.Image) error {
+func (p *Printer) Print(image image.Image, rb bool) error {
-	data := makePrintData(p.LastStatus, image)
+	data := makePrintData(p.LastStatus, image, rb)
 	if data == nil {
 		return errUnknownMedia
 	}