From c4f236bdf9614b52e436e2365b408cfdc3ebdae8 Mon Sep 17 00:00:00 2001
From: Milan Nikolic <gen2brain@gmail.com>
Date: Wed, 24 Jun 2026 13:16:09 +0200
Subject: [PATCH] Add Command button, issue #33

---
 cbconvert.go              | 50 +++++++++++++++++++++++++++++++++++++++
 cbconvert_test.go         | 21 ++++++++++++++++
 cmd/cbconvert-gui/main.go | 38 +++++++++++++++++++++++++++--
 3 files changed, 107 insertions(+), 2 deletions(-)

diff --git a/cbconvert.go b/cbconvert.go
index 49a53d5..3540268 100644
--- a/cbconvert.go
+++ b/cbconvert.go
@@ -153,6 +153,56 @@ func New(o Options) *Converter {
 	return c
 }
 
+// Args returns the non-default options as cbconvert convert command-line flags.
+func (o Options) Args() []string {
+	def := NewOptions()
+
+	var args []string
+
+	str := func(name, val, dflt string) {
+		if val != dflt {
+			args = append(args, "--"+name, val)
+		}
+	}
+	num := func(name string, val, dflt int) {
+		if val != dflt {
+			args = append(args, "--"+name, strconv.Itoa(val))
+		}
+	}
+	flag := func(name string, val bool) {
+		if val {
+			args = append(args, "--"+name)
+		}
+	}
+
+	num("width", o.Width, def.Width)
+	num("height", o.Height, def.Height)
+	flag("fit", o.Fit)
+	str("format", o.Format, def.Format)
+	str("archive", o.Archive, def.Archive)
+	num("zip-level", o.ZipLevel, def.ZipLevel)
+	num("quality", o.Quality, def.Quality)
+	num("effort", o.Effort, def.Effort)
+	flag("lossless", o.Lossless)
+	flag("combine", o.Combine)
+	str("outfile", o.OutFile, def.OutFile)
+	num("filter", o.Filter, def.Filter)
+	flag("no-cover", o.NoCover)
+	flag("no-rgb", o.NoRGB)
+	flag("no-nonimage", o.NoNonImage)
+	flag("no-convert", o.NoConvert)
+	str("suffix", o.Suffix, def.Suffix)
+	flag("grayscale", o.Grayscale)
+	num("rotate", o.Rotate, def.Rotate)
+	num("brightness", o.Brightness, def.Brightness)
+	num("contrast", o.Contrast, def.Contrast)
+	flag("recursive", o.Recursive)
+	str("outdir", o.OutDir, def.OutDir)
+	num("size", o.Size, def.Size)
+
+	return args
+}
+
 // Cancel cancels the operation.
 func (c *Converter) Cancel() {
 	if c.OnCancel != nil {
diff --git a/cbconvert_test.go b/cbconvert_test.go
index 6a0600b..67b55de 100644
--- a/cbconvert_test.go
+++ b/cbconvert_test.go
@@ -103,6 +103,27 @@ func TestThumbnail(t *testing.T) {
 	}
 }
 
+func TestArgs(t *testing.T) {
+	opts := NewOptions()
+	if got := opts.Args(); len(got) != 0 {
+		t.Errorf("defaults should emit no flags, got %v", got)
+	}
+
+	opts.Format = "webp"
+	opts.Quality = 90
+	opts.Effort = 4
+	opts.Lossless = true
+	opts.Width = 1200
+	opts.Grayscale = true
+	opts.OutDir = "/out"
+
+	got := strings.Join(opts.Args(), " ")
+	want := "--width 1200 --format webp --quality 90 --effort 4 --lossless --grayscale --outdir /out"
+	if got != want {
+		t.Errorf("Args() = %q, want %q", got, want)
+	}
+}
+
 func TestConvertResize(t *testing.T) {
 	tmpDir, err := os.MkdirTemp(os.TempDir(), "cbc")
 	if err != nil {
diff --git a/cmd/cbconvert-gui/main.go b/cmd/cbconvert-gui/main.go
index 52e63dd..deb7044 100644
--- a/cmd/cbconvert-gui/main.go
+++ b/cmd/cbconvert-gui/main.go
@@ -310,6 +310,34 @@ func setActive() {
 	}
 }
 
+// shellArg quotes a command-line argument that contains whitespace.
+func shellArg(s string) string {
+	if strings.ContainsAny(s, " \t") {
+		return `"` + strings.ReplaceAll(s, `"`, `\"`) + `"`
+	}
+
+	return s
+}
+
+func commandLine() string {
+	parts := append([]string{"cbconvert", "convert"}, options().Args()...)
+	for _, file := range files {
+		parts = append(parts, file.Path)
+	}
+
+	for i, p := range parts {
+		parts[i] = shellArg(p)
+	}
+
+	return strings.Join(parts, " ")
+}
+
+func onCommand(iup.Ihandle) int {
+	iup.GetText("Command Line", commandLine(), -1)
+
+	return iup.DEFAULT
+}
+
 // zipLevel maps the compression dropdown selection to Options.ZipLevel.
 func zipLevel(value string) int {
 	switch value {
@@ -1083,11 +1111,16 @@ func buttons() iup.Ihandle {
 		SetAttribute("TIP", "Save current settings to a profile").
 		SetCallback("ACTION", iup.ActionFunc(onSave))
 
-	profile := iup.List().SetAttributes("DROPDOWN=YES, EXPAND=HORIZONTAL").SetHandle("Profile").
+	command := iup.Button("Command").SetAttributes("PADDING=DEFAULTBUTTONPADDING").
+		SetAttribute("TIP", "Show the equivalent command line").
+		SetCallback("ACTION", iup.ActionFunc(onCommand))
+
+	profile := iup.List().SetAttributes("DROPDOWN=YES").SetHandle("Profile").
 		SetAttribute("TIP", "Select a settings profile").
 		SetCallback("VALUECHANGED_CB", iup.ValueChangedFunc(onProfileSelect))
 
-	iup.Normalizer(addFiles, addDir, remove, removeAll, thumbnail, cover, convert, reset, save).SetAttribute("NORMALIZE", "BOTH")
+	iup.Normalizer(addFiles, addDir, remove, removeAll, thumbnail, cover, convert, reset, save, command).SetAttribute("NORMALIZE", "BOTH")
+	iup.Normalizer(addFiles, addDir, remove, removeAll, thumbnail, cover, convert, reset, save, command, profile).SetAttribute("NORMALIZE", "HORIZONTAL")
 
 	return iup.Vbox(
 		iup.Vbox(
@@ -1111,6 +1144,7 @@ func buttons() iup.Ihandle {
 			profile,
 			reset,
 			save,
+			command,
 		).SetAttribute("NGAP", "2"),
 	).SetHandle("Buttons").SetAttributes("ALIGNMENT=ACENTER")
 }