Handle Lossless

cmd/cbconvert-gui/state.go

@@ -1,10 +1,40 @@
 package main
 
 import (
+	"runtime/debug"
+	"strings"
+
 	"github.com/gen2brain/cbconvert/cmd/cbconvert-gui/i18n"
 	"github.com/gen2brain/iup-go/iup"
 )
 
+// jxlLosslessBuild reports whether wasm2go and nodynamic leave zune-jpegxl (lossless-only) as the only jxl encoder.
+var jxlLosslessBuild = func() bool {
+	info, ok := debug.ReadBuildInfo()
+	if !ok {
+		return false
+	}
+	var wasm2go, nodynamic bool
+	for _, kv := range info.Settings {
+		if kv.Key != "-tags" {
+			continue
+		}
+		for _, t := range strings.Split(kv.Value, ",") {
+			switch t {
+			case "wasm2go":
+				wasm2go = true
+			case "nodynamic":
+				nodynamic = true
+			}
+		}
+	}
+	return wasm2go && nodynamic
+}()
+
+// userLossless is the user's Lossless preference, tracked separately because a jxl
+// wasm2go build force-sets the widget on.
+var userLossless bool
+
 func setActive() {
 	if busy {
 		return
@@ -68,7 +98,15 @@ func setActive() {
 	}
 
 	canLossless := opts.Format == "webp" || opts.Format == "avif" || opts.Format == "jxl"
-	losslessOn := canLossless && opts.Lossless
+	jxlLossless := jxlLosslessBuild && opts.Format == "jxl"
+
+	// jxl wasm2go forces lossless on; otherwise show the user's preference so it doesn't stay stuck on.
+	losslessVal := "OFF"
+	if jxlLossless || userLossless {
+		losslessVal = "ON"
+	}
+	iup.GetHandle("Lossless").SetAttribute("VALUE", losslessVal)
+	losslessOn := jxlLossless || (canLossless && userLossless)
 
 	if (opts.Format == "jpeg" || canLossless) && !opts.NoConvert && !losslessOn {
 		iup.GetHandle("VboxQuality").SetAttribute("ACTIVE", "YES")
@@ -84,6 +122,11 @@ func setActive() {
 		iup.GetHandle("Lossless").SetAttribute("ACTIVE", "NO")
 	}
 
+	if jxlLossless {
+		iup.GetHandle("Lossless").SetAttribute("ACTIVE", "NO")
+		iup.GetHandle("VboxEffort").SetAttribute("ACTIVE", "NO")
+	}
+
 	if opts.Width != 0 && opts.Height != 0 && !opts.NoConvert {
 		iup.GetHandle("Fit").SetAttribute("ACTIVE", "YES")
 	} else {