Translations: disable gettext by default for C++ and the viewer

api/cpp/CMakeLists.txt

@@ -110,6 +110,7 @@ define_cargo_feature(renderer-winit-software "Enable support for the software re
 define_cargo_feature(backend-qt "Enable Qt based rendering backend" ON)
 
 define_cargo_feature(experimental "Enable experimental features (no compatibility guarantees)" OFF)
+define_cargo_feature(gettext "Enable support of translations using gettext" OFF)
 
 # Compat options
 option(SLINT_FEATURE_BACKEND_GL_ALL "This feature is an alias for SLINT_FEATURE_BACKEND_WINIT and SLINT_FEATURE_RENDERER_WINIT_FEMTOVG." OFF)

api/cpp/Cargo.toml

@@ -35,6 +35,7 @@ renderer-winit-skia = ["i-slint-backend-selector/renderer-winit-skia"]
 renderer-winit-skia-opengl = ["i-slint-backend-selector/renderer-winit-skia-opengl"]
 renderer-winit-skia-vulkan = ["i-slint-backend-selector/renderer-winit-skia-vulkan"]
 renderer-winit-software = ["i-slint-backend-selector/renderer-winit-software"]
+gettext = ["i-slint-core/gettext-rs"]
 
 experimental = ["i-slint-renderer-skia", "raw-window-handle"]
 
@@ -44,7 +45,7 @@ default = ["backend-winit", "renderer-winit-femtovg", "backend-qt", "experimenta
 i-slint-backend-selector = { version = "=1.0.3", path="../../internal/backends/selector" }
 i-slint-backend-testing = { version = "=1.0.3", path="../../internal/backends/testing", optional = true }
 i-slint-renderer-skia = { version = "=1.0.3", path="../../internal/renderers/skia", optional = true, features = ["x11", "wayland"] }
-i-slint-core = { version = "=1.0.3", path="../../internal/core", features = ["ffi", "gettext-rs"] }
+i-slint-core = { version = "=1.0.3", path="../../internal/core", features = ["ffi"] }
 slint-interpreter = { version = "=1.0.3", path="../../internal/interpreter", default-features = false, features = ["ffi", "compat-1-0"], optional = true }
 raw-window-handle = { version = "0.5", optional = true }
 # Enable image-rs' default features to make all image formats to C++ users

docs/language/src/concepts/translations.md

@@ -74,6 +74,7 @@ export component MenuItem {
 
 ## Extract Translatable Strings
 
+
 Use the `slint-tr-extractor` tool to generate a `.pot` file from `.slint` files.
 You can run it like so:
 
@@ -151,7 +152,7 @@ With these sttings, Slint will look for `gallery.mo` in the `lang/fr/LC_MESSAGES
 
 ### Select and Load Translations with C++
 
-TODO: Adjust this to whatever we determine as the final mechanism of accessing gettext.
+You need to enable the feature by passing `-DSLINT_FEATURE_GETTEXT=1` when compiling Slint.
 
 In C++ application using cmake, the `domain_name` is the CMake target name.
 
@@ -187,5 +188,8 @@ int main()
 
 ## Previewing Translations with `slint-viewer`
 
+The `slint-viewer` need to be compiled with the `gettext` feature
+
 When previewing `.slint` files with `slint-viewer`, use the `--translation-domain` and `--translation-dir`.
 command line option to automatically load translations and display them based on the current locale.
+

tools/viewer/Cargo.toml

@@ -27,6 +27,13 @@ renderer-winit-skia = ["slint-interpreter/renderer-winit-skia"]
 renderer-winit-skia-opengl = ["slint-interpreter/renderer-winit-skia-opengl"]
 renderer-winit-skia-vulkan = ["slint-interpreter/renderer-winit-skia-vulkan"]
 
+## Enable the translations using [gettext](https://www.gnu.org/software/gettext/gettext)
+##
+## the `@tr(...)` code from .slint files will be transformed into call to `dgettext`.
+## You should pass --translation-domain and --translation-dir command line argument
+## so that the viewer can find the translation
+gettext = ["i-slint-core/gettext-rs"]
+
 # Compat
 backend-gl-all = ["backend-winit", "renderer-winit-femtovg"]
 backend-gl-wayland = ["backend-winit-wayland", "renderer-winit-femtovg"]
@@ -35,7 +42,7 @@ backend-gl-x11 = ["backend-winit-x11", "renderer-winit-femtovg"]
 default = ["backend-qt", "backend-winit", "renderer-winit-femtovg"]
 
 [dependencies]
-i-slint-core = { version = "=1.0.3", path="../../internal/core", features = ["gettext-rs"] }
+i-slint-core = { version = "=1.0.3", path="../../internal/core" }
 slint-interpreter = { version = "=1.0.3", path = "../../internal/interpreter", default-features = false, features = ["display-diagnostics", "compat-1-0"] }
 i-slint-backend-selector = { version = "=1.0.3", path="../../internal/backends/selector" }
 

tools/viewer/main.rs

@@ -53,10 +53,13 @@ struct Cli {
     #[arg(long, value_names(&["callback", "handler"]), number_of_values = 2, action)]
     on: Vec<String>,
 
+    #[cfg(feature = "gettext")]
     /// Translation domain
     #[arg(long = "translation-domain", action)]
     translation_domain: Option<String>,
 
+    #[cfg(feature = "gettext")]
+    /// Translation directory where the translation files are searched for
     #[arg(long = "translation-dir", action)]
     translation_dir: Option<std::path::PathBuf>,
 }
@@ -77,6 +80,7 @@ fn main() -> Result<()> {
         std::env::set_var("SLINT_BACKEND", backend);
     }
 
+    #[cfg(feature = "gettext")]
     if let Some(dirname) = args.translation_dir.clone() {
         i_slint_core::translations::gettext_bindtextdomain(
             args.translation_domain.as_ref().map(String::as_str).unwrap_or_default(),
@@ -153,6 +157,7 @@ fn init_compiler(
     fswatcher: Option<Arc<Mutex<notify::RecommendedWatcher>>>,
 ) -> slint_interpreter::ComponentCompiler {
     let mut compiler = slint_interpreter::ComponentCompiler::default();
+    #[cfg(feature = "gettext")]
     if let Some(domain) = args.translation_domain.clone() {
         compiler.set_translation_domain(domain);
     }