general: Add translation infrastructure

src/application.rs

@@ -18,6 +18,7 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 use crate::deps::*;
+use crate::i18n::*;
 
 use adw::prelude::*;
 use adw::subclass::prelude::*;
@@ -173,9 +174,9 @@ impl LpApplication {
                 String::from("Jakub Steiner"),
                 String::from("Tobias Bernard"),
             ])
-            .copyright("© 2021 The GNOME Project")
+            .copyright(&i18n("© 2021 The GNOME Project"))
             .license_type(gtk::License::Gpl30)
-            .program_name("Image Viewer")
+            .program_name(&i18n("Image Viewer"))
             .logo_icon_name(config::APP_ID)
             .version(config::VERSION)
             .build();

src/i18n.rs

@@ -0,0 +1,221 @@
+// i18n.rs
+//
+// Copyright 2018 Daniel García Moreno <danigm@wadobo.com>
+//
+// Copied from https://gitlab.gnome.org/GNOME/fractal/-/blob/376248fd4a3bff05897ef39111a4e6d1a558f333/fractal-gtk/src/util/i18n.rs
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+use gettextrs::gettext;
+use gettextrs::ngettext;
+use gettextrs::npgettext;
+use gettextrs::pgettext;
+use regex::Captures;
+use regex::Regex;
+
+#[allow(dead_code)]
+fn freplace(input: String, args: &[&str]) -> String {
+    let mut parts = input.split("{}");
+    let mut output = parts.next().unwrap_or_default().to_string();
+    for (p, a) in parts.zip(args.iter()) {
+        output += &(a.to_string() + &p.to_string());
+    }
+    output
+}
+
+#[allow(dead_code)]
+fn kreplace(input: String, kwargs: &[(&str, &str)]) -> String {
+    let mut s = input;
+    for (k, v) in kwargs {
+        if let Ok(re) = Regex::new(&format!("\\{{{}\\}}", k)) {
+            s = re
+                .replace_all(&s, |_: &Captures<'_>| v.to_string())
+                .to_string();
+        }
+    }
+
+    s
+}
+
+// Simple translations functions
+
+#[allow(dead_code)]
+pub fn i18n(format: &str) -> String {
+    gettext(format)
+}
+
+#[allow(dead_code)]
+pub fn i18n_f(format: &str, args: &[&str]) -> String {
+    let s = gettext(format);
+    freplace(s, args)
+}
+
+#[allow(dead_code)]
+pub fn i18n_k(format: &str, kwargs: &[(&str, &str)]) -> String {
+    let s = gettext(format);
+    kreplace(s, kwargs)
+}
+
+// Singular and plural translations functions
+
+#[allow(dead_code)]
+pub fn ni18n(single: &str, multiple: &str, number: u32) -> String {
+    ngettext(single, multiple, number)
+}
+
+#[allow(dead_code)]
+pub fn ni18n_f(single: &str, multiple: &str, number: u32, args: &[&str]) -> String {
+    let s = ngettext(single, multiple, number);
+    freplace(s, args)
+}
+
+#[allow(dead_code)]
+pub fn ni18n_k(single: &str, multiple: &str, number: u32, kwargs: &[(&str, &str)]) -> String {
+    let s = ngettext(single, multiple, number);
+    kreplace(s, kwargs)
+}
+
+// Translations with context functions
+
+#[allow(dead_code)]
+pub fn pi18n(ctx: &str, format: &str) -> String {
+    pgettext(ctx, format)
+}
+
+#[allow(dead_code)]
+pub fn pi18n_f(ctx: &str, format: &str, args: &[&str]) -> String {
+    let s = pgettext(ctx, format);
+    freplace(s, args)
+}
+
+#[allow(dead_code)]
+pub fn pi18n_k(ctx: &str, format: &str, kwargs: &[(&str, &str)]) -> String {
+    let s = pgettext(ctx, format);
+    kreplace(s, kwargs)
+}
+
+// Singular and plural with context
+
+#[allow(dead_code)]
+pub fn pni18n(ctx: &str, single: &str, multiple: &str, number: u32) -> String {
+    npgettext(ctx, single, multiple, number)
+}
+
+#[allow(dead_code)]
+pub fn pni18n_f(ctx: &str, single: &str, multiple: &str, number: u32, args: &[&str]) -> String {
+    let s = npgettext(ctx, single, multiple, number);
+    freplace(s, args)
+}
+
+#[allow(dead_code)]
+pub fn pni18n_k(
+    ctx: &str,
+    single: &str,
+    multiple: &str,
+    number: u32,
+    kwargs: &[(&str, &str)],
+) -> String {
+    let s = npgettext(ctx, single, multiple, number);
+    kreplace(s, kwargs)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn test_i18n() {
+        let out = i18n("translate1");
+        assert_eq!(out, "translate1");
+
+        let out = ni18n("translate1", "translate multi", 1);
+        assert_eq!(out, "translate1");
+        let out = ni18n("translate1", "translate multi", 2);
+        assert_eq!(out, "translate multi");
+    }
+
+    #[test]
+    fn test_i18n_f() {
+        let out = i18n_f("{} param", &["one"]);
+        assert_eq!(out, "one param");
+
+        let out = i18n_f("middle {} param", &["one"]);
+        assert_eq!(out, "middle one param");
+
+        let out = i18n_f("end {}", &["one"]);
+        assert_eq!(out, "end one");
+
+        let out = i18n_f("multiple {} and {}", &["one", "two"]);
+        assert_eq!(out, "multiple one and two");
+
+        let out = ni18n_f("singular {} and {}", "plural {} and {}", 2, &["one", "two"]);
+        assert_eq!(out, "plural one and two");
+        let out = ni18n_f("singular {} and {}", "plural {} and {}", 1, &["one", "two"]);
+        assert_eq!(out, "singular one and two");
+    }
+
+    #[test]
+    fn test_i18n_k() {
+        let out = i18n_k("{one} param", &[("one", "one")]);
+        assert_eq!(out, "one param");
+
+        let out = i18n_k("middle {one} param", &[("one", "one")]);
+        assert_eq!(out, "middle one param");
+
+        let out = i18n_k("end {one}", &[("one", "one")]);
+        assert_eq!(out, "end one");
+
+        let out = i18n_k("multiple {one} and {two}", &[("one", "1"), ("two", "two")]);
+        assert_eq!(out, "multiple 1 and two");
+
+        let out = i18n_k("multiple {two} and {one}", &[("one", "1"), ("two", "two")]);
+        assert_eq!(out, "multiple two and 1");
+
+        let out = i18n_k("multiple {one} and {one}", &[("one", "1"), ("two", "two")]);
+        assert_eq!(out, "multiple 1 and 1");
+
+        let out = ni18n_k(
+            "singular {one} and {two}",
+            "plural {one} and {two}",
+            1,
+            &[("one", "1"), ("two", "two")],
+        );
+        assert_eq!(out, "singular 1 and two");
+        let out = ni18n_k(
+            "singular {one} and {two}",
+            "plural {one} and {two}",
+            2,
+            &[("one", "1"), ("two", "two")],
+        );
+        assert_eq!(out, "plural 1 and two");
+    }
+
+    #[test]
+    fn test_pi18n() {
+        let out = pi18n("This is the context", "translate1");
+        assert_eq!(out, "translate1");
+
+        let out = pni18n("context", "translate1", "translate multi", 1);
+        assert_eq!(out, "translate1");
+        let out = pni18n("The context string", "translate1", "translate multi", 2);
+        assert_eq!(out, "translate multi");
+
+        let out = pi18n_f("Context for translation", "{} param", &["one"]);
+        assert_eq!(out, "one param");
+
+        let out = pi18n_k("context", "{one} param", &[("one", "one")]);
+        assert_eq!(out, "one param");
+    }
+}

src/main.rs

@@ -23,6 +23,7 @@ use gtk::gio::{self, prelude::*};
 mod application;
 mod config;
 mod file_model;
+mod i18n;
 mod thumbnail;
 mod util;
 mod widgets;

src/widgets/image_view.rs

@@ -18,6 +18,7 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 use crate::deps::*;
+use crate::i18n::*;
 
 use adw::subclass::prelude::*;
 use glib::clone;
@@ -375,8 +376,8 @@ impl LpImageView {
                 wallpaper::SetOn::Background,
             )
             .await {
-                Ok(_) => "Set as wallpaper.",
-                Err(_) => "Could not set wallpaper.",
+                Ok(_) => i18n("Set as wallpaper."),
+                Err(_) => i18n("Could not set wallpaper."),
             };
 
             view.activate_action(

src/window.rs

@@ -18,6 +18,7 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 use crate::deps::*;
+use crate::i18n::*;
 
 use adw::subclass::prelude::*;
 use glib::clone;
@@ -180,7 +181,7 @@ mod imp {
                         obj.set_image_from_file(&file, false);
                     } else {
                         obj.show_toast(
-                            format!("\"{}\" is not a valid image.", info.display_name()),
+                            i18n_f("\"{}\" is not a valid image.", &[&info.display_name()]),
                             adw::ToastPriority::High,
                         );
                     }
@@ -296,7 +297,7 @@ impl LpWindow {
         if let Err(e) = imp.image_view.copy() {
             log::error!("Failed to copy to clipboard: {}", e);
         } else {
-            self.show_toast("Image copied to clipboard", adw::ToastPriority::High);
+            self.show_toast(i18n("Image copied to clipboard"), adw::ToastPriority::High);
         }
     }
 
@@ -380,7 +381,7 @@ impl LpWindow {
     #[template_callback]
     fn window_title(&self, file: Option<gio::File>) -> String {
         file.and_then(|f| util::get_file_display_name(&f)) // If the file exists, get display name
-            .unwrap_or_else(|| String::from("Image Viewer")) // Return that or the default if there's nothing
+            .unwrap_or_else(|| i18n("Image Viewer")) // Return that or the default if there's nothing
     }
 
     // We also have a closure that returns `adw::FlapFoldPolicy`.