Allow additional l10n resource in AppLauncher

CHANGELOG.md

@@ -12,6 +12,7 @@ You can find its changes [documented below](#070---2021-01-01).
 - WindowCloseRequested/WindowDisconnected event when a window is closing ([#1254] by [@rjwittams])
 - RichTextBuilder ([#1520] by [@Maan2003])
 - `get_external_handle` on `DelegateCtx` ([#1526] by [@Maan2003])
+- `AppLauncher::localization_resources` to use custom l10n resources. ([#1528] by [@edwin0cheng])
 
 ### Changed
 

druid/src/app.rs

@@ -33,6 +33,7 @@ type EnvSetupFn<T> = dyn FnOnce(&mut Env, &T);
 pub struct AppLauncher<T> {
     windows: Vec<WindowDesc<T>>,
     env_setup: Option<Box<EnvSetupFn<T>>>,
+    l10n_resources: Option<(Vec<String>, String)>,
     delegate: Option<Box<dyn AppDelegate<T>>>,
     ext_event_host: ExtEventHost,
 }
@@ -107,6 +108,7 @@ impl<T: Data> AppLauncher<T> {
         AppLauncher {
             windows: vec![window],
             env_setup: None,
+            l10n_resources: None,
             delegate: None,
             ext_event_host: ExtEventHost::new(),
         }
@@ -146,6 +148,19 @@ impl<T: Data> AppLauncher<T> {
         self
     }
 
+    /// Use custom localization resource
+    ///
+    /// `resources` is a list of file names that contain strings. `base_dir`
+    /// is a path to a directory that includes per-locale subdirectories.
+    ///
+    /// This directory should be of the structure `base_dir/{locale}/{resource}`,
+    /// where '{locale}' is a valid BCP47 language tag, and {resource} is a `.ftl`
+    /// included in `resources`.
+    pub fn localization_resources(mut self, resources: Vec<String>, base_dir: String) -> Self {
+        self.l10n_resources = Some((resources, base_dir));
+        self
+    }
+
     /// Returns an [`ExtEventSink`] that can be moved between threads,
     /// and can be used to submit commands back to the application.
     ///
@@ -161,7 +176,11 @@ impl<T: Data> AppLauncher<T> {
     pub fn launch(mut self, data: T) -> Result<(), PlatformError> {
         let app = Application::new()?;
 
-        let mut env = Env::default();
+        let mut env = self
+            .l10n_resources
+            .map(|it| Env::with_i10n(it.0, &it.1))
+            .unwrap_or_default();
+
         if let Some(f) = self.env_setup.take() {
             f(&mut env, &data);
         }

druid/src/env.rs

@@ -467,37 +467,43 @@ impl Data for EnvImpl {
     }
 }
 
+// Colors are from https://sashat.me/2017/01/11/list-of-20-simple-distinct-colors/
+// They're picked for visual distinction and accessbility (99 percent)
+const DEBUG_COLOR: &[Color] = &[
+    Color::rgb8(230, 25, 75),
+    Color::rgb8(60, 180, 75),
+    Color::rgb8(255, 225, 25),
+    Color::rgb8(0, 130, 200),
+    Color::rgb8(245, 130, 48),
+    Color::rgb8(70, 240, 240),
+    Color::rgb8(240, 50, 230),
+    Color::rgb8(250, 190, 190),
+    Color::rgb8(0, 128, 128),
+    Color::rgb8(230, 190, 255),
+    Color::rgb8(170, 110, 40),
+    Color::rgb8(255, 250, 200),
+    Color::rgb8(128, 0, 0),
+    Color::rgb8(170, 255, 195),
+    Color::rgb8(0, 0, 128),
+    Color::rgb8(128, 128, 128),
+    Color::rgb8(255, 255, 255),
+    Color::rgb8(0, 0, 0),
+];
+
 impl Default for Env {
     fn default() -> Self {
-        let l10n = L10nManager::new(vec!["builtin.ftl".into()], "./resources/i18n/");
-
-        // Colors are from https://sashat.me/2017/01/11/list-of-20-simple-distinct-colors/
-        // They're picked for visual distinction and accessbility (99 percent)
-        let debug_colors = vec![
-            Color::rgb8(230, 25, 75),
-            Color::rgb8(60, 180, 75),
-            Color::rgb8(255, 225, 25),
-            Color::rgb8(0, 130, 200),
-            Color::rgb8(245, 130, 48),
-            Color::rgb8(70, 240, 240),
-            Color::rgb8(240, 50, 230),
-            Color::rgb8(250, 190, 190),
-            Color::rgb8(0, 128, 128),
-            Color::rgb8(230, 190, 255),
-            Color::rgb8(170, 110, 40),
-            Color::rgb8(255, 250, 200),
-            Color::rgb8(128, 0, 0),
-            Color::rgb8(170, 255, 195),
-            Color::rgb8(0, 0, 128),
-            Color::rgb8(128, 128, 128),
-            Color::rgb8(255, 255, 255),
-            Color::rgb8(0, 0, 0),
-        ];
+        Env::with_i10n(vec!["builtin.ftl".into()], "./resources/i18n/")
+    }
+}
+
+impl Env {
+    pub(crate) fn with_i10n(resources: Vec<String>, base_dir: &str) -> Self {
+        let l10n = L10nManager::new(resources, base_dir);
 
         let inner = EnvImpl {
             l10n: Arc::new(l10n),
             map: HashMap::new(),
-            debug_colors,
+            debug_colors: DEBUG_COLOR.into(),
         };
 
         let env = Env(Arc::new(inner))