From 6f3c026ec7f3b8d8c121b6f77dd51a6e8c519e57 Mon Sep 17 00:00:00 2001
From: Zibi Braniecki <zbraniecki@mozilla.com>
Date: Mon, 2 Aug 2021 09:54:08 +0000
Subject: [PATCH] Bug 1613705 - [localization] part4: Enable observer on
 Localization. r=emilio,nika

Depends on D111178

Differential Revision: https://phabricator.services.mozilla.com/D113247
---
 intl/l10n/Localization.cpp                 | 22 +++++++++++++++++++---
 intl/l10n/Localization.h                   |  9 +++++++--
 intl/l10n/rust/localization-ffi/src/lib.rs | 14 +++++++++++++-
 3 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/intl/l10n/Localization.cpp b/intl/l10n/Localization.cpp
index de48a4950ab0..eae9be6d206a 100644
--- a/intl/l10n/Localization.cpp
+++ b/intl/l10n/Localization.cpp
@@ -82,14 +82,15 @@ static FallibleTArray<Nullable<L10nMessage>> ConvertToL10nMessages(
   return l10nMessages;
 }
 
-NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(Localization, mGlobal)
 NS_IMPL_CYCLE_COLLECTING_ADDREF(Localization)
 NS_IMPL_CYCLE_COLLECTING_RELEASE(Localization)
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(Localization)
   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
   NS_INTERFACE_MAP_ENTRY(nsIObserver)
-  NS_INTERFACE_MAP_ENTRY(nsISupports)
+  NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIObserver)
 NS_INTERFACE_MAP_END
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_WEAK(Localization, mGlobal)
 
 /* static */
 already_AddRefed<Localization> Localization::Create(
@@ -100,12 +101,14 @@ already_AddRefed<Localization> Localization::Create(
 Localization::Localization(const nsTArray<nsCString>& aResIds, bool aIsSync)
     : mIsSync(aIsSync) {
   ffi::localization_new(&aResIds, mIsSync, getter_AddRefs(mRaw));
+  RegisterObservers();
 }
 
 Localization::Localization(nsIGlobalObject* aGlobal,
                            const nsTArray<nsCString>& aResIds, bool aIsSync)
     : mGlobal(aGlobal), mIsSync(aIsSync) {
   ffi::localization_new(&aResIds, mIsSync, getter_AddRefs(mRaw));
+  RegisterObservers();
 }
 
 Localization::Localization(nsIGlobalObject* aGlobal,
@@ -120,12 +123,14 @@ Localization::Localization(nsIGlobalObject* aGlobal, bool aIsSync)
     : mGlobal(aGlobal), mIsSync(aIsSync) {
   nsTArray<nsCString> resIds;
   ffi::localization_new(&resIds, mIsSync, getter_AddRefs(mRaw));
+  RegisterObservers();
 }
 
 Localization::Localization(nsIGlobalObject* aGlobal)
     : mGlobal(aGlobal), mIsSync(false) {
   nsTArray<nsCString> resIds;
   ffi::localization_new(&resIds, mIsSync, getter_AddRefs(mRaw));
+  RegisterObservers();
 }
 
 already_AddRefed<Localization> Localization::Constructor(
@@ -167,7 +172,18 @@ Localization::Observe(nsISupports* aSubject, const char* aTopic,
   return NS_OK;
 }
 
-void Localization::OnChange() {}
+void Localization::RegisterObservers() {
+  DebugOnly<nsresult> rv = Preferences::AddWeakObservers(this, kObservedPrefs);
+  MOZ_ASSERT(NS_SUCCEEDED(rv), "Adding observers failed.");
+
+  nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+
+  if (obs) {
+    obs->AddObserver(this, INTL_APP_LOCALES_CHANGED, true);
+  }
+}
+
+void Localization::OnChange() { ffi::localization_on_change(mRaw.get()); }
 
 void Localization::SetIsSync(bool aIsSync) {
   MOZ_ASSERT(!aIsSync, "We should only move from sync to async!");
diff --git a/intl/l10n/Localization.h b/intl/l10n/Localization.h
index f6c25581bbe3..4d8af7337d46 100644
--- a/intl/l10n/Localization.h
+++ b/intl/l10n/Localization.h
@@ -9,6 +9,7 @@
 
 #include "nsCycleCollectionParticipant.h"
 #include "nsIObserver.h"
+#include "nsWeakReference.h"
 #include "nsWrapperCache.h"
 #include "mozilla/ErrorResult.h"
 #include "mozilla/dom/Promise.h"
@@ -20,13 +21,16 @@
 namespace mozilla {
 namespace intl {
 
-class Localization : public nsIObserver, public nsWrapperCache {
+class Localization : public nsIObserver,
+                     public nsWrapperCache,
+                     public nsSupportsWeakReference {
   template <typename T, typename... Args>
   friend already_AddRefed<T> mozilla::MakeAndAddRef(Args&&... aArgs);
 
  public:
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
-  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(Localization)
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_AMBIGUOUS(Localization,
+                                                         nsIObserver)
   NS_DECL_NSIOBSERVER
 
   static already_AddRefed<Localization> Constructor(
@@ -82,6 +86,7 @@ class Localization : public nsIObserver, public nsWrapperCache {
   Localization(nsIGlobalObject* aGlobal, bool aIsSync);
   virtual ~Localization();
 
+  void RegisterObservers();
   virtual void OnChange();
   already_AddRefed<dom::Promise> MaybeWrapPromise(dom::Promise* aInnerPromise);
 
diff --git a/intl/l10n/rust/localization-ffi/src/lib.rs b/intl/l10n/rust/localization-ffi/src/lib.rs
index ed4cc79c2600..dbffe7e47cbd 100644
--- a/intl/l10n/rust/localization-ffi/src/lib.rs
+++ b/intl/l10n/rust/localization-ffi/src/lib.rs
@@ -168,6 +168,10 @@ impl LocalizationRc {
         self.inner.borrow().is_sync()
     }
 
+    pub fn on_change(&self) {
+        self.inner.borrow_mut().on_change();
+    }
+
     pub fn format_value_sync(
         &self,
         id: &nsACString,
@@ -328,7 +332,10 @@ impl LocalizationRc {
 
             assert_eq!(keys.len(), ret_val.len());
 
-            let errors = errors.into_iter().map(|err| err.to_string().into()).collect();
+            let errors = errors
+                .into_iter()
+                .map(|err| err.to_string().into())
+                .collect();
 
             callback(&strong_promise, &ret_val, &errors);
         })
@@ -519,3 +526,8 @@ pub extern "C" fn localization_format_messages(
 pub extern "C" fn localization_upgrade(loc: &LocalizationRc) {
     loc.upgrade();
 }
+
+#[no_mangle]
+pub extern "C" fn localization_on_change(loc: &LocalizationRc) {
+    loc.on_change();
+}