refactor: add STOPPING state for RimeLifecycle

Notify subscribers before the engine is about to stop that the engine is about to stop instead of being in a ready state.

Author: WhiredPlanck

app/src/main/java/com/osfans/trime/core/Rime.kt

@@ -138,7 +138,13 @@ class Rime : RimeApi, RimeLifecycleOwner {
             Timber.w("Skip stopping rime: not at ready state!")
             return
         }
-        dispatcher.stop()
+        lifecycleImpl.emitState(RimeLifecycle.State.STOPPING)
+        Timber.i("Rime finalize()")
+        dispatcher.stop().let {
+            if (it.isNotEmpty()) {
+                Timber.w("${it.size} job(s) didn't get a chance to run!")
+            }
+        }
         lifecycleImpl.emitState(RimeLifecycle.State.STOPPED)
         unregisterRimeNotificationHandler(::handleRimeNotification)
     }

app/src/main/java/com/osfans/trime/core/RimeLifecycle.kt

@@ -34,8 +34,12 @@ class RimeLifecycleImpl : RimeLifecycle {
                 checkAtState(RimeLifecycle.State.STARTING)
                 internalStateFlow.value = RimeLifecycle.State.READY
             }
-            RimeLifecycle.State.STOPPED -> {
+            RimeLifecycle.State.STOPPING -> {
                 checkAtState(RimeLifecycle.State.READY)
+                internalStateFlow.value = RimeLifecycle.State.STOPPING
+            }
+            RimeLifecycle.State.STOPPED -> {
+                checkAtState(RimeLifecycle.State.STOPPING)
                 internalStateFlow.value = RimeLifecycle.State.STOPPED
             }
         }
@@ -53,6 +57,7 @@ interface RimeLifecycle {
     enum class State {
         STARTING,
         READY,
+        STOPPING,
         STOPPED,
     }
 }