Replace MessageComposerNotice with MessageComposerViewEvent to handle transient UI feedback as one-shot side effects.

- Rename `MessageComposerNotice` to `MessageComposerViewEvent`.
- Replace the `notices` list in `MessageComposerState` with an `events` `SharedFlow` in `MessageComposerController`.
- Remove `dismissNotice()` and `emitNotice()` in favor of direct event emission.
- Update `MessageComposerController` to emit `CommandUnavailable` events when commands are triggered in incompatible modes (e.g., during editing).
- Update unit tests to collect and verify events using the `test` library.

Author: andremion

stream-chat-android-compose/src/main/java/io/getstream/chat/android/compose/viewmodel/messages/MessageComposerViewModel.kt

@@ -31,6 +31,7 @@ import io.getstream.chat.android.ui.common.state.messages.MessageInput
 import io.getstream.chat.android.ui.common.state.messages.MessageMode
 import io.getstream.chat.android.ui.common.state.messages.Reply
 import io.getstream.chat.android.ui.common.state.messages.composer.MessageComposerState
+import io.getstream.chat.android.ui.common.state.messages.composer.MessageComposerViewEvent
 import io.getstream.chat.android.ui.common.utils.typing.TypingUpdatesBuffer
 import io.getstream.result.Result
 import io.getstream.result.call.Call
@@ -56,6 +57,12 @@ public class MessageComposerViewModel(
      */
     public val inputFocusEvents: SharedFlow<Unit> = messageComposerController.inputFocusEvents
 
+    /**
+     * One-shot events emitted by the composer, such as feedback for unavailable commands. UI
+     * layers collect this flow and react with transient UI.
+     */
+    public val events: SharedFlow<MessageComposerViewEvent> = messageComposerController.events
+
     /**
      * The full UI state that has all the required data.
      */

stream-chat-android-ui-common/api/stream-chat-android-ui-common.api

@@ -2281,21 +2281,6 @@ public final class io/getstream/chat/android/ui/common/state/messages/composer/A
 	public fun toString ()Ljava/lang/String;
 }
 
-public abstract interface class io/getstream/chat/android/ui/common/state/messages/composer/MessageComposerNotice {
-}
-
-public final class io/getstream/chat/android/ui/common/state/messages/composer/MessageComposerNotice$CommandUnavailable : io/getstream/chat/android/ui/common/state/messages/composer/MessageComposerNotice {
-	public static final field $stable I
-	public fun <init> (Lio/getstream/chat/android/ui/common/state/messages/MessageAction;)V
-	public final fun component1 ()Lio/getstream/chat/android/ui/common/state/messages/MessageAction;
-	public final fun copy (Lio/getstream/chat/android/ui/common/state/messages/MessageAction;)Lio/getstream/chat/android/ui/common/state/messages/composer/MessageComposerNotice$CommandUnavailable;
-	public static synthetic fun copy$default (Lio/getstream/chat/android/ui/common/state/messages/composer/MessageComposerNotice$CommandUnavailable;Lio/getstream/chat/android/ui/common/state/messages/MessageAction;ILjava/lang/Object;)Lio/getstream/chat/android/ui/common/state/messages/composer/MessageComposerNotice$CommandUnavailable;
-	public fun equals (Ljava/lang/Object;)Z
-	public final fun getAction ()Lio/getstream/chat/android/ui/common/state/messages/MessageAction;
-	public fun hashCode ()I
-	public fun toString ()Ljava/lang/String;
-}
-
 public final class io/getstream/chat/android/ui/common/state/messages/composer/MessageComposerState {
 	public static final field $stable I
 	public fun <init> ()V
@@ -2317,8 +2302,7 @@ public final class io/getstream/chat/android/ui/common/state/messages/composer/M
 	public fun <init> (Ljava/lang/String;Ljava/util/List;Lio/getstream/chat/android/ui/common/state/messages/MessageAction;Ljava/util/List;Ljava/util/List;Ljava/util/List;Lio/getstream/chat/android/models/LinkPreview;ILio/getstream/chat/android/ui/common/state/messages/MessageMode;ZLjava/util/Set;ZLio/getstream/chat/android/models/User;Lio/getstream/chat/android/ui/common/state/messages/composer/RecordingState;ZZ)V
 	public fun <init> (Ljava/lang/String;Ljava/util/List;Lio/getstream/chat/android/ui/common/state/messages/MessageAction;Ljava/util/List;Ljava/util/List;Ljava/util/List;Lio/getstream/chat/android/models/LinkPreview;ILio/getstream/chat/android/ui/common/state/messages/MessageMode;ZLjava/util/Set;ZLio/getstream/chat/android/models/User;Lio/getstream/chat/android/ui/common/state/messages/composer/RecordingState;ZZLjava/util/Set;)V
 	public fun <init> (Ljava/lang/String;Ljava/util/List;Lio/getstream/chat/android/ui/common/state/messages/MessageAction;Ljava/util/List;Ljava/util/List;Ljava/util/List;Lio/getstream/chat/android/models/LinkPreview;ILio/getstream/chat/android/ui/common/state/messages/MessageMode;ZLjava/util/Set;ZLio/getstream/chat/android/models/User;Lio/getstream/chat/android/ui/common/state/messages/composer/RecordingState;ZZLjava/util/Set;Lio/getstream/chat/android/models/Command;)V
-	public fun <init> (Ljava/lang/String;Ljava/util/List;Lio/getstream/chat/android/ui/common/state/messages/MessageAction;Ljava/util/List;Ljava/util/List;Ljava/util/List;Lio/getstream/chat/android/models/LinkPreview;ILio/getstream/chat/android/ui/common/state/messages/MessageMode;ZLjava/util/Set;ZLio/getstream/chat/android/models/User;Lio/getstream/chat/android/ui/common/state/messages/composer/RecordingState;ZZLjava/util/Set;Lio/getstream/chat/android/models/Command;Ljava/util/List;)V
-	public synthetic fun <init> (Ljava/lang/String;Ljava/util/List;Lio/getstream/chat/android/ui/common/state/messages/MessageAction;Ljava/util/List;Ljava/util/List;Ljava/util/List;Lio/getstream/chat/android/models/LinkPreview;ILio/getstream/chat/android/ui/common/state/messages/MessageMode;ZLjava/util/Set;ZLio/getstream/chat/android/models/User;Lio/getstream/chat/android/ui/common/state/messages/composer/RecordingState;ZZLjava/util/Set;Lio/getstream/chat/android/models/Command;Ljava/util/List;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public synthetic fun <init> (Ljava/lang/String;Ljava/util/List;Lio/getstream/chat/android/ui/common/state/messages/MessageAction;Ljava/util/List;Ljava/util/List;Ljava/util/List;Lio/getstream/chat/android/models/LinkPreview;ILio/getstream/chat/android/ui/common/state/messages/MessageMode;ZLjava/util/Set;ZLio/getstream/chat/android/models/User;Lio/getstream/chat/android/ui/common/state/messages/composer/RecordingState;ZZLjava/util/Set;Lio/getstream/chat/android/models/Command;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
 	public final fun component1 ()Ljava/lang/String;
 	public final fun component10 ()Z
 	public final fun component11 ()Ljava/util/Set;
@@ -2329,7 +2313,6 @@ public final class io/getstream/chat/android/ui/common/state/messages/composer/M
 	public final fun component16 ()Z
 	public final fun component17 ()Ljava/util/Set;
 	public final fun component18 ()Lio/getstream/chat/android/models/Command;
-	public final fun component19 ()Ljava/util/List;
 	public final fun component2 ()Ljava/util/List;
 	public final fun component3 ()Lio/getstream/chat/android/ui/common/state/messages/MessageAction;
 	public final fun component4 ()Ljava/util/List;
@@ -2338,8 +2321,8 @@ public final class io/getstream/chat/android/ui/common/state/messages/composer/M
 	public final fun component7 ()Lio/getstream/chat/android/models/LinkPreview;
 	public final fun component8 ()I
 	public final fun component9 ()Lio/getstream/chat/android/ui/common/state/messages/MessageMode;
-	public final fun copy (Ljava/lang/String;Ljava/util/List;Lio/getstream/chat/android/ui/common/state/messages/MessageAction;Ljava/util/List;Ljava/util/List;Ljava/util/List;Lio/getstream/chat/android/models/LinkPreview;ILio/getstream/chat/android/ui/common/state/messages/MessageMode;ZLjava/util/Set;ZLio/getstream/chat/android/models/User;Lio/getstream/chat/android/ui/common/state/messages/composer/RecordingState;ZZLjava/util/Set;Lio/getstream/chat/android/models/Command;Ljava/util/List;)Lio/getstream/chat/android/ui/common/state/messages/composer/MessageComposerState;
-	public static synthetic fun copy$default (Lio/getstream/chat/android/ui/common/state/messages/composer/MessageComposerState;Ljava/lang/String;Ljava/util/List;Lio/getstream/chat/android/ui/common/state/messages/MessageAction;Ljava/util/List;Ljava/util/List;Ljava/util/List;Lio/getstream/chat/android/models/LinkPreview;ILio/getstream/chat/android/ui/common/state/messages/MessageMode;ZLjava/util/Set;ZLio/getstream/chat/android/models/User;Lio/getstream/chat/android/ui/common/state/messages/composer/RecordingState;ZZLjava/util/Set;Lio/getstream/chat/android/models/Command;Ljava/util/List;ILjava/lang/Object;)Lio/getstream/chat/android/ui/common/state/messages/composer/MessageComposerState;
+	public final fun copy (Ljava/lang/String;Ljava/util/List;Lio/getstream/chat/android/ui/common/state/messages/MessageAction;Ljava/util/List;Ljava/util/List;Ljava/util/List;Lio/getstream/chat/android/models/LinkPreview;ILio/getstream/chat/android/ui/common/state/messages/MessageMode;ZLjava/util/Set;ZLio/getstream/chat/android/models/User;Lio/getstream/chat/android/ui/common/state/messages/composer/RecordingState;ZZLjava/util/Set;Lio/getstream/chat/android/models/Command;)Lio/getstream/chat/android/ui/common/state/messages/composer/MessageComposerState;
+	public static synthetic fun copy$default (Lio/getstream/chat/android/ui/common/state/messages/composer/MessageComposerState;Ljava/lang/String;Ljava/util/List;Lio/getstream/chat/android/ui/common/state/messages/MessageAction;Ljava/util/List;Ljava/util/List;Ljava/util/List;Lio/getstream/chat/android/models/LinkPreview;ILio/getstream/chat/android/ui/common/state/messages/MessageMode;ZLjava/util/Set;ZLio/getstream/chat/android/models/User;Lio/getstream/chat/android/ui/common/state/messages/composer/RecordingState;ZZLjava/util/Set;Lio/getstream/chat/android/models/Command;ILjava/lang/Object;)Lio/getstream/chat/android/ui/common/state/messages/composer/MessageComposerState;
 	public fun equals (Ljava/lang/Object;)Z
 	public final fun getAction ()Lio/getstream/chat/android/ui/common/state/messages/MessageAction;
 	public final fun getActiveCommand ()Lio/getstream/chat/android/models/Command;
@@ -2353,7 +2336,6 @@ public final class io/getstream/chat/android/ui/common/state/messages/composer/M
 	public final fun getLinkPreview ()Lio/getstream/chat/android/models/LinkPreview;
 	public final fun getMentionSuggestions ()Ljava/util/List;
 	public final fun getMessageMode ()Lio/getstream/chat/android/ui/common/state/messages/MessageMode;
-	public final fun getNotices ()Ljava/util/List;
 	public final fun getOwnCapabilities ()Ljava/util/Set;
 	public final fun getPollsEnabled ()Z
 	public final fun getRecording ()Lio/getstream/chat/android/ui/common/state/messages/composer/RecordingState;
@@ -2364,6 +2346,21 @@ public final class io/getstream/chat/android/ui/common/state/messages/composer/M
 	public fun toString ()Ljava/lang/String;
 }
 
+public abstract interface class io/getstream/chat/android/ui/common/state/messages/composer/MessageComposerViewEvent {
+}
+
+public final class io/getstream/chat/android/ui/common/state/messages/composer/MessageComposerViewEvent$CommandUnavailable : io/getstream/chat/android/ui/common/state/messages/composer/MessageComposerViewEvent {
+	public static final field $stable I
+	public fun <init> (Lio/getstream/chat/android/ui/common/state/messages/MessageAction;)V
+	public final fun component1 ()Lio/getstream/chat/android/ui/common/state/messages/MessageAction;
+	public final fun copy (Lio/getstream/chat/android/ui/common/state/messages/MessageAction;)Lio/getstream/chat/android/ui/common/state/messages/composer/MessageComposerViewEvent$CommandUnavailable;
+	public static synthetic fun copy$default (Lio/getstream/chat/android/ui/common/state/messages/composer/MessageComposerViewEvent$CommandUnavailable;Lio/getstream/chat/android/ui/common/state/messages/MessageAction;ILjava/lang/Object;)Lio/getstream/chat/android/ui/common/state/messages/composer/MessageComposerViewEvent$CommandUnavailable;
+	public fun equals (Ljava/lang/Object;)Z
+	public final fun getAction ()Lio/getstream/chat/android/ui/common/state/messages/MessageAction;
+	public fun hashCode ()I
+	public fun toString ()Ljava/lang/String;
+}
+
 public abstract class io/getstream/chat/android/ui/common/state/messages/composer/RecordingState {
 	public static final field $stable I
 }

stream-chat-android-ui-common/src/main/kotlin/io/getstream/chat/android/ui/common/feature/messages/composer/MessageComposerController.kt

@@ -45,8 +45,8 @@ import io.getstream.chat.android.ui.common.state.messages.MessageInput
 import io.getstream.chat.android.ui.common.state.messages.MessageMode
 import io.getstream.chat.android.ui.common.state.messages.Reply
 import io.getstream.chat.android.ui.common.state.messages.ThreadReply
-import io.getstream.chat.android.ui.common.state.messages.composer.MessageComposerNotice
 import io.getstream.chat.android.ui.common.state.messages.composer.MessageComposerState
+import io.getstream.chat.android.ui.common.state.messages.composer.MessageComposerViewEvent
 import io.getstream.chat.android.ui.common.state.messages.composer.MessageValidator
 import io.getstream.chat.android.ui.common.state.messages.composer.RecordingState
 import io.getstream.chat.android.ui.common.state.messages.composer.isAvailableFor
@@ -254,6 +254,14 @@ public class MessageComposerController(
      */
     public val inputFocusEvents: SharedFlow<Unit> = _inputFocusEvents.asSharedFlow()
 
+    private val _events = MutableSharedFlow<MessageComposerViewEvent>(extraBufferCapacity = 1)
+
+    /**
+     * One-shot events emitted by the composer, such as feedback for unavailable commands. UI
+     * layers collect this flow and react with transient UI (e.g. a snackbar).
+     */
+    public val events: SharedFlow<MessageComposerViewEvent> = _events.asSharedFlow()
+
     // Insertion-ordered map keyed by attachment key (EXTRA_SOURCE_URI or fallback).
     // Tracks picker selections independently of edit-mode attachments, so selections
     // survive entering and exiting edit mode.
@@ -973,15 +981,15 @@ public class MessageComposerController(
      * command switches).
      *
      * When the command is not available for the current composer action (edit mode or a
-     * moderation command during reply), emits a [MessageComposerNotice.CommandUnavailable]
-     * into [MessageComposerState.notices] and returns without changing the active command.
+     * moderation command during reply), emits a [MessageComposerViewEvent.CommandUnavailable]
+     * on [events] and returns without changing the active command.
      *
      * @param command The command that was selected.
      */
     public fun selectCommand(command: Command) {
         val action = activeAction
         if (!command.isAvailableFor(action)) {
-            if (action != null) emitNotice(MessageComposerNotice.CommandUnavailable(action))
+            if (action != null) _events.tryEmit(MessageComposerViewEvent.CommandUnavailable(action))
             return
         }
         if (config.activeCommandEnabled && commandStash == null) {
@@ -1010,21 +1018,6 @@ public class MessageComposerController(
         }
     }
 
-    /**
-     * Removes [notice] from [MessageComposerState.notices]. Call this from the UI layer after
-     * a notice has been rendered and dismissed. Identical notices are removed one at a time
-     * so queued snackbars drain in order.
-     *
-     * @param notice The notice to remove.
-     */
-    public fun dismissNotice(notice: MessageComposerNotice) {
-        _state.update { it.copy(notices = it.notices - notice) }
-    }
-
-    private fun emitNotice(notice: MessageComposerNotice) {
-        _state.update { it.copy(notices = it.notices + notice) }
-    }
-
     private fun stashPreCommandState() {
         val currentText = _messageInput.value.text
         // A pure command trigger (e.g. "/" or "/gi") is not user draft content — it is the
@@ -1206,15 +1199,15 @@ public class MessageComposerController(
      * Shows the command suggestion list popup if necessary.
      *
      * While the composer is in edit mode, typing a command trigger suppresses the popup and
-     * emits a [MessageComposerNotice.CommandUnavailable] so the UI can inform the user that
+     * emits a [MessageComposerViewEvent.CommandUnavailable] so the UI can inform the user that
      * commands are blocked.
      */
     private fun handleCommandSuggestions() {
         val containsCommand = CommandPattern.matcher(messageText).find()
         val action = activeAction
         if (containsCommand && action is Edit) {
             _state.update { it.copy(commandSuggestions = emptyList()) }
-            emitNotice(MessageComposerNotice.CommandUnavailable(action))
+            _events.tryEmit(MessageComposerViewEvent.CommandUnavailable(action))
             return
         }
         val suggestions = if (containsCommand) {

stream-chat-android-ui-common/src/main/kotlin/io/getstream/chat/android/ui/common/state/messages/composer/MessageComposerState.kt

@@ -51,10 +51,6 @@ import io.getstream.chat.android.ui.common.state.messages.MessageMode
  * editable unless the user doesn't have proper [ChannelCapabilities] to send messages, otherwise it's disabled.
  * @param selectedMentions The list of selected mentions in the current input.
  * @param activeCommand The command that is currently active (selected from the suggestion popup).
- * @param notices Transient feedback messages emitted by the composer (e.g. when the user attempts
- * an action that is unavailable for the current [action]). The UI layer renders each notice and
- * removes it via
- * [io.getstream.chat.android.ui.common.feature.messages.composer.MessageComposerController.dismissNotice].
  */
 public data class MessageComposerState @JvmOverloads constructor(
     val inputValue: String = "",
@@ -75,5 +71,4 @@ public data class MessageComposerState @JvmOverloads constructor(
     val sendEnabled: Boolean = true,
     val selectedMentions: Set<Mention> = emptySet(),
     val activeCommand: Command? = null,
-    val notices: List<MessageComposerNotice> = emptyList(),
 )

…ssages/composer/MessageComposerNotice.kt …ges/composer/MessageComposerViewEvent.ktstream-chat-android-ui-common/src/main/kotlin/io/getstream/chat/android/ui/common/state/messages/composer/MessageComposerNotice.kt renamed to stream-chat-android-ui-common/src/main/kotlin/io/getstream/chat/android/ui/common/state/messages/composer/MessageComposerViewEvent.kt stream-chat-android-ui-common/src/main/kotlin/io/getstream/chat/android/ui/common/state/messages/composer/MessageComposerNotice.kt renamed to stream-chat-android-ui-common/src/main/kotlin/io/getstream/chat/android/ui/common/state/messages/composer/MessageComposerViewEvent.kt

@@ -19,24 +19,20 @@ package io.getstream.chat.android.ui.common.state.messages.composer
 import io.getstream.chat.android.ui.common.state.messages.MessageAction
 
 /**
- * Transient feedback surfaced by the composer. Emitted into [MessageComposerState.notices] and
- * consumed by the UI layer, which typically renders each notice as a snackbar and removes it
- * via [io.getstream.chat.android.ui.common.feature.messages.composer.MessageComposerController.dismissNotice]
- * once rendered.
- *
- * In v8 this hierarchy may absorb [ValidationError] so the composer exposes a single notice stream
- * for both blocking validation and informational feedback.
+ * One-shot side-effect events emitted by the composer. Consumers typically collect these from
+ * [io.getstream.chat.android.ui.common.feature.messages.composer.MessageComposerController.events]
+ * and react with transient UI (e.g. a snackbar).
  */
-public interface MessageComposerNotice {
+public interface MessageComposerViewEvent {
 
     /**
-     * Emitted when the user attempts to select or trigger a command that is not available for
-     * the current composer [action] (e.g. tapping a moderation command while in reply mode,
-     * or typing `/` while in edit mode).
+     * Emitted when the user attempts to trigger a command that is not available for the current
+     * composer [action] (e.g. tapping a moderation command while in reply mode, or typing `/`
+     * while in edit mode).
      *
      * @param action The composer action that blocked the command.
      */
     public data class CommandUnavailable(
         val action: MessageAction,
-    ) : MessageComposerNotice
+    ) : MessageComposerViewEvent
 }