Add spacing between composer snackbar and input row (#6423)

* Add 16 dp gap between snackbar and composer input

Address the SDK Testing Feedback ticket about snackbar spacing in the
fixed-style composer. Override the snackbar lambda at the composer
call site to add 16 dp bottom padding around the visible card.
Combined with the existing 16 dp padding inside StreamSnackbar, the
visible gap above the input row is now 32 dp.

Other changes:
- StreamSnackbar.modifier now applies to the outer Box instead of the
  inner Surface (idiomatic Compose; internal-only API).
- Replace the hardcoded 4.dp shadow with StreamTokens.elevation3.
- The new entry in the api dump is the auto-generated holder for the
  inline snackbar lambda.

* Drop redundant outer padding around composer input row

The Row's padding(vertical = spacing2xs) added 8 dp to the composer
surface with no Figma backing; the inner padding already provides the
spec spacing. Also remove a wrapContentHeight() from the
MessageComposer call in ChannelScreen — Column already grants
intrinsic vertical sizing to its children, so the modifier had no
effect.

Re-record MessageComposerTest snapshots.

* Expose composer snackbar via ChatComponentFactory

Add MessageComposerSnackbar to the factory with a matching
MessageComposerSnackbarParams holder, mirroring the pattern used by the
audio-recording snackbars. The default keeps the 16 dp bottom padding
introduced in the previous commit. Customers can now override the
composer-level snackbar appearance the same way they can override other
composer slots.

Author: andremion

stream-chat-android-compose/api/stream-chat-android-compose.api

@@ -1957,6 +1957,7 @@ public final class io/getstream/chat/android/compose/ui/messages/composer/Compos
 	public final fun getLambda$-1206314464$stream_chat_android_compose_release ()Lkotlin/jvm/functions/Function2;
 	public final fun getLambda$-1267828661$stream_chat_android_compose_release ()Lkotlin/jvm/functions/Function2;
 	public final fun getLambda$-1344661276$stream_chat_android_compose_release ()Lkotlin/jvm/functions/Function2;
+	public final fun getLambda$-1407581416$stream_chat_android_compose_release ()Lkotlin/jvm/functions/Function3;
 	public final fun getLambda$-173232017$stream_chat_android_compose_release ()Lkotlin/jvm/functions/Function2;
 	public final fun getLambda$1180759242$stream_chat_android_compose_release ()Lkotlin/jvm/functions/Function2;
 	public final fun getLambda$1309976052$stream_chat_android_compose_release ()Lkotlin/jvm/functions/Function2;
@@ -3446,6 +3447,7 @@ public abstract interface class io/getstream/chat/android/compose/ui/theme/ChatC
 	public fun MessageComposerQuotedMessage (Lio/getstream/chat/android/compose/ui/theme/MessageComposerQuotedMessageParams;Landroidx/compose/runtime/Composer;I)V
 	public fun MessageComposerSaveButton (Lio/getstream/chat/android/compose/ui/theme/MessageComposerSaveButtonParams;Landroidx/compose/runtime/Composer;I)V
 	public fun MessageComposerSendButton (Lio/getstream/chat/android/compose/ui/theme/MessageComposerSendButtonParams;Landroidx/compose/runtime/Composer;I)V
+	public fun MessageComposerSnackbar (Lio/getstream/chat/android/compose/ui/theme/MessageComposerSnackbarParams;Landroidx/compose/runtime/Composer;I)V
 	public fun MessageComposerTrailingContent (Lio/getstream/chat/android/compose/ui/theme/MessageComposerTrailingContentParams;Landroidx/compose/runtime/Composer;I)V
 	public fun MessageComposerUserSuggestionItem (Lio/getstream/chat/android/compose/ui/theme/MessageComposerUserSuggestionItemParams;Landroidx/compose/runtime/Composer;I)V
 	public fun MessageComposerUserSuggestionItemCenterContent (Lio/getstream/chat/android/compose/ui/theme/MessageComposerUserSuggestionItemCenterContentParams;Landroidx/compose/runtime/Composer;I)V
@@ -3636,6 +3638,7 @@ public final class io/getstream/chat/android/compose/ui/theme/ChatComponentFacto
 	public static fun MessageComposerQuotedMessage (Lio/getstream/chat/android/compose/ui/theme/ChatComponentFactory;Lio/getstream/chat/android/compose/ui/theme/MessageComposerQuotedMessageParams;Landroidx/compose/runtime/Composer;I)V
 	public static fun MessageComposerSaveButton (Lio/getstream/chat/android/compose/ui/theme/ChatComponentFactory;Lio/getstream/chat/android/compose/ui/theme/MessageComposerSaveButtonParams;Landroidx/compose/runtime/Composer;I)V
 	public static fun MessageComposerSendButton (Lio/getstream/chat/android/compose/ui/theme/ChatComponentFactory;Lio/getstream/chat/android/compose/ui/theme/MessageComposerSendButtonParams;Landroidx/compose/runtime/Composer;I)V
+	public static fun MessageComposerSnackbar (Lio/getstream/chat/android/compose/ui/theme/ChatComponentFactory;Lio/getstream/chat/android/compose/ui/theme/MessageComposerSnackbarParams;Landroidx/compose/runtime/Composer;I)V
 	public static fun MessageComposerTrailingContent (Lio/getstream/chat/android/compose/ui/theme/ChatComponentFactory;Lio/getstream/chat/android/compose/ui/theme/MessageComposerTrailingContentParams;Landroidx/compose/runtime/Composer;I)V
 	public static fun MessageComposerUserSuggestionItem (Lio/getstream/chat/android/compose/ui/theme/ChatComponentFactory;Lio/getstream/chat/android/compose/ui/theme/MessageComposerUserSuggestionItemParams;Landroidx/compose/runtime/Composer;I)V
 	public static fun MessageComposerUserSuggestionItemCenterContent (Lio/getstream/chat/android/compose/ui/theme/ChatComponentFactory;Lio/getstream/chat/android/compose/ui/theme/MessageComposerUserSuggestionItemCenterContentParams;Landroidx/compose/runtime/Composer;I)V
@@ -4835,6 +4838,18 @@ public final class io/getstream/chat/android/compose/ui/theme/MessageComposerSen
 	public fun toString ()Ljava/lang/String;
 }
 
+public final class io/getstream/chat/android/compose/ui/theme/MessageComposerSnackbarParams {
+	public static final field $stable I
+	public fun <init> (Landroidx/compose/material3/SnackbarData;)V
+	public final fun component1 ()Landroidx/compose/material3/SnackbarData;
+	public final fun copy (Landroidx/compose/material3/SnackbarData;)Lio/getstream/chat/android/compose/ui/theme/MessageComposerSnackbarParams;
+	public static synthetic fun copy$default (Lio/getstream/chat/android/compose/ui/theme/MessageComposerSnackbarParams;Landroidx/compose/material3/SnackbarData;ILjava/lang/Object;)Lio/getstream/chat/android/compose/ui/theme/MessageComposerSnackbarParams;
+	public fun equals (Ljava/lang/Object;)Z
+	public final fun getData ()Landroidx/compose/material3/SnackbarData;
+	public fun hashCode ()I
+	public fun toString ()Ljava/lang/String;
+}
+
 public final class io/getstream/chat/android/compose/ui/theme/MessageComposerTrailingContentParams {
 	public static final field $stable I
 	public fun <init> (Lio/getstream/chat/android/ui/common/state/messages/composer/MessageComposerState;)V

stream-chat-android-compose/src/main/java/io/getstream/chat/android/compose/ui/messages/ChannelScreen.kt

@@ -31,7 +31,6 @@ import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.ime
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.safeDrawingPadding
-import androidx.compose.foundation.layout.wrapContentHeight
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.SnackbarDuration
@@ -367,9 +366,7 @@ internal fun DefaultBottomBarContent(
 
     Column {
         MessageComposer(
-            modifier = Modifier
-                .fillMaxWidth()
-                .wrapContentHeight(),
+            modifier = Modifier.fillMaxWidth(),
             viewModel = composerViewModel,
             isAttachmentPickerVisible = attachmentsPickerViewModel.isPickerVisible,
             onAttachmentsClick = attachmentsPickerViewModel::togglePickerVisibility,

stream-chat-android-compose/src/main/java/io/getstream/chat/android/compose/ui/messages/composer/MessageComposer.kt

@@ -57,6 +57,7 @@ import io.getstream.chat.android.compose.ui.theme.LocalChatUiConfig
 import io.getstream.chat.android.compose.ui.theme.MessageComposerInputParams
 import io.getstream.chat.android.compose.ui.theme.MessageComposerLeadingContentParams
 import io.getstream.chat.android.compose.ui.theme.MessageComposerParams
+import io.getstream.chat.android.compose.ui.theme.MessageComposerSnackbarParams
 import io.getstream.chat.android.compose.ui.theme.MessageComposerTrailingContentParams
 import io.getstream.chat.android.compose.ui.theme.StreamTokens
 import io.getstream.chat.android.compose.ui.util.SnackbarPopup
@@ -299,7 +300,6 @@ public fun MessageComposer(
 
         Row(
             modifier = Modifier
-                .padding(vertical = StreamTokens.spacing2xs)
                 .fillMaxWidth()
                 .padding(
                     start = StreamTokens.spacingMd,
@@ -330,7 +330,11 @@ public fun MessageComposer(
             )
 
             if (snackbarHostState.currentSnackbarData != null) {
-                SnackbarPopup(hostState = snackbarHostState)
+                SnackbarPopup(hostState = snackbarHostState) { snackbarData ->
+                    ChatTheme.componentFactory.MessageComposerSnackbar(
+                        params = MessageComposerSnackbarParams(data = snackbarData),
+                    )
+                }
             }
         }
     }

stream-chat-android-compose/src/main/java/io/getstream/chat/android/compose/ui/theme/ChatComponentFactory.kt

@@ -1705,6 +1705,22 @@ public interface ChatComponentFactory {
         StreamSnackbar(snackbarData = params.data)
     }
 
+    /**
+     * The snackbar shown above the message composer for validation errors and command-related
+     * events.
+     *
+     * Override this method to provide a custom snackbar appearance for the composer.
+     *
+     * @param params Parameters for this component.
+     */
+    @Composable
+    public fun MessageComposerSnackbar(params: MessageComposerSnackbarParams) {
+        StreamSnackbar(
+            modifier = Modifier.padding(bottom = StreamTokens.spacingMd),
+            snackbarData = params.data,
+        )
+    }
+
     /**
      * The default avatar component that displays an image from a URL or falls back to a placeholder.
      * This component serves as the foundational UI for all avatar types.

stream-chat-android-compose/src/main/java/io/getstream/chat/android/compose/ui/theme/ChatComponentFactoryParams.kt

@@ -1282,6 +1282,15 @@ public data class MessageComposerAudioRecordingHintParams(
     val data: SnackbarData,
 )
 
+/**
+ * Parameters for [ChatComponentFactory.MessageComposerSnackbar].
+ *
+ * @param data The snackbar data containing the message, variant, and optional action.
+ */
+public data class MessageComposerSnackbarParams(
+    val data: SnackbarData,
+)
+
 /**
  * Parameters for [ChatComponentFactory.Avatar].
  *

stream-chat-android-compose/src/main/java/io/getstream/chat/android/compose/ui/util/StreamSnackbar.kt

@@ -75,7 +75,7 @@ internal data class StreamSnackbarVisuals(
  * snackbar's variant), and an optional action button.
  *
  * @param snackbarData The [SnackbarData] driving the message, variant, and optional action.
- * @param modifier Modifier applied to the inner [Surface] (e.g. to control width or padding).
+ * @param modifier Modifier for styling.
  */
 @Composable
 internal fun StreamSnackbar(
@@ -85,9 +85,9 @@ internal fun StreamSnackbar(
     val actionLabel = snackbarData.visuals.actionLabel
     val variant = (snackbarData.visuals as? StreamSnackbarVisuals)?.variant
         ?: StreamSnackbarVariant.Default
-    Box(modifier = Modifier.padding(StreamTokens.spacingMd)) {
+    Box(modifier = modifier.padding(StreamTokens.spacingMd)) {
         Surface(
-            modifier = modifier.shadow(4.dp, shape = SnackbarShape),
+            modifier = Modifier.shadow(elevation = StreamTokens.elevation3, shape = SnackbarShape),
             shape = SnackbarShape,
             color = ChatTheme.colors.backgroundCoreInverse,
             contentColor = ChatTheme.colors.textOnInverse,