Empty composer when message is sent

features/messages/src/main/java/io/element/android/x/features/messages/MessagesScreen.kt

@@ -34,6 +34,7 @@ import androidx.compose.ui.zIndex
 import com.airbnb.mvrx.compose.collectAsState
 import com.airbnb.mvrx.compose.mavericksViewModel
 import io.element.android.x.core.data.LogCompositions
+import io.element.android.x.core.data.StableCharSequence
 import io.element.android.x.designsystem.components.avatar.AvatarData
 import io.element.android.x.features.messages.model.MessagesItemGroupPosition
 import io.element.android.x.features.messages.model.MessagesTimelineItemState
@@ -58,6 +59,8 @@ fun MessagesScreen(
     val timelineItems by viewModel.collectAsState(MessagesViewState::timelineItems)
     val hasMoreToLoad by viewModel.collectAsState(MessagesViewState::hasMoreToLoad)
     val composerFullScreen by composerViewModel.collectAsState(MessageComposerViewState::isFullScreen)
+    val composerCanSendMessage by composerViewModel.collectAsState(MessageComposerViewState::isSendButtonVisible)
+    val composerText by composerViewModel.collectAsState(MessageComposerViewState::text)
     MessagesContent(
         roomTitle = roomTitle,
         roomAvatar = roomAvatar,
@@ -65,9 +68,15 @@ fun MessagesScreen(
         hasMoreToLoad = hasMoreToLoad,
         onReachedLoadMore = viewModel::loadMore,
         onBackPressed = onBackPressed,
-        onSendMessage = viewModel::sendMessage,
+        onSendMessage = {
+            viewModel.sendMessage(it)
+            composerViewModel.updateText("")
+        },
         composerFullScreen = composerFullScreen,
         onComposerFullScreenChange = composerViewModel::onComposerFullScreenChange,
+        onComposerTextChange = composerViewModel::updateText,
+        composerCanSendMessage = composerCanSendMessage,
+        composerText = composerText,
     )
 }
 
@@ -82,6 +91,9 @@ fun MessagesContent(
     onSendMessage: (CharSequence) -> Unit,
     composerFullScreen: Boolean,
     onComposerFullScreenChange: () -> Unit,
+    onComposerTextChange: (CharSequence) -> Unit,
+    composerCanSendMessage: Boolean,
+    composerText: StableCharSequence?,
 ) {
     LogCompositions(tag = "MessagesScreen", msg = "Content")
     val lazyListState = rememberLazyListState()
@@ -133,6 +145,9 @@ fun MessagesContent(
                     onSendMessage = onSendMessage,
                     fullscreen = composerFullScreen,
                     onFullscreenToggle = onComposerFullScreenChange,
+                    onComposerTextChange = onComposerTextChange,
+                    composerCanSendMessage = composerCanSendMessage,
+                    composerText = composerText?.charSequence,
                     modifier = Modifier
                         .fillMaxWidth()
                         .let {

features/messages/src/main/java/io/element/android/x/features/messages/textcomposer/MessageComposerViewModel.kt

@@ -3,6 +3,7 @@ package io.element.android.x.features.messages.textcomposer
 import com.airbnb.mvrx.MavericksViewModel
 import com.airbnb.mvrx.MavericksViewModelFactory
 import com.airbnb.mvrx.ViewModelContext
+import io.element.android.x.core.data.StableCharSequence
 import io.element.android.x.matrix.MatrixClient
 import io.element.android.x.matrix.MatrixInstance
 
@@ -35,4 +36,13 @@ class MessageComposerViewModel(
             )
         }
     }
+
+    fun updateText(newText: CharSequence) {
+        setState {
+            copy(
+                text = StableCharSequence(newText),
+                isSendButtonVisible = newText.isNotEmpty(),
+            )
+        }
+    }
 }

features/messages/src/main/java/io/element/android/x/features/messages/textcomposer/MessageComposerViewState.kt

@@ -1,7 +1,10 @@
 package io.element.android.x.features.messages.textcomposer
 
+import androidx.compose.runtime.Stable
 import com.airbnb.mvrx.MavericksState
+import io.element.android.x.core.data.StableCharSequence
 
+@Stable
 data class MessageComposerViewState(
     // val roomId: String,
     // val canSendMessage: CanSendStatus = CanSendStatus.Allowed,
@@ -11,6 +14,6 @@ data class MessageComposerViewState(
     // val sendMode: SendMode = SendMode.Regular("", false),
     // val voiceRecordingUiState: VoiceMessageRecorderView.RecordingUiState = VoiceMessageRecorderView.RecordingUiState.Idle,
     // val voiceBroadcastState: VoiceBroadcastState? = null,
-    val text: CharSequence? = null,
+    val text: StableCharSequence? = null,
     val isFullScreen: Boolean = false,
 ) : MavericksState

libraries/core/src/main/java/io/element/android/x/core/data/StableCharSequence.kt

@@ -0,0 +1,11 @@
+package io.element.android.x.core.data
+
+/**
+ * Wrapper for a CharSequence, which support mutation of the CharSequence.
+ */
+class StableCharSequence(val charSequence: CharSequence) {
+    private val hash = charSequence.toString().hashCode()
+
+    override fun hashCode() = hash
+    override fun equals(other: Any?) = other is StableCharSequence && other.hash == hash
+}

libraries/textcomposer/src/main/java/io/element/android/x/textcomposer/TextComposer.kt

@@ -4,6 +4,7 @@ import android.net.Uri
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.viewinterop.AndroidView
+import androidx.core.view.isInvisible
 import androidx.core.view.isVisible
 import io.element.android.x.element.resources.R as ElementR
 
@@ -13,6 +14,9 @@ fun TextComposer(
     modifier: Modifier = Modifier,
     fullscreen: Boolean,
     onFullscreenToggle: () -> Unit,
+    onComposerTextChange: (CharSequence) -> Unit,
+    composerCanSendMessage: Boolean,
+    composerText: CharSequence?,
 ) {
     AndroidView(
         modifier = modifier,
@@ -25,6 +29,7 @@ fun TextComposer(
                     }
 
                     override fun onTextChanged(text: CharSequence) {
+                        onComposerTextChange(text)
                     }
 
                     override fun onCloseRelatedMessage() {
@@ -59,7 +64,8 @@ fun TextComposer(
             // Example of Compose -> View communication
             val messageComposerView = (view as MessageComposerView)
             messageComposerView.toggleFullScreen(fullscreen)
-            messageComposerView.sendButton.isVisible = true
+            messageComposerView.sendButton.isInvisible = !composerCanSendMessage
+            messageComposerView.setTextIfDifferent(composerText ?: "")
         }
     )
 }