[stable-24.0] Migrate empty views to composable

app/src/main/java/com/nextcloud/talk/chat/ui/ChatEmptyState.kt

@@ -0,0 +1,175 @@
+/*
+ * Nextcloud Talk - Android Client
+ *
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+package com.nextcloud.talk.chat.ui
+
+import android.content.res.Configuration
+import androidx.compose.foundation.Image
+import androidx.compose.foundation.isSystemInDarkTheme
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.material3.darkColorScheme
+import androidx.compose.material3.lightColorScheme
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.BlendMode
+import androidx.compose.ui.graphics.ColorFilter
+import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.res.colorResource
+import androidx.compose.ui.res.painterResource
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import com.nextcloud.talk.R
+
+@Composable
+fun ChatEmptyState(type: ChatEmptyStateType, modifier: Modifier = Modifier) {
+    val iconRes: Int
+    val text: String
+
+    when (type) {
+        is ChatEmptyStateType.Lobby -> {
+            iconRes = R.drawable.ic_room_service_black_24dp
+            text = type.text
+        }
+        ChatEmptyStateType.Offline -> {
+            iconRes = R.drawable.ic_signal_wifi_off_white_24dp
+            text = stringResource(R.string.no_offline_messages_saved)
+        }
+        ChatEmptyStateType.NoMessages -> {
+            iconRes = R.drawable.ic_comment
+            text = stringResource(R.string.nc_chat_no_messages)
+        }
+    }
+
+    Box(
+        modifier = modifier.fillMaxSize(),
+        contentAlignment = Alignment.Center
+    ) {
+        Column(
+            modifier = Modifier.padding(horizontal = 16.dp),
+            horizontalAlignment = Alignment.CenterHorizontally
+        ) {
+            Image(
+                painter = painterResource(iconRes),
+                contentDescription = null,
+                modifier = Modifier.size(64.dp),
+                contentScale = ContentScale.Fit,
+                colorFilter = ColorFilter.tint(colorResource(R.color.grey_600), BlendMode.SrcIn)
+            )
+            Text(
+                text = text,
+                modifier = Modifier.padding(top = 16.dp),
+                color = colorResource(R.color.grey_600),
+                fontSize = 16.sp,
+                textAlign = TextAlign.Center
+            )
+        }
+    }
+}
+
+private const val PREVIEW_WIDTH_DP = 360
+private const val PREVIEW_HEIGHT_DP = 640
+
+@Preview(name = "Lobby · Light", widthDp = PREVIEW_WIDTH_DP, heightDp = PREVIEW_HEIGHT_DP)
+@Preview(
+    name = "Lobby · Dark",
+    widthDp = PREVIEW_WIDTH_DP,
+    heightDp = PREVIEW_HEIGHT_DP,
+    uiMode = Configuration.UI_MODE_NIGHT_YES
+)
+@Composable
+private fun LobbyPreview() {
+    val colorScheme = if (isSystemInDarkTheme()) darkColorScheme() else lightColorScheme()
+    MaterialTheme(colorScheme = colorScheme) {
+        Surface(modifier = Modifier.fillMaxSize()) {
+            ChatEmptyState(
+                type = ChatEmptyStateType.Lobby(
+                    text = "You are currently waiting in the lobby.\n\n" +
+                        "This meeting is scheduled for Monday, 2 Jun 2026 at 10:00 – in 45 minutes"
+                )
+            )
+        }
+    }
+}
+
+@Preview(name = "Lobby · RTL / Arabic", widthDp = PREVIEW_WIDTH_DP, heightDp = PREVIEW_HEIGHT_DP, locale = "ar")
+@Composable
+private fun LobbyRtlPreview() {
+    MaterialTheme(colorScheme = lightColorScheme()) {
+        Surface(modifier = Modifier.fillMaxSize()) {
+            ChatEmptyState(
+                type = ChatEmptyStateType.Lobby(
+                    text = "أنت في انتظار الدخول إلى القاعة."
+                )
+            )
+        }
+    }
+}
+
+@Preview(name = "Offline · Light", widthDp = PREVIEW_WIDTH_DP, heightDp = PREVIEW_HEIGHT_DP)
+@Preview(
+    name = "Offline · Dark",
+    widthDp = PREVIEW_WIDTH_DP,
+    heightDp = PREVIEW_HEIGHT_DP,
+    uiMode = Configuration.UI_MODE_NIGHT_YES
+)
+@Composable
+private fun OfflinePreview() {
+    val colorScheme = if (isSystemInDarkTheme()) darkColorScheme() else lightColorScheme()
+    MaterialTheme(colorScheme = colorScheme) {
+        Surface(modifier = Modifier.fillMaxSize()) {
+            ChatEmptyState(type = ChatEmptyStateType.Offline)
+        }
+    }
+}
+
+@Preview(name = "Offline · RTL / Arabic", widthDp = PREVIEW_WIDTH_DP, heightDp = PREVIEW_HEIGHT_DP, locale = "ar")
+@Composable
+private fun OfflineRtlPreview() {
+    MaterialTheme(colorScheme = lightColorScheme()) {
+        Surface(modifier = Modifier.fillMaxSize()) {
+            ChatEmptyState(type = ChatEmptyStateType.Offline)
+        }
+    }
+}
+
+@Preview(name = "No messages · Light", widthDp = PREVIEW_WIDTH_DP, heightDp = PREVIEW_HEIGHT_DP)
+@Preview(
+    name = "No messages · Dark",
+    widthDp = PREVIEW_WIDTH_DP,
+    heightDp = PREVIEW_HEIGHT_DP,
+    uiMode = Configuration.UI_MODE_NIGHT_YES
+)
+@Composable
+private fun NoMessagesPreview() {
+    val colorScheme = if (isSystemInDarkTheme()) darkColorScheme() else lightColorScheme()
+    MaterialTheme(colorScheme = colorScheme) {
+        Surface(modifier = Modifier.fillMaxSize()) {
+            ChatEmptyState(type = ChatEmptyStateType.NoMessages)
+        }
+    }
+}
+
+@Preview(name = "No messages · RTL / Arabic", widthDp = PREVIEW_WIDTH_DP, heightDp = PREVIEW_HEIGHT_DP, locale = "ar")
+@Composable
+private fun NoMessagesRtlPreview() {
+    MaterialTheme(colorScheme = lightColorScheme()) {
+        Surface(modifier = Modifier.fillMaxSize()) {
+            ChatEmptyState(type = ChatEmptyStateType.NoMessages)
+        }
+    }
+}

app/src/main/java/com/nextcloud/talk/chat/ui/ChatEmptyStateType.kt

@@ -0,0 +1,19 @@
+/*
+ * Nextcloud Talk - Android Client
+ *
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+package com.nextcloud.talk.chat.ui
+
+sealed class ChatEmptyStateType {
+    /** Waiting in lobby before a meeting starts. [text] is assembled by the caller and may include a timer. */
+    data class Lobby(val text: String) : ChatEmptyStateType()
+
+    /** Device is offline and no messages are cached locally. */
+    data object Offline : ChatEmptyStateType()
+
+    /** Conversation exists but has no messages yet. */
+    data object NoMessages : ChatEmptyStateType()
+}