feat: Add Conjugate tab to Conjugate app (#563)

app/src/main/java/be/scri/App.kt

@@ -49,6 +49,7 @@ import be.scri.ui.screens.download.DataDownloadViewModel
 import be.scri.ui.screens.download.DownloadActions
 import be.scri.ui.screens.download.DownloadDataScreen
 import be.scri.ui.screens.settings.SettingsScreen
+import be.scri.ui.screens.conjugate.ConjugateScreen
 import be.scri.ui.theme.ScribeTheme
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.launch
@@ -167,13 +168,12 @@ fun ScribeApp(
                             }
                             is BottomBarScreen.Conjugate -> {
                                 Box(
-                                    modifier =
-                                        Modifier.fillMaxSize(),
-                                    contentAlignment = Alignment.Center,
+                                    modifier = Modifier.fillMaxSize()
                                 ) {
-                                    Text(
-                                        text = "Conjugate App",
-                                        style = MaterialTheme.typography.headlineMedium,
+                                    ConjugateScreen(
+                                        isDarkTheme = isDarkTheme,
+                                        downloadStates = downloadStates,
+                                        onDownloadAction = onDownloadAction
                                     )
                                 }
                                 HandleBackPress(pagerState, coroutineScope)

app/src/main/java/be/scri/helpers/arabic/ARInterfaceVariables.kt

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package be.scri.helpers.arabic
+
+/**
+ * Interface variables for Arabic language keyboards.
+ */
+object ARInterfaceVariables {
+    const val LANGUAGE = "العربية"
+    const val INVALID_COMMAND_MSG_WIKIDATA = "في Wikidata"
+    const val INVALID_COMMAND_TEXT_WIKIDATA_1 =
+        "Wikidata هي قاعدة بيانات معرفية يتم تحريرها بشكل تعاوني ويتم إدارتها من قبل مؤسسة ويكيميديا. تعمل كمصدر للبيانات المفتوحة لمشاريع مثل ويكيبيديا والعديد من المشاريع الأخرى."
+    const val INVALID_COMMAND_TEXT_WIKIDATA_2 =
+        "يستخدم Scribe بيانات اللغة من Wikidata للعديد من ميزاته الأساسية. نحصل على معلومات مثل أجناس الأسماء، وتصريف الأفعال والمزيد!"
+    const val INVALID_COMMAND_TEXT_WIKIDATA_3 =
+        "يمكنك إنشاء حساب في wikidata.org للانضمام إلى المجتمع الذي يدعم Scribe والعديد من المشاريع الأخرى. ساعدنا في تقديم المعلومات المجانية للعالم!"
+}

app/src/main/java/be/scri/helpers/bengali/BNInterfaceVariables.kt

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package be.scri.helpers.bengali
+
+/**
+ * Interface variables for Bengali language keyboards.
+ */
+object BNInterfaceVariables {
+    const val LANGUAGE = "বাংলা"
+    const val INVALID_COMMAND_MSG_WIKIDATA = "উইকিডাটায় নেই"
+    const val INVALID_COMMAND_TEXT_WIKIDATA_1 =
+        "উইকিডাটা হল একটি সহযোগিতামূলকভাবে সম্পাদিত জ্ঞান গ্রাফ যা উইকিমিডিয়া ফাউন্ডেশন দ্বারা রক্ষণাবেক্ষণ করা হয়। এটি উইকিপিডিয়ার মতো প্রকল্প এবং আরও অনেক প্রকল্পের জন্য একটি উন্মুক্ত ডেটা উৎস হিসাবে কাজ করে।"
+    const val INVALID_COMMAND_TEXT_WIKIDATA_2 =
+        "Scribe তার অনেক মূল বৈশিষ্ট্যের জন্য উইকিডাটার ভাষার ডেটা ব্যবহার করে। আমরা যেমন তথ্য পাই: বিশেষ্য লিঙ্গ, ক্রিয়াপদ সংযোজন এবং আরও অনেক কিছু!"
+    const val INVALID_COMMAND_TEXT_WIKIDATA_3 =
+        "আপনি wikidata.org-এ একটি অ্যাকাউন্ট তৈরি করতে পারেন এবং Scribe এবং অন্যান্য অনেক প্রকল্পকে সমর্থনকারী কমিউনিটিতে যোগ দিতে পারেন। আমাদের সাহায্য করুন বিনামূল্যে তথ্য বিশ্বে পৌঁছে দিতে!"
+}

app/src/main/java/be/scri/helpers/hindi/HIInterfaceVariables.kt

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package be.scri.helpers.hindi
+
+/**
+ * Interface variables for Hindi language keyboards.
+ */
+object HIInterfaceVariables {
+    const val LANGUAGE = "हिन्दी"
+    const val INVALID_COMMAND_MSG_WIKIDATA = "Wikidata में नहीं"
+    const val INVALID_COMMAND_TEXT_WIKIDATA_1 =
+        "Wikidata is a collaboratively edited knowledge graph that's maintained by the Wikimedia Foundation. It serves as a source of open data for projects like Wikipedia and countless others."
+    const val INVALID_COMMAND_TEXT_WIKIDATA_2 =
+        "Scribe uses Wikidata's language data for many of its core features. We get information like noun genders, verb conjugations and much more!"
+    const val INVALID_COMMAND_TEXT_WIKIDATA_3 =
+        "You can make an account at wikidata.org to join the community that's supporting Scribe and so many other projects. Help us bring free information to the world!"
+}

app/src/main/java/be/scri/helpers/indonesian/IDInterfaceVariables.kt

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package be.scri.helpers.indonesian
+
+/**
+ * Interface variables for Indonesian language keyboards.
+ */
+object IDInterfaceVariables {
+    const val LANGUAGE = "Indonesia"
+    const val INVALID_COMMAND_MSG_WIKIDATA = "Tidak dalam Wikidata"
+    const val INVALID_COMMAND_TEXT_WIKIDATA_1 =
+        "Wikidata adalah grafik pengetahuan yang disunting secara kolaboratif yang dikelola oleh Wikimedia Foundation. Ia berfungsi sebagai sumber data terbuka bagi proyek seperti Wikipedia dan berbagai proyek lainnya."
+    const val INVALID_COMMAND_TEXT_WIKIDATA_2 =
+        "Scribe menggunakan data bahasa milik Wikidata untuk banyak fitur utama. Kami mendapatkan informasi seperti kata benda bergender, konjugasi kata kerja, dan banyak lagi!"
+    const val INVALID_COMMAND_TEXT_WIKIDATA_3 =
+        "Kamu bisa membuat akun di wikidata.org untuk bergabung dengan komunitas yang mendukung Scribe dan banyak proyek lainnya. Bantu kami membawakan informasi secara gratis untuk dunia!"
+}

app/src/main/java/be/scri/helpers/kannada/KNInterfaceVariables.kt

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package be.scri.helpers.kannada
+
+/**
+ * Interface variables for Kannada language keyboards.
+ */
+object KNInterfaceVariables {
+    const val LANGUAGE = "ಕನ್ನಡ"
+    const val INVALID_COMMAND_MSG_WIKIDATA = "ವಿಕಿಡೇಟಾ ನಲ್ಲಿ ಇಲ್ಲ"
+    const val INVALID_COMMAND_TEXT_WIKIDATA_1 =
+        "Wikidata is a collaboratively edited knowledge graph that's maintained by the Wikimedia Foundation. It serves as a source of open data for projects like Wikipedia and countless others."
+    const val INVALID_COMMAND_TEXT_WIKIDATA_2 =
+        "Scribe uses Wikidata's language data for many of its core features. We get information like noun genders, verb conjugations and much more!"
+    const val INVALID_COMMAND_TEXT_WIKIDATA_3 =
+        "You can make an account at wikidata.org to join the community that's supporting Scribe and so many other projects. Help us bring free information to the world!"
+}

app/src/main/java/be/scri/helpers/korean/KOInterfaceVariables.kt

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package be.scri.helpers.korean
+
+/**
+ * Interface variables for Korean language keyboards.
+ */
+object KOInterfaceVariables {
+    const val LANGUAGE = "한국어"
+    const val INVALID_COMMAND_MSG_WIKIDATA = "위키데이터에 없음"
+    const val INVALID_COMMAND_TEXT_WIKIDATA_1 =
+        "위키데이터는 위키미디어 재단에 의해 유지되는 협업 편집 지식 그래프입니다. 이는 위키백과와 수많은 다른 프로젝트를 위한 개방형 데이터의 출처로 사용됩니다."
+    const val INVALID_COMMAND_TEXT_WIKIDATA_2 =
+        "Scribe는 많은 핵심 기능에서 위키데이터의 언어 데이터를 사용합니다. 우리는 명사의 성별, 동사의 활용 등 다양한 정보를 얻습니다!"
+    const val INVALID_COMMAND_TEXT_WIKIDATA_3 =
+        "wikidata.org에서 계정을 만들면 Scribe와 많은 다른 프로젝트를 지원하는 커뮤니티에 참여할 수 있습니다. 함께 세상에 유용한 정보를 나누는 데 도움을 주세요!"
+}

app/src/main/java/be/scri/helpers/marathi/MRInterfaceVariables.kt

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package be.scri.helpers.marathi
+
+/**
+ * Interface variables for Marathi language keyboards.
+ */
+object MRInterfaceVariables {
+    const val LANGUAGE = "मराठी"
+    const val INVALID_COMMAND_MSG_WIKIDATA = "विकिडाटामध्ये नाही"
+    const val INVALID_COMMAND_TEXT_WIKIDATA_1 =
+        "विकिडाटा हे सहयोगाने संपादित ज्ञान ग्राफ आहे, जे विकिमीडिया फाउंडेशनद्वारा देखभाल केले जाते. हे विकिपीडिया आणि इतर अनेक प्रकल्पांसाठी खुला डेटा स्रोत आहे."
+    const val INVALID_COMMAND_TEXT_WIKIDATA_2 =
+        "स्क्राइब विकिडाटाच्या भाषा डेटाचा वापर त्याच्या अनेक मुख्य वैशिष्ट्यांसाठी करतो. आम्हाला या डेटामधून संज्ञा लिंग, क्रियापद रूपांतरण आणि इतर माहिती मिळते!"
+    const val INVALID_COMMAND_TEXT_WIKIDATA_3 =
+        "तुम्ही wikidata.org वर खाती बनवून त्या समुदायात सामील होऊ शकता, जो स्क्राइब आणि इतर अनेक प्रकल्पांना समर्थन देत आहे. आमच्यासोबत मोफत माहिती जगभर पोहचविण्यात मदत करा!"
+}

app/src/main/java/be/scri/helpers/tamil/TAInterfaceVariables.kt

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package be.scri.helpers.tamil
+
+/**
+ * Interface variables for Tamil language keyboards.
+ */
+object TAInterfaceVariables {
+    const val LANGUAGE = "தமிழ்"
+    const val INVALID_COMMAND_MSG_WIKIDATA = "விக்கிடேட்டாவில் இல்லை"
+    const val INVALID_COMMAND_TEXT_WIKIDATA_1 =
+        "Wikidata is a collaboratively edited knowledge graph that's maintained by the Wikimedia Foundation. It serves as a source of open data for projects like Wikipedia and countless others."
+    const val INVALID_COMMAND_TEXT_WIKIDATA_2 =
+        "Scribe uses Wikidata's language data for many of its core features. We get information like noun genders, verb conjugations and much more!"
+    const val INVALID_COMMAND_TEXT_WIKIDATA_3 =
+        "You can make an account at wikidata.org to join the community that's supporting Scribe and so many other projects. Help us bring free information to the world!"
+}

app/src/main/java/be/scri/helpers/telugu/TEInterfaceVariables.kt

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package be.scri.helpers.telugu
+
+/**
+ * Interface variables for Telugu language keyboards.
+ */
+object TEInterfaceVariables {
+    const val LANGUAGE = "తెలుగు"
+    const val INVALID_COMMAND_MSG_WIKIDATA = "వికీడేటాలో లేదు"
+    const val INVALID_COMMAND_TEXT_WIKIDATA_1 =
+        "Wikidata is a collaboratively edited knowledge graph that's maintained by the Wikimedia Foundation. It serves as a source of open data for projects like Wikipedia and countless others."
+    const val INVALID_COMMAND_TEXT_WIKIDATA_2 =
+        "Scribe uses Wikidata's language data for many of its core features. We get information like noun genders, verb conjugations and much more!"
+    const val INVALID_COMMAND_TEXT_WIKIDATA_3 =
+        "You can make an account at wikidata.org to join the community that's supporting Scribe and so many other projects. Help us bring free information to the world!"
+}

app/src/main/java/be/scri/helpers/turkish/TRInterfaceVariables.kt

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package be.scri.helpers.turkish
+
+/**
+ * Interface variables for Turkish language keyboards.
+ */
+object TRInterfaceVariables {
+    const val LANGUAGE = "Türkçe"
+    const val INVALID_COMMAND_MSG_WIKIDATA = "Wikidata'da değil"
+    const val INVALID_COMMAND_TEXT_WIKIDATA_1 =
+        "Wikimedia Vakfı tarafından barındırılan Wikidata, kolaboratif çok dilli bir bilgi grafiğidir. Wikipedia ve diğer birçok projeler için açık veri kaynağı olarak hizmet eder."
+    const val INVALID_COMMAND_TEXT_WIKIDATA_2 =
+        "Scribe, birçok temel özelliği için Wikidata'nın dil verilerini kullanır. İsim cinsiyetleri, fiil çekimleri ve çok daha fazlasını Wikidata'dan alırız!"
+    const val INVALID_COMMAND_TEXT_WIKIDATA_3 =
+        "wikidata.org adresinde bir hesap oluşturabilir, Scribe'ı ve diğer birçok projeyi destekleyen bu topluluğa katılabilirsiniz. Dünya'ya ücretsiz bilgi getirmemize yardımcı olun!"
+}

app/src/main/java/be/scri/ui/screens/conjugate/ConjugateScreen.kt

@@ -0,0 +1,154 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package be.scri.ui.screens.conjugate
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.painterResource
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.unit.dp
+import androidx.lifecycle.viewmodel.compose.viewModel
+import be.scri.R
+import be.scri.ui.common.appcomponents.PageTitle
+import be.scri.ui.common.components.DownloadDataOptionComp
+import be.scri.ui.screens.download.DownloadState
+
+/**
+ * Main Conjugate Screen displaying empty state and download action.
+ */
+@Composable
+fun ConjugateScreen(
+    isDarkTheme: Boolean,
+    downloadStates: Map<String, DownloadState>,
+    onDownloadAction: (String, Boolean) -> Unit,
+    modifier: Modifier = Modifier,
+    viewModel: ConjugateViewModel = viewModel(),
+) {
+    val isDataAvailable by viewModel.isDataAvailable.collectAsState()
+    val conjugateDownloadState = downloadStates["conjugate_data"] ?: DownloadState.Ready
+
+    Scaffold(
+        topBar = {
+            // Using PageTitle as a stand-in for the shared TabBar from issue #560 
+            // if an explicit TabBar component is not present in the current branch.
+            PageTitle(
+                pageTitle = "Conjugate", // Can be replaced by i18n string
+                modifier = Modifier.fillMaxWidth()
+            )
+        },
+        modifier = modifier.fillMaxSize(),
+    ) { paddingValues ->
+        Box(
+            modifier = Modifier
+                .fillMaxSize()
+                .padding(paddingValues),
+            contentAlignment = Alignment.Center
+        ) {
+            if (!isDataAvailable) {
+                ConjugateEmptyState(
+                    isDarkTheme = isDarkTheme,
+                    downloadState = conjugateDownloadState,
+                    onDownloadClick = {
+                        onDownloadAction("conjugate_data", false)
+                    }
+                )
+            } else {
+                // Next page content (out of scope for #563)
+                Text("Conjugation UI will be here")
+            }
+        }
+    }
+}
+
+/**
+ * The "No Data" Empty state representation for Conjugation.
+ */
+@Composable
+fun ConjugateEmptyState(
+    isDarkTheme: Boolean,
+    downloadState: DownloadState,
+    onDownloadClick: () -> Unit,
+    modifier: Modifier = Modifier,
+) {
+    Column(
+        modifier = modifier.padding(16.dp),
+        horizontalAlignment = Alignment.CenterHorizontally,
+        verticalArrangement = Arrangement.Center
+    ) {
+        // SVG Placeholder logo
+        Icon(
+            painter = painterResource(id = R.drawable.scribe_logo),
+            contentDescription = null,
+            modifier = Modifier.size(120.dp),
+            tint = MaterialTheme.colorScheme.onSurfaceVariant
+        )
+
+        Spacer(modifier = Modifier.height(24.dp))
+
+        Text(
+            text = stringResource(id = R.string.i18n_app_download_menu_option_conjugate_description),
+            style = MaterialTheme.typography.bodyLarge,
+            textAlign = TextAlign.Center,
+            color = MaterialTheme.colorScheme.onSurface
+        )
+
+        Spacer(modifier = Modifier.height(32.dp))
+
+        DownloadDataOptionComp(
+            onClick = onDownloadClick,
+            isDarkTheme = isDarkTheme,
+            downloadState = downloadState,
+            modifier = Modifier.padding(horizontal = 16.dp)
+        )
+
+        Spacer(modifier = Modifier.height(16.dp))
+
+        Text(
+            text = stringResource(id = R.string.i18n_app_download_menu_option_conjugate_download_data_start),
+            style = MaterialTheme.typography.bodyMedium,
+            textAlign = TextAlign.Center,
+            color = MaterialTheme.colorScheme.onSurfaceVariant
+        )
+    }
+}
+
+@androidx.compose.ui.tooling.preview.Preview(showBackground = true)
+@Composable
+fun ConjugateEmptyStatePreview() {
+    MaterialTheme {
+        ConjugateEmptyState(
+            isDarkTheme = false,
+            downloadState = DownloadState.Ready,
+            onDownloadClick = {}
+        )
+    }
+}
+
+@androidx.compose.ui.tooling.preview.Preview(showBackground = true, uiMode = android.content.res.Configuration.UI_MODE_NIGHT_YES)
+@Composable
+fun ConjugateEmptyStateDarkPreview() {
+    MaterialTheme {
+        ConjugateEmptyState(
+            isDarkTheme = true,
+            downloadState = DownloadState.Ready,
+            onDownloadClick = {}
+        )
+    }
+}

app/src/main/java/be/scri/ui/screens/conjugate/ConjugateViewModel.kt

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package be.scri.ui.screens.conjugate
+
+import androidx.lifecycle.ViewModel
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+
+class ConjugateViewModel : ViewModel() {
+    private val _isDataAvailable = MutableStateFlow(false)
+    val isDataAvailable: StateFlow<Boolean> = _isDataAvailable.asStateFlow()
+
+    // Assuming we would check actual data availability via a repository or ConjugateDataManager.
+    fun checkDataAvailability(hasData: Boolean) {
+        _isDataAvailable.value = hasData
+    }
+}