Search UI skeleton (#651)

* Add UI skeleton for the search feature

This CL adds an UI skeleton of the search feature including:
- The search navigation icon in the NiaTopAppBar
- The text field to enter the search query
- Almost empty ViewModel

app/build.gradle.kts

@@ -83,6 +83,7 @@ dependencies {
     implementation(project(":feature:foryou"))
     implementation(project(":feature:bookmarks"))
     implementation(project(":feature:topic"))
+    implementation(project(":feature:search"))
     implementation(project(":feature:settings"))
 
     implementation(project(":core:common"))

app/src/main/java/com/google/samples/apps/nowinandroid/navigation/NiaNavHost.kt

@@ -24,6 +24,7 @@ import com.google.samples.apps.nowinandroid.feature.bookmarks.navigation.bookmar
 import com.google.samples.apps.nowinandroid.feature.foryou.navigation.forYouNavigationRoute
 import com.google.samples.apps.nowinandroid.feature.foryou.navigation.forYouScreen
 import com.google.samples.apps.nowinandroid.feature.interests.navigation.interestsGraph
+import com.google.samples.apps.nowinandroid.feature.search.navigation.searchScreen
 import com.google.samples.apps.nowinandroid.feature.topic.navigation.navigateToTopic
 import com.google.samples.apps.nowinandroid.feature.topic.navigation.topicScreen
 
@@ -48,6 +49,7 @@ fun NiaNavHost(
         // TODO: handle topic clicks from each top level destination
         forYouScreen(onTopicClick = {})
         bookmarksScreen(onTopicClick = {})
+        searchScreen(onBackClick = navController::popBackStack)
         interestsGraph(
             onTopicClick = { topicId ->
                 navController.navigateToTopic(topicId)

app/src/main/java/com/google/samples/apps/nowinandroid/ui/NiaApp.kt

@@ -165,6 +165,10 @@ fun NiaApp(
                         if (destination != null) {
                             NiaTopAppBar(
                                 titleRes = destination.titleTextId,
+                                navigationIcon = NiaIcons.Search,
+                                navigationIconContentDescription = stringResource(
+                                    id = settingsR.string.top_app_bar_navigation_icon_description,
+                                ),
                                 actionIcon = NiaIcons.Settings,
                                 actionIconContentDescription = stringResource(
                                     id = settingsR.string.top_app_bar_action_icon_description,
@@ -173,6 +177,7 @@ fun NiaApp(
                                     containerColor = Color.Transparent,
                                 ),
                                 onActionClick = { appState.setShowSettingsDialog(true) },
+                                onNavigationClick = { appState.navigateToSearch() },
                             )
                         }
 

app/src/main/java/com/google/samples/apps/nowinandroid/ui/NiaAppState.kt

@@ -41,6 +41,7 @@ import com.google.samples.apps.nowinandroid.feature.foryou.navigation.forYouNavi
 import com.google.samples.apps.nowinandroid.feature.foryou.navigation.navigateToForYou
 import com.google.samples.apps.nowinandroid.feature.interests.navigation.interestsRoute
 import com.google.samples.apps.nowinandroid.feature.interests.navigation.navigateToInterestsGraph
+import com.google.samples.apps.nowinandroid.feature.search.navigation.navigateToSearch
 import com.google.samples.apps.nowinandroid.navigation.TopLevelDestination
 import com.google.samples.apps.nowinandroid.navigation.TopLevelDestination.BOOKMARKS
 import com.google.samples.apps.nowinandroid.navigation.TopLevelDestination.FOR_YOU
@@ -139,6 +140,10 @@ class NiaAppState(
     fun setShowSettingsDialog(shouldShow: Boolean) {
         shouldShowSettingsDialog = shouldShow
     }
+
+    fun navigateToSearch() {
+        navController.navigateToSearch()
+    }
 }
 
 /**

feature/search/.gitignore

@@ -0,0 +1 @@
+/build

feature/search/build.gradle.kts

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import com.android.build.api.dsl.ManagedVirtualDevice
+
+plugins {
+    id("nowinandroid.android.feature")
+    id("nowinandroid.android.library.compose")
+    id("nowinandroid.android.library.jacoco")
+}
+
+android {
+    namespace = "com.google.samples.apps.nowinandroid.feature.search"
+}
+

feature/search/src/androidTest/java/com/google/samples/apps/nowinandroid/feature/search/SearchScreenTest.kt

@@ -0,0 +1,58 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.samples.apps.nowinandroid.feature.search
+
+import androidx.activity.ComponentActivity
+import androidx.compose.ui.test.assertIsFocused
+import androidx.compose.ui.test.junit4.createAndroidComposeRule
+import androidx.compose.ui.test.onNodeWithContentDescription
+import androidx.compose.ui.test.onParent
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+
+/**
+ * UI test for checking the correct behaviour of the Search screen.
+ */
+class SearchScreenTest {
+
+    @get:Rule
+    val composeTestRule = createAndroidComposeRule<ComponentActivity>()
+
+    private lateinit var clearSearchText: String
+
+    @Before
+    fun setup() {
+        composeTestRule.activity.apply {
+            clearSearchText = getString(R.string.clear_search_text)
+        }
+    }
+
+    @Test
+    fun searchTextField_isFocused() {
+        composeTestRule.setContent {
+            SearchScreen()
+        }
+
+        composeTestRule
+            .onNodeWithContentDescription(clearSearchText)
+            // The parent of the IconButton whose contentDescription matches the clearSearchText
+            // should be the TextField for search
+            .onParent()
+            .assertIsFocused()
+    }
+}

feature/search/src/main/AndroidManifest.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright 2023 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+<manifest xmlns:android="http://schemas.android.com/apk/res/android" />

feature/search/src/main/java/com/google/samples/apps/nowinandroid/feature/search/SearchScreen.kt

@@ -0,0 +1,171 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.samples.apps.nowinandroid.feature.search
+
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.WindowInsets
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.safeDrawing
+import androidx.compose.foundation.layout.windowInsetsBottomHeight
+import androidx.compose.foundation.layout.windowInsetsTopHeight
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.TextField
+import androidx.compose.material3.TextFieldDefaults
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.focus.FocusRequester
+import androidx.compose.ui.focus.focusRequester
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import com.google.samples.apps.nowinandroid.core.designsystem.icon.NiaIcons
+import com.google.samples.apps.nowinandroid.core.designsystem.theme.NiaTheme
+import com.google.samples.apps.nowinandroid.core.ui.DevicePreviews
+import com.google.samples.apps.nowinandroid.core.ui.R.string
+import com.google.samples.apps.nowinandroid.core.ui.TrackScreenViewEvent
+import com.google.samples.apps.nowinandroid.feature.search.R as searchR
+
+@Composable
+internal fun SearchRoute(
+    modifier: Modifier = Modifier,
+    onBackClick: () -> Unit,
+    viewModel: SearchViewModel = hiltViewModel(),
+) {
+    SearchScreen(
+        modifier = modifier,
+        onBackClick = onBackClick,
+        onSearchQueryChanged = viewModel::onSearchQueryChanged,
+    )
+}
+
+@Composable
+internal fun SearchScreen(
+    modifier: Modifier = Modifier,
+    onBackClick: () -> Unit = {},
+    onSearchQueryChanged: (String) -> Unit = {},
+) {
+    TrackScreenViewEvent(screenName = "Search")
+    Column(
+        modifier = modifier,
+        horizontalAlignment = Alignment.CenterHorizontally,
+    ) {
+        Spacer(Modifier.windowInsetsTopHeight(WindowInsets.safeDrawing))
+        SearchToolbar(
+            onBackClick = onBackClick,
+            onSearchQueryChanged = onSearchQueryChanged,
+        )
+        Spacer(Modifier.windowInsetsBottomHeight(WindowInsets.safeDrawing))
+    }
+}
+
+@Composable
+private fun SearchToolbar(
+    modifier: Modifier = Modifier,
+    onBackClick: () -> Unit = {},
+    onSearchQueryChanged: (String) -> Unit = {},
+) {
+    Row(
+        verticalAlignment = Alignment.CenterVertically,
+        modifier = modifier.fillMaxWidth(),
+    ) {
+        IconButton(onClick = { onBackClick() }) {
+            Icon(
+                imageVector = NiaIcons.ArrowBack,
+                contentDescription = stringResource(
+                    id = string.back,
+                ),
+            )
+        }
+        SearchTextField(onSearchQueryChanged = onSearchQueryChanged)
+    }
+}
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+private fun SearchTextField(onSearchQueryChanged: (String) -> Unit) {
+    val textState = remember { mutableStateOf("") }
+    val focusRequester = remember { FocusRequester() }
+    TextField(
+        colors = TextFieldDefaults.textFieldColors(
+            focusedIndicatorColor = Color.Transparent,
+            unfocusedIndicatorColor = Color.Transparent,
+            disabledIndicatorColor = Color.Transparent,
+        ),
+        leadingIcon = {
+            Icon(
+                imageVector = NiaIcons.Search,
+                contentDescription = stringResource(
+                    id = searchR.string.search,
+                ),
+                tint = MaterialTheme.colorScheme.onSurface,
+            )
+        },
+        trailingIcon = {
+            IconButton(onClick = { textState.value = "" }) {
+                Icon(
+                    imageVector = NiaIcons.Close,
+                    contentDescription = stringResource(
+                        id = searchR.string.clear_search_text,
+                    ),
+                    tint = MaterialTheme.colorScheme.onSurface,
+                )
+            }
+        },
+        onValueChange = {
+            textState.value = it
+            onSearchQueryChanged(it)
+        },
+        modifier = Modifier
+            .fillMaxWidth()
+            .padding(12.dp)
+            .focusRequester(focusRequester),
+        shape = RoundedCornerShape(32.dp),
+        value = textState.value,
+    )
+    LaunchedEffect(Unit) {
+        focusRequester.requestFocus()
+    }
+}
+
+@Preview
+@Composable
+private fun SearchToolbarPreview() {
+    NiaTheme {
+        SearchToolbar()
+    }
+}
+
+@DevicePreviews
+@Composable
+private fun SearchScreenPreview() {
+    NiaTheme {
+        SearchScreen()
+    }
+}

feature/search/src/main/java/com/google/samples/apps/nowinandroid/feature/search/SearchViewModel.kt

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.samples.apps.nowinandroid.feature.search
+
+import androidx.lifecycle.ViewModel
+import dagger.hilt.android.lifecycle.HiltViewModel
+import javax.inject.Inject
+
+@HiltViewModel
+class SearchViewModel @Inject constructor() : ViewModel() {
+
+    fun onSearchQueryChanged(searchQuery: String) {
+        // TODO: Pass it to UseCase
+        println("New search query is '$searchQuery'")
+    }
+}

feature/search/src/main/java/com/google/samples/apps/nowinandroid/feature/search/navigation/SearchNavigation.kt

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.samples.apps.nowinandroid.feature.search.navigation
+
+import androidx.navigation.NavController
+import androidx.navigation.NavGraphBuilder
+import androidx.navigation.NavOptions
+import androidx.navigation.compose.composable
+import com.google.samples.apps.nowinandroid.feature.search.SearchRoute
+
+const val searchRoute = "search_route"
+
+fun NavController.navigateToSearch(navOptions: NavOptions? = null) {
+    this.navigate(searchRoute, navOptions)
+}
+
+fun NavGraphBuilder.searchScreen(onBackClick: () -> Unit) {
+    // TODO: Handle back stack for each top-level destination. At the moment each top-level
+    // destination may have own search screen's back stack.
+    composable(route = searchRoute) {
+        SearchRoute(onBackClick = onBackClick)
+    }
+}

feature/search/src/main/res/values/strings.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright 2023 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+<resources>
+    <string name="search">Search</string>
+    <string name="clear_search_text">Clear search text</string>
+</resources>

feature/settings/src/main/res/values/strings.xml

@@ -16,6 +16,7 @@
 -->
 <resources>
     <string name="top_app_bar_action_icon_description">Settings</string>
+    <string name="top_app_bar_navigation_icon_description">Search</string>
     <string name="settings_title">Settings</string>
     <string name="loading">Loading...</string>
     <string name="privacy_policy">Privacy policy</string>

settings.gradle.kts

@@ -53,6 +53,7 @@ include(":feature:foryou")
 include(":feature:interests")
 include(":feature:bookmarks")
 include(":feature:topic")
+include(":feature:search")
 include(":feature:settings")
 include(":lint")
 include(":sync:work")