New empty bookmarks handling (#443)

* Added the png file for error state

This should be removed later - couldn't convert the design to vector from svg - there is a problem with the `<mask` tag.

* Added two new strings based on the Figma file

* Redesign and reimplementation for the empty BookmarksScreen along with two clarifying comments.

* Removed the png file and replaced it with vector

* Code refactor after code reviewing

Made contentDescription null, removed extra spaces and renaming for the Composable function as suggested.

* Moved the modifier after Text

* Added a space after the curly bracket to pass the Spotless check

* Spotless apply

* Simplify logic in Bookmarks screen

* Change order of composables in BookmarksScreen and add previews

* Refactor after code review

Removed the space before `if`, and changed the padding from 5 to 8dp.

Co-authored-by: Jolanda Verhoef <JolandaVerhoef@users.noreply.github.com>

core/designsystem/src/main/java/com/google/samples/apps/nowinandroid/core/designsystem/component/LoadingWheel.kt

@@ -42,6 +42,7 @@ import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.graphics.StrokeCap
 import androidx.compose.ui.graphics.drawscope.rotate
 import androidx.compose.ui.graphics.graphicsLayer
+import androidx.compose.ui.platform.LocalInspectionMode
 import androidx.compose.ui.semantics.contentDescription
 import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.unit.dp
@@ -56,7 +57,8 @@ fun NiaLoadingWheel(
     val infiniteTransition = rememberInfiniteTransition()
 
     // Specifies the float animation for slowly drawing out the lines on entering
-    val floatAnimValues = (0 until NUM_OF_LINES).map { remember { Animatable(1F) } }
+    val startValue = if (LocalInspectionMode.current) 0F else 1F
+    val floatAnimValues = (0 until NUM_OF_LINES).map { remember { Animatable(startValue) } }
     LaunchedEffect(floatAnimValues) {
         (0 until NUM_OF_LINES).map { index ->
             launch {

feature/bookmarks/src/main/java/com/google/samples/apps/nowinandroid/feature/bookmarks/BookmarksScreen.kt

@@ -16,14 +16,17 @@
 
 package com.google.samples.apps.nowinandroid.feature.bookmarks
 
+import androidx.annotation.VisibleForTesting
+import androidx.compose.foundation.Image
 import androidx.compose.foundation.layout.Arrangement
-import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.WindowInsets
-import androidx.compose.foundation.layout.fillMaxHeight
 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.safeDrawing
 import androidx.compose.foundation.layout.windowInsetsBottomHeight
 import androidx.compose.foundation.layout.wrapContentSize
@@ -31,19 +34,29 @@ import androidx.compose.foundation.lazy.grid.GridCells.Adaptive
 import androidx.compose.foundation.lazy.grid.GridItemSpan
 import androidx.compose.foundation.lazy.grid.LazyVerticalGrid
 import androidx.compose.foundation.lazy.grid.rememberLazyGridState
+import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.testTag
+import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.ExperimentalLifecycleComposeApi
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import com.google.samples.apps.nowinandroid.core.designsystem.component.NiaLoadingWheel
+import com.google.samples.apps.nowinandroid.core.designsystem.theme.NiaTheme
+import com.google.samples.apps.nowinandroid.core.domain.model.SaveableNewsResource
+import com.google.samples.apps.nowinandroid.core.model.data.previewNewsResources
 import com.google.samples.apps.nowinandroid.core.ui.NewsFeedUiState
+import com.google.samples.apps.nowinandroid.core.ui.NewsFeedUiState.Loading
+import com.google.samples.apps.nowinandroid.core.ui.NewsFeedUiState.Success
 import com.google.samples.apps.nowinandroid.core.ui.TrackScrollJank
 import com.google.samples.apps.nowinandroid.core.ui.newsFeed
 
@@ -61,8 +74,39 @@ internal fun BookmarksRoute(
     )
 }
 
+/**
+ * Displays the user's bookmarked articles. Includes support for loading and empty states.
+ */
+@VisibleForTesting(otherwise = VisibleForTesting.PRIVATE)
+@Composable
+internal fun BookmarksScreen(
+    feedState: NewsFeedUiState,
+    removeFromBookmarks: (String) -> Unit,
+    modifier: Modifier = Modifier
+) {
+    when (feedState) {
+        Loading -> LoadingState(modifier)
+        is Success -> if (feedState.feed.isNotEmpty()) {
+            BookmarksGrid(feedState, removeFromBookmarks, modifier)
+        } else {
+            EmptyState(modifier)
+        }
+    }
+}
+
 @Composable
-fun BookmarksScreen(
+private fun LoadingState(modifier: Modifier = Modifier) {
+    NiaLoadingWheel(
+        modifier = modifier
+            .fillMaxWidth()
+            .wrapContentSize()
+            .testTag("forYou:loading"),
+        contentDesc = stringResource(id = R.string.saved_loading),
+    )
+}
+
+@Composable
+private fun BookmarksGrid(
     feedState: NewsFeedUiState,
     removeFromBookmarks: (String) -> Unit,
     modifier: Modifier = Modifier
@@ -79,41 +123,80 @@ fun BookmarksScreen(
             .fillMaxSize()
             .testTag("bookmarks:feed")
     ) {
+        newsFeed(
+            feedState = feedState,
+            onNewsResourcesCheckedChanged = { id, _ -> removeFromBookmarks(id) },
+        )
+        item(span = { GridItemSpan(maxLineSpan) }) {
+            Spacer(Modifier.windowInsetsBottomHeight(WindowInsets.safeDrawing))
+        }
+    }
+}
 
-        when (feedState) {
-            is NewsFeedUiState.Loading -> {
-                item(span = { GridItemSpan(maxLineSpan) }) {
-                    NiaLoadingWheel(
-                        modifier = Modifier
-                            .fillMaxWidth()
-                            .wrapContentSize()
-                            .testTag("forYou:loading"),
-                        contentDesc = stringResource(id = R.string.saved_loading),
-                    )
-                }
-            }
+@Composable
+private fun EmptyState(modifier: Modifier = Modifier) {
+    Column(
+        modifier = modifier
+            .padding(16.dp)
+            .fillMaxSize()
+            .testTag("bookmarks:empty"),
+        verticalArrangement = Arrangement.Center,
+        horizontalAlignment = Alignment.CenterHorizontally
+    ) {
+        Image(
+            modifier = Modifier.fillMaxWidth(),
+            painter = painterResource(id = R.drawable.img_empty_bookmarks),
+            contentDescription = null
+        )
+
+        Spacer(modifier = Modifier.height(16.dp))
+
+        Text(
+            text = stringResource(id = R.string.bookmarks_empty_error),
+            modifier = Modifier.fillMaxWidth(),
+            textAlign = TextAlign.Center,
+            style = MaterialTheme.typography.titleMedium,
+            fontWeight = FontWeight.Bold
+        )
 
-            is NewsFeedUiState.Success -> {
-                if (feedState.feed.isNotEmpty()) {
-                    newsFeed(
-                        feedState = feedState,
-                        onNewsResourcesCheckedChanged = { id, _ -> removeFromBookmarks(id) },
-                    )
-                    item(span = { GridItemSpan(maxLineSpan) }) {
-                        Spacer(Modifier.windowInsetsBottomHeight(WindowInsets.safeDrawing))
-                    }
-                } else item(span = { GridItemSpan(maxLineSpan) }) {
-                    Box(
-                        modifier = Modifier
-                            .fillMaxHeight()
-                            .wrapContentSize()
-                            .testTag("bookmarks:empty"),
-                        contentAlignment = Alignment.Center
-                    ) {
-                        Text(text = stringResource(id = R.string.bookmarks_empty))
-                    }
+        Spacer(modifier = Modifier.height(8.dp))
+
+        Text(
+            text = stringResource(id = R.string.bookmarks_empty_description),
+            modifier = Modifier.fillMaxWidth(),
+            textAlign = TextAlign.Center,
+            style = MaterialTheme.typography.bodyMedium
+        )
+    }
+}
+
+@Preview
+@Composable
+private fun LoadingStatePreview() {
+    NiaTheme {
+        LoadingState()
+    }
+}
+
+@Preview
+@Composable
+private fun BookmarksGridPreview() {
+    NiaTheme {
+        BookmarksGrid(
+            feedState = Success(
+                previewNewsResources.map {
+                    SaveableNewsResource(it, false)
                 }
-            }
-        }
+            ),
+            removeFromBookmarks = {}
+        )
+    }
+}
+
+@Preview
+@Composable
+fun EmptyStatePreview() {
+    NiaTheme {
+        EmptyState()
     }
 }

feature/bookmarks/src/main/res/drawable/img_empty_bookmarks.xml

@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright 2022 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.
+-->
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="192dp"
+    android:height="192dp"
+    android:viewportWidth="64"
+    android:viewportHeight="64">
+    <path
+        android:fillColor="#8B418F"
+        android:pathData="M16,1C15.448,1 15,1.448 15,2C15,2.552 15.448,3 16,3V1ZM58,52C58,52.552 58.448,53 59,53C59.552,53 60,52.552 60,52H58ZM16,3H55V1H16V3ZM58,6V52H60V6H58ZM55,3C56.657,3 58,4.343 58,6H60C60,3.239 57.761,1 55,1V3Z" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M45,10H9C6.791,10 5,11.791 5,14V55.854C5,59.177 8.817,61.051 11.446,59.019L24.554,48.89C25.995,47.777 28.005,47.777 29.446,48.89L42.554,59.019C45.183,61.051 49,59.177 49,55.854V14C49,11.791 47.209,10 45,10Z"
+        android:strokeColor="#8B418F"
+        android:strokeLineCap="round"
+        android:strokeWidth="2" />
+</vector>

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

@@ -20,5 +20,6 @@
     <string name="top_app_bar_title">Saved</string>
     <string name="top_app_bar_action_search">Search</string>
     <string name="top_app_bar_action_menu">Menu</string>
-    <string name="bookmarks_empty">No bookmarks yet!</string>
+    <string name="bookmarks_empty_error">No saved updates</string>
+    <string name="bookmarks_empty_description">Updates you save will be stored here\nto read later</string>
 </resources>