MotionCompose: List loading

Change-Id: Ia7c23a9ced74070f3db860d0558d77df44dccbeb

Author: yaraki

MotionCompose/README.md

@@ -27,3 +27,7 @@ https://user-images.githubusercontent.com/1237536/142575353-8ed5cc04-34e3-45ea-9
 ### [Layout > Fade through](app/src/main/java/com/example/android/compose/motion/demo/fadethrough)
 
 https://user-images.githubusercontent.com/1237536/142538271-480a5573-4231-414a-88cd-9fd9951fc792.mp4
+
+### [List > Loading](app/src/main/java/com/example/android/compose/motion/demo/loading)
+
+https://user-images.githubusercontent.com/1237536/143526001-7621d2db-1228-4011-ae84-1572909e7806.mp4

MotionCompose/app/build.gradle

@@ -67,9 +67,15 @@ dependencies {
     implementation 'androidx.lifecycle:lifecycle-runtime-ktx:2.4.0'
     implementation 'androidx.activity:activity-compose:1.4.0'
 
-    def accompanist_version = '0.21.2-beta'
+    def accompanist_version = '0.21.3-beta'
     implementation "com.google.accompanist:accompanist-flowlayout:$accompanist_version"
     implementation "com.google.accompanist:accompanist-insets-ui:$accompanist_version"
+    implementation "com.google.accompanist:accompanist-placeholder:$accompanist_version"
+
+    def lifecycle_version = '2.4.0'
+    implementation "androidx.lifecycle:lifecycle-viewmodel-compose:$lifecycle_version"
+
+    implementation "androidx.paging:paging-compose:1.0.0-alpha14"
 
     testImplementation 'junit:junit:4.13.2'
     androidTestImplementation 'com.google.truth:truth:1.1.3'

MotionCompose/app/src/main/java/com/example/android/compose/motion/demo/Cheese.kt

@@ -16,6 +16,7 @@
 
 package com.example.android.compose.motion.demo
 
+import androidx.annotation.DrawableRes
 import com.example.android.compose.motion.R
 
 val CheeseImages = listOf(
@@ -25,3 +26,157 @@ val CheeseImages = listOf(
     R.drawable.cheese_4,
     R.drawable.cheese_5
 )
+
+val CheeseNames = listOf(
+    "Abbaye de Belloc", "Abbaye du Mont des Cats", "Abertam", "Abondance", "Ackawi",
+    "Acorn", "Adelost", "Affidelice au Chablis", "Afuega'l Pitu", "Airag", "Airedale",
+    "Aisy Cendre", "Allgauer Emmentaler", "Alverca", "Ambert", "American Cheese",
+    "Ami du Chambertin", "Anejo Enchilado", "Anneau du Vic-Bilh", "Anthoriro", "Appenzell",
+    "Aragon", "Ardi Gasna", "Ardrahan", "Armenian String", "Aromes au Gene de Marc",
+    "Asadero", "Asiago", "Aubisque Pyrenees", "Autun", "Avaxtskyr", "Baby Swiss",
+    "Babybel", "Baguette Laonnaise", "Bakers", "Baladi", "Balaton", "Bandal", "Banon",
+    "Barry's Bay Cheddar", "Basing", "Basket Cheese", "Bath Cheese", "Bavarian Bergkase",
+    "Baylough", "Beaufort", "Beauvoorde", "Beenleigh Blue", "Beer Cheese", "Bel Paese",
+    "Bergader", "Bergere Bleue", "Berkswell", "Beyaz Peynir", "Bierkase", "Bishop Kennedy",
+    "Blarney", "Bleu d'Auvergne", "Bleu de Gex", "Bleu de Laqueuille",
+    "Bleu de Septmoncel", "Bleu Des Causses", "Blue", "Blue Castello", "Blue Rathgore",
+    "Blue Vein (Australian)", "Blue Vein Cheeses", "Bocconcini", "Bocconcini (Australian)",
+    "Boeren Leidenkaas", "Bonchester", "Bosworth", "Bougon", "Boule Du Roves",
+    "Boulette d'Avesnes", "Boursault", "Boursin", "Bouyssou", "Bra", "Braudostur",
+    "Breakfast Cheese", "Brebis du Lavort", "Brebis du Lochois", "Brebis du Puyfaucon",
+    "Bresse Bleu", "Brick", "Brie", "Brie de Meaux", "Brie de Melun", "Brillat-Savarin",
+    "Brin", "Brin d' Amour", "Brin d'Amour", "Brinza (Burduf Brinza)",
+    "Briquette de Brebis", "Briquette du Forez", "Broccio", "Broccio Demi-Affine",
+    "Brousse du Rove", "Bruder Basil", "Brusselae Kaas (Fromage de Bruxelles)", "Bryndza",
+    "Buchette d'Anjou", "Buffalo", "Burgos", "Butte", "Butterkase", "Button (Innes)",
+    "Buxton Blue", "Cabecou", "Caboc", "Cabrales", "Cachaille", "Caciocavallo", "Caciotta",
+    "Caerphilly", "Cairnsmore", "Calenzana", "Cambazola", "Camembert de Normandie",
+    "Canadian Cheddar", "Canestrato", "Cantal", "Caprice des Dieux", "Capricorn Goat",
+    "Capriole Banon", "Carre de l'Est", "Casciotta di Urbino", "Cashel Blue", "Castellano",
+    "Castelleno", "Castelmagno", "Castelo Branco", "Castigliano", "Cathelain",
+    "Celtic Promise", "Cendre d'Olivet", "Cerney", "Chabichou", "Chabichou du Poitou",
+    "Chabis de Gatine", "Chaource", "Charolais", "Chaumes", "Cheddar",
+    "Cheddar Clothbound", "Cheshire", "Chevres", "Chevrotin des Aravis", "Chontaleno",
+    "Civray", "Coeur de Camembert au Calvados", "Coeur de Chevre", "Colby", "Cold Pack",
+    "Comte", "Coolea", "Cooleney", "Coquetdale", "Corleggy", "Cornish Pepper",
+    "Cotherstone", "Cotija", "Cottage Cheese", "Cottage Cheese (Australian)",
+    "Cougar Gold", "Coulommiers", "Coverdale", "Crayeux de Roncq", "Cream Cheese",
+    "Cream Havarti", "Crema Agria", "Crema Mexicana", "Creme Fraiche", "Crescenza",
+    "Croghan", "Crottin de Chavignol", "Crottin du Chavignol", "Crowdie", "Crowley",
+    "Cuajada", "Curd", "Cure Nantais", "Curworthy", "Cwmtawe Pecorino",
+    "Cypress Grove Chevre", "Danablu (Danish Blue)", "Danbo", "Danish Fontina",
+    "Daralagjazsky", "Dauphin", "Delice des Fiouves", "Denhany Dorset Drum", "Derby",
+    "Dessertnyj Belyj", "Devon Blue", "Devon Garland", "Dolcelatte", "Doolin",
+    "Doppelrhamstufel", "Dorset Blue Vinney", "Double Gloucester", "Double Worcester",
+    "Dreux a la Feuille", "Dry Jack", "Duddleswell", "Dunbarra", "Dunlop", "Dunsyre Blue",
+    "Duroblando", "Durrus", "Dutch Mimolette (Commissiekaas)", "Edam", "Edelpilz",
+    "Emental Grand Cru", "Emlett", "Emmental", "Epoisses de Bourgogne", "Esbareich",
+    "Esrom", "Etorki", "Evansdale Farmhouse Brie", "Evora De L'Alentejo", "Exmoor Blue",
+    "Explorateur", "Feta", "Feta (Australian)", "Figue", "Filetta", "Fin-de-Siecle",
+    "Finlandia Swiss", "Finn", "Fiore Sardo", "Fleur du Maquis", "Flor de Guia",
+    "Flower Marie", "Folded", "Folded cheese with mint", "Fondant de Brebis",
+    "Fontainebleau", "Fontal", "Fontina Val d'Aosta", "Formaggio di capra", "Fougerus",
+    "Four Herb Gouda", "Fourme d' Ambert", "Fourme de Haute Loire", "Fourme de Montbrison",
+    "Fresh Jack", "Fresh Mozzarella", "Fresh Ricotta", "Fresh Truffles", "Fribourgeois",
+    "Friesekaas", "Friesian", "Friesla", "Frinault", "Fromage a Raclette", "Fromage Corse",
+    "Fromage de Montagne de Savoie", "Fromage Frais", "Fruit Cream Cheese",
+    "Frying Cheese", "Fynbo", "Gabriel", "Galette du Paludier", "Galette Lyonnaise",
+    "Galloway Goat's Milk Gems", "Gammelost", "Gaperon a l'Ail", "Garrotxa", "Gastanberra",
+    "Geitost", "Gippsland Blue", "Gjetost", "Gloucester", "Golden Cross", "Gorgonzola",
+    "Gornyaltajski", "Gospel Green", "Gouda", "Goutu", "Gowrie", "Grabetto", "Graddost",
+    "Grafton Village Cheddar", "Grana", "Grana Padano", "Grand Vatel",
+    "Grataron d' Areches", "Gratte-Paille", "Graviera", "Greuilh", "Greve",
+    "Gris de Lille", "Gruyere", "Gubbeen", "Guerbigny", "Halloumi",
+    "Halloumy (Australian)", "Haloumi-Style Cheese", "Harbourne Blue", "Havarti",
+    "Heidi Gruyere", "Hereford Hop", "Herrgardsost", "Herriot Farmhouse", "Herve",
+    "Hipi Iti", "Hubbardston Blue Cow", "Hushallsost", "Iberico", "Idaho Goatster",
+    "Idiazabal", "Il Boschetto al Tartufo", "Ile d'Yeu", "Isle of Mull", "Jarlsberg",
+    "Jermi Tortes", "Jibneh Arabieh", "Jindi Brie", "Jubilee Blue", "Juustoleipa",
+    "Kadchgall", "Kaseri", "Kashta", "Kefalotyri", "Kenafa", "Kernhem", "Kervella Affine",
+    "Kikorangi", "King Island Cape Wickham Brie", "King River Gold", "Klosterkaese",
+    "Knockalara", "Kugelkase", "L'Aveyronnais", "L'Ecir de l'Aubrac", "La Taupiniere",
+    "La Vache Qui Rit", "Laguiole", "Lairobell", "Lajta", "Lanark Blue", "Lancashire",
+    "Langres", "Lappi", "Laruns", "Lavistown", "Le Brin", "Le Fium Orbo", "Le Lacandou",
+    "Le Roule", "Leafield", "Lebbene", "Leerdammer", "Leicester", "Leyden", "Limburger",
+    "Lincolnshire Poacher", "Lingot Saint Bousquet d'Orb", "Liptauer", "Little Rydings",
+    "Livarot", "Llanboidy", "Llanglofan Farmhouse", "Loch Arthur Farmhouse",
+    "Loddiswell Avondale", "Longhorn", "Lou Palou", "Lou Pevre", "Lyonnais", "Maasdam",
+    "Macconais", "Mahoe Aged Gouda", "Mahon", "Malvern", "Mamirolle", "Manchego",
+    "Manouri", "Manur", "Marble Cheddar", "Marbled Cheeses", "Maredsous", "Margotin",
+    "Maribo", "Maroilles", "Mascares", "Mascarpone", "Mascarpone (Australian)",
+    "Mascarpone Torta", "Matocq", "Maytag Blue", "Meira", "Menallack Farmhouse",
+    "Menonita", "Meredith Blue", "Mesost", "Metton (Cancoillotte)", "Meyer Vintage Gouda",
+    "Mihalic Peynir", "Milleens", "Mimolette", "Mine-Gabhar", "Mini Baby Bells", "Mixte",
+    "Molbo", "Monastery Cheeses", "Mondseer", "Mont D'or Lyonnais", "Montasio",
+    "Monterey Jack", "Monterey Jack Dry", "Morbier", "Morbier Cru de Montagne",
+    "Mothais a la Feuille", "Mozzarella", "Mozzarella (Australian)",
+    "Mozzarella di Bufala", "Mozzarella Fresh, in water", "Mozzarella Rolls", "Munster",
+    "Murol", "Mycella", "Myzithra", "Naboulsi", "Nantais", "Neufchatel",
+    "Neufchatel (Australian)", "Niolo", "Nokkelost", "Northumberland", "Oaxaca",
+    "Olde York", "Olivet au Foin", "Olivet Bleu", "Olivet Cendre",
+    "Orkney Extra Mature Cheddar", "Orla", "Oschtjepka", "Ossau Fermier", "Ossau-Iraty",
+    "Oszczypek", "Oxford Blue", "P'tit Berrichon", "Palet de Babligny", "Paneer", "Panela",
+    "Pannerone", "Pant ys Gawn", "Parmesan (Parmigiano)", "Parmigiano Reggiano",
+    "Pas de l'Escalette", "Passendale", "Pasteurized Processed", "Pate de Fromage",
+    "Patefine Fort", "Pave d'Affinois", "Pave d'Auge", "Pave de Chirac", "Pave du Berry",
+    "Pecorino", "Pecorino in Walnut Leaves", "Pecorino Romano", "Peekskill Pyramid",
+    "Pelardon des Cevennes", "Pelardon des Corbieres", "Penamellera", "Penbryn",
+    "Pencarreg", "Perail de Brebis", "Petit Morin", "Petit Pardou", "Petit-Suisse",
+    "Picodon de Chevre", "Picos de Europa", "Piora", "Pithtviers au Foin",
+    "Plateau de Herve", "Plymouth Cheese", "Podhalanski", "Poivre d'Ane", "Polkolbin",
+    "Pont l'Eveque", "Port Nicholson", "Port-Salut", "Postel", "Pouligny-Saint-Pierre",
+    "Pourly", "Prastost", "Pressato", "Prince-Jean", "Processed Cheddar", "Provolone",
+    "Provolone (Australian)", "Pyengana Cheddar", "Pyramide", "Quark",
+    "Quark (Australian)", "Quartirolo Lombardo", "Quatre-Vents", "Quercy Petit",
+    "Queso Blanco", "Queso Blanco con Frutas --Pina y Mango", "Queso de Murcia",
+    "Queso del Montsec", "Queso del Tietar", "Queso Fresco", "Queso Fresco (Adobera)",
+    "Queso Iberico", "Queso Jalapeno", "Queso Majorero", "Queso Media Luna",
+    "Queso Para Frier", "Queso Quesadilla", "Rabacal", "Raclette", "Ragusano", "Raschera",
+    "Reblochon", "Red Leicester", "Regal de la Dombes", "Reggianito", "Remedou",
+    "Requeson", "Richelieu", "Ricotta", "Ricotta (Australian)", "Ricotta Salata", "Ridder",
+    "Rigotte", "Rocamadour", "Rollot", "Romano", "Romans Part Dieu", "Roncal", "Roquefort",
+    "Roule", "Rouleau De Beaulieu", "Royalp Tilsit", "Rubens", "Rustinu", "Saaland Pfarr",
+    "Saanenkaese", "Saga", "Sage Derby", "Sainte Maure", "Saint-Marcellin",
+    "Saint-Nectaire", "Saint-Paulin", "Salers", "Samso", "San Simon", "Sancerre",
+    "Sap Sago", "Sardo", "Sardo Egyptian", "Sbrinz", "Scamorza", "Schabzieger", "Schloss",
+    "Selles sur Cher", "Selva", "Serat", "Seriously Strong Cheddar", "Serra da Estrela",
+    "Sharpam", "Shelburne Cheddar", "Shropshire Blue", "Siraz", "Sirene", "Smoked Gouda",
+    "Somerset Brie", "Sonoma Jack", "Sottocenare al Tartufo", "Soumaintrain",
+    "Sourire Lozerien", "Spenwood", "Sraffordshire Organic", "St. Agur Blue Cheese",
+    "Stilton", "Stinking Bishop", "String", "Sussex Slipcote", "Sveciaost", "Swaledale",
+    "Sweet Style Swiss", "Swiss", "Syrian (Armenian String)", "Tala", "Taleggio", "Tamie",
+    "Tasmania Highland Chevre Log", "Taupiniere", "Teifi", "Telemea", "Testouri",
+    "Tete de Moine", "Tetilla", "Texas Goat Cheese", "Tibet", "Tillamook Cheddar",
+    "Tilsit", "Timboon Brie", "Toma", "Tomme Brulee", "Tomme d'Abondance",
+    "Tomme de Chevre", "Tomme de Romans", "Tomme de Savoie", "Tomme des Chouans", "Tommes",
+    "Torta del Casar", "Toscanello", "Touree de L'Aubier", "Tourmalet",
+    "Trappe (Veritable)", "Trois Cornes De Vendee", "Tronchon", "Trou du Cru", "Truffe",
+    "Tupi", "Turunmaa", "Tymsboro", "Tyn Grug", "Tyning", "Ubriaco", "Ulloa",
+    "Vacherin-Fribourgeois", "Valencay", "Vasterbottenost", "Venaco", "Vendomois",
+    "Vieux Corse", "Vignotte", "Vulscombe", "Waimata Farmhouse Blue",
+    "Washed Rind Cheese (Australian)", "Waterloo", "Weichkaese", "Wellington",
+    "Wensleydale", "White Stilton", "Whitestone Farmhouse", "Wigmore", "Woodside Cabecou",
+    "Xanadu", "Xynotyro", "Yarg Cornish", "Yarra Valley Pyramid", "Yorkshire Blue",
+    "Zamorano", "Zanetti Grana Padano", "Zanetti Parmigiano Reggiano"
+)
+
+data class Cheese(
+    val id: Long,
+    val name: String,
+    @DrawableRes val image: Int
+) {
+    companion object {
+        fun all(): List<Cheese> {
+            return CheeseNames.mapIndexed { i, name ->
+                Cheese(
+                    id = (i + 1).toLong(),
+                    name = name,
+                    image = CheeseImages[
+                            ((name.hashCode() % CheeseImages.size) + CheeseImages.size)
+                                    % CheeseImages.size
+                    ]
+                )
+            }
+        }
+    }
+}

MotionCompose/app/src/main/java/com/example/android/compose/motion/demo/Demo.kt

@@ -19,6 +19,7 @@ package com.example.android.compose.motion.demo
 import androidx.compose.runtime.Composable
 import com.example.android.compose.motion.demo.fade.FadeDemo
 import com.example.android.compose.motion.demo.fadethrough.FadeThroughDemo
+import com.example.android.compose.motion.demo.loading.LoadingDemo
 
 enum class Demo(
     val title: String,
@@ -51,5 +52,17 @@ enum class Demo(
             "AnimatedContent"
         ),
         content = { FadeThroughDemo() }
+    ),
+
+    Loading(
+        title = "List > Loading",
+        description = """
+            Motion provides timely feedback and the status of user actions. An animated placeholder
+            UI can indicate that content is loading.
+        """.trimIndent().replace('\n', ' '),
+        apis = listOf(
+            "Modifier.placeholder", "AnimationSpec"
+        ),
+        content = { LoadingDemo() }
     )
 }

MotionCompose/app/src/main/java/com/example/android/compose/motion/demo/loading/CheeseDataSource.kt

@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2021 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.
+ */
+
+package com.example.android.compose.motion.demo.loading
+
+import androidx.paging.PagingSource
+import androidx.paging.PagingState
+import com.example.android.compose.motion.demo.Cheese
+import kotlinx.coroutines.delay
+
+class CheeseDataSource : PagingSource<Int, Cheese>() {
+
+    override fun getRefreshKey(state: PagingState<Int, Cheese>): Int? {
+        return state.anchorPosition
+    }
+
+    override suspend fun load(params: LoadParams<Int>): LoadResult<Int, Cheese> {
+        return params.key.let { position ->
+            val all = Cheese.all()
+            if (position == null) {
+                LoadResult.Page(
+                    emptyList(),
+                    prevKey = null,
+                    nextKey = 0,
+                    itemsBefore = 0,
+                    itemsAfter = all.size
+                )
+            } else {
+                // Simulate slow network.
+                delay(3000)
+                LoadResult.Page(
+                    all.subList(
+                        position,
+                        (position + params.loadSize).coerceAtMost(all.size)
+                    ),
+                    prevKey = (position - params.loadSize).orNullIf { it < 0 },
+                    nextKey = (position + params.loadSize).orNullIf { it >= all.size },
+                    itemsBefore = position,
+                    itemsAfter = (all.size - position - params.loadSize).coerceAtLeast(0)
+                )
+            }
+        }
+    }
+}
+
+private fun Int.orNullIf(condition: (Int) -> Boolean): Int? {
+    return if (condition(this)) null else this
+}