Add pagination samples

samples/pagination/README.md

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+# Pagination samples
+
+This directory contains samples that demonstrate how to implement pagination with the Apollo normalized cache.
+
+These are 3 variations of an Android app that uses the [GitHub GraphQL API](https://docs.github.com/en/graphql) to fetch and display a list of repositories.
+
+- [manual](./manual): manually merge pages together and store the result into the cache using the [`ApolloStore`](https://apollographql.github.io/apollo-kotlin-normalized-cache-incubating/kdoc/normalized-cache-incubating/com.apollographql.cache.normalized/-apollo-store/index.html?query=interface%20ApolloStore) API.
+- [pagination-support](./pagination-support): use the normalized cache pagination support (`@typePolicy(connectionFields: ...)` / [`ConnectionMetadataGenerator`](https://apollographql.github.io/apollo-kotlin-normalized-cache-incubating/kdoc/normalized-cache-incubating/com.apollographql.cache.normalized.api/-connection-metadata-generator/index.html?query=class%20ConnectionMetadataGenerator(connectionTypes:%20Set%3CString%3E)%20:%20MetadataGenerator), [`ConnectionRecordMerger`](https://apollographql.github.io/apollo-kotlin-normalized-cache-incubating/kdoc/normalized-cache-incubating/com.apollographql.cache.normalized.api/-connection-record-merger.html?query=val%20ConnectionRecordMerger:%20FieldRecordMerger)) to automatically merge pages together in the cache.
+- [pagination-support-with-jetpack-paging](./pagination-support-with-jetpack-paging): demonstrates how to use the normalized cache pagination support along with the [Android Jetpack Paging library](https://developer.android.com/topic/libraries/architecture/paging/v3-overview). 
+
+Please refer to the `README.md` in each sample for more details.

samples/pagination/manual/.gitignore

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+.DS_Store
+build
+out
+.gradle
+*.iml
+.idea/*
+!.idea/copyright
+!.idea/codeStyles
+local.properties

samples/pagination/manual/README.md

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+# Pagination sample: manual merging of pages
+
+Displays a list of repositories fetched from the [GitHub GraphQL API](https://docs.github.com/en/graphql). 
+
+Note: to execute the app, provide a [GitHub access token](https://developer.github.com/v4/guides/forming-calls/#authenticating-with-graphql) in the `gradle.properties` file.
+
+## Architecture
+
+- `MainActivity` shows a `LazyColumn` listing the repositories by watching `RepositoryListQuery`.  
+- When scrolling to the end of the list, `fetchAndMergeNextPage()` is called, which
+  1. Gets the current list from the cache
+  2. Fetches the next page from the network
+  3. Manually merges the next page with the current list
+  4. Updates the cache with the merged list using the [`ApolloStore`](https://apollographql.github.io/apollo-kotlin-normalized-cache-incubating/kdoc/normalized-cache-incubating/com.apollographql.cache.normalized/-apollo-store/index.html?query=interface%20ApolloStore) API
+- Writing to the cache triggers an emission to the watcher, and the `LazyColumn` is updated with the updated list. 
+
+The gist of it is [here](app/src/main/java/com/example/apollokotlinpaginationsample/repository/Apollo.kt#L43).

samples/pagination/manual/app/build.gradle.kts

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+fun prop(key: String) = project.findProperty(key).toString()
+
+plugins {
+    id("com.android.application")
+    id("org.jetbrains.kotlin.android")
+    id("com.apollographql.apollo").version("4.0.0-rc.2")
+    id("org.jetbrains.kotlin.plugin.compose").version("2.0.0")
+}
+
+android {
+    namespace = "com.example.apollokotlinpaginationsample"
+    compileSdk = 34
+
+    defaultConfig {
+        applicationId = "com.example.apollokotlinpaginationsample"
+        minSdk = 24
+        targetSdk = 34
+        versionCode = 1
+        versionName = "1.0"
+
+        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
+        vectorDrawables {
+            useSupportLibrary = true
+        }
+
+        buildConfigField("String", "GITHUB_OAUTH_KEY", "\"${prop("githubOauthKey")}\"")
+    }
+
+    buildTypes {
+        release {
+            isMinifyEnabled = false
+            proguardFiles(getDefaultProguardFile("proguard-android-optimize.txt"), "proguard-rules.pro")
+        }
+    }
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_1_8
+        targetCompatibility = JavaVersion.VERSION_1_8
+    }
+
+    kotlinOptions {
+        jvmTarget = "1.8"
+    }
+
+    buildFeatures {
+        compose = true
+        buildConfig = true
+    }
+
+    packaging {
+        resources {
+            excludes += "/META-INF/{AL2.0,LGPL2.1}"
+        }
+    }
+}
+
+apollo {
+    service("main") {
+        packageName.set("com.example.apollokotlinpaginationsample.graphql")
+
+        introspection {
+            endpointUrl.set("https://api.github.com/graphql")
+            schemaFile.set(file("src/main/graphql/schema.graphqls"))
+            headers.put("Authorization", "Bearer ${prop("githubOauthKey")}")
+        }
+    }
+}
+
+dependencies {
+    implementation("androidx.core:core-ktx:1.13.1")
+    implementation("androidx.lifecycle:lifecycle-runtime-ktx:2.8.3")
+    implementation("androidx.activity:activity-compose:1.9.0")
+    implementation(platform("androidx.compose:compose-bom:2024.06.00"))
+    implementation("androidx.compose.ui:ui")
+    implementation("androidx.compose.ui:ui-graphics")
+    implementation("androidx.compose.ui:ui-tooling-preview")
+    implementation("androidx.compose.material3:material3")
+
+    implementation("com.apollographql.apollo:apollo-runtime")
+    implementation("com.apollographql.cache:normalized-cache-sqlite-incubating:0.0.3-SNAPSHOT")
+
+    debugImplementation("androidx.compose.ui:ui-tooling")
+    debugImplementation("androidx.compose.ui:ui-test-manifest")
+}

samples/pagination/manual/app/proguard-rules.pro

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+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile

samples/pagination/manual/app/src/main/AndroidManifest.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools">
+
+    <uses-permission android:name="android.permission.INTERNET" />
+
+    <application
+        android:name=".Application"
+        android:allowBackup="true"
+        android:dataExtractionRules="@xml/data_extraction_rules"
+        android:fullBackupContent="@xml/backup_rules"
+        android:icon="@mipmap/ic_launcher"
+        android:label="@string/app_name"
+        android:networkSecurityConfig="@xml/network_security_config"
+        android:roundIcon="@mipmap/ic_launcher_round"
+        android:supportsRtl="true"
+        android:theme="@style/Theme.ApolloKotlinPaginationSample"
+        tools:targetApi="31">
+        <activity
+            android:name=".ui.MainActivity"
+            android:exported="true"
+            android:theme="@style/Theme.ApolloKotlinPaginationSample">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+
+</manifest>

samples/pagination/manual/app/src/main/graphql/extra.graphqls

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+extend schema
+@link(
+    url: "https://specs.apollo.dev/kotlin_labs/v0.3",
+    import: ["@nonnull", "@typePolicy"]
+)
+
+extend type Query @nonnull(fields: "organization")
+extend type RepositoryConnection @nonnull(fields: "edges")
+extend type RepositoryEdge @nonnull(fields: "node")
+
+extend type Repository @typePolicy(keyFields: "id")

samples/pagination/manual/app/src/main/graphql/operations.graphql

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+query RepositoryListQuery($first: Int = 15, $after: String) {
+    organization(login: "github") {
+        repositories(first: $first, after: $after) {
+            pageInfo {
+                hasNextPage
+                endCursor
+            }
+            edges {
+                cursor
+                node {
+                    ...RepositoryFields
+                }
+            }
+        }
+    }
+}
+
+fragment RepositoryFields on Repository {
+    name
+    description
+    stargazers(first: 0) {
+        totalCount
+    }
+}