| <html devsite="true"> |
| <head> |
| <title>Pager</title> |
| {% setvar book_path %}/reference/androidx/_book.yaml{% endsetvar %} |
| {% include "_shared/_reference-head-tags.html" %} |
| </head> |
| <body> |
| <div itemscope="" itemtype="http://developers.google.com/ReferenceObject"> |
| <meta itemprop="name" content="Pager"> |
| <meta itemprop="path" content="androidx.paging"> |
| <meta itemprop="property" content="getFlow()"> |
| <meta itemprop="language" content="JAVA"> |
| </div> |
| <div id="header-block"> |
| <div> |
| <h1>Pager</h1> |
| </div> |
| </div> |
| <div id="refdoc-switcher-placeholder"></div> |
| <p> |
| <pre>public final class <a href="/reference/androidx/paging/Pager.html">Pager</a><Key extends <a href="https://developer.android.com/reference/java/lang/Object.html">Object</a>, Value extends <a href="https://developer.android.com/reference/java/lang/Object.html">Object</a>></pre> |
| </p> |
| <hr> |
| <p>Primary entry point into Paging; constructor for a reactive stream of <code><a href="/reference/androidx/paging/PagingData.html">PagingData</a></code>.</p> |
| <p>Each <code><a href="/reference/androidx/paging/PagingData.html">PagingData</a></code> represents a snapshot of the backing paginated data. Updates to the backing dataset should be represented by a new instance of <code><a href="/reference/androidx/paging/PagingData.html">PagingData</a></code>.</p> |
| <p>PagingSource.invalidate and calls to AsyncPagingDataDiffer.refresh or PagingDataAdapter.refresh will notify <code><a href="/reference/androidx/paging/Pager.html">Pager</a></code> that the backing dataset has been updated and a new <code><a href="/reference/androidx/paging/PagingData.html">PagingData</a></code> / PagingSource pair will be generated to represent an updated snapshot.</p> |
| <p><code><a href="/reference/androidx/paging/PagingData.html">PagingData</a></code> can be transformed to alter data as it loads, and presented in a <code>RecyclerView</code> via <code>AsyncPagingDataDiffer</code> or <code>PagingDataAdapter</code>.</p> |
| <p>LiveData support is available as an extension property provided by the <code>androidx.paging:paging-runtime</code> artifact.</p> |
| <p>RxJava support is available as extension properties provided by the <code>androidx.paging:paging-rxjava2</code> artifact.</p> |
| <pre class="prettyprint lang-kotlin"> |
| import androidx.paging.insertSeparators |
| |
| /* |
| * Create letter separators in an alphabetically sorted list. |
| * |
| * For example, if the input is: |
| * "apple", "apricot", "banana", "carrot" |
| * |
| * The operator would output: |
| * "A", "apple", "apricot", "B", "banana", "C", "carrot" |
| */ |
| pagingDataStream.map { pagingData -> |
| // map outer stream, so we can perform transformations on each paging generation |
| pagingData.insertSeparators { before: String?, after: String? -> |
| if (after != null && before?.first() != after.first()) { |
| // separator - after is first item that starts with its first letter |
| after.first().toUpperCase().toString() |
| } else { |
| // no separator - either end of list, or first letters of before/after are the same |
| null |
| } |
| } |
| }</pre> |
| <h2>Summary</h2> |
| <div class="devsite-table-wrapper"> |
| <table class="responsive"> |
| <colgroup> |
| <col width="40%"> |
| <col> |
| </colgroup> |
| <thead> |
| <tr> |
| <th colspan="100%"><h3>Public constructors</h3></th> |
| </tr> |
| </thead> |
| <tbody class="list"> |
| <tr> |
| <td> |
| <div><code>@<a href="/reference/[JVM root]/<Error class: unknown class>.html"><Error class: unknown class></a><br>@<a href="https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-opt-in/index.html">OptIn</a>(markerClass = )<br><Key extends <a href="https://developer.android.com/reference/java/lang/Object.html">Object</a>, Value extends <a href="https://developer.android.com/reference/java/lang/Object.html">Object</a>> <a href="/reference/androidx/paging/Pager.html#Pager([Error type: Unresolved type for PagingConfig],kotlin.Any,kotlin.Function0)">Pager</a>(<br> @<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> <a href="/reference/[JVM root]/<Error class: unknown class>.html"><Error class: unknown class></a> config,<br> Key initialKey,<br> @<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> Function0<@<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> <a href="/reference/[JVM root]/<Error class: unknown class>.html"><Error class: unknown class></a><@<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> Key, @<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> Value>> pagingSourceFactory<br>)</code></div> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <div><code>@<a href="/reference/[JVM root]/<Error class: unknown class>.html"><Error class: unknown class></a><br><Key extends <a href="https://developer.android.com/reference/java/lang/Object.html">Object</a>, Value extends <a href="https://developer.android.com/reference/java/lang/Object.html">Object</a>> <a href="/reference/androidx/paging/Pager.html#Pager([Error type: Unresolved type for PagingConfig],kotlin.Any,[Error type: Unresolved type for RemoteMediator<Key, Value>],kotlin.Function0)">Pager</a>(<br> @<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> <a href="/reference/[JVM root]/<Error class: unknown class>.html"><Error class: unknown class></a> config,<br> Key initialKey,<br> <a href="/reference/[JVM root]/<Error class: unknown class>.html"><Error class: unknown class></a><@<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> Key, @<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> Value> remoteMediator,<br> @<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> Function0<@<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> <a href="/reference/[JVM root]/<Error class: unknown class>.html"><Error class: unknown class></a><@<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> Key, @<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> Value>> pagingSourceFactory<br>)</code></div> |
| </td> |
| </tr> |
| </tbody> |
| </table> |
| </div> |
| <div class="devsite-table-wrapper"> |
| <table class="responsive"> |
| <colgroup> |
| <col width="40%"> |
| <col> |
| </colgroup> |
| <thead> |
| <tr> |
| <th colspan="100%"><h3>Public methods</h3></th> |
| </tr> |
| </thead> |
| <tbody class="list"> |
| <tr> |
| <td><code>final @<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> <a href="/reference/[JVM root]/<Error class: unknown class>.html"><Error class: unknown class></a><@<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> <a href="/reference/androidx/paging/PagingData.html">PagingData</a><@<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> Value>></code></td> |
| <td> |
| <div><code><a href="/reference/androidx/paging/Pager.html#getFlow()">getFlow</a>()</code></div> |
| <p>A cold Flow of <code><a href="/reference/androidx/paging/PagingData.html">PagingData</a></code>, which emits new instances of <code><a href="/reference/androidx/paging/PagingData.html">PagingData</a></code> once they become invalidated by PagingSource.invalidate or calls to AsyncPagingDataDiffer.refresh or PagingDataAdapter.refresh.</p> |
| </td> |
| </tr> |
| </tbody> |
| </table> |
| </div> |
| <div class="list"> |
| <h2>Public constructors</h2> |
| <div class="api-item"><a name="Pager([Error type: Unresolved type for PagingConfig], kotlin.Any, kotlin.Function0)"></a><a name="Pager-[Error type: Unresolved type for PagingConfig]-kotlin.Any-kotlin.Function0-"></a><a name="pager"></a> |
| <div class="api-name-block"> |
| <div> |
| <h3 id="Pager([Error type: Unresolved type for PagingConfig],kotlin.Any,kotlin.Function0)">Pager</h3> |
| </div> |
| </div> |
| <pre class="api-signature no-pretty-print">@<a href="/reference/[JVM root]/<Error class: unknown class>.html"><Error class: unknown class></a><br>@<a href="https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-opt-in/index.html">OptIn</a>(markerClass = )<br>public <Key extends <a href="https://developer.android.com/reference/java/lang/Object.html">Object</a>, Value extends <a href="https://developer.android.com/reference/java/lang/Object.html">Object</a>> <a href="/reference/androidx/paging/Pager.html#Pager([Error type: Unresolved type for PagingConfig],kotlin.Any,kotlin.Function0)">Pager</a>(<br> @<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> <a href="/reference/[JVM root]/<Error class: unknown class>.html"><Error class: unknown class></a> config,<br> Key initialKey,<br> @<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> Function0<@<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> <a href="/reference/[JVM root]/<Error class: unknown class>.html"><Error class: unknown class></a><@<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> Key, @<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> Value>> pagingSourceFactory<br>)</pre> |
| </div> |
| <div class="api-item"><a name="Pager([Error type: Unresolved type for PagingConfig], kotlin.Any, [Error type: Unresolved type for RemoteMediator<Key, Value>], kotlin.Function0)"></a><a name="Pager-[Error type: Unresolved type for PagingConfig]-kotlin.Any-[Error type: Unresolved type for RemoteMediator<Key, Value>]-kotlin.Function0-"></a><a name="pager"></a> |
| <div class="api-name-block"> |
| <div> |
| <h3 id="Pager([Error type: Unresolved type for PagingConfig],kotlin.Any,[Error type: Unresolved type for RemoteMediator<Key, Value>],kotlin.Function0)">Pager</h3> |
| </div> |
| </div> |
| <pre class="api-signature no-pretty-print">@<a href="/reference/[JVM root]/<Error class: unknown class>.html"><Error class: unknown class></a><br>public <Key extends <a href="https://developer.android.com/reference/java/lang/Object.html">Object</a>, Value extends <a href="https://developer.android.com/reference/java/lang/Object.html">Object</a>> <a href="/reference/androidx/paging/Pager.html#Pager([Error type: Unresolved type for PagingConfig],kotlin.Any,[Error type: Unresolved type for RemoteMediator<Key, Value>],kotlin.Function0)">Pager</a>(<br> @<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> <a href="/reference/[JVM root]/<Error class: unknown class>.html"><Error class: unknown class></a> config,<br> Key initialKey,<br> <a href="/reference/[JVM root]/<Error class: unknown class>.html"><Error class: unknown class></a><@<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> Key, @<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> Value> remoteMediator,<br> @<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> Function0<@<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> <a href="/reference/[JVM root]/<Error class: unknown class>.html"><Error class: unknown class></a><@<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> Key, @<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> Value>> pagingSourceFactory<br>)</pre> |
| <div class="devsite-table-wrapper"> |
| <table class="responsive"> |
| <colgroup> |
| <col width="40%"> |
| <col> |
| </colgroup> |
| <thead> |
| <tr> |
| <th colspan="100%">Parameters</th> |
| </tr> |
| </thead> |
| <tbody class="list"> |
| <tr> |
| <td><code>@<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> <a href="/reference/[JVM root]/<Error class: unknown class>.html"><Error class: unknown class></a> config</code></td> |
| <td> |
| <p>The configuration</p> |
| </td> |
| </tr> |
| </tbody> |
| </table> |
| </div> |
| </div> |
| </div> |
| <div class="list"> |
| <h2>Public methods</h2> |
| <div class="api-item"><a name="getFlow--"></a><a name="getflow"></a> |
| <div class="api-name-block"> |
| <div> |
| <h3 id="getFlow()">getFlow</h3> |
| </div> |
| </div> |
| <pre class="api-signature no-pretty-print">public final @<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> <a href="/reference/[JVM root]/<Error class: unknown class>.html"><Error class: unknown class></a><@<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> <a href="/reference/androidx/paging/PagingData.html">PagingData</a><@<a href="/reference/androidx/annotation/NonNull.html">NonNull</a> Value>> <a href="/reference/androidx/paging/Pager.html#getFlow()">getFlow</a>()</pre> |
| <p>A cold Flow of <code><a href="/reference/androidx/paging/PagingData.html">PagingData</a></code>, which emits new instances of <code><a href="/reference/androidx/paging/PagingData.html">PagingData</a></code> once they become invalidated by PagingSource.invalidate or calls to AsyncPagingDataDiffer.refresh or PagingDataAdapter.refresh.</p> |
| </div> |
| </div> |
| </body> |
| </html> |
| |
