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<h1>PositionalDataSource.Companion</h1>
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<pre>object PositionalDataSource.Companion</pre>
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<h2>Summary</h2>
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<th colspan="2"><h3>Public functions</h3></th>
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<td><code><a href="https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html">Int</a></code></td>
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<div><code><a href="/reference/kotlin/androidx/paging/PositionalDataSource.Companion.html#computeInitialLoadPosition(androidx.paging.PositionalDataSource.LoadInitialParams,kotlin.Int)">computeInitialLoadPosition</a>(<br>&nbsp;&nbsp;&nbsp;&nbsp;params:&nbsp;<a href="/reference/kotlin/androidx/paging/PositionalDataSource.LoadInitialParams.html">PositionalDataSource.LoadInitialParams</a>,<br>&nbsp;&nbsp;&nbsp;&nbsp;totalCount:&nbsp;<a href="https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html">Int</a><br>)</code></div>
<p>Helper for computing an initial position in <code><a href="/reference/kotlin/androidx/paging/PositionalDataSource.html#loadInitial(androidx.paging.PositionalDataSource.LoadInitialParams)">loadInitial</a></code> when total data set size can be computed ahead of loading.</p>
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<td><code><a href="https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html">Int</a></code></td>
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<div><code><a href="/reference/kotlin/androidx/paging/PositionalDataSource.Companion.html#computeInitialLoadSize(androidx.paging.PositionalDataSource.LoadInitialParams,kotlin.Int,kotlin.Int)">computeInitialLoadSize</a>(<br>&nbsp;&nbsp;&nbsp;&nbsp;params:&nbsp;<a href="/reference/kotlin/androidx/paging/PositionalDataSource.LoadInitialParams.html">PositionalDataSource.LoadInitialParams</a>,<br>&nbsp;&nbsp;&nbsp;&nbsp;initialLoadPosition:&nbsp;<a href="https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html">Int</a>,<br>&nbsp;&nbsp;&nbsp;&nbsp;totalCount:&nbsp;<a href="https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html">Int</a><br>)</code></div>
<p>Helper for computing an initial load size in <code><a href="/reference/kotlin/androidx/paging/PositionalDataSource.html#loadInitial(androidx.paging.PositionalDataSource.LoadInitialParams)">loadInitial</a></code> when total data set size can be computed ahead of loading.</p>
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<h2>Public functions</h2>
<div><a name="computeInitialLoadPosition(androidx.paging.PositionalDataSource.LoadInitialParams, kotlin.Int)"></a><a name="computeInitialLoadPosition-androidx.paging.PositionalDataSource.LoadInitialParams-kotlin.Int-"></a>
<h3 class="api-name" id="computeInitialLoadPosition(androidx.paging.PositionalDataSource.LoadInitialParams,kotlin.Int)">computeInitialLoadPosition</h3>
<pre class="api-signature no-pretty-print">fun&nbsp;<a href="/reference/kotlin/androidx/paging/PositionalDataSource.Companion.html#computeInitialLoadPosition(androidx.paging.PositionalDataSource.LoadInitialParams,kotlin.Int)">computeInitialLoadPosition</a>(<br>&nbsp;&nbsp;&nbsp;&nbsp;params:&nbsp;<a href="/reference/kotlin/androidx/paging/PositionalDataSource.LoadInitialParams.html">PositionalDataSource.LoadInitialParams</a>,<br>&nbsp;&nbsp;&nbsp;&nbsp;totalCount:&nbsp;<a href="https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html">Int</a><br>):&nbsp;<a href="https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html">Int</a></pre>
<p>Helper for computing an initial position in <code><a href="/reference/kotlin/androidx/paging/PositionalDataSource.html#loadInitial(androidx.paging.PositionalDataSource.LoadInitialParams)">loadInitial</a></code> when total data set size can be computed ahead of loading.</p>
<p>The value computed by this function will do bounds checking, page alignment, and positioning based on initial load size requested.</p>
<p>Example usage in a <code><a href="/reference/kotlin/androidx/paging/PositionalDataSource.html">PositionalDataSource</a></code> subclass:</p>
<pre class="prettyprint">class ItemDataSource extends PositionalDataSource&lt;Item&gt; {<br> private int computeCount() {<br> // actual count code here<br> }<br><br> private List&lt;Item&gt; loadRangeInternal(int startPosition, int loadCount) {<br> // actual load code here<br> }<br><br> @Override<br> public void loadInitial(@NonNull LoadInitialParams params,<br> @NonNull LoadInitialCallback&lt;Item&gt; callback) {<br> int totalCount = computeCount();<br> int position = computeInitialLoadPosition(params, totalCount);<br> int loadSize = computeInitialLoadSize(params, position, totalCount);<br> callback.onResult(loadRangeInternal(position, loadSize), position, totalCount);<br> }<br><br> @Override<br> public void loadRange(@NonNull LoadRangeParams params,<br> @NonNull LoadRangeCallback&lt;Item&gt; callback) {<br> callback.onResult(loadRangeInternal(params.startPosition, params.loadSize));<br> }<br>}</pre>
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<td><code><a href="https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html">Int</a></code></td>
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<p>Position to start loading at.</p>
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<th colspan="2">Parameters</th>
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<td><code>params:&nbsp;<a href="/reference/kotlin/androidx/paging/PositionalDataSource.LoadInitialParams.html">PositionalDataSource.LoadInitialParams</a></code></td>
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<p>Params passed to <code><a href="/reference/kotlin/androidx/paging/PositionalDataSource.html#loadInitial(androidx.paging.PositionalDataSource.LoadInitialParams)">loadInitial</a></code>, including page size, and requested start / loadSize.</p>
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<td><code>totalCount:&nbsp;<a href="https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html">Int</a></code></td>
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<p>Total size of the data set.</p>
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<th colspan="2">See also</th>
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<td><code><a href="/reference/kotlin/androidx/paging/PositionalDataSource.Companion.html#computeInitialLoadSize(androidx.paging.PositionalDataSource.LoadInitialParams,kotlin.Int,kotlin.Int)">computeInitialLoadSize</a></code></td>
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<div><a name="computeInitialLoadSize(androidx.paging.PositionalDataSource.LoadInitialParams, kotlin.Int, kotlin.Int)"></a><a name="computeInitialLoadSize-androidx.paging.PositionalDataSource.LoadInitialParams-kotlin.Int-kotlin.Int-"></a>
<h3 class="api-name" id="computeInitialLoadSize(androidx.paging.PositionalDataSource.LoadInitialParams,kotlin.Int,kotlin.Int)">computeInitialLoadSize</h3>
<pre class="api-signature no-pretty-print">fun&nbsp;<a href="/reference/kotlin/androidx/paging/PositionalDataSource.Companion.html#computeInitialLoadSize(androidx.paging.PositionalDataSource.LoadInitialParams,kotlin.Int,kotlin.Int)">computeInitialLoadSize</a>(<br>&nbsp;&nbsp;&nbsp;&nbsp;params:&nbsp;<a href="/reference/kotlin/androidx/paging/PositionalDataSource.LoadInitialParams.html">PositionalDataSource.LoadInitialParams</a>,<br>&nbsp;&nbsp;&nbsp;&nbsp;initialLoadPosition:&nbsp;<a href="https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html">Int</a>,<br>&nbsp;&nbsp;&nbsp;&nbsp;totalCount:&nbsp;<a href="https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html">Int</a><br>):&nbsp;<a href="https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html">Int</a></pre>
<p>Helper for computing an initial load size in <code><a href="/reference/kotlin/androidx/paging/PositionalDataSource.html#loadInitial(androidx.paging.PositionalDataSource.LoadInitialParams)">loadInitial</a></code> when total data set size can be computed ahead of loading.</p>
<p>This function takes the requested load size, and bounds checks it against the value returned by <code><a href="/reference/kotlin/androidx/paging/PositionalDataSource.Companion.html#computeInitialLoadPosition(androidx.paging.PositionalDataSource.LoadInitialParams,kotlin.Int)">computeInitialLoadPosition</a></code>.</p>
<p>Example usage in a <code><a href="/reference/kotlin/androidx/paging/PositionalDataSource.html">PositionalDataSource</a></code> subclass:</p>
<pre class="prettyprint">class ItemDataSource extends PositionalDataSource&lt;Item&gt; {<br> private int computeCount() {<br> // actual count code here<br> }<br><br> private List&lt;Item&gt; loadRangeInternal(int startPosition, int loadCount) {<br> // actual load code here<br> }<br><br> @Override<br> public void loadInitial(@NonNull LoadInitialParams params,<br> @NonNull LoadInitialCallback&lt;Item&gt; callback) {<br> int totalCount = computeCount();<br> int position = computeInitialLoadPosition(params, totalCount);<br> int loadSize = computeInitialLoadSize(params, position, totalCount);<br> callback.onResult(loadRangeInternal(position, loadSize), position, totalCount);<br> }<br><br> @Override<br> public void loadRange(@NonNull LoadRangeParams params,<br> @NonNull LoadRangeCallback&lt;Item&gt; callback) {<br> callback.onResult(loadRangeInternal(params.startPosition, params.loadSize));<br> }<br>}</pre>
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<th colspan="2">Returns</th>
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<td><code><a href="https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html">Int</a></code></td>
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<p>Number of items to load.</p>
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<td><code>params:&nbsp;<a href="/reference/kotlin/androidx/paging/PositionalDataSource.LoadInitialParams.html">PositionalDataSource.LoadInitialParams</a></code></td>
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<p>Params passed to <code><a href="/reference/kotlin/androidx/paging/PositionalDataSource.html#loadInitial(androidx.paging.PositionalDataSource.LoadInitialParams)">loadInitial</a></code>, including page size, and requested start / loadSize.</p>
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<td><code>initialLoadPosition:&nbsp;<a href="https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html">Int</a></code></td>
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<p>Value returned by <code><a href="/reference/kotlin/androidx/paging/PositionalDataSource.Companion.html#computeInitialLoadPosition(androidx.paging.PositionalDataSource.LoadInitialParams,kotlin.Int)">computeInitialLoadPosition</a></code></p>
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<td><code>totalCount:&nbsp;<a href="https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html">Int</a></code></td>
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<p>Total size of the data set.</p>
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<th colspan="2">See also</th>
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<td><code><a href="/reference/kotlin/androidx/paging/PositionalDataSource.Companion.html#computeInitialLoadPosition(androidx.paging.PositionalDataSource.LoadInitialParams,kotlin.Int)">computeInitialLoadPosition</a></code></td>
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