Tusky-App-Android/app/src/main/java/com/keylesspalace/tusky/components/report/adapter/StatusesPagingSource.kt

89 lines
3.2 KiB
Kotlin

/* Copyright 2021 Tusky Contributors
*
* This file is a part of Tusky.
*
* This program is free software; you can redistribute it and/or modify it under the terms of the
* GNU General Public License as published by the Free Software Foundation; either version 3 of the
* License, or (at your option) any later version.
*
* Tusky is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
* the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
* Public License for more details.
*
* You should have received a copy of the GNU General Public License along with Tusky; if not,
* see <http://www.gnu.org/licenses>. */
package com.keylesspalace.tusky.components.report.adapter
import android.util.Log
import androidx.paging.PagingSource
import androidx.paging.PagingState
import com.keylesspalace.tusky.entity.Status
import com.keylesspalace.tusky.network.MastodonApi
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.async
import kotlinx.coroutines.rx3.await
import kotlinx.coroutines.withContext
class StatusesPagingSource(
private val accountId: String,
private val mastodonApi: MastodonApi
) : PagingSource<String, Status>() {
override fun getRefreshKey(state: PagingState<String, Status>): String? {
return state.anchorPosition?.let { anchorPosition ->
state.closestItemToPosition(anchorPosition)?.id
}
}
override suspend fun load(params: LoadParams<String>): LoadResult<String, Status> {
val key = params.key
try {
val result = if (params is LoadParams.Refresh && key != null) {
withContext(Dispatchers.IO) {
val initialStatus = async { getSingleStatus(key) }
val additionalStatuses = async { getStatusList(maxId = key, limit = params.loadSize - 1) }
listOf(initialStatus.await()) + additionalStatuses.await()
}
} else {
val maxId = if (params is LoadParams.Refresh || params is LoadParams.Append) {
params.key
} else {
null
}
val minId = if (params is LoadParams.Prepend) {
params.key
} else {
null
}
getStatusList(minId = minId, maxId = maxId, limit = params.loadSize)
}
return LoadResult.Page(
data = result,
prevKey = result.firstOrNull()?.id,
nextKey = result.lastOrNull()?.id
)
} catch (e: Exception) {
Log.w("StatusesPagingSource", "failed to load statuses", e)
return LoadResult.Error(e)
}
}
private suspend fun getSingleStatus(statusId: String): Status {
return mastodonApi.statusObservable(statusId).await()
}
private suspend fun getStatusList(minId: String? = null, maxId: String? = null, limit: Int): List<Status> {
return mastodonApi.accountStatusesObservable(
accountId = accountId,
maxId = maxId,
sinceId = null,
minId = minId,
limit = limit,
excludeReblogs = true
).await()
}
}