44 lines
1.4 KiB
Kotlin
44 lines
1.4 KiB
Kotlin
/*
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* Copyright (C) 2018 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package com.h.pixeldroid.fragments.feeds.cachedFeeds
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import androidx.lifecycle.ViewModel
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import androidx.lifecycle.viewModelScope
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import androidx.paging.*
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import com.h.pixeldroid.objects.FeedContentDatabase
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import kotlinx.coroutines.flow.Flow
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/**
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* ViewModel for the cached feeds.
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* The ViewModel works with the [FeedContentRepository] to get the data.
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*/
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class FeedViewModel<T: FeedContentDatabase>(private val repository: FeedContentRepository<T>) : ViewModel() {
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private var currentResult: Flow<PagingData<T>>? = null
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fun flow(): Flow<PagingData<T>> {
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val lastResult = currentResult
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if (lastResult != null) {
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return lastResult
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}
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val newResult: Flow<PagingData<T>> = repository.stream()
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.cachedIn(viewModelScope)
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currentResult = newResult
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return newResult
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}
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}
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