1 /* 2 * Copyright (C) 2024 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.photopicker.features.categorygrid.data 18 19 import android.os.CancellationSignal 20 import androidx.paging.PagingSource 21 import com.android.photopicker.data.model.Group 22 import com.android.photopicker.data.model.GroupPageKey 23 import com.android.photopicker.data.model.Media 24 import com.android.photopicker.data.model.MediaPageKey 25 26 /** 27 * Powers UI with data for the category feature which includes the category grid, media sets grid, 28 * and media set content grid. This class owns the responsibility to: 29 * - fetch categories, albums, media sets and media on demand 30 * - cache data if required 31 * - keep track of data updates in the data source 32 * - detect and refresh stale data 33 */ 34 interface CategoryDataService { 35 companion object { 36 const val TAG: String = "PhotopickerSearchCategoryService" 37 } 38 39 /** 40 * Creates a paging source that can load categories and albums. 41 * 42 * @param category the parent [Category]. If the parent category is null then the method returns 43 * root categories. 44 * @param cancellationSignal An optional [CancellationSignal] that can be marked as cancelled 45 * when the query results are no longer required. 46 * @return The [PagingSource] that fetches a page using [GroupPageKey]. A page in the paging 47 * source contains a [List] of [Group.Category] items. 48 */ getCategoriesnull49 fun getCategories( 50 parentCategory: Group.Category? = null, 51 cancellationSignal: CancellationSignal? = null, 52 ): PagingSource<GroupPageKey, Group> 53 54 /** 55 * Creates a paging source that can load media sets. Leaf categories contain [MediaSet]-s. A 56 * [MediaSet] can only contain media items. 57 * 58 * @param category the parent [Category]. 59 * @param cancellationSignal An optional [CancellationSignal] that can be marked as cancelled 60 * when the query results are no longer required. 61 * @return The [PagingSource] that fetches a page using [GroupPageKey]. A page in the paging 62 * source contains a [List] of [Group.MediaSet] items. 63 */ 64 fun getMediaSets( 65 category: Group.Category, 66 cancellationSignal: CancellationSignal? = null, 67 ): PagingSource<GroupPageKey, Group.MediaSet> 68 69 /** 70 * Creates a paging source that can load media items of a media set. 71 * 72 * @param mediaSet the parent [MediaSet]. 73 * @param cancellationSignal An optional [CancellationSignal] that can be marked as cancelled 74 * when the query results are no longer required. 75 * @return The [PagingSource] that fetches a page using [MediaPageKey]. A page in the paging 76 * source contains a [List] of [Media] items. 77 */ 78 fun getMediaSetContents( 79 mediaSet: Group.MediaSet, 80 cancellationSignal: CancellationSignal? = null, 81 ): PagingSource<MediaPageKey, Media> 82 } 83