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.intentresolver.contentpreview.payloadtoggle.domain.model
18
19 /** A window of data loaded from a cursor. */
20 data class LoadedWindow<K, V>(
21 /** First cursor page index loaded within this window. */
22 val firstLoadedPageNum: Int,
23 /** Last cursor page index loaded within this window. */
24 val lastLoadedPageNum: Int,
25 /** Keys of cursor data within this window, grouped by loaded page. */
26 val pages: List<Set<K>>,
27 /** Merged set of all cursor data within this window. */
28 val merged: Map<K, V>,
29 /** Is there more data to the left of this window? */
30 val hasMoreLeft: Boolean,
31 /** Is there more data to the right of this window? */
32 val hasMoreRight: Boolean,
33 )
34
35 /** Number of loaded pages stored within this [LoadedWindow]. */
36 val LoadedWindow<*, *>.numLoadedPages: Int
37 get() = (lastLoadedPageNum - firstLoadedPageNum) + 1
38
39 /** Inserts [newPage] to the right, and removes the leftmost page from the window. */
shiftWindowRightnull40 fun <K, V> LoadedWindow<K, V>.shiftWindowRight(
41 newPage: Map<K, V>,
42 hasMore: Boolean,
43 ): LoadedWindow<K, V> =
44 LoadedWindow(
45 firstLoadedPageNum = firstLoadedPageNum + 1,
46 lastLoadedPageNum = lastLoadedPageNum + 1,
47 pages = pages.drop(1) + listOf(newPage.keys),
48 merged =
49 buildMap {
50 putAll(merged)
51 pages.first().forEach(::remove)
52 putAll(newPage)
53 },
54 hasMoreLeft = true,
55 hasMoreRight = hasMore,
56 )
57
58 /** Inserts [newPage] to the right, increasing the size of the window to accommodate it. */
expandWindowRightnull59 fun <K, V> LoadedWindow<K, V>.expandWindowRight(
60 newPage: Map<K, V>,
61 hasMore: Boolean,
62 ): LoadedWindow<K, V> =
63 LoadedWindow(
64 firstLoadedPageNum = firstLoadedPageNum,
65 lastLoadedPageNum = lastLoadedPageNum + 1,
66 pages = pages + listOf(newPage.keys),
67 merged = merged + newPage,
68 hasMoreLeft = hasMoreLeft,
69 hasMoreRight = hasMore,
70 )
71
72 /** Inserts [newPage] to the left, and removes the rightmost page from the window. */
73 fun <K, V> LoadedWindow<K, V>.shiftWindowLeft(
74 newPage: Map<K, V>,
75 hasMore: Boolean,
76 ): LoadedWindow<K, V> =
77 LoadedWindow(
78 firstLoadedPageNum = firstLoadedPageNum - 1,
79 lastLoadedPageNum = lastLoadedPageNum - 1,
80 pages = listOf(newPage.keys) + pages.dropLast(1),
81 merged =
82 buildMap {
83 putAll(newPage)
84 putAll(merged - pages.last())
85 },
86 hasMoreLeft = hasMore,
87 hasMoreRight = true,
88 )
89
90 /** Inserts [newPage] to the left, increasing the size olf the window to accommodate it. */
expandWindowLeftnull91 fun <K, V> LoadedWindow<K, V>.expandWindowLeft(
92 newPage: Map<K, V>,
93 hasMore: Boolean,
94 ): LoadedWindow<K, V> =
95 LoadedWindow(
96 firstLoadedPageNum = firstLoadedPageNum - 1,
97 lastLoadedPageNum = lastLoadedPageNum,
98 pages = listOf(newPage.keys) + pages,
99 merged = newPage + merged,
100 hasMoreLeft = hasMore,
101 hasMoreRight = hasMoreRight,
102 )
103