| Igor Demin | 1eb703eb | 2021-04-24 02:57:27 +0300 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2021 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 androidx.compose.ui.window |
| 18 | |
| 19 | import androidx.compose.runtime.Composable |
| 20 | import androidx.compose.runtime.getValue |
| 21 | import androidx.compose.runtime.mutableStateOf |
| 22 | import androidx.compose.runtime.saveable.Saver |
| 23 | import androidx.compose.runtime.saveable.listSaver |
| 24 | import androidx.compose.runtime.saveable.rememberSaveable |
| 25 | import androidx.compose.runtime.setValue |
| 26 | import androidx.compose.ui.unit.dp |
| 27 | |
| 28 | /** |
| 29 | * Creates a [WindowState] that is remembered across compositions. |
| 30 | * |
| 31 | * Changes to the provided initial values will **not** result in the state being recreated or |
| 32 | * changed in any way if it has already been created. |
| 33 | * |
| 34 | * @param placement the initial value for [WindowState.placement] |
| 35 | * @param isMinimized the initial value for [WindowState.isMinimized] |
| 36 | * @param position the initial value for [WindowState.position] |
| 37 | * @param size the initial value for [WindowState.size] |
| 38 | */ |
| 39 | @Composable |
| 40 | fun rememberWindowState( |
| 41 | placement: WindowPlacement = WindowPlacement.Floating, |
| 42 | isMinimized: Boolean = false, |
| 43 | position: WindowPosition = WindowPosition.PlatformDefault, |
| 44 | size: WindowSize = WindowSize(800.dp, 600.dp), |
| 45 | ): WindowState = rememberSaveable(saver = WindowStateImpl.Saver(position)) { |
| 46 | WindowStateImpl( |
| 47 | placement, |
| 48 | isMinimized, |
| 49 | position, |
| 50 | size |
| 51 | ) |
| 52 | } |
| 53 | |
| 54 | /** |
| 55 | * A state object that can be hoisted to control and observe window attributes |
| 56 | * (size/position/state). |
| 57 | * |
| 58 | * In most cases, this will be created via [rememberWindowState]. |
| 59 | * |
| 60 | * @param placement the initial value for [WindowState.placement] |
| 61 | * @param isMinimized the initial value for [WindowState.isMinimized] |
| 62 | * @param position the initial value for [WindowState.position] |
| 63 | * @param size the initial value for [WindowState.size] |
| 64 | */ |
| 65 | fun WindowState( |
| 66 | placement: WindowPlacement = WindowPlacement.Floating, |
| 67 | isMinimized: Boolean = false, |
| 68 | position: WindowPosition = WindowPosition.PlatformDefault, |
| 69 | size: WindowSize = WindowSize(800.dp, 600.dp) |
| 70 | ): WindowState = WindowStateImpl( |
| 71 | placement, isMinimized, position, size |
| 72 | ) |
| 73 | |
| 74 | /** |
| 75 | * A state object that can be hoisted to control and observe window attributes |
| 76 | * (size/position/state). |
| 77 | * |
| 78 | * In most cases, this will be created via [rememberWindowState]. |
| 79 | */ |
| 80 | interface WindowState { |
| 81 | /** |
| 82 | * Describes how the window is placed on the screen. |
| 83 | */ |
| 84 | var placement: WindowPlacement |
| 85 | |
| 86 | /** |
| 87 | * `true` if the window is minimized. |
| 88 | */ |
| 89 | var isMinimized: Boolean |
| 90 | |
| 91 | /** |
| 92 | * Current position of the window. If position is not specified ([WindowPosition.isSpecified] |
| 93 | * is false) then once the window shows on the screen the position will be set to |
| 94 | * absolute values [WindowPosition.Absolute]. |
| 95 | */ |
| 96 | var position: WindowPosition |
| 97 | |
| 98 | /** |
| 99 | * Current size of the window. |
| 100 | */ |
| 101 | var size: WindowSize |
| 102 | } |
| 103 | |
| 104 | private class WindowStateImpl( |
| 105 | placement: WindowPlacement, |
| 106 | isMinimized: Boolean, |
| 107 | position: WindowPosition, |
| 108 | size: WindowSize |
| 109 | ) : WindowState { |
| 110 | override var placement by mutableStateOf(placement) |
| 111 | override var isMinimized by mutableStateOf(isMinimized) |
| 112 | override var position by mutableStateOf(position) |
| 113 | override var size by mutableStateOf(size) |
| 114 | |
| 115 | companion object { |
| 116 | /** |
| 117 | * The default [Saver] implementation for [WindowStateImpl]. |
| 118 | */ |
| 119 | fun Saver(unspecifiedPosition: WindowPosition) = listSaver<WindowState, Any>( |
| 120 | save = { |
| 121 | listOf( |
| 122 | it.placement.ordinal, |
| 123 | it.isMinimized, |
| 124 | it.position.isSpecified, |
| 125 | it.position.x.value, |
| 126 | it.position.y.value, |
| 127 | it.size.width.value, |
| 128 | it.size.height.value, |
| 129 | ) |
| 130 | }, |
| 131 | restore = { state -> |
| 132 | WindowStateImpl( |
| 133 | placement = WindowPlacement.values()[state[0] as Int], |
| 134 | isMinimized = state[1] as Boolean, |
| 135 | position = if (state[2] as Boolean) { |
| 136 | WindowPosition((state[3] as Float).dp, (state[4] as Float).dp) |
| 137 | } else { |
| 138 | unspecifiedPosition |
| 139 | }, |
| 140 | size = WindowSize((state[5] as Float).dp, (state[6] as Float).dp), |
| 141 | ) |
| 142 | } |
| 143 | ) |
| 144 | } |
| 145 | } |