1 /*
2  * Copyright 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.core.features
18 
19 import com.android.photopicker.data.model.Media
20 import kotlinx.coroutines.CompletableDeferred
21 import kotlinx.coroutines.flow.Flow
22 
23 /**
24  * Parameter interface for passing additional parameters to a [Location]'s implementer via
25  * [FeatureManager#composeLocation].
26  *
27  * By default all Locations receive the None parameter, but this interface can be extended and then
28  * location code can cast to the expected type with a pattern such as:
29  * ```
30  * val clickAction = params as? LocationParams.WithClickAction
31  * clickAction?.onClick()
32  * ```
33  *
34  * Or narrow the type using a `when` block. These interfaces can be combined into custom types to
35  * ensure compile time type-checking of parameter types. `Any` should not be used to pass
36  * parameters.
37  */
38 sealed interface LocationParams {
39 
40     /** The default parameters, which represents no additional parameters provided. */
41     object None : LocationParams
42 
43     /**
44      * A generic click handler parameter. Including this as a parameter doesn't attach the click
45      * handler to anything, the implementer must call this method in response to the click action.
46      */
interfacenull47     fun interface WithClickAction : LocationParams {
48         fun onClick()
49     }
50 
51     /** Requirements for attaching a [MediaPreloader] to the compose UI. */
52     interface WithMediaPreloader : LocationParams {
53 
54         // Method which can be called to obtain a deferred for the currently requested preload
55         // operation.
obtainDeferrednull56         fun obtainDeferred(): CompletableDeferred<Boolean>
57 
58         // Flow to trigger the start of media preloads.
59         val preloadMedia: Flow<Set<Media>>
60     }
61 }
62