1 /* 2 * Copyright 2020 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.tooling.preview 18 19 import kotlin.jvm.JvmDefaultWithCompatibility 20 import kotlin.reflect.KClass 21 22 /** 23 * Interface to be implemented by any provider of values that you want to be injected as @[Preview] 24 * parameters. This allows providing sample information for previews. 25 */ 26 @JvmDefaultWithCompatibility 27 interface PreviewParameterProvider<T> { 28 /** [Sequence] of values of type [T] to be passed as @[Preview] parameter. */ 29 val values: Sequence<T> 30 31 /** Returns the number of elements in the [values] [Sequence]. */ 32 val count 33 get() = values.count() 34 } 35 36 /** 37 * [PreviewParameter] can be applied to any parameter of a @[Preview]. 38 * 39 * @param provider A [PreviewParameterProvider] class to use to inject values to the annotated 40 * parameter. 41 * @param limit Max number of values from [provider] to inject to this parameter. 42 */ 43 annotation class PreviewParameter( 44 val provider: KClass<out PreviewParameterProvider<*>>, 45 val limit: Int = Int.MAX_VALUE 46 ) 47