1 /* 2 * Copyright 2022 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.glance.appwidget 18 19 import androidx.compose.runtime.Composable 20 import androidx.glance.Emittable 21 import androidx.glance.EmittableWithChildren 22 import androidx.glance.GlanceComposable 23 import androidx.glance.GlanceModifier 24 import androidx.glance.GlanceNode 25 26 /** 27 * This composable is a marker used by [AppWidgetSession] to indicate that the result of a 28 * composition should be ignored. 29 * 30 * If this composable is present in the [Emittable] tree, [AppWidgetSession] will not translate the 31 * tree and update the app widget. 32 */ 33 @Composable 34 @GlanceComposable IgnoreResultnull35internal fun IgnoreResult() { 36 GlanceNode(::EmittableIgnoreResult) {} 37 } 38 39 internal class EmittableIgnoreResult : Emittable { 40 override var modifier: GlanceModifier = GlanceModifier 41 <lambda>null42 override fun copy() = EmittableIgnoreResult().also { it.modifier = modifier } 43 } 44 45 /** 46 * Returns true if this [Emittable] is an [EmittableIgnoreResult] or contains an 47 * [EmittableIgnoreResult] in its children. 48 */ shouldIgnoreResultnull49internal fun Emittable.shouldIgnoreResult(): Boolean { 50 if (this is EmittableIgnoreResult) { 51 return true 52 } else if (this is EmittableWithChildren) { 53 if (children.any { it.shouldIgnoreResult() }) return true 54 } 55 return false 56 } 57