| /* |
| * Copyright 2020 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package androidx.compose.foundation.animation |
| |
| import android.view.ViewConfiguration |
| import androidx.compose.animation.core.DecayAnimationSpec |
| import androidx.compose.animation.core.FloatDecayAnimationSpec |
| import androidx.compose.animation.core.generateDecayAnimationSpec |
| import androidx.compose.ui.unit.Density |
| import kotlin.math.sign |
| |
| @Deprecated( |
| "AndroidFlingDecaySpec has been renamed to FloatAndroidFlingDecaySpec", |
| replaceWith = ReplaceWith("FloatAndroidFlingDecaySpec") |
| ) |
| typealias AndroidFlingDecaySpec = FloatAndroidFlingDecaySpec |
| |
| /** |
| * A native Android fling curve decay. |
| * |
| * @param density density of the display |
| */ |
| class FloatAndroidFlingDecaySpec(density: Density) : FloatDecayAnimationSpec { |
| |
| private val flingCalculator = AndroidFlingCalculator( |
| ViewConfiguration.getScrollFriction(), |
| density |
| ) |
| |
| override val absVelocityThreshold: Float get() = 0f |
| |
| private fun flingDistance(startVelocity: Float): Float = |
| flingCalculator.flingDistance(startVelocity) * sign(startVelocity) |
| |
| override fun getTarget(start: Float, startVelocity: Float): Float = |
| start + flingDistance(startVelocity) |
| |
| override fun getValue(playTime: Long, start: Float, startVelocity: Float): Float = |
| start + flingCalculator.flingInfo(startVelocity).position(playTime) |
| |
| override fun getDurationMillis(start: Float, startVelocity: Float): Long = |
| flingCalculator.flingDuration(startVelocity) |
| |
| override fun getVelocity(playTime: Long, start: Float, startVelocity: Float): Float = |
| flingCalculator.flingInfo(startVelocity).velocity(playTime) |
| } |
| |
| /** |
| * Creates a [DecayAnimationSpec] using the native Android fling decay. This can then be used to |
| * animate any type [T]. |
| * |
| * @param density density of the display |
| */ |
| fun <T> androidFlingDecay(density: Density): DecayAnimationSpec<T> = |
| FloatAndroidFlingDecaySpec(density).generateDecayAnimationSpec() |
