commonMain.androidx.compose.foundation.gestures.FlingBehavior.kt Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of foundation-desktop Show documentation

Higher level abstractions of the Compose UI primitives. This library is design system agnostic, providing the high-level building blocks for both application and design-system developers

There is a newer version: 1.8.0-alpha01

Show newest version

/*
 * Copyright 2021 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.gestures

import androidx.compose.runtime.Stable

/**
 * Interface to specify fling behavior.
 *
 * When drag has ended with velocity in [scrollable], [performFling] is invoked to perform fling
 * animation and update state via [ScrollScope.scrollBy]
 */
@Stable
interface FlingBehavior {
    /**
     * Perform settling via fling animation with given velocity and suspend until fling has
     * finished.
     *
     * This functions is called with [ScrollScope] to drive the state change of the
     * [androidx.compose.foundation.gestures.ScrollableState] via [ScrollScope.scrollBy].
     *
     * This function must return correct velocity left after it is finished flinging in order to
     * guarantee proper nested scroll support.
     *
     * @param initialVelocity velocity available for fling in the orientation specified in
     * [androidx.compose.foundation.gestures.scrollable] that invoked this method.
     *
     * @return remaining velocity after fling operation has ended
     */
    suspend fun ScrollScope.performFling(initialVelocity: Float): Float
}