/*
* Copyright 2022 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.tv.foundation
import androidx.compose.animation.core.AnimationSpec
import androidx.compose.animation.core.CubicBezierEasing
import androidx.compose.animation.core.tween
import androidx.compose.foundation.ExperimentalFoundationApi
import androidx.compose.foundation.gestures.BringIntoViewSpec
import androidx.compose.foundation.gestures.Orientation
import androidx.compose.foundation.gestures.ScrollableState
import androidx.compose.foundation.gestures.scrollable
import androidx.compose.ui.Modifier
import androidx.compose.ui.platform.debugInspectorInfo
import androidx.compose.ui.platform.inspectable
import kotlin.math.abs
/* Copied from
compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/gestures/
Scrollable.kt and modified */
/**
* Configure touch scrolling and flinging for the UI element in a single [Orientation].
*
* Users should update their state themselves using default [ScrollableState] and its
* `consumeScrollDelta` callback or by implementing [ScrollableState] interface manually and reflect
* their own state in UI when using this component.
*
* @param state [ScrollableState] state of the scrollable. Defines how scroll events will be
* interpreted by the user land logic and contains useful information about on-going events.
* @param orientation orientation of the scrolling
* @param pivotOffsets offsets of child element within the parent and starting edge of the child
* from the pivot defined by the parentOffset.
* @param enabled whether or not scrolling in enabled
* @param reverseDirection reverse the direction of the scroll, so top to bottom scroll will
* behave like bottom to top and left to right will behave like right to left.
* drag events when this scrollable is being dragged.
*/
@OptIn(ExperimentalFoundationApi::class)
@ExperimentalTvFoundationApi
fun Modifier.scrollableWithPivot(
state: ScrollableState,
orientation: Orientation,
pivotOffsets: PivotOffsets,
enabled: Boolean = true,
reverseDirection: Boolean = false
): Modifier = this then Modifier.inspectable(debugInspectorInfo {
name = "scrollableWithPivot"
properties["orientation"] = orientation
properties["state"] = state
properties["enabled"] = enabled
properties["reverseDirection"] = reverseDirection
properties["pivotOffsets"] = pivotOffsets
}) {
Modifier.scrollable(
state = state,
orientation = orientation,
enabled = enabled,
reverseDirection = reverseDirection,
overscrollEffect = null,
bringIntoViewSpec = TvBringIntoViewSpec(pivotOffsets, enabled)
)
}
@OptIn(ExperimentalFoundationApi::class)
private class TvBringIntoViewSpec(
val pivotOffsets: PivotOffsets,
val userScrollEnabled: Boolean
) : BringIntoViewSpec {
override val scrollAnimationSpec: AnimationSpec<Float> = tween<Float>(
durationMillis = 125,
easing = CubicBezierEasing(0.25f, 0.1f, .25f, 1f)
)
override fun calculateScrollDistance(offset: Float, size: Float, containerSize: Float): Float {
if (!userScrollEnabled) return 0f
val leadingEdgeOfItemRequestingFocus = offset
val trailingEdgeOfItemRequestingFocus = offset + size
val sizeOfItemRequestingFocus =
abs(trailingEdgeOfItemRequestingFocus - leadingEdgeOfItemRequestingFocus)
val childSmallerThanParent = sizeOfItemRequestingFocus <= containerSize
val initialTargetForLeadingEdge =
pivotOffsets.parentFraction * containerSize -
(pivotOffsets.childFraction * sizeOfItemRequestingFocus)
val spaceAvailableToShowItem = containerSize - initialTargetForLeadingEdge
val targetForLeadingEdge =
if (childSmallerThanParent && spaceAvailableToShowItem < sizeOfItemRequestingFocus) {
containerSize - sizeOfItemRequestingFocus
} else {
initialTargetForLeadingEdge
}
return leadingEdgeOfItemRequestingFocus - targetForLeadingEdge
}
override fun hashCode(): Int {
var result = pivotOffsets.hashCode()
result = 31 * result + userScrollEnabled.hashCode()
return result
}
override fun equals(other: Any?): Boolean {
if (other !is TvBringIntoViewSpec) return false
return pivotOffsets == other.pivotOffsets && userScrollEnabled == other.userScrollEnabled
}
}