Compose 动画 AnimatedVisibility

AnimatedVisibility(
        //定义内容是否应该可见
        visible = shown,
        /*
        slideIn、slideInVertically、slideInVertically 只能同时存在一个
        enter = slideInVertically(
            //从离本身(小于零(上方)大于零(下方))fullHeight位置滑入
            initialOffsetY = { fullHeight -> -fullHeight },
            animationSpec = tween(durationMillis = 250, easing = FastOutLinearInEasing)
        ),
        enter = slideInHorizontally(
            //从离本身(小于零(上方)大于零(下方))fullHeight位置滑入
            initialOffsetX = { fullWidth ->-fullWidth },
            animationSpec = tween(durationMillis = 2500, easing = LinearOutSlowInEasing)
        ),
        */
        enter = slideIn(
            // 从在 initialOffset 中定义的起始偏移量到 IntOffset(0, 0)。
            // 滑动的方向可以通过配置initialOffset来控制。
            // 正x值表示从右向左滑动，而负x值将向右滑动内容。 同样，正负y值分别对应于向上和向下滑动。
            initialOffset = { (fullWidth, fullHeight) ->IntOffset(-fullWidth,-fullHeight) },
            // animationSpec配置动画限制
            // tween：配置持续时间和缓动曲线的
            // repeatable：配置重复的动画（几次,动画,结尾开始或从头开始）
            // repeatable(5,tween(durationMillis = 2500, easing = LinearOutSlowInEasing),RepeatMode.Reverse)
            // infiniteRepeatable：配置重复的动画（动画,结尾开始或从头开始）
            // spring
            // durationMillis过渡时间。easing速度处理，默认LinearOutSlowInEasing
            // FastOutSlowInEasing:先加速再减速
            // LinearOutSlowInEasing:减速
            // FastOutLinearInEasing：加速
            // LinearEasing：匀速
            animationSpec =tween(durationMillis = 2500, easing = LinearOutSlowInEasing)
        ) + fadeIn(
            //不透明度从0.1f 到 1f
            initialAlpha = 0.1f,
            animationSpec = tween(durationMillis = 2500,easing = LinearEasing)
        ),
        //scaleIn()
        
        exit = slideOutVertically(
            // Exits by sliding out from offset 0 to -fullHeight.
            targetOffsetY = { fullHeight -> -fullHeight },
            animationSpec = tween(durationMillis = 250, easing = FastOutLinearInEasing)
        )
    ) {
......
}

 

val alpha by infiniteTransition.animateFloat(
    initialValue = 0f,
    targetValue = 1f,
    animationSpec = infiniteRepeatable(
      
        animation = keyframes {
            durationMillis = 1000
            // 添加一个关键帧，以便动画值在时间为：timeStamp。 例如：0.8f at 150 // ms
            0.7f at 500
        },
        repeatMode = RepeatMode.Reverse
    )
)
Row(
    modifier = Modifier
        .heightIn(min = 64.dp)
        .padding(16.dp),
    verticalAlignment = Alignment.CenterVertically
) {
    Box(
        modifier = Modifier
            .size(48.dp)
            .clip(CircleShape)
            .background(Color.LightGray.copy(alpha = alpha))
    )
    Spacer(modifier = Modifier.width(16.dp))
    Box(
        modifier = Modifier
            .fillMaxWidth()
            .height(32.dp)
            .background(Color.LightGray.copy(alpha = alpha))
    )
}

/**
 * The modified element can be horizontally swiped away.
 *
 * @param onDismissed Called when the element is swiped to the edge of the screen.
 */
private fun Modifier.swipeToDismiss(
    onDismissed: () -> Unit
): Modifier = composed {
    // This `Animatable` stores the horizontal offset for the element.
    val offsetX = remember { Animatable(0f) }
    pointerInput(Unit) {
        // Used to calculate a settling position of a fling animation.
        val decay = splineBasedDecay<Float>(this)
        // Wrap in a coroutine scope to use suspend functions for touch events and animation.
        coroutineScope {
            while (true) {
                // Wait for a touch down event.
                val pointerId = awaitPointerEventScope { awaitFirstDown().id }
                // Interrupt any ongoing animation.
                offsetX.stop()
                // Prepare for drag events and record velocity of a fling.
                val velocityTracker = VelocityTracker()
                // Wait for drag events.
                awaitPointerEventScope {
                    horizontalDrag(pointerId) { change ->
                        // Record the position after offset
                        val horizontalDragOffset = offsetX.value + change.positionChange().x
                        launch {
                            // Overwrite the `Animatable` value while the element is dragged.
                            offsetX.snapTo(horizontalDragOffset)
                        }
                        // Record the velocity of the drag.
                        velocityTracker.addPosition(change.uptimeMillis, change.position)
                        // Consume the gesture event, not passed to external
                        change.consumePositionChange()
                    }
                }
                // Dragging finished. Calculate the velocity of the fling.
                val velocity = velocityTracker.calculateVelocity().x
                // Calculate where the element eventually settles after the fling animation.
                val targetOffsetX = decay.calculateTargetValue(offsetX.value, velocity)
                // The animation should end as soon as it reaches these bounds.
                offsetX.updateBounds(
                    lowerBound = -size.width.toFloat(),
                    upperBound = size.width.toFloat()
                )
                launch {
                    if (targetOffsetX.absoluteValue <= size.width) {
                        // Not enough velocity; Slide back to the default position.
                        offsetX.animateTo(targetValue = 0f, initialVelocity = velocity)
                    } else {
                        // Enough velocity to slide away the element to the edge.
                        offsetX.animateDecay(velocity, decay)
                        // The element was swiped away.
                        onDismissed()
                    }
                }
            }
        }
    }
        // Apply the horizontal offset to the element.
        .offset { IntOffset(offsetX.value.roundToInt(), 0) }
}