多点触控：平移、缩放、旋转

要检测用于平移、缩放和旋转的多点触控手势，可以使用 transformable 修饰符。此修饰符本身不会转换元素，它只检测手势。

@Composable
private fun TransformableSample() {
    // set up all transformation states
    var scale by remember { mutableStateOf(1f) }
    var rotation by remember { mutableStateOf(0f) }
    var offset by remember { mutableStateOf(Offset.Zero) }
    val state = rememberTransformableState { zoomChange, offsetChange, rotationChange ->
        scale *= zoomChange
        rotation += rotationChange
        offset += offsetChange
    }
    Box(
        Modifier
            // apply other transformations like rotation and zoom
            // on the pizza slice emoji
            .graphicsLayer(
                scaleX = scale,
                scaleY = scale,
                rotationZ = rotation,
                translationX = offset.x,
                translationY = offset.y
            )
            // add transformable to listen to multitouch transformation events
            // after offset
            .transformable(state = state)
            .background(Color.Blue)
            .fillMaxSize()
    )
}
GesturesSnippets.kt

如果您需要将缩放、平移和旋转与其他手势结合使用，可以使用 PointerInputScope.detectTransformGestures 检测器。