Ability to translate the position of a view after layout phase

[lucabartoletti]

Ability to apply a traslation to a view position after the layout phase by absolute value or by percentage on the container size.

This could be handy in cases where we need to tweak the position of a element in a complex layout without have to create a custom Layout.

[nicksnyder]

I think this would be easily accomplished by creating a custom layout (possible name OffsetLayout).

Something like this (incomplete implementation)

public class OffsetLayout: Layout {

    public let offset: CGPoint
    public let sublayout: Layout

    public init(offset: CGPoint, sublayout: Layout, /* other standard parameters */) {
        self.offset = offset
        self.sublayout = sublayout
    }

    public func measurement(within maxSize: CGSize) -> LayoutMeasurement {
        let measurement = sublayout.measure(within: maxSize)
        return LayoutMeasurement(layout: self, size: measurement.size, maxSize: maxSize, sublayouts: [sublayout])
    }

    public func arrangement(within rect: CGRect, measurement: LayoutMeasurement) -> LayoutArrangement {
        let offsetRect = CGRectOffset(rect, offset.x, offset.y)
        let position = sublayout.arrangement(within: offsetRect, measurement: measurement)
        return LayoutArrangement(layout: self, frame: rect, sublayouts: [offsetRect])
    }
}

This would probably be appropriate to add as a base layout in LayoutKit.

Do you have an example of a layout where a percentage offset would be useful?