How to find the clipped rect if a layer is clipped by another mask layer

queyue_crk

To test if a layer is clipped by another layer, we can use:
layer.isMasked()
But how to find out the clipped rect? Or how to find the axis and area of visualize part of masked layer

kevgski

Doesn't look like there is anything in the JS API to help with that so here's what I came up with.

let sketch = require('sketch')
let document = sketch.getSelectedDocument()

let selection = document.selectedLayers.layers[0]

let mask = findMask(selection)
let intersection = intersectRect(mask,selection)

function findMask(layer) {
  // ensure selected object actually is masked
  if (!layer.sketchObject.isMasked()) { return nil }
  let objectIndex = selection.index
  let parent = selection.parent
  
  // remove all layers above selected object
  // as the masking layer is always below
  let possibleLayers = parent.layers.slice(0,objectIndex)

  // loop down through next layers to find the closest mask object
  for (let i=possibleLayers.length-1; i >= 0; i--) {
      if (possibleLayers[i].sketchObject.hasClippingMask()) {
          return possibleLayers[i]
      }
  }

  return false

}

function intersectRect(layer1,layer2) {
  return CGRectIntersection(
      layer1.sketchObject.rect(),
      layer2.sketchObject.rect())
}