wip(core): Started working on support for stacks in core

packages/core/src/stack.mjs

@@ -0,0 +1,82 @@
+import { Attributes } from './attributes.mjs'
+import { Point } from './point.mjs'
+import * as utils from './utils.mjs'
+
+export function Stack(name=null) {
+  // Non-enumerable properties
+  utils.addNonEnumProp(this, 'freeId', 0)
+  utils.addNonEnumProp(this, 'topLeft', false)
+  utils.addNonEnumProp(this, 'bottomRight', false)
+  utils.addNonEnumProp(this, 'width', false)
+  utils.addNonEnumProp(this, 'height', false)
+  utils.addNonEnumProp(this, 'layout', { move: { x: 0, y: 0 } })
+
+  // Enumerable properties
+  this.attributes = new Attributes()
+  this.parts = new Set()
+  this.name = name
+
+  return this
+}
+
+/* Adds a part to the stack */
+Stack.prototype.addPart = function(part) {
+  if (part) this.parts.add(part)
+
+  return this
+}
+
+/* Returns a list of parts in this stack */
+Stack.prototype.getPartList = function(part) {
+  return [...this.parts]
+}
+
+/* Returns a list of names of parts in this stack */
+Stack.prototype.getPartNames = function(part) {
+  return [...this.parts].map(p => p.name)
+}
+
+/** Homes the stack so that its top left corner is in (0,0) */
+Stack.prototype.home = function () {
+  const parts = this.getPartList()
+  if (parts.length < 1) return this
+  for (const part of this.getPartList()) {
+    part.home()
+  }
+
+  if (parts.length === 1) {
+    this.topLeft = part.topLeft
+    this.bottomRigth = part.bottomRight
+    this.width = part.width
+    this.height = part.height
+
+    return this
+  }
+
+  return this.boundary()
+}
+
+/** Calculates the stack's bounding box and sets it */
+Stack.prototype.home = function () {
+  this.topLeft = new Point(Infinity, Infinity)
+  this.bottomRight = new Point(-Infinity, -Infinity)
+  for (const part of this.getPartList()) {
+    if (part.topLeft.x < this.topLeft.x) this.topLeft.x = part.topLeft.x
+    if (part.topLeft.y < this.topLeft.y) this.topLeft.y = part.topLeft.y
+    if (part.bottomRight.x > this.bottomRight.x) this.bottomRight.x = part.bottomRight.x
+    if (part.bottomRight.y > this.bottomRight.y) this.bottomRight.y = part.bottomRight.y
+  }
+
+  // Fix infinity if it's not overwritten
+  if (this.topLeft.x === Infinity) this.topLeft.x = 0
+  if (this.topLeft.y === Infinity) this.topLeft.y = 0
+  if (this.bottomRight.x === -Infinity) this.bottomRight.x = 0
+  if (this.bottomRight.y === -Infinity) this.bottomRight.y = 0
+
+  this.width = this.bottomRight.x - this.topLeft.x
+  this.height = this.bottomRight.y - this.topLeft.y
+
+  return this
+}
+
+export default Stack