added geometry and positioning methods to `A` (#1110)

1 files changed, 69 insertions, 0 deletions

diff --git a/src/modules/core/containerGeometry.js b/src/modules/core/containerGeometry.js
new file mode 100644
index 0000000..50342b8
--- /dev/null
+++ b/src/modules/core/containerGeometry.js
@@ -0,0 +1,69 @@
+import Matrix from '../../types/Matrix.js'
+import Point from '../../types/Point.js'
+import { proportionalSize } from '../../utils/utils.js'
+
+export function dmove (dx, dy) {
+  this.children().forEach((child, i) => {
+    // Get the childs bbox
+    const bbox = child.bbox()
+    // Get childs matrix
+    const m = new Matrix(child)
+    // Translate childs matrix by amount and
+    // transform it back into parents space
+    const matrix = m.translate(dx, dy).transform(m.inverse())
+    // Calculate new x and y from old box
+    const p = new Point(bbox.x, bbox.y).transform(matrix)
+    // Move element
+    child.move(p.x, p.y)
+  })
+
+  return this
+}
+
+export function dx (dx) {
+  return this.dmove(dx, 0)
+}
+
+export function dy (dy) {
+  return this.dmove(0, dy)
+}
+
+export function height (height, box = this.bbox()) {
+  if (height == null) return box.height
+  return this.size(box.width, height, box)
+}
+
+export function move (x = 0, y = 0, box = this.bbox()) {
+  const dx = x - box.x
+  const dy = y - box.y
+
+  return this.dmove(dx, dy)
+}
+
+export function size (width, height, box = this.bbox()) {
+  const p = proportionalSize(this, width, height, box)
+  const scaleX = p.width / box.width
+  const scaleY = p.height / box.height
+
+  this.children().forEach((child, i) => {
+    const o = new Point(box).transform(new Matrix(child).inverse())
+    child.scale(scaleX, scaleY, o.x, o.y)
+  })
+
+  return this
+}
+
+export function width (width, box = this.bbox()) {
+  if (width == null) return box.width
+  return this.size(width, box.height, box)
+}
+
+export function x (x, box = this.bbox()) {
+  if (x == null) return box.x
+  return this.move(x, box.y, box)
+}
+
+export function y (y, box = this.bbox()) {
+  if (y == null) return box.y
+  return this.move(box.x, y, box)
+}