The positioning-strategy module implements a function to calculate where to position an element relative to another element.

Usage

This module exports a single function,

function calculateChildPosition(
  strategy,
  parentRect,
  childDimension,
  viewportDimension,
  options
): { left: number, top: number }

Parameters

• strategy The wanted position of the child relative to the parent represented by the combination of two axes: (top, bottom) and (left, center, right)

  Possible values are:
  "top left", "top center", "top right",
  "bottom left", "bottom center", "bottom right",
  "left top", "left center", "left bottom",
  "right top", "right center", "right bottom",
  including the shorthands: "top", "bottom", "left" and "right"

• parentRect An object representing the rectangle of the parent. It has these properties:

  • left The distance from the left edge of the viewport to the element.
  • top The distance from the top edge of the viewport to the element.
  • width The width of the element.
  • height The height of the element.

• childDimension An object representing the size of the child you want to position.

  • width The width of the element.
  • height The height of the element.

• viewportDimension An object representing the size of the viewport.

  • width The width of the element.
  • height The height of the element.

• options Optional.

  • gap The distance between the child and the parent.

Return value

It returns an object representing where to position the child relative to the parent element. It contains these properties:

• left The distance from the left edge of the viewport to the child.
• top The distance from the top edge of the viewport to the child.