Organize and layout items based on various algorithms

Visualizations of output data:

top-down	left-right	diagonal	alt-diagonal	binary-tree

Install the module with: npm install layout

// Load in layout
var layout = require('layout');

// Generate a new layer to organize items on
var layer = layout('top-down');

// Add items that you want to organize
layer.addItem({'height': 20, 'width': 10, 'meta': 'medium'});
layer.addItem({'height': 10, 'width': 10, 'meta': 'small'});
layer.addItem({'height': 50, 'width': 40, 'meta': 'large'});

// Export the info
var info = layer['export']();

// We get back the width and height of the pack as well as organized items
{
    height: 80,
    width: 40,
    items: [{
        height: 10,
        width: 10,
        meta: 'small',
        x: 0,
        y: 0
    }, {
        height: 20,
        width: 10,
        meta: 'medium',
        x: 0,
        y: 10
    }, {
        height: 50,
        width: 40,
        meta: 'large',
        x: 0,
        y: 30
    }]
}

Layout is a constructor function

/**
 * Layout adds items in an algorithmic fashion
 * @constructor
 * @param {String|Object} [algorithm="top-down"] Name of algorithm or custom algorithm to use
 *   Available algorithms are listed in the Algorithms section
 * @param {Mixed} [options] Options to provide for the algorithm
 */

Items can be added via addItem which are required to have a height and width. Any additional info should be stored inside of meta.

/**
 * @param {Object} item Item to store -- this currently is mutated in-memory
 * @param {Number} item.width Width of the item
 * @param {Number} item.height Height of the item
 * @param {Mixed} [item.meta] Any meta data you would like to store related to the item
 */

export is how you take your items and organize them.

/**
 * @returns {Object} retObj
 * @returns {Number} retObj.height Height of the processed layout
 * @returns {Number} retObj.width Width of the processed layout
 * @returns {Mixed[]} retObj.items Organized items
 */

Currently layout supports 5 different layout types which are listed below.

The top-down algorithm places items vertically.

By default, it sorts from smallest (top) to largest (bottom). However, this can be disabled via sort: false.

Options:

• sort Boolean Flag to enable/disable sorting from smallest (top) to largest (bottom)
  • By default, this is enabled (true)

The left-right algorithm places items horizontally.

By default, it sorts from smallest (left) to largest (right). However, this can be disabled via sort: false.

Options:

• sort Boolean Flag to enable/disable sorting from smallest (left) to largest (right)
  • By default, this is enabled (true)

The diagonal algorithm places items diagonally (top-left to bottom-right).

By default, it sorts from smallest (top-left) to largest (bottom-right). However, this can be disabled via sort: false.

Options:

• sort Boolean Flag to enable/disable sorting from smallest (top-left) to largest (bottom-right)
  • By default, this is enabled (true)

The alt-diagonal algorithm places items diagonally (top-right to bottom-left).

By default, it sorts from smallest (top-right) to largest (bottom-left). However, this can be disabled via sort: false.

Options:

• sort Boolean Flag to enable/disable sorting from smallest (top-right) to largest (bottom-left)
  • By default, this is enabled (true)

The binary-tree algorithm packs items via the binary tree algorithm.

This is an efficient way to pack items into the smallest container possible.

You can add your own algorithm via layout.addAlgorithm

/**
 * Method to add new algorithms via
 * @param {String} name Name of algorithm
 * @param {Object} algorithm Algorithm to bind under name
 * @param {Function} algorithm.sort Algorithm to sort object by
 * @param {Function} algorithm.placeItems Algorithm to place items by
 */

In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint via npm run lint and test via npm test.

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Copyright (c) 2012-2014 Todd Wolfson Licensed under the MIT license.