layout

Organize and layout items based on various algorithms

Visualizations of output data:

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

Getting Started

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
    }]
}

Documentation

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
 */

Algorithms

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

top-down

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)

left-right

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)

diagonal

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)

alt-diagonal

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)

binary-tree

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

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

Custom algorithms

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
 */

Contributing

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.

Donating

Support this project and others by twolfson via gratipay.

License

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