Animatable layouts, FlexScrollView & widgets for famo.us.

Above anything, famous-flex is a concept in which renderables are seperated from how they are layed-out. This makes it possible to change layouts on the fly and animate the renderables from one layout to another. For instance, you can layout a collection of renderables using a CollectionLayout, and change that into a ListLayout. When using flow-mode the renderables will smoothly transition from the old state to the new state using physics, particles and springs.

Demos

• famous-flex-demo (source)
• AnimationController demo (source)
• Chat demo (source)
• DatePicker demo (source)
• TabBar demo (source)
• TabBarController demo (source)

Getting started

• Installation

Core concepts

• LayoutController
• Layout function
• Datasource
• Layout literals
• Layout helpers

Views / widgets

• LayoutController
• AnimationController
• ScrollController
• FlexScrollView
• DatePicker
• TabBar
• TabBarController

Layouts

• ProportionalLayout
• HeaderFooterLayout
• NavBarLayout
• TabBarLayout
• ListLayout (scrollable)
• CollectionLayout (scrollable)
• WheelLayout (scrollable)
• CoverLayout (scrollable)

Resources

• Documentation

Installation

Install using bower or npm:

bower install famous-flex

npm install famous-flex

LayoutController

LayoutController is a view that lays out renderables based on:

• a layout-function
• a data-source containing renderables
• optional layout-options

Example of laying out renderables using a CollectionLayout:

var LayoutController = require('famous-flex/LayoutController');
var CollectionLayout = require('famous-flex/layouts/CollectionLayout'); // import standard layout

// create collection-layout
var layoutController = new LayoutController({
    layout: CollectionLayout,
    layoutOptions: {
        itemSize: [100, 100],
        gutter: [20, 20],
        justify: true
    },
    flow: true,    // smoothly animates renderables when changing the layout
    direction: 1,  // 0 = X, 1 = Y, undefined = use default from selected layout-function
    dataSource: [
        new Surface({content: 'surface1'}),
        new Surface({content: 'surface2'}),
        new Surface({content: 'surface3'})
    ]
});
this.add(layoutController); // add layout-controller to the render-tree

When the flow option is enabled, renderables are animated smoothly between layout states.

Layout function

A layout is represented as a Function, which takes a context argument and an optional options argument. The purpose of the function is to lay-out the renderables in the data-source by calling context.set() on a renderable. The renderables can be enumerated by calling context.next(), context.prev() or by using the id of the renderable.

Famous-flex comes shipped with various standard layouts, but it is also very easy to create your own layout-functions. View LayoutContext for more details on creating your own layout-functions.

/**
 * @param {LayoutContext} context Context used for enumerating renderables and setting the layout
 * @param {Object} [options] additional layout-options that are passed to the function
 */
function LayoutFunction(context, options) {

    // simple layout-function that lays out renderables from top to bottom
    var node = context.next();
    var y = 0;
    while (node) {
        context.set(node, {
            size: [context.size[0], 100],
            translate: [0, y, 0]
        });
        y += 100;
        node = context.next();
    }
};

For optimal performance, the layout function is only executed when:

• A resize occurs
• An option is changed on the layout-controller
• When the content is scrolled

Datasource

The data-source contains the renderables that are to be layed-out. It can be one of three things:

• An Array
• A LinkedListViewSequence
• A VirtualViewSequence
• An Object with key/value pairs

In case of an Array or a ViewSequence, use context.next() in your layout-function to enumerate all the renderables in the data-source:

var layoutController = new LayoutController({
    layout: function (context, options) {
        var y = 0;
        var node = context.next();
        while (node) {
            context.set(node, {
                size: [context.size[0], 100],
                translate: [0, y, 0]
            });
            y += 100;
            node = context.next();
        }
    },
    dataSource: [
        new Surface({content: 'surface1'}),
        new Surface({content: 'surface2'}),
        new Surface({content: 'surface3'})
    ]
});

Sometimes it is easier to identify renderables by an id, rather than a sequence. In that case use context.get() or directly pass the data-source id to the context.set() function:

var layoutController = new LayoutController({
    layout: function (context, options) {
        context.set('one', {
            size: [100, 100],
            translate: [0, 0, 0]
        });
        context.set('two', {
            size: [100, 100],
            translate: [100, 0, 0]
        });
        context.set('three', {
            size: [100, 100],
            translate: [200, 0, 0]
        });
    },
    dataSource: {
        'one': new Surface({content: 'one'}),
        'two': new Surface({content: 'two'}),
        'three': new Surface({content: 'three'})
    }
});

Layout literals

Layout literals are objects which describe layouts through a definition rather than a function. The following example describes the use of a layout literal using dock semantics (see LayoutDockHelper):

var layoutController = new LayoutController({
    layout: {dock: [
        ['top', 'header', 50],
        ['bottom', 'footer', 50],
        ['fill', 'content']
    ]},
    dataSource: {
        header: new Surface({content: 'Header'}),
        footer: new Surface({content: 'Footer'}),
        content: new Surface({content: 'Content'})
    }
});

Layout literals are implemented through LayoutHelpers. To create your own layout literals, perform the following steps:

• Create a LayoutHelper (see LayoutDockHelper for an example).
• Implement the parse function on the LayoutHelper.
• Register the helper using LayoutUtility.registerHelper.

Layout helpers

Layout helpers are special classes that simplify writing layout functions.

Helper	Literal	Description
LayoutDockHelper	dock	Layout renderables using docking semantics.

Standard layouts

Layout	DataSource	Scrollable	Description
ProportionalLayout	LinkedListViewSequence / Array	No	Lays out renderables sequentially and sizes them proportionally.
HeaderFooterLayout	Id-based	No	Layout containing a top-header, bottom- footer and content.
NavBarLayout	Id-based	No	Layout containing one or more left and right items and a title.
TabBarLayout	Id-based	No	Tab-bar layout.
Scrollable layouts:
ListLayout	LinkedListViewSequence / Array	Yes	List layout with margins, spacing and optionally sticky headers.
CollectionLayout	LinkedListViewSequence / Array	Yes	Lays out renderables in a grid with a specific width & height.
WheelLayout	LinkedListViewSequence / Array	Yes	Lays out renderables in a wheel (slot-machine) formation.
CoverLayout	LinkedListViewSequence / Array	Yes	Lays out renderables in a wheel (slot-machine) formation.

Documentation

Class	Description
LayoutController	Lays out renderables and optionally animates between layout states.
AnimationController	Animating between famo.us views in awesome ways.
ScrollController	Scrollable LayoutController (base class for FlexScrollView).
FlexScrollView	Flexible scroll-view with pull-to-refresh, margins & spacing and more good stuff.
DatePicker	Date/time picker wheel.
TabBar	TabBar widget.
TabBarController	TabBarController widget.
LayoutContext	Context used for writing layout-functions.
LayoutUtility	Utility class containing helper functions.
VirtualViewSequence	Infinite view-sequence which uses a factory delegate to create renderables.
LinkedListViewSequence	Linked-list based View-sequence which resolves various issues with the stock famo.us ViewSequence.

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© 2014 - 2016 Hein Rutjes