IjzerenHein/famous-flex

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.

Standard layouts

Documentation

Contribute

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© 2014 - 2016 Hein Rutjes