https://autorrege.es/static/js/mira/core/BehaviourEnvironment.js

1
2/**
3 * BehaviourEnvironment
4 *
5 * @class BehaviourEnvironment
6 */
7(function(ns) {
8
9    // check if media query supported, assume browser with media query support also support :root
10    var _mqSupport,
11        _desktopSize = 1024;
12    try {
13        _mqSupport = !!(document.querySelectorAll(':root'));
14    }
15    catch (e) {
16        _mqSupport = false;
17    }
18
19    /**
20     * Constructs BehaviourEnvironment objects.
21     * Should only be called from create method.
22     *
23     *  data-environment JSON specification
24     *  {
25     *      'window':{
26     *          'minWidth':<Number>
27     *          'maxWidth':<Number>
28     *      }
29     *  }
30     *
31     * @class BehaviourEnvironment
32     * @constructor
33     * @param {Object} element DOM Element
34     */
35    var BehaviourEnvironment = function(element,properties) {
36
37        // is the environment suitable, by default it is
38        this._suitable = true;
39
40        // set properties object
41        this._properties = properties;
42
43        // listen for environment changes
44        this._listen();
45
46        // test the environment
47        this._test();
48    
49    };
50
51    /**
52     * Static method construct creates behaviour environment objects
53     *
54     * @method construct
55     * @class BehaviourEnvironment
56     */
57    BehaviourEnvironment.construct = function(element) {
58
59        // check if has specifications
60        var specifications = element.getAttribute('data-environment');
61        if (!specifications) {
62            return null;
63        }
64    
65        var properties = null;
66        try {
67            properties = JSON.parse(specifications);
68        }
69        catch(e) {
70            console.warn("BehaviourEnvironment: data-environment attribute should have format data-environment='{\"foo\":\"bar\"}'");
71            return null;
72        }
73    
74        return new mira.core.BehaviourEnvironment(element,properties)
75    
76    };
77
78
79    // prototype shortcut
80    var p = BehaviourEnvironment.prototype;
81
82
83    /**
84     * Adds listeners to the environment to act when it changes
85     *
86     * @method _listen
87     * @class BehaviourEnvironment
88     */
89    p._listen = function() {
90
91        if (this._properties.window) {
92            var responsiveWindow = mira.utils.ResponsiveWindow.getInstance();
93            Observer.subscribe(responsiveWindow, 'resize', this._test.bind(this));
94        }
95
96    };
97
98    /**
99     * Checks if the current environment has the requested properties
100     *
101     * @method _test
102     * @class BehaviourEnvironment
103     */
104    p._test = function() {
105
106        // test environment properties
107        var win,width,state,suitable = true;
108
109        // test window sizes
110        if (win = this._properties.window) {
111
112            // get window size
113            width = _mqSupport ? mira.window.getWidth() : _desktopSize;
114
115            // check max width
116            if (win.maxWidth && width > win.maxWidth) {
117                suitable = false;
118            }
119
120            // check min width
121            if (win.minWidth && width < win.minWidth) {
122                suitable = false;
123            }
124
125        }          
126
127        // fire changed event if environment suitability changed
128        if (suitable != this._suitable) {
129            this._suitable = suitable;
130            Observer.publish(this, 'change');
131        }
132    };
133
134    /**
135     * Returns the suitability of the current environment
136     *
137     * @method isSuitable
138     * @class BehaviourEnvironment
139     * @return {Boolean} The suitability of the environment
140     */
141    p.isSuitable = function() {
142        return this._suitable;
143    };
144
145    // Register class
146    Namespace.register(ns).BehaviourEnvironment = BehaviourEnvironment;
147
148}('mira.core'));