2025-04-02 21:57:33 +08:00

75 lines
1.9 KiB
JavaScript

/**
* Delegate to handle a media query being matched and unmatched.
*
* @param {object} options
* @param {function} options.match callback for when the media query is matched
* @param {function} [options.unmatch] callback for when the media query is unmatched
* @param {function} [options.setup] one-time callback triggered the first time a query is matched
* @param {boolean} [options.deferSetup=false] should the setup callback be run immediately, rather than first time query is matched?
* @constructor
*/
function QueryHandler(options) {
this.options = options;
!options.deferSetup && this.setup();
}
QueryHandler.prototype = {
constructor : QueryHandler,
/**
* coordinates setup of the handler
*
* @function
*/
setup : function() {
if(this.options.setup) {
this.options.setup();
}
this.initialised = true;
},
/**
* coordinates setup and triggering of the handler
*
* @function
*/
on : function() {
!this.initialised && this.setup();
this.options.match && this.options.match();
},
/**
* coordinates the unmatch event for the handler
*
* @function
*/
off : function() {
this.options.unmatch && this.options.unmatch();
},
/**
* called when a handler is to be destroyed.
* delegates to the destroy or unmatch callbacks, depending on availability.
*
* @function
*/
destroy : function() {
this.options.destroy ? this.options.destroy() : this.off();
},
/**
* determines equality by reference.
* if object is supplied compare options, if function, compare match callback
*
* @function
* @param {object || function} [target] the target for comparison
*/
equals : function(target) {
return this.options === target || this.options.match === target;
}
};
module.exports = QueryHandler;