forked from tohe/wmdeit_kaform
50 lines
1.4 KiB
JavaScript
50 lines
1.4 KiB
JavaScript
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(function($K)
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{
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$K.add('module', 'visibility', {
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init: function(app, context)
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{
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this.app = app;
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this.$win = app.$win;
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// defaults
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var defaults = {
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tolerance: 15 // px
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};
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// context
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this.context = context;
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this.params = context.getParams(defaults);
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this.$element = context.getElement();
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},
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// public
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start: function()
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{
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this.$win.on('scroll.kube.visibility resize.kube.visibility', this._check.bind(this));
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this._check();
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},
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stop: function()
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{
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this.$win.off('.kube.visibility');
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},
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// private
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_check: function()
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{
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var docViewTop = this.$win.scrollTop();
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var docViewBottom = docViewTop + this.$win.height();
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var elemTop = this.$element.offset().top;
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var elemBottom = elemTop + this.$element.height();
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var check = ((elemBottom >= docViewTop) && (elemTop <= docViewBottom) && (elemBottom <= (docViewBottom + this.params.tolerance)) && (elemTop >= docViewTop));
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if (check)
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{
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this.app.broadcast('visibility.visible', this, this.$element);
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}
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else
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{
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this.app.broadcast('visibility.invisible', this, this.$element);
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}
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}
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});
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})(Kube);
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