2017-08-18 19:52:41 +00:00
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import { ImageCache } from './';
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2017-08-03 17:43:04 +00:00
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/**
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* Notifies about the successful download of an <tt>Image</tt> source. The name
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* is inspired by <tt>Image</tt>. The downloaded <tt>Image</tt> source is not
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* available because (1) I do not know how to get it from {@link ImageCache} and
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* (2) we do not need it bellow. The function was explicitly introduced to cut
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* down on unnecessary <tt>ImageCache</tt> <tt>observer</tt> instances.
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*
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* @private
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* @returns {void}
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*/
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function _onLoad() {
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// ImageCache requires an observer; otherwise, we do not need it because we
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// merely want to initiate the download and do not care what happens with it
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// afterwards.
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}
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/**
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* Initiates the retrieval of a specific <tt>Image</tt> source (if it has not
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* been initiated already). Due to limitations of {@link ImageCache}, the source
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* may have at most one <tt>uri</tt>. The name is inspired by <tt>Image</tt>.
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*
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* @param {Object} source - The <tt>Image</tt> source with preferably exactly
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* one <tt>uri</tt>.
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* @public
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* @returns {void}
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*/
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export function prefetch(source) {
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ImageCache.get().on(source, /* observer */ _onLoad, /* immutable */ true);
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}
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