38 lines
1.1 KiB
JavaScript
38 lines
1.1 KiB
JavaScript
 
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// @ts-check
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/**
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* Files without the local program: when Kokkoja is opened from a web
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* site, an image file comes from the browser's own file chooser, and
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* anything to be saved is a download.
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*/
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/**
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* Let the user choose an image file.
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* @returns {Promise<File | null>} Null if none was chosen.
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*/
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export function pickImageFile() {
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return new Promise((resolve) => {
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const picker = document.createElement('input');
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picker.type = 'file';
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picker.accept = 'image/*';
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picker.addEventListener('change', () => resolve(picker.files?.[0] ?? null));
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picker.addEventListener('cancel', () => resolve(null));
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picker.click();
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});
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}
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/**
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* Give the user a file, through the browser's downloads.
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* @param {string} name
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* @param {Blob} content
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*/
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export function download(name, content) {
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const address = URL.createObjectURL(content);
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const link = document.createElement('a');
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link.href = address;
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link.download = name;
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document.body.append(link);
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link.click();
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link.remove();
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// The browser has begun the download; the address can go a moment later.
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setTimeout(() => URL.revokeObjectURL(address), 10000);
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}
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