Function openBrowserFilePicker

src/browser/files.ts:18–84

({
  allowMultiple,
  imagesOnly,
}: {
  allowMultiple: boolean;
  imagesOnly?: boolean;
})

};

function openBrowserFilePicker({
  allowMultiple,
  imagesOnly,
}: {
  allowMultiple: boolean;
  imagesOnly?: boolean;
}): Promise<File[]> {
  return new Promise((resolve, reject) => {
    const input = document.createElement("input");
    let settled = false;

    function cleanup(): void {
      input.removeEventListener("cancel", handleCancel);
      input.removeEventListener("change", handleChange);
      input.remove();
    }

    function finish(files: File[]): void {
      if (settled) {
        return;
      }
      settled = true;
      cleanup();
      resolve(files);
    }

    function fail(error: unknown): void {
      if (settled) {
        return;
      }
      settled = true;
      cleanup();
      reject(error);
    }

    function handleCancel(): void {
      finish([]);
    }

    function handleChange(): void {
      finish(Array.from(input.files ?? []));
    }

    input.type = "file";
    input.multiple = allowMultiple;
    if (imagesOnly) {
      input.accept = "image/*";
    }
    Object.assign(input.style, {
      height: "1px",
      left: "-9999px",
      opacity: "0",
      position: "fixed",
      top: "0",
      width: "1px",
    });
    input.addEventListener("cancel", handleCancel);
    input.addEventListener("change", handleChange);