stable-diffusion-webui-ux/javascript/imageParams.js

window.onload = function () {
  window.addEventListener("drop", (e) => {
    const target = e.composedPath()[0];
    if (target.placeholder.indexOf("Prompt") == -1) return;

    let prompt_target =
      get_tab_index("tabs") == 1
        ? "img2img_prompt_image"
        : "txt2img_prompt_image";

    e.stopPropagation();
    e.preventDefault();
    const imgParent = gradioApp().getElementById(prompt_target);
    const files = e.dataTransfer.files;
    const fileInput = imgParent.querySelector('input[type="file"]');
    if (fileInput) {
      fileInput.files = files;
      fileInput.dispatchEvent(new Event("change"));
    }
  });
};