feat: add paste from clipboard

- add paste image from clipboard (ctrl+v)
- validate if the file is an image

frontend/src/App.tsx

@@ -77,10 +77,12 @@ function App() {
   // Initial version creation
   function doCreate(referenceImages: string[]) {
     setReferenceImages(referenceImages);
-    doGenerateCode({
-      generationType: "create",
-      image: referenceImages[0],
-    });
+    if (referenceImages.length > 0) {
+      doGenerateCode({
+        generationType: "create",
+        image: referenceImages[0],
+      });
+    }
   }
 
   // Subsequent updates

frontend/src/components/ImageUpload.tsx

@@ -1,4 +1,4 @@
-import { useState, useEffect, useMemo } from "react";
+import { useState, useEffect, useMemo, useCallback } from "react";
 import { useDropzone } from "react-dropzone";
 // import { PromptImage } from "../../../types";
 import { toast } from "react-hot-toast";
@@ -89,6 +89,37 @@ function ImageUpload({ setReferenceImages }: Props) {
       },
     });
 
+  const pasteEvent = useCallback(
+    (event: ClipboardEvent) => {
+      const clipboardData = event.clipboardData;
+      if (!clipboardData) return;
+
+      const items = clipboardData.items;
+      const files = [];
+      for (let i = 0; i < items.length; i++) {
+        const file = items[i].getAsFile();
+        if (file && file.type.startsWith("image/")) {
+          files.push(file);
+        }
+      }
+
+      // Convert images to data URLs and set the prompt images state
+      Promise.all(files.map((file) => fileToDataURL(file)))
+        .then((dataUrls) => {
+          setReferenceImages(dataUrls.map((dataUrl) => dataUrl as string));
+        })
+        .catch((error) => {
+          // TODO: Display error to user
+          console.error("Error reading files:", error);
+        });
+    },
+    [setReferenceImages]
+  );
+
+  useEffect(() => {
+    window.addEventListener("paste", pasteEvent);
+  }, [pasteEvent]);
+
   useEffect(() => {
     return () => files.forEach((file) => URL.revokeObjectURL(file.preview));
   }, [files]); // Added files as a dependency
@@ -108,7 +139,7 @@ function ImageUpload({ setReferenceImages }: Props) {
       {/* eslint-disable-next-line @typescript-eslint/no-explicit-any */}
       <div {...getRootProps({ style: style as any })}>
         <input {...getInputProps()} />
-        <p>Drop a screenshot here, or click to select</p>
+        <p>Drop a screenshot here, paste from clipboard, or click to select</p>
       </div>
     </section>
   );