feat: support drop images #398 (#402)

src/editor/core/event/handlers/drop.ts

@@ -1,9 +1,19 @@
 import { CanvasEvent } from '../CanvasEvent'
+import { pasteImage } from './paste'
 
 export function drop(evt: DragEvent, host: CanvasEvent) {
   evt.preventDefault()
   const data = evt.dataTransfer?.getData('text')
   if (data) {
     host.input(data)
+  } else {
+    const files = evt.dataTransfer?.files
+    if (!files) return
+    for (let i = 0; i < files.length; i++) {
+      const file = files[i]
+      if (file.type.startsWith('image')) {
+        pasteImage(host, file)
+      }
+    }
   }
 }