重构 DropArea 组件：用条件渲染替换 EmptyFlow，增强拖放视觉效果，并移除未使用的 EmptyFlow.vue 文件

src/components/composer/flow/DropArea.vue

@@ -1,6 +1,24 @@
 <template>
-  <div class="drop-area">
-    <q-icon name="add" size="32px" />
+  <div
+    class="drop-area"
+    @dragenter="isDragging = true"
+    @dragleave="isDragging = false"
+    @drop="isDragging = false"
+    :class="{
+      'drop-area-dragging': isDragging,
+    }"
+  >
+    <template v-if="type === 'add'">
+      <div class="add-area">
+        <q-icon name="add" size="32px" />
+      </div>
+    </template>
+    <template v-else-if="type === 'empty'">
+      <div class="empty-area">
+        <q-icon name="drag_indicator" size="32px" />
+        <div class="text-body2">从左侧拖拽命令到这里开始编排</div>
+      </div>
+    </template>
   </div>
 </template>
 
@@ -8,25 +26,82 @@
 import { defineComponent } from "vue";
 
 export default defineComponent({
-  name: "DropArea",
+  name: "EmptyFlow",
+  props: {
+    type: {
+      type: String,
+      default: "add",
+    },
+  },
+  data() {
+    return {
+      isDragging: false,
+    };
+  },
 });
 </script>
 
 <style scoped>
 .drop-area {
-  flex: 1;
-  min-height: 50px;
-  border-radius: 8px;
-  margin: 8px;
   display: flex;
   align-items: center;
   justify-content: center;
-  color: #9994;
-  border: 2px dashed #9994;
+  border: 2px dashed #e0e0e0;
+  border-radius: 4px;
+  margin: 8px 0;
+  transition: all 0.3s ease;
+  flex: 1;
+  user-select: none;
+  transition: all 0.3s ease;
 }
 
 .body--dark .drop-area {
-  color: #6664;
-  border: 2px dashed #6664;
+  border-color: #676666;
+}
+
+.drop-area:hover,
+.drop-area-dragging {
+  border-color: #bdbdbd;
+  background-color: #f9f9f9;
+}
+
+.body--dark .drop-area:hover,
+.body--dark .drop-area-dragging {
+  border: 2px dashed #676666;
+  background-color: #303132;
+}
+
+.drop-area-dragging {
+  position: relative;
+  animation: shake 0.5s ease-in-out infinite;
+}
+
+@keyframes shake {
+  0%,
+  100% {
+    transform: rotate(0deg);
+  }
+  25% {
+    transform: rotate(-0.1deg);
+  }
+  75% {
+    transform: rotate(0.1deg);
+  }
+}
+
+.add-area,
+.empty-area {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  color: grey
+}
+
+.add-area {
+  height: 30px;
+}
+
+.empty-area {
+  height: 200px;
 }
 </style>