Feat: Solved the conflict between the Handle click and drag events of the canvas node #3221 (#8413)

### What problem does this PR solve?

Feat: Solved the conflict between the Handle click and drag events of
the canvas node #3221

### Type of change


- [x] New Feature (non-breaking change which adds functionality)

web/src/pages/agent/canvas/node/dropdown/next-step-dropdown.tsx

   DropdownMenuLabel,
   DropdownMenuTrigger,
 } from '@/components/ui/dropdown-menu';
+import { IModalProps } from '@/interfaces/common';
 import { Operator } from '@/pages/agent/constant';
 import { AgentInstanceContext, HandleContext } from '@/pages/agent/context';
 import OperatorIcon from '@/pages/agent/operator-icon';
-import { PropsWithChildren, useContext } from 'react';
+import { PropsWithChildren, createContext, useContext } from 'react';
 
 type OperatorItemProps = { operators: Operator[] };
 
+const HideModalContext = createContext<IModalProps<any>['showModal']>(() => {});
+
 function OperatorItemList({ operators }: OperatorItemProps) {
   const { addCanvasNode } = useContext(AgentInstanceContext);
   const { nodeId, id, type, position } = useContext(HandleContext);
+  const hideModal = useContext(HideModalContext);
 
   return (
     <ul className="space-y-2">
               id,
               position,
             })}
+            onSelect={() => hideModal?.()}
           >
             <OperatorIcon name={x}></OperatorIcon>
             {x}
   );
 }
 
-export function NextStepDropdown({ children }: PropsWithChildren) {
+export function NextStepDropdown({
+  children,
+  hideModal,
+}: PropsWithChildren & IModalProps<any>) {
   return (
-    <DropdownMenu>
+    <DropdownMenu open onOpenChange={hideModal}>
       <DropdownMenuTrigger asChild>{children}</DropdownMenuTrigger>
       <DropdownMenuContent
         onClick={(e) => e.stopPropagation()}
         className="w-[300px] font-semibold"
       >
         <DropdownMenuLabel>Next Step</DropdownMenuLabel>
-        <AccordionOperators></AccordionOperators>
+        <HideModalContext.Provider value={hideModal}>
+          <AccordionOperators></AccordionOperators>
+        </HideModalContext.Provider>
       </DropdownMenuContent>
     </DropdownMenu>
   );

web/src/pages/agent/canvas/node/handle.tsx

+import { useSetModalState } from '@/hooks/common-hooks';
 import { cn } from '@/lib/utils';
 import { Handle, HandleProps } from '@xyflow/react';
 import { Plus } from 'lucide-react';
   nodeId,
   ...props
 }: HandleProps & { nodeId: string }) {
+  const { visible, hideModal, showModal } = useSetModalState();
+
   const value = useMemo(
     () => ({
       nodeId,
 
   return (
     <HandleContext.Provider value={value}>
-      <NextStepDropdown>
-        <Handle
-          {...props}
-          className={cn(
-            'inline-flex justify-center items-center !bg-background-checked !size-4 !rounded-sm !border-none ',
-            className,
-          )}
-          onClick={(e) => {
-            e.stopPropagation();
-          }}
-        >
-          <Plus className="size-3 pointer-events-none" />
-        </Handle>
-      </NextStepDropdown>
+      <Handle
+        {...props}
+        className={cn(
+          'inline-flex justify-center items-center !bg-background-checked !size-4 !rounded-sm !border-none ',
+          className,
+        )}
+        onClick={(e) => {
+          e.stopPropagation();
+          showModal();
+        }}
+      >
+        <Plus className="size-3 pointer-events-none" />
+        {visible && (
+          <NextStepDropdown hideModal={hideModal}>
+            <span></span>
+          </NextStepDropdown>
+        )}
+      </Handle>
     </HandleContext.Provider>
   );
 }

web/src/pages/agent/canvas/node/message-node.tsx

 import { memo } from 'react';
 import { NodeHandleId } from '../../constant';
 import { CommonHandle } from './handle';
-import { LeftHandleStyle, RightHandleStyle } from './handle-icon';
+import { LeftHandleStyle } from './handle-icon';
 import styles from './index.less';
 import NodeHeader from './node-header';
 import { NodeWrapper } from './node-wrapper';
           nodeId={id}
           id={NodeHandleId.End}
         ></CommonHandle>
-        <CommonHandle
+        {/* <CommonHandle
           type="source"
           position={Position.Right}
           isConnectable={isConnectable}
           id={NodeHandleId.Start}
           nodeId={id}
           isConnectableEnd={false}
-        ></CommonHandle>
+        ></CommonHandle> */}
         <NodeHeader
           id={id}
           name={data.name}