feat: add events for when selection starts and ends.

packages/core/src/container/FlowRenderer/index.tsx

@@ -45,6 +45,8 @@ const FlowRenderer = ({
   onMoveEnd,
   selectionKeyCode,
   selectBoxOnDrag,
+  onSelectionStart,
+  onSelectionEnd,
   multiSelectionKeyCode,
   zoomActivationKeyCode,
   elementsSelectable,
@@ -112,6 +114,8 @@ const FlowRenderer = ({
       noPanClassName={noPanClassName}
     >
       <UserSelection
+        onSelectionStart={onSelectionStart}
+        onSelectionEnd={onSelectionEnd}
         onClick={onClick}
         onMouseEnter={onPaneMouseEnter}
         onMouseMove={onPaneMouseMove}

packages/core/src/container/ReactFlow/index.tsx

@@ -92,6 +92,8 @@ const ReactFlow = forwardRef<ReactFlowRefType, ReactFlowProps>(
       onSelectionDrag,
       onSelectionDragStop,
       onSelectionContextMenu,
+      onSelectionStart,
+      onSelectionEnd,
       connectionMode = ConnectionMode.Strict,
       connectionLineType = ConnectionLineType.Bezier,
       connectionLineStyle,
@@ -219,6 +221,8 @@ const ReactFlow = forwardRef<ReactFlowRefType, ReactFlowProps>(
             onPaneScroll={onPaneScroll}
             onPaneContextMenu={onPaneContextMenu}
             onSelectionContextMenu={onSelectionContextMenu}
+            onSelectionStart={onSelectionStart}
+            onSelectionEnd={onSelectionEnd}
             onEdgeUpdate={onEdgeUpdate}
             onEdgeContextMenu={onEdgeContextMenu}
             onEdgeDoubleClick={onEdgeDoubleClick}