initial commit

components/ai-elements/edge.tsx

@@ -0,0 +1,143 @@
+import type { EdgeProps, InternalNode, Node } from "@xyflow/react";
+import {
+  BaseEdge,
+  getBezierPath,
+  getSimpleBezierPath,
+  Position,
+  useInternalNode,
+} from "@xyflow/react";
+
+const Temporary = ({
+  id,
+  sourceX,
+  sourceY,
+  targetX,
+  targetY,
+  sourcePosition,
+  targetPosition,
+}: EdgeProps) => {
+  const [edgePath] = getSimpleBezierPath({
+    sourcePosition,
+    sourceX,
+    sourceY,
+    targetPosition,
+    targetX,
+    targetY,
+  });
+
+  return (
+    <BaseEdge
+      className="stroke-1 stroke-ring"
+      id={id}
+      path={edgePath}
+      style={{
+        strokeDasharray: "5, 5",
+      }}
+    />
+  );
+};
+
+const getHandleCoordsByPosition = (
+  node: InternalNode<Node>,
+  handlePosition: Position
+) => {
+  // Choose the handle type based on position - Left is for target, Right is for source
+  const handleType = handlePosition === Position.Left ? "target" : "source";
+
+  const handle = node.internals.handleBounds?.[handleType]?.find(
+    (h) => h.position === handlePosition
+  );
+
+  if (!handle) {
+    return [0, 0] as const;
+  }
+
+  let offsetX = handle.width / 2;
+  let offsetY = handle.height / 2;
+
+  // this is a tiny detail to make the markerEnd of an edge visible.
+  // The handle position that gets calculated has the origin top-left, so depending which side we are using, we add a little offset
+  // when the handlePosition is Position.Right for example, we need to add an offset as big as the handle itself in order to get the correct position
+  switch (handlePosition) {
+    case Position.Left: {
+      offsetX = 0;
+      break;
+    }
+    case Position.Right: {
+      offsetX = handle.width;
+      break;
+    }
+    case Position.Top: {
+      offsetY = 0;
+      break;
+    }
+    case Position.Bottom: {
+      offsetY = handle.height;
+      break;
+    }
+    default: {
+      throw new Error(`Invalid handle position: ${handlePosition}`);
+    }
+  }
+
+  const x = node.internals.positionAbsolute.x + handle.x + offsetX;
+  const y = node.internals.positionAbsolute.y + handle.y + offsetY;
+
+  return [x, y] as const;
+};
+
+const getEdgeParams = (
+  source: InternalNode<Node>,
+  target: InternalNode<Node>
+) => {
+  const sourcePos = Position.Right;
+  const [sx, sy] = getHandleCoordsByPosition(source, sourcePos);
+  const targetPos = Position.Left;
+  const [tx, ty] = getHandleCoordsByPosition(target, targetPos);
+
+  return {
+    sourcePos,
+    sx,
+    sy,
+    targetPos,
+    tx,
+    ty,
+  };
+};
+
+const Animated = ({ id, source, target, markerEnd, style }: EdgeProps) => {
+  const sourceNode = useInternalNode(source);
+  const targetNode = useInternalNode(target);
+
+  if (!(sourceNode && targetNode)) {
+    return null;
+  }
+
+  const { sx, sy, tx, ty, sourcePos, targetPos } = getEdgeParams(
+    sourceNode,
+    targetNode
+  );
+
+  const [edgePath] = getBezierPath({
+    sourcePosition: sourcePos,
+    sourceX: sx,
+    sourceY: sy,
+    targetPosition: targetPos,
+    targetX: tx,
+    targetY: ty,
+  });
+
+  return (
+    <>
+      <BaseEdge id={id} markerEnd={markerEnd} path={edgePath} style={style} />
+      <circle fill="var(--primary)" r="4">
+        <animateMotion dur="2s" path={edgePath} repeatCount="indefinite" />
+      </circle>
+    </>
+  );
+};
+
+export const Edge = {
+  Animated,
+  Temporary,
+};