feat(edges): add smooth step type

README.md

@@ -223,7 +223,7 @@ You can find an example of how to implement a custom node with multiple handles
 
 # Edges
 
-React Flow comes with three [edge types](#edge-types--custom-edges) (`straight`, `default`, `step`). As the names indicate, the edges differ in the representation. The default type is a bezier edge. You create edges by adding them to your `elements` array of the `ReactFlow` component.
+React Flow comes with three [edge types](#edge-types--custom-edges) (`default`, `straight`, `step`, `smoothstep`). As the names indicate, the edges differ in the representation. The default type is a bezier edge. You create edges by adding them to your `elements` array of the `ReactFlow` component.
 
 Edge example: `{ id: 'e1-2', type: 'straight', source: '1', target: '2', animated: true, label: 'edge label' }`
 
@@ -246,13 +246,14 @@ You can find an example with lots of different edges in the [edges example](http
 
 ### Edge Types & Custom Edges
 
-The basic edge types are `straight`, `default` and `step`. The default `edgeTypes` object looks like this:
+The basic edge types are `default` (bezier), `straight`, `step` and `smoothedge`. The default `edgeTypes` object looks like this:
 
 ```javascript
 {
   default: BezierEdge,
   straight: StraightEdge,
-  step: StepEdge
+  step: StepEdge,
+  smoothstep: SmoothStepEdge
 }
 ```
 

example/src/Edges/index.js

@@ -4,13 +4,14 @@ import ReactFlow, { removeElements, addEdge, MiniMap, Controls, Background } fro
 
 import CustomEdge from './CustomEdge';
 
-const onNodeDragStop = node => console.log('drag stop', node);
-const onElementClick = element => console.log('click', element);
-const onLoad = reactFlowInstance => reactFlowInstance.fitView();
+const onNodeDragStop = (node) => console.log('drag stop', node);
+const onElementClick = (element) => console.log('click', element);
+const onLoad = (reactFlowInstance) => reactFlowInstance.fitView();
 
 const initialElements = [
   { id: '1', type: 'input', data: { label: 'Input 1' }, position: { x: 250, y: 0 } },
   { id: '2', data: { label: 'Node 2' }, position: { x: 150, y: 100 } },
+  { id: '2a', data: { label: 'Node 2a' }, position: { x: 0, y: 180 } },
   { id: '3', data: { label: 'Node 3' }, position: { x: 250, y: 200 } },
   { id: '4', data: { label: 'Node 4' }, position: { x: 400, y: 300 } },
   { id: '3a', data: { label: 'Node 3a' }, position: { x: 150, y: 300 } },
@@ -19,20 +20,27 @@ const initialElements = [
   { id: '7', type: 'output', data: { label: 'Output 7' }, position: { x: 250, y: 550 } },
   { id: '8', type: 'output', data: { label: 'Output 8' }, position: { x: 525, y: 600 } },
   { id: 'e1-2', source: '1', target: '2', label: 'bezier edge (default)' },
+  { id: 'e2-2a', source: '2', target: '2a', type: 'smoothstep', label: 'smoothstep edge' },
   { id: 'e2-3', source: '2', target: '3', type: 'step', label: 'step edge' },
   { id: 'e3-4', source: '3', target: '4', type: 'straight', label: 'straight edge' },
   { id: 'e3-3a', source: '3', target: '3a', type: 'straight', label: 'label only edge', style: { stroke: 'none' } },
   { id: 'e3-5', source: '4', target: '5', animated: true, label: 'animated styled edge', style: { stroke: 'red' } },
   { id: 'e5-6', source: '5', target: '6', label: 'styled label', labelStyle: { fill: 'red', fontWeight: 700 } },
-  { id: 'e5-7', source: '5', target: '7', label: 'label with styled bg', labelBgStyle: { fill: '#eee', fillOpacity: 0.7 } },
+  {
+    id: 'e5-7',
+    source: '5',
+    target: '7',
+    label: 'label with styled bg',
+    labelBgStyle: { fill: '#eee', fillOpacity: 0.7 },
+  },
   { id: 'e5-8', source: '5', target: '8', type: 'custom', label: 'custom edge' },
 ];
 
 const EdgesFlow = () => {
   const [elements, setElements] = useState(initialElements);
 
-  const onElementsRemove = (elementsToRemove) => setElements(els => removeElements(elementsToRemove, els));
-  const onConnect = (params) => setElements(els => addEdge(params, els));
+  const onElementsRemove = (elementsToRemove) => setElements((els) => removeElements(elementsToRemove, els));
+  const onConnect = (params) => setElements((els) => addEdge(params, els));
 
   return (
     <ReactFlow
@@ -45,7 +53,7 @@ const EdgesFlow = () => {
       onLoad={onLoad}
       snapToGrid={true}
       edgeTypes={{
-        custom: CustomEdge
+        custom: CustomEdge,
       }}
     >
       <MiniMap />
@@ -53,6 +61,6 @@ const EdgesFlow = () => {
       <Background />
     </ReactFlow>
   );
-}
+};
 
-export default EdgesFlow;
+export default EdgesFlow;

example/src/Horizontal/index.js

@@ -2,10 +2,17 @@ import React, { useState } from 'react';
 
 import ReactFlow, { removeElements, addEdge } from 'react-flow-renderer';
 
-const onLoad = reactFlowInstance => reactFlowInstance.fitView();
+const onLoad = (reactFlowInstance) => reactFlowInstance.fitView();
 
 const initialElements = [
-  { id: '1', sourcePosition: 'right', type: 'input', className: 'dark-node', data: { label: 'Input' }, position: { x: 0, y: 80 } },
+  {
+    id: '1',
+    sourcePosition: 'right',
+    type: 'input',
+    className: 'dark-node',
+    data: { label: 'Input' },
+    position: { x: 0, y: 80 },
+  },
   { id: '2', sourcePosition: 'right', targetPosition: 'left', data: { label: 'A Node' }, position: { x: 250, y: 0 } },
   { id: '3', sourcePosition: 'right', targetPosition: 'left', data: { label: 'Node 3' }, position: { x: 250, y: 160 } },
   { id: '4', sourcePosition: 'right', targetPosition: 'left', data: { label: 'Node 4' }, position: { x: 500, y: 0 } },
@@ -14,8 +21,8 @@ const initialElements = [
   { id: '7', sourcePosition: 'right', targetPosition: 'left', data: { label: 'Node 7' }, position: { x: 750, y: 50 } },
   { id: '8', sourcePosition: 'right', targetPosition: 'left', data: { label: 'Node 8' }, position: { x: 750, y: 300 } },
 
-  { id: 'e1-2', source: '1', target: '2', animated: true,  },
-  { id: 'e1-3', source: '1', target: '3', animated: true, },
+  { id: 'e1-2', source: '1', target: '2', animated: true },
+  { id: 'e1-3', source: '1', target: '3', animated: true },
   { id: 'e1-4', source: '2', target: '4', label: 'edge label' },
   { id: 'e3-5', source: '3', target: '5', animated: true },
   { id: 'e3-6', source: '3', target: '6', animated: true },
@@ -25,18 +32,19 @@ const initialElements = [
 
 const HorizontalFlow = () => {
   const [elements, setElements] = useState(initialElements);
-  const onElementsRemove = (elementsToRemove) =>
-    setElements(els => removeElements(elementsToRemove, els));
-  const onConnect = (params) => setElements(els => addEdge(params, els));
+  const onElementsRemove = (elementsToRemove) => setElements((els) => removeElements(elementsToRemove, els));
+  const onConnect = (params) => setElements((els) => addEdge(params, els));
   const changeClassName = () => {
-    setElements(elms => elms.map(el => {
-      if (el.type === 'input') {
-        el.className = el.className ? '' : 'dark-node';
-      }
+    setElements((elms) =>
+      elms.map((el) => {
+        if (el.type === 'input') {
+          el.className = el.className ? '' : 'dark-node';
+        }
 
-      return {...el};
-    }))
-  }
+        return { ...el };
+      })
+    );
+  };
 
   return (
     <ReactFlow
@@ -46,14 +54,11 @@ const HorizontalFlow = () => {
       onLoad={onLoad}
       selectNodesOnDrag={false}
     >
-      <button
-        onClick={changeClassName}
-        style={{ position: 'absolute', right: 10, top: 30, zIndex: 4 }}
-      >
+      <button onClick={changeClassName} style={{ position: 'absolute', right: 10, top: 30, zIndex: 4 }}>
         change class name
       </button>
     </ReactFlow>
   );
-}
+};
 
 export default HorizontalFlow;

example/src/Overview/index.js

@@ -2,49 +2,118 @@ import React, { useState } from 'react';
 
 import ReactFlow, { removeElements, addEdge, MiniMap, Controls, Background } from 'react-flow-renderer';
 
-const onNodeDragStart = node => console.log('drag start', node);
-const onNodeDragStop = node => console.log('drag stop', node);
-const onElementClick = element => console.log('click', element);
-const onSelectionChange = elements => console.log('selection change', elements);
+const onNodeDragStart = (node) => console.log('drag start', node);
+const onNodeDragStop = (node) => console.log('drag stop', node);
+const onElementClick = (element) => console.log('click', element);
+const onSelectionChange = (elements) => console.log('selection change', elements);
 const onLoad = (reactFlowInstance) => {
   console.log('graph loaded:', reactFlowInstance);
   reactFlowInstance.fitView();
 };
 
 const initialElements = [
-  { id: '1', type: 'input', data: { label: <>Welcome to <strong>React Flow!</strong></> }, position: { x: 250, y: 0 } },
-  { id: '2', data: { label: <>This is a <strong>default node</strong></> }, position: { x: 100, y: 100 } },
   {
-    id: '3', data: { label: <>This one has a <strong>custom style</strong></> }, position: { x: 400, y: 100 },
+    id: '1',
+    type: 'input',
+    data: {
+      label: (
+        <>
+          Welcome to <strong>React Flow!</strong>
+        </>
+      ),
+    },
+    position: { x: 250, y: 0 },
+  },
+  {
+    id: '2',
+    data: {
+      label: (
+        <>
+          This is a <strong>default node</strong>
+        </>
+      ),
+    },
+    position: { x: 100, y: 100 },
+  },
+  {
+    id: '3',
+    data: {
+      label: (
+        <>
+          This one has a <strong>custom style</strong>
+        </>
+      ),
+    },
+    position: { x: 400, y: 100 },
     style: { background: '#eee', color: '#222', border: '1px solid #bbb', width: 180 },
   },
   {
-    id: '4', position: { x: 250, y: 200 },
-    data: { label: <>You can find the docs on <a href="https://github.com/wbkd/react-flow" target="_blank" rel="noopener noreferrer">Github</a></> }
+    id: '4',
+    position: { x: 250, y: 200 },
+    data: {
+      label: (
+        <>
+          You can find the docs on{' '}
+          <a href="https://github.com/wbkd/react-flow" target="_blank" rel="noopener noreferrer">
+            Github
+          </a>
+        </>
+      ),
+    },
+  },
+  {
+    id: '5',
+    data: {
+      label: (
+        <>
+          Or check out the other <strong>examples</strong>
+        </>
+      ),
+    },
+    position: { x: 250, y: 300 },
+  },
+  {
+    id: '6',
+    type: 'output',
+    data: {
+      label: (
+        <>
+          An <strong>output node</strong>
+        </>
+      ),
+    },
+    position: { x: 100, y: 480 },
   },
-  { id: '5', data: { label: <>Or check out the other <strong>examples</strong></> }, position: { x: 250, y: 300 } },
-  { id: '6', type: 'output', data: { label: <>An <strong>output node</strong></> }, position: { x: 100, y: 450 } },
   { id: '7', type: 'output', data: { label: 'Another output node' }, position: { x: 400, y: 450 } },
   { id: 'e1-2', source: '1', target: '2', label: 'this is an edge label' },
   { id: 'e1-3', source: '1', target: '3' },
   { id: 'e3-4', source: '3', target: '4', animated: true, label: 'animated edge' },
-  { id: 'e4-5', source: '4', target: '5', },
-  { id: 'e5-6', source: '5', target: '6', },
-  { id: 'e5-7', source: '5', target: '7', type: 'step', label: 'a step edge', labelStyle: { fill: 'red', fontWeight: 700 } },
+  { id: 'e4-5', source: '4', target: '5' },
+  { id: 'e5-6', source: '5', target: '6', type: 'smoothstep', label: 'smooth step edge' },
+  {
+    id: 'e5-7',
+    source: '5',
+    target: '7',
+    type: 'step',
+    label: 'a step edge',
+    labelStyle: { fill: 'red', fontWeight: 700 },
+  },
 ];
 
 const OverviewFlow = () => {
   const [elements, setElements] = useState(initialElements);
 
   const addRandomNode = () => {
-    setElements(els => els.concat({
-      id: (els.length + 1).toString(),
-      data: { label: 'Added node' },
-      position: { x: Math.random() * window.innerWidth, y: Math.random() * window.innerHeight }
-    }));
+    setElements((els) =>
+      els.concat({
+        id: (els.length + 1).toString(),
+        data: { label: 'Added node' },
+        position: { x: Math.random() * window.innerWidth, y: Math.random() * window.innerHeight },
+      })
+    );
   };
-  const onElementsRemove = (elementsToRemove) => setElements(els => removeElements(elementsToRemove, els));
-  const onConnect = (params) => setElements(els => addEdge(params, els));
+  const onElementsRemove = (elementsToRemove) => setElements((els) => removeElements(elementsToRemove, els));
+  const onConnect = (params) => setElements((els) => addEdge(params, els));
 
   return (
     <ReactFlow
@@ -63,7 +132,7 @@ const OverviewFlow = () => {
       snapGrid={[16, 16]}
     >
       <MiniMap
-        nodeColor={n => {
+        nodeColor={(n) => {
           if (n.type === 'input') return 'blue';
           if (n.type === 'output') return 'green';
           if (n.type === 'default') return 'red';
@@ -72,10 +141,7 @@ const OverviewFlow = () => {
         }}
       />
       <Controls />
-      <Background
-        color="#888"
-        gap={16}
-      />
+      <Background color="#888" gap={16} />
 
       <button
         type="button"
@@ -87,6 +153,6 @@ const OverviewFlow = () => {
       </button>
     </ReactFlow>
   );
-}
+};
 
-export default OverviewFlow;
+export default OverviewFlow;

src/components/Edges/SmoothStepEdge.tsx

@@ -0,0 +1,145 @@
+import React, { memo } from 'react';
+
+import EdgeText from './EdgeText';
+import { EdgeBezierProps, Position } from '../../types';
+
+// These are some helper methods for drawing the round corners
+// The name indicates the direction of the path. "bottomLeftCorner" goes
+// from bottom to the left and "leftBottomCorner" goes from left to the bottom.
+// We have to consider the direction of the paths because of the animated lines.
+
+const bottomLeftCorner = (cornerX: number, cornerY: number, cornerSize: number): string =>
+  `L ${cornerX},${cornerY - cornerSize}Q ${cornerX},${cornerY} ${cornerX + cornerSize},${cornerY}`;
+
+const leftBottomCorner = (cornerX: number, cornerY: number, cornerSize: number): string =>
+  `L ${cornerX + cornerSize},${cornerY}Q ${cornerX},${cornerY} ${cornerX},${cornerY - cornerSize}`;
+
+const bottomRightCorner = (cornerX: number, cornerY: number, cornerSize: number): string =>
+  `L ${cornerX},${cornerY - cornerSize}Q ${cornerX},${cornerY} ${cornerX - cornerSize},${cornerY}`;
+
+const rightBottomCorner = (cornerX: number, cornerY: number, cornerSize: number): string =>
+  `L ${cornerX - cornerSize},${cornerY}Q ${cornerX},${cornerY} ${cornerX},${cornerY - cornerSize}`;
+
+const leftTopCorner = (cornerX: number, cornerY: number, cornerSize: number): string =>
+  `L ${cornerX + cornerSize},${cornerY}Q ${cornerX},${cornerY} ${cornerX},${cornerY + cornerSize}`;
+
+const topLeftCorner = (cornerX: number, cornerY: number, cornerSize: number): string =>
+  `L ${cornerX},${cornerY + cornerSize}Q ${cornerX},${cornerY} ${cornerX + cornerSize},${cornerY}`;
+
+const topRightCorner = (cornerX: number, cornerY: number, cornerSize: number): string =>
+  `L ${cornerX},${cornerY + cornerSize}Q ${cornerX},${cornerY} ${cornerX - cornerSize},${cornerY}`;
+
+const rightTopCorner = (cornerX: number, cornerY: number, cornerSize: number): string =>
+  `L ${cornerX - cornerSize},${cornerY}Q ${cornerX},${cornerY} ${cornerX},${cornerY + cornerSize}`;
+
+export default memo(
+  ({
+    sourceX,
+    sourceY,
+    targetX,
+    targetY,
+    label,
+    labelStyle,
+    labelShowBg,
+    labelBgStyle,
+    style,
+    sourcePosition = Position.Bottom,
+    targetPosition = Position.Top,
+  }: EdgeBezierProps) => {
+    const yOffset = Math.abs(targetY - sourceY) / 2;
+    const centerY = targetY < sourceY ? targetY + yOffset : targetY - yOffset;
+
+    const xOffset = Math.abs(targetX - sourceX) / 2;
+    const centerX = targetX < sourceX ? targetX + xOffset : targetX - xOffset;
+
+    const cornerWidth = Math.min(5, Math.abs(targetX - sourceX));
+    const cornerHeight = Math.min(5, Math.abs(targetY - sourceY));
+    const cornerSize = Math.min(cornerWidth, cornerHeight, xOffset, yOffset);
+
+    const leftAndRight = [Position.Left, Position.Right];
+
+    let path;
+    let firstCornerPath = null;
+    let secondCornerPath = null;
+
+    // default case: source and target positions are top or bottom
+    if (sourceX < targetX) {
+      firstCornerPath =
+        sourceY < targetY
+          ? bottomLeftCorner(sourceX, centerY, cornerSize)
+          : topLeftCorner(sourceX, centerY, cornerSize);
+      secondCornerPath =
+        sourceY < targetY
+          ? rightTopCorner(targetX, centerY, cornerSize)
+          : rightBottomCorner(targetX, centerY, cornerSize);
+    } else if (sourceX > targetX) {
+      firstCornerPath =
+        sourceY < targetY
+          ? bottomRightCorner(sourceX, centerY, cornerSize)
+          : topRightCorner(sourceX, centerY, cornerSize);
+      secondCornerPath =
+        sourceY < targetY
+          ? leftTopCorner(targetX, centerY, cornerSize)
+          : leftBottomCorner(targetX, centerY, cornerSize);
+    }
+
+    if (leftAndRight.includes(sourcePosition) && leftAndRight.includes(targetPosition)) {
+      if (sourceX < targetX) {
+        firstCornerPath =
+          sourceY < targetY
+            ? rightTopCorner(centerX, sourceY, cornerSize)
+            : rightBottomCorner(centerX, sourceY, cornerSize);
+        secondCornerPath =
+          sourceY < targetY
+            ? bottomLeftCorner(centerX, targetY, cornerSize)
+            : topLeftCorner(centerX, targetY, cornerSize);
+      }
+    } else if (leftAndRight.includes(sourcePosition) && !leftAndRight.includes(targetPosition)) {
+      if (sourceX < targetX) {
+        firstCornerPath =
+          sourceY < targetY
+            ? rightTopCorner(targetX, sourceY, cornerSize)
+            : rightBottomCorner(targetX, sourceY, cornerSize);
+      } else if (sourceX > targetX) {
+        firstCornerPath =
+          sourceY < targetY
+            ? bottomRightCorner(sourceX, targetY, cornerSize)
+            : topRightCorner(sourceX, targetY, cornerSize);
+      }
+      secondCornerPath = '';
+    } else if (!leftAndRight.includes(sourcePosition) && leftAndRight.includes(targetPosition)) {
+      if (sourceX < targetX) {
+        firstCornerPath =
+          sourceY < targetY
+            ? bottomLeftCorner(sourceX, targetY, cornerSize)
+            : topLeftCorner(sourceX, targetY, cornerSize);
+      } else if (sourceX > targetX) {
+        firstCornerPath =
+          sourceY < targetY
+            ? bottomRightCorner(sourceX, targetY, cornerSize)
+            : topRightCorner(sourceX, targetY, cornerSize);
+      }
+      secondCornerPath = '';
+    }
+
+    path = `M ${sourceX},${sourceY}${firstCornerPath}${secondCornerPath}L ${targetX},${targetY}`;
+
+    const text = label ? (
+      <EdgeText
+        x={centerX}
+        y={centerY}
+        label={label}
+        labelStyle={labelStyle}
+        labelShowBg={labelShowBg}
+        labelBgStyle={labelBgStyle}
+      />
+    ) : null;
+
+    return (
+      <>
+        <path style={style} className="react-flow__edge-path" d={path} />
+        {text}
+      </>
+    );
+  }
+);

src/container/EdgeRenderer/utils.ts

@@ -3,6 +3,7 @@ import { ComponentType } from 'react';
 import StraightEdge from '../../components/Edges/StraightEdge';
 import BezierEdge from '../../components/Edges/BezierEdge';
 import StepEdge from '../../components/Edges/StepEdge';
+import SmoothStepEdge from '../../components/Edges/SmoothStepEdge';
 import wrapEdge from '../../components/Edges/wrapEdge';
 
 import { EdgeTypesType, EdgeCompProps } from '../../types';
@@ -12,6 +13,7 @@ export function createEdgeTypes(edgeTypes: EdgeTypesType): EdgeTypesType {
     default: wrapEdge((edgeTypes.default || BezierEdge) as ComponentType<EdgeCompProps>),
     straight: wrapEdge((edgeTypes.bezier || StraightEdge) as ComponentType<EdgeCompProps>),
     step: wrapEdge((edgeTypes.step || StepEdge) as ComponentType<EdgeCompProps>),
+    smoothstep: wrapEdge((edgeTypes.step || SmoothStepEdge) as ComponentType<EdgeCompProps>),
   };
 
   const wrappedTypes = {} as EdgeTypesType;

src/container/ReactFlow/index.tsx

@@ -17,6 +17,7 @@ import SelectionListener from '../../components/SelectionListener';
 import BezierEdge from '../../components/Edges/BezierEdge';
 import StraightEdge from '../../components/Edges/StraightEdge';
 import StepEdge from '../../components/Edges/StepEdge';
+import SmoothStepEdge from '../../components/Edges/SmoothStepEdge';
 import { createEdgeTypes } from '../EdgeRenderer/utils';
 import Wrapper from './Wrapper';
 import {
@@ -135,6 +136,7 @@ ReactFlow.defaultProps = {
     default: BezierEdge,
     straight: StraightEdge,
     step: StepEdge,
+    smoothstep: SmoothStepEdge,
   },
   connectionLineType: ConnectionLineType.Bezier,
   deleteKeyCode: 8,