From 1a3aaac5b3d1f1af7ac2d72df89ec529ca22a133 Mon Sep 17 00:00:00 2001
From: Colin Dawson <me@cjdawson.com>
Date: Fri, 13 Mar 2026 00:55:21 +0000
Subject: [PATCH] The visualiser now has on hover highlighting

---
 src/Sass/visualiser.scss                      |  42 +++++++
 .../components/VisualisetTab.tsx              | 104 ++++++++++++++----
 2 files changed, 127 insertions(+), 19 deletions(-)

diff --git a/src/Sass/visualiser.scss b/src/Sass/visualiser.scss
index 2528f67..4bcdd0e 100644
--- a/src/Sass/visualiser.scss
+++ b/src/Sass/visualiser.scss
@@ -46,6 +46,23 @@
   text-align: center;
   letter-spacing: 0.2px;
   box-shadow: 0 6px 14px rgba($blue, 0.2);
+  transition:
+    opacity 0.16s ease,
+    transform 0.16s ease,
+    box-shadow 0.16s ease;
+}
+
+.visualiser-node.is-hovered {
+  transform: translateY(-1px);
+  box-shadow: 0 10px 22px rgba($blue, 0.33);
+}
+
+.visualiser-node.is-related {
+  box-shadow: 0 8px 18px rgba($blue, 0.27);
+}
+
+.visualiser-node.is-dim {
+  opacity: 0.45;
 }
 
 .visualiser-node-content {
@@ -160,6 +177,10 @@
   stroke-width: 2px;
   stroke-dasharray: 4, 4;
   vector-effect: non-scaling-stroke;
+  transition:
+    opacity 0.16s ease,
+    stroke-width 0.16s ease,
+    stroke 0.16s ease;
 }
 
 .visualiser-outcome-connector-arrow {
@@ -176,6 +197,27 @@
   stroke-linecap: round;
   stroke-linejoin: round;
   user-select: none;
+  transition:
+    opacity 0.16s ease,
+    fill 0.16s ease;
+}
+
+.visualiser-outcome-connector-line.is-active {
+  stroke-width: 2.6px;
+  stroke: rgba($blue, 0.75);
+  stroke-dasharray: 0;
+}
+
+.visualiser-outcome-connector-line.is-dim {
+  opacity: 0.2;
+}
+
+.visualiser-outcome-connector-label.is-active {
+  fill: darken($blue, 8%);
+}
+
+.visualiser-outcome-connector-label.is-dim {
+  opacity: 0.25;
 }
 
 @include color-mode(dark) {
diff --git a/src/modules/manager/workflowTemplates/components/VisualisetTab.tsx b/src/modules/manager/workflowTemplates/components/VisualisetTab.tsx
index 4e55789..ad09638 100644
--- a/src/modules/manager/workflowTemplates/components/VisualisetTab.tsx
+++ b/src/modules/manager/workflowTemplates/components/VisualisetTab.tsx
@@ -295,6 +295,7 @@ const VisualiserTab: React.FC<VisualiserTabProps> = ({
   }, []);
   const levels = React.useMemo(() => buildLevels(tasks), [tasks]);
   const edges = React.useMemo(() => buildEdges(tasks), [tasks]);
+  const [hoveredGuid, setHoveredGuid] = React.useState<string | null>(null);
   const levelByGuid = React.useMemo(() => {
     const levelMap = new Map<string, number>();
     levels.forEach((level, levelIndex) => {
@@ -408,6 +409,31 @@ const VisualiserTab: React.FC<VisualiserTabProps> = ({
 
     return sharedLaneByTarget;
   }, [edges, levelByGuid, edgeLaneOffsetByKey, nodePositions]);
+  const connectedByGuid = React.useMemo(() => {
+    const map = new Map<string, Set<string>>();
+
+    tasks.forEach((task) => {
+      map.set(task.config.guid as string, new Set<string>());
+    });
+
+    edges.forEach((edge) => {
+      const source = map.get(edge.sourceGuid) ?? new Set<string>();
+      source.add(edge.targetGuid);
+      map.set(edge.sourceGuid, source);
+
+      const target = map.get(edge.targetGuid) ?? new Set<string>();
+      target.add(edge.sourceGuid);
+      map.set(edge.targetGuid, target);
+    });
+
+    return map;
+  }, [tasks, edges]);
+  const relatedGuids = React.useMemo(() => {
+    if (!hoveredGuid) {
+      return new Set<string>();
+    }
+    return connectedByGuid.get(hoveredGuid) ?? new Set<string>();
+  }, [hoveredGuid, connectedByGuid]);
 
   React.useEffect(() => {
     const measurePositions = () => {
@@ -470,6 +496,22 @@ const VisualiserTab: React.FC<VisualiserTabProps> = ({
     };
   }, [levels]);
 
+  const labelCollisionState = new Map<string, number[]>();
+  const getAdjustedLabelY = (x: number, preferredY: number): number => {
+    const bucket = Math.round(x / 8).toString();
+    const used = labelCollisionState.get(bucket) ?? [];
+
+    let y = preferredY;
+    const minGap = 2.1;
+    while (used.some((existingY) => Math.abs(existingY - y) < minGap)) {
+      y += minGap;
+    }
+
+    used.push(y);
+    labelCollisionState.set(bucket, used);
+    return y;
+  };
+
   return (
     <div className="visualiser-root">
       <div className="visualiser-container" ref={visualiserContainerRef}>
@@ -483,22 +525,31 @@ const VisualiserTab: React.FC<VisualiserTabProps> = ({
                   gap: "40px",
                 }}
               >
-                {level.map((task) => (
-                  <div
-                    key={task.config.guid as string}
-                    className="visualiser-node"
-                    data-guid={task.config.guid as string}
-                  >
-                    <div className="visualiser-node-content">
-                      <ValidationErrorIcon
-                        visible={
-                          taskValidation[task.config.guid as string] === false
-                        }
-                      />
-                      <span>{(task.config.name as string) || task.type}</span>
+                {level.map((task) => {
+                  const guid = task.config.guid as string;
+                  const isHovered = hoveredGuid === guid;
+                  const isRelated =
+                    hoveredGuid !== null && relatedGuids.has(guid);
+                  const isDim =
+                    hoveredGuid !== null && !isHovered && !isRelated;
+
+                  return (
+                    <div
+                      key={guid}
+                      className={`visualiser-node${isHovered ? " is-hovered" : ""}${isRelated ? " is-related" : ""}${isDim ? " is-dim" : ""}`}
+                      data-guid={guid}
+                      onMouseEnter={() => setHoveredGuid(guid)}
+                      onMouseLeave={() => setHoveredGuid(null)}
+                    >
+                      <div className="visualiser-node-content">
+                        <ValidationErrorIcon
+                          visible={taskValidation[guid] === false}
+                        />
+                        <span>{(task.config.name as string) || task.type}</span>
+                      </div>
                     </div>
-                  </div>
-                ))}
+                  );
+                })}
               </div>
             </div>
           ))}
@@ -643,11 +694,17 @@ const VisualiserTab: React.FC<VisualiserTabProps> = ({
                 return tEnum(matchedOutcome ?? outcome);
               })
               .join(", ");
+            const edgeIsActive =
+              hoveredGuid !== null &&
+              (edge.sourceGuid === hoveredGuid ||
+                edge.targetGuid === hoveredGuid);
+            const edgeIsDim = hoveredGuid !== null && !edgeIsActive;
+            const adjustedLabelY = getAdjustedLabelY(labelX, labelY - 1.25);
 
             return (
               <g key={`${edge.sourceGuid}-${edge.targetGuid}`}>
                 <path
-                  className="visualiser-outcome-connector-line"
+                  className={`visualiser-outcome-connector-line${edgeIsActive ? " is-active" : ""}${edgeIsDim ? " is-dim" : ""}`}
                   d={path}
                   markerEnd={
                     isMergedLeft ? undefined : "url(#visualiser-arrow)"
@@ -656,8 +713,8 @@ const VisualiserTab: React.FC<VisualiserTabProps> = ({
                 {label && (
                   <text
                     x={labelX}
-                    y={labelY - 1.25}
-                    className="visualiser-outcome-connector-label"
+                    y={adjustedLabelY}
+                    className={`visualiser-outcome-connector-label${edgeIsActive ? " is-active" : ""}${edgeIsDim ? " is-dim" : ""}`}
                     textAnchor={labelAnchor}
                     dominantBaseline="middle"
                   >
@@ -676,11 +733,20 @@ const VisualiserTab: React.FC<VisualiserTabProps> = ({
 
               const endX = target.x - target.width / 2;
               const endY = target.y;
+              const mergedIsActive =
+                hoveredGuid !== null &&
+                (hoveredGuid === targetGuid ||
+                  edges.some(
+                    (edge) =>
+                      edge.targetGuid === targetGuid &&
+                      edge.sourceGuid === hoveredGuid,
+                  ));
+              const mergedIsDim = hoveredGuid !== null && !mergedIsActive;
 
               return (
                 <path
                   key={`merged-left-${targetGuid}`}
-                  className="visualiser-outcome-connector-line"
+                  className={`visualiser-outcome-connector-line${mergedIsActive ? " is-active" : ""}${mergedIsDim ? " is-dim" : ""}`}
                   d={`M ${laneX} ${endY} L ${endX} ${endY}`}
                   markerEnd="url(#visualiser-arrow)"
                 />