Add existing to tracked

node_modules/@cesium/widgets/Source/Timeline/TimelineTrack.js

@@ -0,0 +1,74 @@
+import { Color, defined, JulianDate } from "@cesium/engine";
+
+/**
+ * @private
+ */
+function TimelineTrack(interval, pixelHeight, color, backgroundColor) {
+  this.interval = interval;
+  this.height = pixelHeight;
+  this.color = color || new Color(0.5, 0.5, 0.5, 1.0);
+  this.backgroundColor = backgroundColor || new Color(0.0, 0.0, 0.0, 0.0);
+}
+
+TimelineTrack.prototype.render = function (context, renderState) {
+  const startInterval = this.interval.start;
+  const stopInterval = this.interval.stop;
+
+  const spanStart = renderState.startJulian;
+  const spanStop = JulianDate.addSeconds(
+    renderState.startJulian,
+    renderState.duration,
+    new JulianDate(),
+  );
+
+  if (
+    JulianDate.lessThan(startInterval, spanStart) &&
+    JulianDate.greaterThan(stopInterval, spanStop)
+  ) {
+    //The track takes up the entire visible span.
+    context.fillStyle = this.color.toCssColorString();
+    context.fillRect(0, renderState.y, renderState.timeBarWidth, this.height);
+  } else if (
+    JulianDate.lessThanOrEquals(startInterval, spanStop) &&
+    JulianDate.greaterThanOrEquals(stopInterval, spanStart)
+  ) {
+    //The track only takes up some of the visible span, compute that span.
+    let x;
+    let start, stop;
+    for (x = 0; x < renderState.timeBarWidth; ++x) {
+      const currentTime = JulianDate.addSeconds(
+        renderState.startJulian,
+        (x / renderState.timeBarWidth) * renderState.duration,
+        new JulianDate(),
+      );
+      if (
+        !defined(start) &&
+        JulianDate.greaterThanOrEquals(currentTime, startInterval)
+      ) {
+        start = x;
+      } else if (
+        !defined(stop) &&
+        JulianDate.greaterThanOrEquals(currentTime, stopInterval)
+      ) {
+        stop = x;
+      }
+    }
+
+    context.fillStyle = this.backgroundColor.toCssColorString();
+    context.fillRect(0, renderState.y, renderState.timeBarWidth, this.height);
+
+    if (defined(start)) {
+      if (!defined(stop)) {
+        stop = renderState.timeBarWidth;
+      }
+      context.fillStyle = this.color.toCssColorString();
+      context.fillRect(
+        start,
+        renderState.y,
+        Math.max(stop - start, 1),
+        this.height,
+      );
+    }
+  }
+};
+export default TimelineTrack;