add useClockOffsets composable

documentation update to useTimeBounds

src/plugins/timeConductor/useClockOffsets.js

@@ -0,0 +1,59 @@
+/*****************************************************************************
+ * Open MCT Web, Copyright (c) 2014-2024, United States Government
+ * as represented by the Administrator of the National Aeronautics and Space
+ * Administration. All rights reserved.
+ *
+ * Open MCT Web is licensed under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * http://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * Open MCT Web includes source code licensed under additional open source
+ * licenses. See the Open Source Licenses file (LICENSES.md) included with
+ * this source code distribution or the Licensing information page available
+ * at runtime from the About dialog for additional information.
+ *****************************************************************************/
+
+import { onBeforeUnmount, shallowRef } from 'vue';
+
+import { TIME_CONTEXT_EVENTS } from '../../api/time/constants.js';
+
+/**
+ * Provides reactive `offsets`,
+ * as well as a function to observe and update offsets changes,
+ * which automatically stops observing when the component is unmounted.
+ *
+ * @param {OpenMCT} openmct the Open MCT API
+ * @returns {{
+ *   observeClockOffsets: () => void,
+ *   offsets: import('vue').Ref<object>,
+ * }}
+ */
+export function useClockOffsets(openmct, options) {
+  let stopObservingClockOffsets;
+
+  const offsets = shallowRef(openmct.time.getClockOffsets());
+
+  onBeforeUnmount(() => stopObservingClockOffsets?.());
+
+  function observeClockOffsets() {
+    openmct.time.on(TIME_CONTEXT_EVENTS.clockOffsetsChanged, updateClockOffsets);
+    stopObservingClockOffsets = () =>
+      openmct.time.off(TIME_CONTEXT_EVENTS.clockOffsetsChanged, updateClockOffsets);
+  }
+
+  function updateClockOffsets(_offsets) {
+    offsets.value = _offsets;
+  }
+
+  return {
+    observeClockOffsets,
+    offsets
+  };
+}

src/plugins/timeConductor/useTimeBounds.js

@@ -26,8 +26,8 @@ import { TIME_CONTEXT_EVENTS } from '../../api/time/constants.js';
 import throttle from '../../utils/throttle.js';
 
 /**
- * Provides reactive `bounds` and `offsets`,
- * as well as a function to observe when bounds and update the component's time mode,
+ * Provides reactive `bounds`,
+ * as well as a function to observe and update bounds changes,
  * which automatically stops observing when the component is unmounted.
  *
  * @param {OpenMCT} openmct the Open MCT API