Keep fire and camera selections bound to their source records

src/app/constructCatalog.js

@@ -219,7 +219,7 @@ export function createApplicationCatalog({
       ],
       [
         'alpr-cameras',
-        () => createApplicationAlpr({ surface, source: sources.alpr }),
+        () => sessionModel('alpr-cameras', () => createApplicationAlpr({ surface, source: sources.alpr })),
       ],
       [
         'street-level',
@@ -326,14 +326,14 @@ export function createApplicationCatalog({
       [
         'local-firms',
         () =>
-          createApplicationFirms({
+          sessionModel('local-firms', () => createApplicationFirms({
             surface,
             id: 'local-firms',
             name: 'FIRMS Active Fires',
             icon: '▲',
             source: 'NASA FIRMS · LIVE',
             feed: sources.firms,
-          }),
+          })),
       ],
     ];
     const available = (id) => availability.isAvailable(id);

src/layers/alpr/index.js

@@ -68,6 +68,7 @@ export function createAlprCamerasLayer({
     renderSaturated: false,
   };
   let renderer = null;
+  let restoringView = false;
 
   function setAlprStatus(status, error = null) {
     if (state.status === status && state.error === error) return;
@@ -112,7 +113,7 @@ export function createAlprCamerasLayer({
   }
 
   function scheduleLoad() {
-    if (!state.enabled) return;
+    if (!state.enabled || !renderer || restoringView) return;
     clearUnavailableRetry({ resetBackoff: false });
     clearTimeout(state.debounceTimer);
     // A view the accepted tiles already cover is a local filter: show it now.
@@ -130,7 +131,7 @@ export function createAlprCamerasLayer({
   }
 
   async function loadCameras() {
-    if (!state.enabled || !renderer?.ready) return;
+    if (!state.enabled || !renderer?.ready || restoringView) return;
     clearTimeout(state.debounceTimer);
     state.debounceTimer = null;
     clearUnavailableRetry({ resetBackoff: false });
@@ -197,14 +198,14 @@ export function createAlprCamerasLayer({
         state.lastQueryBox = null;
         state.lastQueryZoom = null;
         clearUnavailableRetry();
-        renderer.renderRecords();
+        if (!restoringView) renderer?.renderRecords();
         setAlprStatus('zoom-in');
         return;
       }
       const { records, stale, saturated } = validateAlprSnapshot(snapshot);
       // Resolve marker floors (bounded wait, warm cells answer at once) so new
       // markers are placed on the floor instead of clamped then moved.
-      await renderer.prepareFloors(records);
+      await renderer?.prepareFloors(records);
       if (
         requestAbort.signal.aborted ||
         state.abort !== requestAbort ||
@@ -230,8 +231,8 @@ export function createAlprCamerasLayer({
       clearUnavailableRetry();
       // Stale and saturated are independent facts; a cached response that also
       // hit the cap must still warn about coverage, not just about freshness.
-      renderer.renderRecords();
-      setAlprStatus(renderer.count() ? (stale ? 'stale' : 'ready') : 'empty');
+      if (!restoringView) renderer?.renderRecords();
+      setAlprStatus((renderer?.count() ?? records.length) ? (stale ? 'stale' : 'ready') : 'empty');
     } catch (error) {
       if (
         error?.name === 'AbortError' ||
@@ -265,7 +266,11 @@ export function createAlprCamerasLayer({
     source: source.label || msg('Mapped camera locations'),
     updateInterval: 0,
     statsRefreshInterval: 1000,
-    init(viewer, options = {}) {
+    init(viewer, options) {
+      this.attachRenderer(viewer, options);
+    },
+    attachRenderer(viewer, options = {}) {
+      restoringView = Boolean(options.waitForCameraRestore);
       if (renderer?.ready) throw new Error('ALPR layer is already initialized');
       if (typeof rendererFactory !== 'function')
         throw new TypeError('An ALPR renderer factory is required');
@@ -276,6 +281,24 @@ export function createAlprCamerasLayer({
         engine: options.engine,
       });
       renderer.init(viewer, { onMove: scheduleLoad });
+      if (state.enabled) {
+        renderer.setVisible(true);
+        if (!restoringView) renderer.renderRecords();
+      }
+    },
+    detachRenderer() {
+      restoringView = true;
+      clearTimeout(state.debounceTimer);
+      renderer?.destroy({ retainContext: true });
+      renderer = null;
+    },
+    resumeViewport() {
+      if (!restoringView) return;
+      restoringView = false;
+      if (state.enabled && renderer) {
+        renderer.renderRecords();
+        if (!state.loading) scheduleLoad();
+      }
     },
     enable() {
       if (state.enabled) return;

src/layers/alpr/render/cesium.js

@@ -44,7 +44,7 @@ export function createAlprCesiumRenderer({ state, services, source }) {
       if (visible) native.creditPresented = false;
       if (native.dataSource) native.dataSource.show = visible;
     },
-    destroy() {
+    destroy(options) {
       presentation.destroyOverlay();
       removeMove?.();
       removeMove = null;
@@ -52,7 +52,7 @@ export function createAlprCesiumRenderer({ state, services, source }) {
       removeFrame = null;
       native.clickHandler?.destroy();
       native.clickHandler = null;
-      presentation.clearRendered();
+      presentation.clearRendered(options);
       if (native.dataSource && native.viewer)
         native.viewer.dataSources.remove(native.dataSource, true);
       native.dataSource = null;

src/layers/alpr/render/cesiumPresentation.js

@@ -304,7 +304,7 @@ export function createAlprPresentation({ state, native, services, source }) {
     return { south, west, north, east };
   }
 
-  function clearRendered() {
+  function clearRendered({ retainContext = false } = {}) {
     hideOnMapCredit();
     floors.cancel();
     floorResolve = null;
@@ -312,7 +312,7 @@ export function createAlprPresentation({ state, native, services, source }) {
     visibleRecords = [];
     clampedMarkers.clear();
     if (native.dataSource?.entities) native.dataSource.entities.removeAll();
-    removeEntityContextsForLayer(LAYER_ID);
+    if (!retainContext) removeEntityContextsForLayer(LAYER_ID);
   }
 
   function hideOnMapCredit() {

src/layers/alpr/render/navara.js

@@ -449,7 +449,7 @@ export function createAlprNavaraRenderer(engine, { state, services, source }) {
     else hideOnMapCredit();
     request();
   }
-  function clearRendered() {
+  function clearRendered({ retainContext = false } = {}) {
     hideOnMapCredit();
     generation++;
     floors.cancel();
@@ -464,7 +464,7 @@ export function createAlprNavaraRenderer(engine, { state, services, source }) {
       selected.commit();
       spritesDirty = false;
     }
-    services.context.removeEntityContextsForLayer(LAYER_ID);
+    if (!retainContext) services.context.removeEntityContextsForLayer(LAYER_ID);
   }
   function frame() {
     const camera = engine.camera.livePosition;
@@ -582,9 +582,9 @@ export function createAlprNavaraRenderer(engine, { state, services, source }) {
       request();
       return true;
     },
-    destroy() {
+    destroy(options) {
       if (!initialized) return;
-      clearRendered();
+      clearRendered(options);
       overlay.destroy();
       removeClick?.();
       removeClick = null;

src/layers/firms/lifecycle.js

@@ -12,7 +12,10 @@ export function createLifecycle({
   const { id, overlayHost } = config;
 
   const methods = {
-    init(viewer, { engine = null } = {}) {
+    init(viewer, options) {
+      this.attachRenderer(viewer, options);
+    },
+    attachRenderer(viewer, { engine = null, waitForCameraRestore = false } = {}) {
       if (layerState._destroyed) return;
       if (layerState._renderer) return;
       layerState._renderer = config.renderer.create({
@@ -25,14 +28,36 @@ export function createLifecycle({
       layerState._viewer = layerState._renderer.view;
       layerState._dataSource = layerState._renderer.dataSource;
       layerState._renderer.setVisible(false);
+      layerState._restoringViewport = waitForCameraRestore;
+      if (layerState._enabled && !waitForCameraRestore) {
+        this.showRenderer();
+        layerState._renderer.onEnable();
+      }
     },
 
-    async enable(viewer) {
-      if (layerState._destroyed) return;
-      layerState._enabled = true;
-      if (!layerState._dataSource) this.init(viewer);
-      const renderer = layerState._renderer;
-      layerState._viewer = layerState._renderer.view;
+    resumeViewport() {
+      if (!layerState._restoringViewport) return;
+      layerState._restoringViewport = false;
+      if (layerState._enabled && layerState._renderer) {
+        this.showRenderer();
+        layerState._renderer.onEnable();
+      }
+    },
+
+    detachRenderer() {
+      components.selection.removeClickHandler();
+      components.viewport.removeMoveEndWatcher();
+      components.viewport.removeLodWatcher();
+      unregisterPickOwner(id);
+      components.rendering.removeDetectionCollections(layerState._viewer);
+      layerState._renderer?.destroy();
+      layerState._renderer = layerState._viewer = layerState._dataSource = null;
+      layerState._pickIndexById.clear();
+      layerState._labelCandidates = [];
+      layerState._camSnapValid = false;
+    },
+
+    showRenderer() {
       if (layerState._billboards) {
         // The camera can have moved anywhere while the layer was off: moveEnd
         // was not being listened to, and the preRender watcher is inert while
@@ -51,14 +76,18 @@ export function createLifecycle({
       registerPickOwner(id, (pickedId) =>
         layerState._pickIndexById.has(pickedId),
       );
+      components.rendering.renderCurrentLod(true);
+    },
+
+    async enable(viewer) {
+      if (layerState._destroyed) return;
+      if (!layerState._dataSource) this.init(viewer);
+      layerState._enabled = true;
+      const renderer = layerState._renderer;
+      this.showRenderer();
       if (!layerState._fires.length && !layerState._loading)
         await components.ingestion.loadHeatmap();
-      if (
-        layerState._enabled &&
-        !layerState._destroyed &&
-        layerState._renderer === renderer
-      )
-        renderer.onEnable();
+      if (layerState._enabled && layerState._renderer === renderer) renderer.onEnable();
     },
 
     disable() {