ui: Add area selections to permalinks

Note: This CL breaks compatibility with older versions of the UI when
permalinks are created containing area selections.

This is not as disruptive as it used to be since Primiano's explicit
deserialization change - i.e. the trace can still be loaded but none of
the permalink data will be restored.

Change-Id: I880eb3a8c052fefc5d394e916dcad817ff9c1eb4

ui/src/core/load_trace.ts

@@ -288,6 +288,8 @@ async function loadTraceIntoEngine(
     }
   }
 
+  await trace.plugins.onTraceReady();
+
   if (serializedAppState !== undefined) {
     // Wait that plugins have completed their actions and then proceed with
     // the final phase of app state restore.
@@ -296,8 +298,6 @@ async function loadTraceIntoEngine(
     deserializeAppStatePhase2(serializedAppState, trace);
   }
 
-  await trace.plugins.onTraceReady();
-
   return trace;
 }
 

ui/src/core/state_serialization.ts

@@ -83,6 +83,13 @@ export function serializeAppState(trace: TraceImpl): SerializedAppState {
       trackKey: stateSel.trackUri,
       eventId: stateSel.eventId.toString(),
     });
+  } else if (stateSel.kind === 'area') {
+    selection.push({
+      kind: 'AREA',
+      trackUris: stateSel.trackUris,
+      start: stateSel.start,
+      end: stateSel.end,
+    });
   }
 
   const plugins = new Array<SerializedPluginState>();
@@ -202,6 +209,12 @@ export function deserializeAppStatePhase2(
       case 'TRACK_EVENT':
         selMgr.selectTrackEvent(sel.trackKey, parseInt(sel.eventId));
         break;
+      case 'AREA':
+        selMgr.selectArea({
+          start: sel.start,
+          end: sel.end,
+          trackUris: sel.trackUris,
+        });
     }
   }
 }

ui/src/public/state_serialization_schema.ts

@@ -35,6 +35,12 @@ const SELECTION_SCHEMA = z.discriminatedUnion('kind', [
     trackKey: z.string(),
     eventId: z.string(),
   }),
+  z.object({
+    kind: z.literal('AREA'),
+    start: zTime,
+    end: zTime,
+    trackUris: z.array(z.string()),
+  }),
 ]);
 
 export type SerializedSelection = z.infer<typeof SELECTION_SCHEMA>;