ui: decontrollify Flows

- Move logic as-is to FlowManager.
- Remove FlowEventsPanel, nobody was using it after killing TabsV1
- clean up some plumbing from globals -> Trace

Change-Id: I8202079c59052f444833fa9392b1ad3d8f30c260

ui/src/common/actions.ts

@@ -281,14 +281,6 @@ export const StateActions = {
     state.highlightedSliceId = args.sliceId;
   },
 
-  setHighlightedFlowLeftId(state: StateDraft, args: {flowId: number}) {
-    state.focusedFlowIdLeft = args.flowId;
-  },
-
-  setHighlightedFlowRightId(state: StateDraft, args: {flowId: number}) {
-    state.focusedFlowIdRight = args.flowId;
-  },
-
   setHoverCursorTimestamp(state: StateDraft, args: {ts: time}) {
     state.hoverCursorTimestamp = args.ts;
   },

ui/src/common/empty_state.ts

@@ -66,8 +66,6 @@ export function createEmptyState(): State {
     hoverCursorTimestamp: Time.INVALID,
     hoveredNoteTimestamp: Time.INVALID,
     highlightedSliceId: -1,
-    focusedFlowIdLeft: -1,
-    focusedFlowIdRight: -1,
 
     recordingInProgress: false,
     recordingCancelled: false,

ui/src/common/state.ts

@@ -205,8 +205,6 @@ export interface State {
   hoverCursorTimestamp: time;
   hoveredNoteTimestamp: time;
   highlightedSliceId: number;
-  focusedFlowIdLeft: number;
-  focusedFlowIdRight: number;
 
   /**
    * Trace recording

ui/src/controller/trace_controller.ts

@@ -51,10 +51,6 @@ import {
 } from '../trace_processor/wasm_engine_proxy';
 import {showModal} from '../widgets/modal';
 import {Child, Children, Controller} from './controller';
-import {
-  FlowEventsController,
-  FlowEventsControllerArgs,
-} from './flow_events_controller';
 import {LoadingManager} from './loading_manager';
 import {TraceErrorController} from './trace_error_controller';
 import {
@@ -235,11 +231,6 @@ export class TraceController extends Controller<States> {
         const engine = assertExists(this.engine);
         const childControllers: Children = [];
 
-        const flowEventsArgs: FlowEventsControllerArgs = {engine};
-        childControllers.push(
-          Child('flowEvents', FlowEventsController, flowEventsArgs),
-        );
-
         childControllers.push(
           Child('traceError', TraceErrorController, {engine}),
         );

ui/src/core/app_trace_impl.ts

@@ -40,6 +40,7 @@ import {Selection, SelectionOpts} from '../public/selection';
 import {SearchResult} from '../public/search';
 import {raf} from './raf_scheduler';
 import {PivotTableManager} from './pivot_table_manager';
+import {FlowManager} from './flow_manager';
 
 // The pseudo plugin id used for the core instance of AppImpl.
 export const CORE_PLUGIN_ID = '__core__';
@@ -178,6 +179,7 @@ class TraceContext implements Disposable {
   readonly trackMgr = new TrackManagerImpl();
   readonly workspaceMgr = new WorkspaceManagerImpl();
   readonly noteMgr = new NoteManagerImpl();
+  readonly flowMgr: FlowManager;
   readonly pluginSerializableState = createStore<{[key: string]: {}}>({});
   readonly scrollHelper: ScrollHelper;
   readonly pivotTableMgr;
@@ -218,6 +220,13 @@ class TraceContext implements Disposable {
       engine.getProxy('PivotTableManager'),
     );
 
+    this.flowMgr = new FlowManager(
+      engine.getProxy('FlowManager'),
+      this.trackMgr,
+      this.selectionMgr,
+      () => this.workspaceMgr.currentWorkspace,
+    );
+
     this.searchMgr = new SearchManagerImpl({
       timeline: this.timeline,
       trackManager: this.trackMgr,
@@ -243,6 +252,8 @@ class TraceContext implements Disposable {
       this.pivotTableMgr.setSelectionArea(selection);
     }
 
+    this.flowMgr.updateFlows(selection);
+
     // TODO(primiano): this is temporarily necessary until we kill
     // controllers. The flow controller needs to be re-kicked when we change
     // the selection.
@@ -391,6 +402,10 @@ export class TraceImpl implements Trace {
     return this.traceCtx.pivotTableMgr;
   }
 
+  get flows() {
+    return this.traceCtx.flowMgr;
+  }
+
   // App interface implementation.
 
   get pluginId(): string {