1 files changed, 128 insertions, 0 deletions
diff --git a/devtools/client/performance-new/components/panel/ProfilerEventHandling.js b/devtools/client/performance-new/components/panel/ProfilerEventHandling.js
new file mode 100644
index 0000000000..1b415bdf19
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+++ b/devtools/client/performance-new/components/panel/ProfilerEventHandling.js
@@ -0,0 +1,128 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+// @ts-check
+
+/**
+ * @typedef {import("../../@types/perf").PerfFront} PerfFront
+ * @typedef {import("../../@types/perf").RecordingState} RecordingState
+ * @typedef {import("../../@types/perf").State} StoreState
+ * @typedef {import("../../@types/perf").RootTraits} RootTraits
+ * @typedef {import("../../@types/perf").PanelWindow} PanelWindow
+ */
+
+/**
+ * @template P
+ * @typedef {import("react-redux").ResolveThunks<P>} ResolveThunks<P>
+ */
+
+/**
+ * @typedef {Object} StateProps
+ * @property {RecordingState} recordingState
+ * @property {boolean?} isSupportedPlatform
+ */
+
+/**
+ * @typedef {Object} ThunkDispatchProps
+ * @property {typeof actions.reportProfilerReady} reportProfilerReady
+ * @property {typeof actions.reportProfilerStarted} reportProfilerStarted
+ * @property {typeof actions.reportProfilerStopped} reportProfilerStopped
+ */
+
+/**
+ * @typedef {Object} OwnProps
+ * @property {PerfFront} perfFront
+ * @property {RootTraits} traits
+ */
+
+/**
+ * @typedef {ResolveThunks<ThunkDispatchProps>} DispatchProps
+ * @typedef {StateProps & DispatchProps & OwnProps} Props
+ */
+
+"use strict";
+
+const {
+  PureComponent,
+} = require("resource://devtools/client/shared/vendor/react.js");
+const {
+  connect,
+} = require("resource://devtools/client/shared/vendor/react-redux.js");
+const actions = require("resource://devtools/client/performance-new/store/actions.js");
+const selectors = require("resource://devtools/client/performance-new/store/selectors.js");
+
+/**
+ * This component state changes for the performance recording. e.g. If the profiler
+ * suddenly becomes unavailable, it needs to react to those changes, and update the
+ * recordingState in the store.
+ *
+ * @extends {React.PureComponent<Props>}
+ */
+class ProfilerEventHandling extends PureComponent {
+  componentDidMount() {
+    const {
+      perfFront,
+      isSupportedPlatform,
+      reportProfilerReady,
+      reportProfilerStarted,
+      reportProfilerStopped,
+    } = this.props;
+
+    if (!isSupportedPlatform) {
+      return;
+    }
+
+    // Ask for the initial state of the profiler.
+    perfFront.isActive().then(isActive => reportProfilerReady(isActive));
+
+    // Handle when the profiler changes state. It might be us, it might be someone else.
+    this.props.perfFront.on("profiler-started", reportProfilerStarted);
+    this.props.perfFront.on("profiler-stopped", reportProfilerStopped);
+  }
+
+  componentWillUnmount() {
+    switch (this.props.recordingState) {
+      case "not-yet-known":
+      case "available-to-record":
+      case "request-to-stop-profiler":
+      case "request-to-get-profile-and-stop-profiler":
+        // Do nothing for these states.
+        break;
+
+      case "recording":
+      case "request-to-start-recording":
+        this.props.perfFront.stopProfilerAndDiscardProfile();
+        break;
+
+      default:
+        throw new Error("Unhandled recording state.");
+    }
+  }
+
+  render() {
+    return null;
+  }
+}
+
+/**
+ * @param {StoreState} state
+ * @returns {StateProps}
+ */
+function mapStateToProps(state) {
+  return {
+    recordingState: selectors.getRecordingState(state),
+    isSupportedPlatform: selectors.getIsSupportedPlatform(state),
+  };
+}
+
+/** @type {ThunkDispatchProps} */
+const mapDispatchToProps = {
+  reportProfilerReady: actions.reportProfilerReady,
+  reportProfilerStarted: actions.reportProfilerStarted,
+  reportProfilerStopped: actions.reportProfilerStopped,
+};
+
+module.exports = connect(
+  mapStateToProps,
+  mapDispatchToProps
+)(ProfilerEventHandling);