1 files changed, 76 insertions, 0 deletions
diff --git a/browser/components/newtab/content-src/asrouter/components/ImpressionsWrapper/ImpressionsWrapper.jsx b/browser/components/newtab/content-src/asrouter/components/ImpressionsWrapper/ImpressionsWrapper.jsx
new file mode 100644
index 0000000000..8498bde03b
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+++ b/browser/components/newtab/content-src/asrouter/components/ImpressionsWrapper/ImpressionsWrapper.jsx
@@ -0,0 +1,76 @@
+/* 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/. */
+
+import React from "react";
+
+export const VISIBLE = "visible";
+export const VISIBILITY_CHANGE_EVENT = "visibilitychange";
+
+/**
+ * Component wrapper used to send telemetry pings on every impression.
+ */
+export class ImpressionsWrapper extends React.PureComponent {
+  // This sends an event when a user sees a set of new content. If content
+  // changes while the page is hidden (i.e. preloaded or on a hidden tab),
+  // only send the event if the page becomes visible again.
+  sendImpressionOrAddListener() {
+    if (this.props.document.visibilityState === VISIBLE) {
+      this.props.sendImpression({ id: this.props.id });
+    } else {
+      // We should only ever send the latest impression stats ping, so remove any
+      // older listeners.
+      if (this._onVisibilityChange) {
+        this.props.document.removeEventListener(
+          VISIBILITY_CHANGE_EVENT,
+          this._onVisibilityChange
+        );
+      }
+
+      // When the page becomes visible, send the impression stats ping if the section isn't collapsed.
+      this._onVisibilityChange = () => {
+        if (this.props.document.visibilityState === VISIBLE) {
+          this.props.sendImpression({ id: this.props.id });
+          this.props.document.removeEventListener(
+            VISIBILITY_CHANGE_EVENT,
+            this._onVisibilityChange
+          );
+        }
+      };
+      this.props.document.addEventListener(
+        VISIBILITY_CHANGE_EVENT,
+        this._onVisibilityChange
+      );
+    }
+  }
+
+  componentWillUnmount() {
+    if (this._onVisibilityChange) {
+      this.props.document.removeEventListener(
+        VISIBILITY_CHANGE_EVENT,
+        this._onVisibilityChange
+      );
+    }
+  }
+
+  componentDidMount() {
+    if (this.props.sendOnMount) {
+      this.sendImpressionOrAddListener();
+    }
+  }
+
+  componentDidUpdate(prevProps) {
+    if (this.props.shouldSendImpressionOnUpdate(this.props, prevProps)) {
+      this.sendImpressionOrAddListener();
+    }
+  }
+
+  render() {
+    return this.props.children;
+  }
+}
+
+ImpressionsWrapper.defaultProps = {
+  document: global.document,
+  sendOnMount: true,
+};