From a9924e1c32e8445887e3a6b5cdff445d93c2b18f Mon Sep 17 00:00:00 2001
From: Jeremy Rose <jeremya@chromium.org>
Date: Mon, 16 Nov 2020 16:31:46 -0800
Subject: [PATCH] feat: add powerMonitor.onBatteryPower (#26494)

---
 docs/api/power-monitor.md                       | 15 +++++++++++++++
 lib/browser/api/power-monitor.ts                | 11 ++++++++++-
 shell/browser/api/electron_api_power_monitor.cc |  5 +++++
 spec-main/api-power-monitor-spec.ts             |  9 ++++++++-
 4 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/docs/api/power-monitor.md b/docs/api/power-monitor.md
index 1bfceaf3984..0f5e5b53ac7 100644
--- a/docs/api/power-monitor.md
+++ b/docs/api/power-monitor.md
@@ -65,3 +65,18 @@ before considered idle.  `locked` is available on supported systems only.
 Returns `Integer` - Idle time in seconds
 
 Calculate system idle time in seconds.
+
+### `powerMonitor.isOnBatteryPower()`
+
+Returns `Boolean` - Whether the system is on battery power.
+
+To monitor for changes in this property, use the `on-battery` and `on-ac`
+events.
+
+## Properties
+
+### `powerMonitor.onBatteryPower`
+
+A `Boolean` property. True if the system is on battery power.
+
+See [`powerMonitor.isOnBatteryPower()`](#powermonitorisonbatterypower).
diff --git a/lib/browser/api/power-monitor.ts b/lib/browser/api/power-monitor.ts
index d07e773f32f..02fdde2ed56 100644
--- a/lib/browser/api/power-monitor.ts
+++ b/lib/browser/api/power-monitor.ts
@@ -4,7 +4,8 @@ import { app } from 'electron/main';
 const {
   createPowerMonitor,
   getSystemIdleState,
-  getSystemIdleTime
+  getSystemIdleTime,
+  isOnBatteryPower
 } = process._linkedBinding('electron_browser_power_monitor');
 
 class PowerMonitor extends EventEmitter {
@@ -45,6 +46,14 @@ class PowerMonitor extends EventEmitter {
   getSystemIdleTime () {
     return getSystemIdleTime();
   }
+
+  isOnBatteryPower () {
+    return isOnBatteryPower();
+  }
+
+  get onBatteryPower () {
+    return this.isOnBatteryPower();
+  }
 }
 
 module.exports = new PowerMonitor();
diff --git a/shell/browser/api/electron_api_power_monitor.cc b/shell/browser/api/electron_api_power_monitor.cc
index 706228a953f..2a87038d386 100644
--- a/shell/browser/api/electron_api_power_monitor.cc
+++ b/shell/browser/api/electron_api_power_monitor.cc
@@ -136,6 +136,10 @@ int GetSystemIdleTime() {
   return ui::CalculateIdleTime();
 }
 
+bool IsOnBatteryPower() {
+  return base::PowerMonitor::IsOnBatteryPower();
+}
+
 void Initialize(v8::Local<v8::Object> exports,
                 v8::Local<v8::Value> unused,
                 v8::Local<v8::Context> context,
@@ -147,6 +151,7 @@ void Initialize(v8::Local<v8::Object> exports,
   dict.SetMethod("getSystemIdleState",
                  base::BindRepeating(&GetSystemIdleState));
   dict.SetMethod("getSystemIdleTime", base::BindRepeating(&GetSystemIdleTime));
+  dict.SetMethod("isOnBatteryPower", base::BindRepeating(&IsOnBatteryPower));
 }
 
 }  // namespace
diff --git a/spec-main/api-power-monitor-spec.ts b/spec-main/api-power-monitor-spec.ts
index 9ac3644f1e0..c1f55fc5606 100644
--- a/spec-main/api-power-monitor-spec.ts
+++ b/spec-main/api-power-monitor-spec.ts
@@ -167,10 +167,17 @@ describe('powerMonitor', () => {
     });
 
     describe('powerMonitor.getSystemIdleTime', () => {
-      it('notify current system idle time', () => {
+      it('returns current system idle time', () => {
         const idleTime = powerMonitor.getSystemIdleTime();
         expect(idleTime).to.be.at.least(0);
       });
     });
+
+    describe('powerMonitor.onBatteryPower', () => {
+      it('returns a boolean', () => {
+        expect(powerMonitor.onBatteryPower).to.be.a('boolean');
+        expect(powerMonitor.isOnBatteryPower()).to.be.a('boolean');
+      });
+    });
   });
 });