Add files

src/main/power-save-blocker.js

@@ -0,0 +1,34 @@
+module.exports = {
+  enable,
+  disable
+}
+
+const { powerSaveBlocker } = require('electron')
+const log = require('./log')
+
+let blockId = 0
+
+/**
+ * Block the system from entering low-power (sleep) mode or turning off the
+ * display.
+ */
+function enable () {
+  if (powerSaveBlocker.isStarted(blockId)) {
+    // If a power saver block already exists, do nothing.
+    return
+  }
+  blockId = powerSaveBlocker.start('prevent-display-sleep')
+  log(`powerSaveBlocker.enable: ${blockId}`)
+}
+
+/**
+ * Stop blocking the system from entering low-power mode.
+ */
+function disable () {
+  if (!powerSaveBlocker.isStarted(blockId)) {
+    // If a power saver block does not exist, do nothing.
+    return
+  }
+  powerSaveBlocker.stop(blockId)
+  log(`powerSaveBlocker.disable: ${blockId}`)
+}