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assets/webapps/system.gaiamobile.org/js/feature_detector.js

@@ -0,0 +1,65 @@
+/* global BaseModule */
+'use strict';
+
+(function(exports) {
+  /**
+   * This is the feature detector module of the system app.
+   * It is responsible to retrieve device specific information.
+   */
+  var FeatureDetector = function() {
+  };
+
+  FeatureDetector.SERVICES = [
+    'getDeviceMemory'
+  ];
+
+  FeatureDetector.STATES = [
+    'getDeviceType'
+  ];
+
+  BaseModule.create(FeatureDetector, {
+    name: 'FeatureDetector',
+    deviceType: 'phone',
+    _deviceMemoryPromise: null,
+
+    _start: function() {
+      this._getDeviceType();
+      this._getDeviceMemory();
+    },
+
+    _stop: function() {
+      this.deviceType = null;
+      this._deviceMemoryPromise = null;
+    },
+
+    _getDeviceType: function() {
+      // `_GAIA_DEVICE_TYPE_` is a placeholder and will be replaced by real
+      // device type in build time, `system/build/build.js` does the trick.
+      this.deviceType = 'phone';
+    },
+
+    getDeviceType: function() {
+      return this.deviceType;
+    },
+
+    _getDeviceMemory: function() {
+      if ('getFeature' in navigator) {
+        this._deviceMemoryPromise =
+          navigator.getFeature('hardware.memory').catch(() => {
+            this.error('Failed to retrieve total memory of the device.');
+
+            // Return the failsafe value.
+            return 0;
+          });
+      } else {
+        this.error('navigator.getFeature is not available.');
+
+        this._deviceMemoryPromise = Promise.resolve(0);
+      }
+    },
+
+    getDeviceMemory: function() {
+      return this._deviceMemoryPromise;
+    }
+  });
+}(window));