Location chooser

content/public/common/geoposition.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/public/common/geoposition.h"
+#include <math.h>
 
 namespace {
 // Sentinel values to mark invalid data. (WebKit carries companion is_valid
 // bools for this purpose; we may eventually follow that approach, but
 // sentinels worked OK in the Gears code this is based on.)
 const double kBadLatitudeLongitude = 200;
 // Lowest point on land is at approximately -400 meters.
 const int kBadAltitude = -10000;
 const int kBadAccuracy = -1;  // Accuracy must be non-negative.
 const int kBadHeading = -1;  // Heading must be non-negative.
@@ skipping 13 matching lines @@
       error_code(ERROR_CODE_NONE) {
 }
 
 bool Geoposition::Validate() const {
   return latitude >= -90. && latitude <= 90. &&
          longitude >= -180. && longitude <= 180. &&
          accuracy >= 0. &&
          !timestamp.is_null();
 }
 
+// The calculations in this function are experimental and not fully accurate.
+/* static */
+Geoposition Geoposition::ApplyPrecision(const Geoposition& position,
+                                        const int precision) {
+  Geoposition newGeoposition = position;
+  switch (precision) {
+    case 1:
+      // City granuality.
+      newGeoposition.latitude = round(newGeoposition.latitude * 10.0) / 10.0;
+      newGeoposition.longitude = round(newGeoposition.longitude * 10.0) / 10.0;
+      break;
+    case 2:
+      // State granuality.
+      newGeoposition.latitude = round(newGeoposition.latitude);
+      newGeoposition.longitude = round(newGeoposition.longitude);
+      break;
+    case 3:
+      // Country granuality.
+      newGeoposition.latitude = round(newGeoposition.latitude / 10.0);
+      newGeoposition.longitude = round(newGeoposition.longitude / 10.0);
+      break;
+  }
+  return newGeoposition;
+}
+
 }  // namespace content