naiveproxy/net/android/cellular_signal_strength.cc
2018-12-09 21:59:24 -05:00

58 lines
1.7 KiB
C++

// Copyright 2016 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 "net/android/cellular_signal_strength.h"
#include "jni/AndroidCellularSignalStrength_jni.h"
namespace net {
namespace android {
namespace cellular_signal_strength {
namespace {
// GENERATED_JAVA_ENUM_PACKAGE: org.chromium.net
enum CellularSignalStrengthError {
// Value returned by CellularSignalStrength APIs when a valid value is
// unavailable. This value is same as INT32_MIN, but the following code uses
// the explicit value of INT32_MIN so that the auto-generated Java enums work
// correctly.
ERROR_NOT_SUPPORTED = -2147483648,
};
static_assert(
INT32_MIN == ERROR_NOT_SUPPORTED,
"CellularSignalStrengthError.ERROR_NOT_SUPPORTED has unexpected value");
} // namespace
base::Optional<int32_t> GetSignalStrengthLevel() {
int32_t signal_strength_level =
Java_AndroidCellularSignalStrength_getSignalStrengthLevel(
base::android::AttachCurrentThread());
if (signal_strength_level == ERROR_NOT_SUPPORTED)
return base::nullopt;
// |signal_strength_level| is expected to be between 0 and 4 (both inclusive).
// See
// https://developer.android.com/reference/android/telephony/SignalStrength.html#getLevel().
// On some devices, |signal_strength_level| may have a value outside this
// range (e.g., see https://crbug.com/835701). For such devices, cap the value
// to be between 0 and 4.
if (signal_strength_level < 0)
return 0;
if (signal_strength_level > 4)
return 4;
return signal_strength_level;
}
} // namespace cellular_signal_strength
} // namespace android
} // namespace net