c++, java: Optional values return null when they are not available

Signed-off-by: Petre Eftime <[email protected]>

6 files changed, 34 insertions, 19 deletions

diff --git a/api/tinyb/BluetoothAdapter.hpp b/api/tinyb/BluetoothAdapter.hpp
index 2d138705..e7bb5eb1 100644
--- a/api/tinyb/BluetoothAdapter.hpp
+++ b/api/tinyb/BluetoothAdapter.hpp
@@ -196,6 +196,6 @@ public:
     /** Returns the local ID of the adapter.
       * @return The local ID of the adapter.
       */
-    std::string get_modalias ();
+    std::unique_ptr<std::string> get_modalias ();
 
 };
diff --git a/api/tinyb/BluetoothDevice.hpp b/api/tinyb/BluetoothDevice.hpp
index 876782c7..79cda77f 100644
--- a/api/tinyb/BluetoothDevice.hpp
+++ b/api/tinyb/BluetoothDevice.hpp
@@ -169,7 +169,7 @@ public:
     /** Returns the proposed icon name of the device.
       * @return The proposed icon name, or NULL if not set.
       */
-    std::string get_icon ();
+    std::unique_ptr<std::string> get_icon ();
 
     /** Returns the paired state the device.
       * @return The paired state of the device.
@@ -199,8 +199,8 @@ public:
       */
     bool get_legacy_pairing ();
 
-    /** Returns the Received Signal Strength Indicator of the device.
-      * @return The Received Signal Strength Indicator of the device.
+    /** Returns the Received Signal Strength Indicator of the device (0 means unknown).
+      * @return The Received Signal Strength Indicator of the device (0 means unknown).
       */
     int16_t get_rssi ();
 
@@ -214,10 +214,10 @@ public:
       */
     std::vector<std::string> get_uuids ();
 
-    /** Returns the local ID of the adapter.
-      * @return The local ID of the adapter.
+    /** Returns the local ID of the adapter, or nullptr.
+      * @return The local ID of the adapter, or nullptr.
       */
-    std::string get_modalias ();
+    std::unique_ptr<std::string> get_modalias ();
 
     /** Returns the adapter on which this device was discovered or
       * connected.
diff --git a/java/jni/BluetoothAdapter.cxx b/java/jni/BluetoothAdapter.cxx
index c8bf58bd..c7c38589 100644
--- a/java/jni/BluetoothAdapter.cxx
+++ b/java/jni/BluetoothAdapter.cxx
@@ -222,9 +222,11 @@ jobjectArray Java_tinyb_BluetoothAdapter_getUuids(JNIEnv *env, jobject obj)
 jstring Java_tinyb_BluetoothAdapter_getModalias(JNIEnv *env, jobject obj)
 {
     BluetoothAdapter *obj_adapter = getInstance<BluetoothAdapter>(env, obj);
-    std::string modalias = obj_adapter->get_modalias();
+    std::unique_ptr<std::string> modalias = obj_adapter->get_modalias();
+    if(modalias == nullptr)
+        return nullptr;
 
-    return env->NewStringUTF((const char *)modalias.c_str());
+    return env->NewStringUTF((const char *)modalias->c_str());
 }
 
 void Java_tinyb_BluetoothAdapter_delete(JNIEnv *env, jobject obj)
diff --git a/java/jni/BluetoothDevice.cxx b/java/jni/BluetoothDevice.cxx
index 21ffac0b..d0e70007 100644
--- a/java/jni/BluetoothDevice.cxx
+++ b/java/jni/BluetoothDevice.cxx
@@ -151,9 +151,11 @@ jshort Java_tinyb_BluetoothDevice_getAppearance(JNIEnv *env, jobject obj)
 jstring Java_tinyb_BluetoothDevice_getIcon(JNIEnv *env, jobject obj)
 {
     BluetoothDevice *obj_device = getInstance<BluetoothDevice>(env, obj);
-    std::string icon = obj_device->get_icon();
+    std::unique_ptr<std::string> icon = obj_device->get_icon();
+    if (icon == nullptr)
+        return nullptr;
 
-    return env->NewStringUTF((const char *)icon.c_str());
+    return env->NewStringUTF((const char *)icon->c_str());
 }
 
 jboolean Java_tinyb_BluetoothDevice_getPaired(JNIEnv *env, jobject obj)
@@ -236,9 +238,11 @@ jobjectArray Java_tinyb_BluetoothDevice_getUuids(JNIEnv *env, jobject obj)
 jstring Java_tinyb_BluetoothDevice_getModalias(JNIEnv *env, jobject obj)
 {
     BluetoothDevice *obj_device = getInstance<BluetoothDevice>(env, obj);
-    std::string modalias = obj_device->get_modalias();
+    std::unique_ptr<std::string> modalias = obj_device->get_modalias();
+    if (modalias == nullptr)
+        return nullptr;
 
-    return env->NewStringUTF((const char *)modalias.c_str());
+    return env->NewStringUTF((const char *)modalias->c_str());
 }
 
 jobject Java_tinyb_BluetoothDevice_getAdapter(JNIEnv *env, jobject obj)
diff --git a/src/BluetoothAdapter.cpp b/src/BluetoothAdapter.cpp
index 821e3c37..86f1084e 100644
--- a/src/BluetoothAdapter.cpp
+++ b/src/BluetoothAdapter.cpp
@@ -246,7 +246,10 @@ std::vector<std::string> BluetoothAdapter::get_uuids ()
     return uuids;
 }
 
-std::string BluetoothAdapter::get_modalias ()
+std::unique_ptr<std::string> BluetoothAdapter::get_modalias ()
 {
-    return std::string(adapter1_get_modalias (object));
+    const gchar *modalias= adapter1_get_modalias (object);
+    if (modalias == nullptr)
+        return std::unique_ptr<std::string>();
+    return std::unique_ptr<std::string>(new std::string(modalias));
 }
diff --git a/src/BluetoothDevice.cpp b/src/BluetoothDevice.cpp
index cf3a59d4..3d37f862 100644
--- a/src/BluetoothDevice.cpp
+++ b/src/BluetoothDevice.cpp
@@ -232,9 +232,12 @@ uint16_t BluetoothDevice::get_appearance ()
     return device1_get_appearance (object);
 }
 
-std::string BluetoothDevice::get_icon ()
+std::unique_ptr<std::string> BluetoothDevice::get_icon ()
 {
-    return std::string(device1_get_icon (object));
+    const gchar *icon = device1_get_icon (object);
+    if (icon == nullptr)
+        return std::unique_ptr<std::string>();
+    return std::unique_ptr<std::string>(new std::string(icon));
 }
 
 bool BluetoothDevice::get_paired ()
@@ -287,9 +290,12 @@ std::vector<std::string> BluetoothDevice::get_uuids ()
     return uuids;
 }
 
-std::string BluetoothDevice::get_modalias ()
+std::unique_ptr<std::string> BluetoothDevice::get_modalias ()
 {
-    return std::string(device1_get_modalias (object));
+    const gchar *modalias= device1_get_modalias (object);
+    if (modalias == nullptr)
+        return std::unique_ptr<std::string>();
+    return std::unique_ptr<std::string>(new std::string(modalias));
 }
 
 BluetoothAdapter BluetoothDevice::get_adapter ()