apple/AudioObject: add AudioObjectGetStringProperty()

src/apple/AudioObject.cxx

+/*
+ * Copyright 2020 Max Kellermann <max.kellermann@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "AudioObject.hxx"
+#include "StringRef.hxx"
+
+Apple::StringRef
+AudioObjectGetStringProperty(AudioObjectID inObjectID,
+			     const AudioObjectPropertyAddress &inAddress)
+{
+	auto s = AudioObjectGetPropertyDataT<CFStringRef>(inObjectID,
+							  inAddress);
+	return Apple::StringRef(s);
+}

src/apple/AudioObject.hxx

@@ -37,6 +37,10 @@
 
 #include <cstddef>
 
+namespace Apple {
+class StringRef;
+}
+
 inline std::size_t
 AudioObjectGetPropertyDataSize(AudioObjectID inObjectID,
 			       const AudioObjectPropertyAddress &inAddress)
@@ -69,6 +73,10 @@ AudioObjectGetPropertyDataT(AudioObjectID inObjectID,
 	return value;
 }
 
+Apple::StringRef
+AudioObjectGetStringProperty(AudioObjectID inObjectID,
+			     const AudioObjectPropertyAddress &inAddress);
+
 template<typename T>
 AllocatedArray<T>
 AudioObjectGetPropertyDataArray(AudioObjectID inObjectID,

src/apple/meson.build

@@ -12,6 +12,7 @@ audiounit_dep = declare_dependency(
 
 apple = static_library(
   'apple',
+  'AudioObject.cxx',
   'Throw.cxx',
   include_directories: inc,
   dependencies: [

src/output/plugins/OSXOutputPlugin.cxx

@@ -535,19 +535,15 @@ IsAudioDeviceName(AudioDeviceID id, const char *expected_name) noexcept
 		kAudioObjectPropertyElementMaster,
 	};
 
-	CFStringRef cfname;
-	UInt32 size = sizeof(cfname);
-
-	if (AudioObjectGetPropertyData(id, &aopa_name,
-				       0, nullptr,
-				       &size, &cfname) != noErr)
-		return false;
-
-	const Apple::StringRef cfname_(cfname);
-
 	char actual_name[256];
-	if (!cfname_.GetCString(actual_name, sizeof(actual_name)))
+
+	try {
+		auto cfname = AudioObjectGetStringProperty(id, aopa_name);
+		if (!cfname.GetCString(actual_name, sizeof(actual_name)))
+			return false;
+	} catch (...) {
 		return false;
+	}
 
 	return StringIsEqual(actual_name, expected_name);
 }