add Foundation NSString

Packages/com.teach310.core-bluetooth-for-unity/Runtime/Foundation/NSString.cs

@@ -0,0 +1,61 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace CoreBluetooth.Foundation
+{
+    public class NSString : IDisposable
+    {
+        internal SafeNSStringHandle Handle { get; private set; }
+
+        public NSString(string str)
+        {
+            if (str is null)
+                throw new ArgumentNullException(nameof(str));
+
+            Handle = NativeMethods.ns_string_new(str);
+        }
+
+        internal NSString(SafeNSStringHandle handle)
+        {
+            Handle = handle;
+        }
+
+        internal NSString(IntPtr handle)
+        {
+            Handle = new SafeNSStringHandle(handle);
+        }
+
+        public int LengthOfBytesUtf8()
+        {
+            ExceptionUtils.ThrowObjectDisposedExceptionIf(Handle.IsInvalid, this);
+            return NativeMethods.ns_string_length_of_bytes_utf8(Handle);
+        }
+
+        public override string ToString()
+        {
+            ExceptionUtils.ThrowObjectDisposedExceptionIf(Handle.IsInvalid, this);
+            return HandleToString(Handle);
+        }
+
+        public void Dispose()
+        {
+            if (Handle != null && !Handle.IsInvalid)
+                Handle.Dispose();
+        }
+
+        internal static string HandleToString(SafeNSStringHandle handle)
+        {
+            if (handle.IsInvalid)
+                return null;
+
+            NativeMethods.ns_string_get_cstring_and_length(handle, out IntPtr ptr, out int length);
+            if (ptr == IntPtr.Zero)
+                return null;
+
+            if (length == 0)
+                return string.Empty;
+
+            return Marshal.PtrToStringUTF8(ptr, length);
+        }
+    }
+}

Packages/com.teach310.core-bluetooth-for-unity/Runtime/Foundation/NativeMethods.cs

@@ -25,5 +25,14 @@ internal static class NativeMethods
 
         [DllImport(DLL_NAME, CallingConvention = CallingConvention.Cdecl)]
         internal static extern int ns_number_int_value(SafeNSNumberHandle handle);
+
+        [DllImport(DLL_NAME, CallingConvention = CallingConvention.Cdecl)]
+        internal static extern SafeNSStringHandle ns_string_new([MarshalAs(UnmanagedType.LPStr)] string str);
+
+        [DllImport(DLL_NAME, CallingConvention = CallingConvention.Cdecl)]
+        internal static extern int ns_string_length_of_bytes_utf8(SafeNSStringHandle handle);
+
+        [DllImport(DLL_NAME, CallingConvention = CallingConvention.Cdecl)]
+        internal static extern void ns_string_get_cstring_and_length(SafeNSStringHandle handle, out IntPtr ptr, out int length);
     }
 }

Packages/com.teach310.core-bluetooth-for-unity/Runtime/Foundation/SafeNSStringHandle.cs

@@ -0,0 +1,10 @@
+using System;
+
+namespace CoreBluetooth.Foundation
+{
+    internal class SafeNSStringHandle : SafeNSObjectHandle
+    {
+        public SafeNSStringHandle() : base() { }
+        public SafeNSStringHandle(IntPtr handle) : base(handle) { }
+    }
+}

Packages/com.teach310.core-bluetooth-for-unity/Tests/Runtime/Foundation/NSStringTests.cs

@@ -0,0 +1,54 @@
+using CoreBluetooth.Foundation;
+using NUnit.Framework;
+
+namespace CoreBluetoothTests.Foundation
+{
+    public class NSStringTests
+    {
+        [Test]
+        public void New()
+        {
+            using var nsString = new NSString("dummy");
+            Assert.That(nsString.Handle, Is.Not.Null);
+            Assert.That(nsString.Handle.IsInvalid, Is.False);
+        }
+
+        [Test]
+        public void LengthOfBytesUtf8()
+        {
+            using (var nsString = new NSString("a"))
+            {
+                Assert.That(nsString.LengthOfBytesUtf8(), Is.EqualTo(1));
+            }
+
+            using (var nsString = new NSString("あ"))
+            {
+                Assert.That(nsString.LengthOfBytesUtf8(), Is.EqualTo(3));
+            }
+
+            using (var nsString = new NSString("𠮷"))
+            {
+                Assert.That(nsString.LengthOfBytesUtf8(), Is.EqualTo(4));
+            }
+        }
+
+        [Test]
+        public void HandleToString()
+        {
+            using (var nsString = new NSString("dummy"))
+            {
+                Assert.That(NSString.HandleToString(nsString.Handle), Is.EqualTo("dummy"));
+            }
+
+            using (var nsString = new NSString("あいうえお"))
+            {
+                Assert.That(NSString.HandleToString(nsString.Handle), Is.EqualTo("あいうえお"));
+            }
+
+            using (var nsString = new NSString(string.Empty))
+            {
+                Assert.That(NSString.HandleToString(nsString.Handle), Is.EqualTo(string.Empty));
+            }
+        }
+    }
+}

Plugins/CoreBluetoothForUnity/Sources/CoreBluetoothForUnity/FoundationForUnity/FoundationForUnity.swift

@@ -28,3 +28,27 @@ public func ns_number_int_value(_ handle: UnsafeRawPointer) -> Int32 {
     let instance = Unmanaged<NSNumber>.fromOpaque(handle).takeUnretainedValue()
     return instance.int32Value
 }
+
+@_cdecl("ns_string_new")
+public func ns_string_new(_ str: UnsafePointer<CChar>) -> UnsafeMutableRawPointer {
+    let nsstring = NSString(utf8String: str)!
+    return Unmanaged.passRetained(nsstring).toOpaque()
+}
+
+@_cdecl("ns_string_length_of_bytes_utf8")
+public func ns_string_length_of_bytes_utf8(_ handle: UnsafeRawPointer) -> Int32 {
+    let nsstring = Unmanaged<NSString>.fromOpaque(handle).takeUnretainedValue()
+    return Int32(nsstring.lengthOfBytes(using: String.Encoding.utf8.rawValue))
+}
+
+@_cdecl("ns_string_get_cstring_and_length")
+public func ns_string_get_cstring_and_length(_ handle: UnsafeRawPointer, _ ptr: UnsafeMutablePointer<UnsafePointer<CChar>?>, _ length: UnsafeMutablePointer<Int32>) {
+    let nsstring = Unmanaged<NSString>.fromOpaque(handle).takeUnretainedValue()
+    if let cstring = nsstring.utf8String {
+        ptr.pointee = UnsafePointer(cstring)
+        length.pointee = Int32(strlen(cstring))
+    } else {
+        ptr.pointee = nil
+        length.pointee = 0
+    }
+}