Add XML documentation to JValue struct

src/Mono.Android/Android.Runtime/JValue.cs

@@ -3,6 +3,16 @@
 
 namespace Android.Runtime {
 
+	/// <summary>
+	/// Represents a JNI <c>jvalue</c> union, used to pass arguments to Java methods
+	/// via JNI function calls.
+	/// </summary>
+	/// <remarks>
+	/// <para>
+	/// Each constructor corresponds to one of the JNI primitive types or an object reference.
+	/// See the <see href="https://docs.oracle.com/javase/8/docs/technotes/guides/jni/spec/types.html">JNI Type Specification</see>.
+	/// </para>
+	/// </remarks>
 	[StructLayout(LayoutKind.Explicit)]
 	public struct JValue {
 #pragma warning disable 0414
@@ -17,62 +27,122 @@ public struct JValue {
 		[FieldOffset(0)] IntPtr l;
 #pragma warning restore 0414
 
+		/// <summary>
+		/// A <see cref="JValue"/> representing a JNI <c>NULL</c> object reference.
+		/// </summary>
 		public static JValue Zero = new JValue (IntPtr.Zero);
 
+		/// <summary>
+		/// Creates a <see cref="JValue"/> from a <see cref="bool"/> value,
+		/// corresponding to the JNI <c>jboolean</c> type.
+		/// </summary>
+		/// <param name="value">The Boolean value.</param>
 		public JValue (bool value)
 		{
 			this = new JValue ();
 			z = value;
 		}
 
+		/// <summary>
+		/// Creates a <see cref="JValue"/> from an <see cref="sbyte"/> value,
+		/// corresponding to the JNI <c>jbyte</c> type.
+		/// </summary>
+		/// <param name="value">The signed byte value.</param>
 		public JValue (sbyte value)
 		{
 			this = new JValue ();
 			b = value;
 		}
 
+		/// <summary>
+		/// Creates a <see cref="JValue"/> from a <see cref="char"/> value,
+		/// corresponding to the JNI <c>jchar</c> type.
+		/// </summary>
+		/// <param name="value">The character value.</param>
 		public JValue (char value)
 		{
 			this = new JValue ();
 			c = value;
 		}
 
+		/// <summary>
+		/// Creates a <see cref="JValue"/> from a <see cref="short"/> value,
+		/// corresponding to the JNI <c>jshort</c> type.
+		/// </summary>
+		/// <param name="value">The short integer value.</param>
 		public JValue (short value)
 		{
 			this = new JValue ();
 			s = value;
 		}
 
+		/// <summary>
+		/// Creates a <see cref="JValue"/> from an <see cref="int"/> value,
+		/// corresponding to the JNI <c>jint</c> type.
+		/// </summary>
+		/// <param name="value">The integer value.</param>
 		public JValue (int value)
 		{
 			this = new JValue ();
 			i = value;
 		}
 
+		/// <summary>
+		/// Creates a <see cref="JValue"/> from a <see cref="long"/> value,
+		/// corresponding to the JNI <c>jlong</c> type.
+		/// </summary>
+		/// <param name="value">The long integer value.</param>
 		public JValue (long value)
 		{
 			this = new JValue ();
 			j = value;
 		}
 
+		/// <summary>
+		/// Creates a <see cref="JValue"/> from a <see cref="float"/> value,
+		/// corresponding to the JNI <c>jfloat</c> type.
+		/// </summary>
+		/// <param name="value">The single-precision floating-point value.</param>
 		public JValue (float value)
 		{
 			this = new JValue ();
 			f = value;
 		}
 
+		/// <summary>
+		/// Creates a <see cref="JValue"/> from a <see cref="double"/> value,
+		/// corresponding to the JNI <c>jdouble</c> type.
+		/// </summary>
+		/// <param name="value">The double-precision floating-point value.</param>
 		public JValue (double value)
 		{
 			this = new JValue ();
 			d = value;
 		}
 
+		/// <summary>
+		/// Creates a <see cref="JValue"/> from an <see cref="IntPtr"/> value,
+		/// corresponding to a JNI <c>jobject</c> reference.
+		/// </summary>
+		/// <param name="value">The raw JNI object reference handle.</param>
 		public JValue (IntPtr value)
 		{
 			this = new JValue ();
 			l = value;
 		}
 
+		/// <summary>
+		/// Creates a <see cref="JValue"/> from an <see cref="IJavaObject"/> instance,
+		/// corresponding to a JNI <c>jobject</c> reference.
+		/// </summary>
+		/// <param name="value">
+		/// The Java object instance. If <see langword="null"/>, the resulting
+		/// <see cref="JValue"/> will contain <see cref="IntPtr.Zero"/>.
+		/// </param>
+		/// <remarks>
+		/// This constructor extracts the <see cref="IJavaObject.Handle"/> from the
+		/// provided object, or passes <see cref="IntPtr.Zero"/> if the object is <see langword="null"/>.
+		/// </remarks>
 		public JValue (IJavaObject value)
 		{
 			this = new JValue ();