GtkSharp/Source/Libs/CairoSharp/Path.cs

//
// Mono.Cairo.Context.cs
//
// Author:
//   Miguel de Icaza (miguel@novell.com)
//
// This is an OO wrapper API for the Cairo API.
//
// Copyright 2007 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

using System;
using System.Runtime.InteropServices;
using Cairo;

namespace Cairo {

	public class Path : IDisposable
	{
		[StructLayout(LayoutKind.Sequential)]
		struct PathStruct
		{
			public Status Status;
			public IntPtr Data;
			public int NumData;
		}

		IntPtr handle = IntPtr.Zero;
		Status status;
		PathData[] data;

		internal Path (IntPtr handle)
		{
			if (handle == IntPtr.Zero)
				throw new ArgumentException ("handle should not be NULL", "handle");

			this.handle = handle;
			if (CairoDebug.Enabled)
				CairoDebug.OnAllocated (handle);
		}

		~Path ()
		{
			Dispose (false);
		}

		public IntPtr Handle { get { return handle; } }

		public void Dispose ()
		{
			Dispose (true);
			GC.SuppressFinalize (this);
		}

		protected virtual void Dispose (bool disposing)
		{
			if (!disposing || CairoDebug.Enabled)
				CairoDebug.OnDisposed<Path> (handle, disposing);

			if (handle == IntPtr.Zero)
				return;

			NativeMethods.cairo_path_destroy (handle);
			handle = IntPtr.Zero;
		}

		void CheckDisposed ()
		{
			if (handle == IntPtr.Zero)
				throw new ObjectDisposedException ("Object has already been disposed");
		}

		void MarshalData ()
		{
			if (data == null)
			{
				var rawStruct = Marshal.PtrToStructure<PathStruct>(handle);
				status = rawStruct.Status;
				data = new PathData[rawStruct.NumData];
				int oneDataSize = Marshal.SizeOf<PathData>();
				for (int i = 0; i < rawStruct.NumData; i++)
				{
					IntPtr iPtr = new IntPtr(rawStruct.Data.ToInt64() + i * oneDataSize);
					data[i] = Marshal.PtrToStructure<PathData>(iPtr);
				}
			}
		}

		public Status Status
		{
			get
			{
				CheckDisposed ();
				MarshalData ();
				return status;
			}
		}

		public int NumData
		{
			get
			{
				CheckDisposed ();
				MarshalData ();
				return data.Length;
			}
		}

		public PathData[] Data
		{
			get
			{
				CheckDisposed ();
				MarshalData ();
				return data;
			}
		}
	}
}