GtkSharp/cairo/ImageSurface.cs
Andrés G. Aragoneses 70d1827058 cairo: Throw ObjectDisposedException after an object has been disposed
Potentially all these IDisposable classes could be used after being
disposed, which would result in native crashes. We now do an explicit
check and throw an exception in managed land when the object has been
disposed.

This is particularly useful because:
 a/ the native crashes are quite obscure, there no indication that
you're using a disposed object
 b/ Gtk# is passing Context instances to user methods, and disposes them
when the method returns. So if the user code keeps a reference to the
Context, there a good chance it will try to use it after it's disposed.

Other changes in this patch include:
 * Renaming a parameter to be more consistent with the other subsequent
ctor called.
 * Replacing implementation of some [Obsolete()] methods with the call
to the methods they were replaced with, to avoid redundancy and the
need for more CheckDisposed() calls than necessary.
 * Throw ArgumentException when receiving an IntPtr.Zero as a handle,
as a way to protect ourselves from wrapping invalid native pointers,
and throwing ObjectDisposedExceptions because the object was invalid in
the first place.

Signed-off-by: Bertrand Lorentz <bertrand.lorentz@gmail.com>
2013-11-24 15:56:26 +01:00

117 lines
3.3 KiB
C#

//
// Mono.Cairo.ImageSurface.cs
//
// Authors:
// Duncan Mak
// Miguel de Icaza.
//
// (C) Ximian Inc, 2003.
// (C) Novell, Inc. 2003.
//
// This is an OO wrapper API for the Cairo API
//
// Copyright (C) 2004 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;
namespace Cairo {
public class ImageSurface : Surface
{
internal ImageSurface (IntPtr handle, bool owns) : base (handle, owns)
{
}
public ImageSurface (Format format, int width, int height)
: base (NativeMethods.cairo_image_surface_create (format, width, height), true)
{
}
[Obsolete ("Use ImageSurface (byte[] data, Cairo.Format format, int width, int height, int stride)")]
public ImageSurface (ref byte[] data, Cairo.Format format, int width, int height, int stride)
: this (data, format, width, height, stride)
{
}
public ImageSurface (byte[] data, Format format, int width, int height, int stride)
: base (NativeMethods.cairo_image_surface_create_for_data (data, format, width, height, stride), true)
{
}
public ImageSurface (IntPtr data, Format format, int width, int height, int stride)
: base (NativeMethods.cairo_image_surface_create_for_data (data, format, width, height, stride), true)
{
}
public ImageSurface (string filename)
: base (NativeMethods.cairo_image_surface_create_from_png (filename), true)
{
}
public int Width {
get {
CheckDisposed ();
return NativeMethods.cairo_image_surface_get_width (Handle); }
}
public int Height {
get {
CheckDisposed ();
return NativeMethods.cairo_image_surface_get_height (Handle);
}
}
public byte[] Data {
get {
IntPtr ptr = NativeMethods.cairo_image_surface_get_data (Handle);
int length = Height * Stride;
byte[] data = new byte[length];
Marshal.Copy (ptr, data, 0, length);
return data;
}
}
public IntPtr DataPtr {
get {
CheckDisposed ();
return NativeMethods.cairo_image_surface_get_data (Handle);
}
}
public Format Format {
get {
CheckDisposed ();
return NativeMethods.cairo_image_surface_get_format (Handle);
}
}
public int Stride {
get {
CheckDisposed ();
return NativeMethods.cairo_image_surface_get_stride (Handle);
}
}
}
}