Ryujinx-GtkSharp/cairo/FontOptions.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

182 lines
4.3 KiB
C#

//
// Mono.Cairo.FontOptions.cs
//
// Author:
// John Luke (john.luke@gmail.com)
//
// (C) John Luke 2005.
//
// 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;
namespace Cairo
{
public class FontOptions : IDisposable
{
IntPtr handle;
public FontOptions () : this (NativeMethods.cairo_font_options_create ())
{
}
~FontOptions ()
{
Dispose (false);
}
internal FontOptions (IntPtr handle)
{
if (handle == IntPtr.Zero)
throw new ArgumentException ("handle should not be NULL", "handle");
this.handle = handle;
if (CairoDebug.Enabled)
CairoDebug.OnAllocated (handle);
}
public FontOptions Copy ()
{
CheckDisposed ();
return new FontOptions (NativeMethods.cairo_font_options_copy (handle));
}
[Obsolete ("Use Dispose()")]
public void Destroy ()
{
Dispose ();
}
public void Dispose ()
{
Dispose (true);
GC.SuppressFinalize (this);
}
protected virtual void Dispose (bool disposing)
{
if (!disposing || CairoDebug.Enabled)
CairoDebug.OnDisposed<FontOptions> (handle, disposing);
if (!disposing|| handle == IntPtr.Zero)
return;
NativeMethods.cairo_font_options_destroy (handle);
handle = IntPtr.Zero;
}
void CheckDisposed ()
{
if (handle == IntPtr.Zero)
throw new ObjectDisposedException ("Object has already been disposed");
}
public static bool operator == (FontOptions options, FontOptions other)
{
return Equals (options, other);
}
public static bool operator != (FontOptions options, FontOptions other)
{
return !(options == other);
}
public override bool Equals (object other)
{
return Equals (other as FontOptions);
}
bool Equals (FontOptions options)
{
return options != null && NativeMethods.cairo_font_options_equal (Handle, options.Handle);
}
public IntPtr Handle {
get { return handle; }
}
public override int GetHashCode ()
{
return (int) NativeMethods.cairo_font_options_hash (handle);
}
public void Merge (FontOptions other)
{
if (other == null)
throw new ArgumentNullException ("other");
CheckDisposed ();
NativeMethods.cairo_font_options_merge (handle, other.Handle);
}
public Antialias Antialias {
get {
CheckDisposed ();
return NativeMethods.cairo_font_options_get_antialias (handle);
}
set {
CheckDisposed ();
NativeMethods.cairo_font_options_set_antialias (handle, value);
}
}
public HintMetrics HintMetrics {
get {
CheckDisposed ();
return NativeMethods.cairo_font_options_get_hint_metrics (handle);
}
set {
CheckDisposed ();
NativeMethods.cairo_font_options_set_hint_metrics (handle, value);
}
}
public HintStyle HintStyle {
get {
CheckDisposed ();
return NativeMethods.cairo_font_options_get_hint_style (handle);
}
set {
CheckDisposed ();
NativeMethods.cairo_font_options_set_hint_style (handle, value);
}
}
public Status Status {
get {
CheckDisposed ();
return NativeMethods.cairo_font_options_status (handle);
}
}
public SubpixelOrder SubpixelOrder {
get {
CheckDisposed ();
return NativeMethods.cairo_font_options_get_subpixel_order (handle);
}
set {
CheckDisposed ();
NativeMethods.cairo_font_options_set_subpixel_order (handle, value);
}
}
}
}