pythonnet/src/runtime/Util/EventHandlerCollection.cs at v3.0.1 · pythonnet/pythonnet · GitHub

History

128 lines (111 loc) · 3.78 KB

Raw

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

using System;

using System.Collections.Generic;

using System.Reflection;

using System.Runtime.Serialization;

using System.Security.Permissions;

namespace Python.Runtime;

[Serializable]

internal class EventHandlerCollection: Dictionary<object, List<Handler>>

{

readonly EventInfo info;

public EventHandlerCollection(EventInfo @event)

{

info = @event;

}

/// <summary>

/// Register a new Python object event handler with the event.

/// </summary>

internal bool AddEventHandler(BorrowedReference target, PyObject handler)

{

object? obj = null;

if (target != null)

{

var co = (CLRObject)ManagedType.GetManagedObject(target)!;

obj = co.inst;

}

// Create a true delegate instance of the appropriate type to

// wrap the Python handler. Note that wrapper delegate creation

// always succeeds, though calling the wrapper may fail.

Type type = info.EventHandlerType;

Delegate d = PythonEngine.DelegateManager.GetDelegate(type, handler);

// Now register the handler in a mapping from instance to pairs

// of (handler hash, delegate) so we can lookup to remove later.

object key = obj ?? info.ReflectedType;

if (!TryGetValue(key, out var list))

{

list = new List<Handler>();

this[key] = list;

}

list.Add(new Handler(Runtime.PyObject_Hash(handler), d));

// Note that AddEventHandler helper only works for public events,

// so we have to get the underlying add method explicitly.

object[] args = { d };

MethodInfo mi = info.GetAddMethod(true);

mi.Invoke(obj, BindingFlags.Default, null, args, null);

return true;

}

/// <summary>

/// Remove the given Python object event handler.

/// </summary>

internal bool RemoveEventHandler(BorrowedReference target, BorrowedReference handler)

{

object? obj = null;

if (target != null)

{

var co = (CLRObject)ManagedType.GetManagedObject(target)!;

obj = co.inst;

}

nint hash = Runtime.PyObject_Hash(handler);

if (hash == -1 && Exceptions.ErrorOccurred())

{

return false;

}

object key = obj ?? info.ReflectedType;

if (!TryGetValue(key, out var list))

{

Exceptions.SetError(Exceptions.ValueError, "unknown event handler");

return false;

}

object?[] args = { null };

MethodInfo mi = info.GetRemoveMethod(true);

for (var i = 0; i < list.Count; i++)

{

var item = (Handler)list[i];

if (item.hash != hash)

{

continue;

}

args[0] = item.del;

try

{

mi.Invoke(obj, BindingFlags.Default, null, args, null);

}

catch

{

continue;

}

list.RemoveAt(i);

if (list.Count == 0)

{

Remove(key);

}

return true;

}

Exceptions.SetError(Exceptions.ValueError, "unknown event handler");

return false;

}

#region Serializable

[SecurityPermission(SecurityAction.Demand, SerializationFormatter = true)]

protected EventHandlerCollection(SerializationInfo info, StreamingContext context)

: base(info, context)

{

this.info = (EventInfo)info.GetValue("event", typeof(EventInfo));

}

[SecurityPermission(SecurityAction.Demand, SerializationFormatter = true)]

public override void GetObjectData(SerializationInfo info, StreamingContext context)

{

base.GetObjectData(info, context);

info.AddValue("event", this.info);

}

#endregion

}

pythonnet/src/runtime/Util/EventHandlerCollection.cs at v3.0.1 · pythonnet/pythonnet · GitHub

Uh oh!

Expand file tree

Breadcrumbs

EventHandlerCollection.cs

Latest commit

History

Breadcrumbs

EventHandlerCollection.cs

File metadata and controls