gstreamer/gstreamer-sharp/glib-sharp/Signal.cs
2009-08-05 16:48:13 +02:00

421 lines
13 KiB
C#

// GLib.Signal.cs - signal marshaling class
//
// Authors: Mike Kestner <mkestner@novell.com>
// Andrés G. Aragoneses <aaragoneses@novell.com>
//
// Copyright (c) 2005,2008 Novell, Inc.
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of version 2 of the Lesser GNU General
// Public License as published by the Free Software Foundation.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this program; if not, write to the
// Free Software Foundation, Inc., 59 Temple Place - Suite 330,
// Boston, MA 02111-1307, USA.
namespace Gst.GLib {
using System;
using System.Collections;
using System.Runtime.InteropServices;
[Flags]
public enum ConnectFlags {
After = 1 << 0,
Swapped = 1 << 1,
}
public class Signal {
[Flags]
public enum Flags {
RunFirst = 1 << 0,
RunLast = 1 << 1,
RunCleanup = 1 << 2,
NoRecurse = 1 << 3,
Detailed = 1 << 4,
Action = 1 << 5,
NoHooks = 1 << 6
}
[StructLayout (LayoutKind.Sequential)]
public struct InvocationHint {
public uint signal_id;
public uint detail;
public Flags run_type;
}
[StructLayout (LayoutKind.Sequential)]
struct Query {
public uint signal_id;
public IntPtr signal_name;
public IntPtr itype;
public Flags signal_flags;
public IntPtr return_type;
public uint n_params;
public IntPtr param_types;
}
[UnmanagedFunctionPointer (CallingConvention.Cdecl)]
public delegate bool EmissionHookNative (ref InvocationHint hint, uint n_pvals, IntPtr pvals, IntPtr data);
public delegate bool EmissionHook (InvocationHint ihint, object[] inst_and_param_values);
public class EmissionHookMarshaler {
EmissionHook handler;
EmissionHookNative cb;
IntPtr user_data;
GCHandle gch;
public EmissionHookMarshaler (EmissionHook handler)
{
this.handler = handler;
cb = new EmissionHookNative (NativeCallback);
gch = GCHandle.Alloc (this);
}
public EmissionHookMarshaler (EmissionHookNative callback, IntPtr user_data)
{
cb = callback;
this.user_data = user_data;
handler = new EmissionHook (NativeInvoker);
}
bool NativeCallback (ref InvocationHint hint, uint n_pvals, IntPtr pvals_ptr, IntPtr data)
{
object[] pvals = new object [n_pvals];
for (int i = 0; i < n_pvals; i++) {
IntPtr p = new IntPtr ((long) pvals_ptr + i * Marshal.SizeOf (typeof (Value)));
Value v = (Value) Marshal.PtrToStructure (p, typeof (Value));
pvals [i] = v.Val;
}
bool result = handler (hint, pvals);
if (!result)
gch.Free ();
return result;
}
public EmissionHookNative Callback {
get {
return cb;
}
}
bool NativeInvoker (InvocationHint ihint, object[] pvals)
{
int val_sz = Marshal.SizeOf (typeof (Value));
IntPtr buf = Marshal.AllocHGlobal (pvals.Length * val_sz);
Value[] vals = new Value [pvals.Length];
for (int i = 0; i < pvals.Length; i++) {
vals [i] = new Value (pvals [i]);
IntPtr p = new IntPtr ((long) buf + i * val_sz);
Marshal.StructureToPtr (vals [i], p, false);
}
bool result = cb (ref ihint, (uint) pvals.Length, buf, user_data);
foreach (Value v in vals)
v.Dispose ();
Marshal.FreeHGlobal (buf);
return result;
}
public EmissionHook Invoker {
get {
return handler;
}
}
}
ToggleRef tref;
string name;
Type args_type;
SignalClosure before_closure;
SignalClosure after_closure;
Delegate marshaler;
private Signal (GLib.Object obj, string signal_name, Delegate marshaler)
{
tref = obj.ToggleRef;
name = signal_name;
tref.Signals [name] = this;
this.marshaler = marshaler;
}
private Signal (GLib.Object obj, string signal_name, Type args_type)
{
tref = obj.ToggleRef;
name = signal_name;
this.args_type = args_type;
tref.Signals [name] = this;
}
internal void Free ()
{
if (before_closure != null)
before_closure.Dispose ();
if (after_closure != null)
after_closure.Dispose ();
GC.SuppressFinalize (this);
}
void ClosureDisposedCB (object o, EventArgs args)
{
if (o == before_closure) {
before_closure.Disposed -= new EventHandler (ClosureDisposedHandler);
before_closure.Invoked -= new ClosureInvokedHandler (ClosureInvokedCB);
if (tref.Target != null)
tref.Target.BeforeSignals.Remove (name);
before_closure = null;
} else if (o == after_closure) {
after_closure.Disposed -= new EventHandler (ClosureDisposedHandler);
after_closure.Invoked -= new ClosureInvokedHandler (ClosureInvokedCB);
if (tref.Target != null)
tref.Target.AfterSignals.Remove (name);
after_closure = null;
}
if (before_closure == null && after_closure == null)
tref.Signals.Remove (name);
}
EventHandler closure_disposed_cb;
EventHandler ClosureDisposedHandler {
get {
if (closure_disposed_cb == null)
closure_disposed_cb = new EventHandler (ClosureDisposedCB);
return closure_disposed_cb;
}
}
void ClosureInvokedCB (object o, ClosureInvokedArgs args)
{
Delegate handler;
if (o == before_closure)
handler = args.Target.BeforeSignals [name] as Delegate;
else
handler = args.Target.AfterSignals [name] as Delegate;
if (handler != null)
handler.DynamicInvoke (new object[] {args.Target, args.Args});
}
ClosureInvokedHandler closure_invoked_cb;
ClosureInvokedHandler ClosureInvokedHandler {
get {
if (closure_invoked_cb == null)
closure_invoked_cb = new ClosureInvokedHandler (ClosureInvokedCB);
return closure_invoked_cb;
}
}
public static Signal Lookup (GLib.Object obj, string name)
{
return Lookup (obj, name, typeof (EventArgs));
}
public static Signal Lookup (GLib.Object obj, string name, Delegate marshaler)
{
Signal result = obj.ToggleRef.Signals [name] as Signal;
if (result == null)
result = new Signal (obj, name, marshaler);
return result;
}
public static Signal Lookup (GLib.Object obj, string name, Type args_type)
{
Signal result = obj.ToggleRef.Signals [name] as Signal;
if (result == null)
result = new Signal (obj, name, args_type);
return result;
}
public Delegate Handler {
get {
InvocationHint hint = (InvocationHint) Marshal.PtrToStructure (g_signal_get_invocation_hint (tref.Handle), typeof (InvocationHint));
if (hint.run_type == Flags.RunFirst)
return tref.Target.BeforeSignals [name] as Delegate;
else
return tref.Target.AfterSignals [name] as Delegate;
}
}
public void AddDelegate (Delegate d)
{
if (args_type == null)
args_type = d.Method.GetParameters ()[1].ParameterType;
if (d.Method.IsDefined (typeof (ConnectBeforeAttribute), false)) {
tref.Target.BeforeSignals [name] = Delegate.Combine (tref.Target.BeforeSignals [name] as Delegate, d);
if (before_closure == null) {
if (marshaler == null)
before_closure = new SignalClosure (tref.Handle, name, args_type);
else
before_closure = new SignalClosure (tref.Handle, name, marshaler, this);
before_closure.Disposed += ClosureDisposedHandler;
before_closure.Invoked += ClosureInvokedHandler;
before_closure.Connect (false);
}
} else {
tref.Target.AfterSignals [name] = Delegate.Combine (tref.Target.AfterSignals [name] as Delegate, d);
if (after_closure == null) {
if (marshaler == null)
after_closure = new SignalClosure (tref.Handle, name, args_type);
else
after_closure = new SignalClosure (tref.Handle, name, marshaler, this);
after_closure.Disposed += ClosureDisposedHandler;
after_closure.Invoked += ClosureInvokedHandler;
after_closure.Connect (true);
}
}
}
public void RemoveDelegate (Delegate d)
{
if (tref.Target == null)
return;
if (d.Method.IsDefined (typeof (ConnectBeforeAttribute), false)) {
tref.Target.BeforeSignals [name] = Delegate.Remove (tref.Target.BeforeSignals [name] as Delegate, d);
if (tref.Target.BeforeSignals [name] == null && before_closure != null) {
before_closure.Dispose ();
before_closure = null;
}
} else {
tref.Target.AfterSignals [name] = Delegate.Remove (tref.Target.AfterSignals [name] as Delegate, d);
if (tref.Target.AfterSignals [name] == null && after_closure != null) {
after_closure.Dispose ();
after_closure = null;
}
}
}
// format: children-changed::add
private static void ParseSignalDetail (string signal_detail, out string signal_name, out uint gquark)
{
//can't use String.Split because it doesn't accept a string arg (only char) in the 1.x profile
int link_pos = signal_detail.IndexOf ("::");
if (link_pos < 0) {
gquark = 0;
signal_name = signal_detail;
} else if (link_pos == 0) {
throw new FormatException ("Invalid detailed signal: " + signal_detail);
} else {
signal_name = signal_detail.Substring (0, link_pos);
gquark = GetGQuarkFromString (signal_detail.Substring (link_pos + 2));
}
}
public static object Emit (GLib.Object instance, string detailed_signal, params object[] args)
{
uint gquark, signal_id;
string signal_name;
ParseSignalDetail (detailed_signal, out signal_name, out gquark);
signal_id = GetSignalId (signal_name, instance);
if (signal_id <= 0)
throw new ArgumentException ("Invalid signal name: " + signal_name);
GLib.Value[] vals = new GLib.Value [args.Length + 1];
GLib.ValueArray inst_and_params = new GLib.ValueArray ((uint) args.Length + 1);
vals [0] = new GLib.Value (instance);
inst_and_params.Append (vals [0]);
for (int i = 1; i < vals.Length; i++) {
vals [i] = new GLib.Value (args [i - 1]);
inst_and_params.Append (vals [i]);
}
object ret_obj = null;
Query query;
g_signal_query (signal_id, out query);
if (query.return_type != GType.None.Val) {
GLib.Value ret = GLib.Value.Empty;
g_signal_emitv (inst_and_params.ArrayPtr, signal_id, gquark, ref ret);
ret_obj = ret.Val;
ret.Dispose ();
} else
g_signal_emitv (inst_and_params.ArrayPtr, signal_id, gquark, IntPtr.Zero);
foreach (GLib.Value val in vals)
val.Dispose ();
return ret_obj;
}
private static uint GetGQuarkFromString (string str) {
IntPtr native_string = GLib.Marshaller.StringToPtrGStrdup (str);
uint ret = g_quark_from_string (native_string);
GLib.Marshaller.Free (native_string);
return ret;
}
private static uint GetSignalId (string signal_name, GLib.Object obj)
{
IntPtr typeid = GType.ValFromInstancePtr (obj.Handle);
return GetSignalId (signal_name, typeid);
}
private static uint GetSignalId (string signal_name, IntPtr typeid)
{
IntPtr native_name = GLib.Marshaller.StringToPtrGStrdup (signal_name);
uint signal_id = g_signal_lookup (native_name, typeid);
GLib.Marshaller.Free (native_name);
return signal_id;
}
public static ulong AddEmissionHook (string detailed_signal, GLib.GType type, EmissionHook handler_func)
{
uint gquark;
string signal_name;
ParseSignalDetail (detailed_signal, out signal_name, out gquark);
uint signal_id = GetSignalId (signal_name, type.Val);
if (signal_id <= 0)
throw new Exception ("Invalid signal name: " + signal_name);
return g_signal_add_emission_hook (signal_id, gquark, new EmissionHookMarshaler (handler_func).Callback, IntPtr.Zero, IntPtr.Zero);
}
internal static void OverrideDefaultHandler (GType gtype, string name, Delegate cb)
{
IntPtr closure = g_cclosure_new (cb, IntPtr.Zero, IntPtr.Zero);
gtype.EnsureClass ();
uint id = GetSignalId (name, gtype.Val);
g_signal_override_class_closure (id, gtype.Val, closure);
}
[DllImport("libgobject-2.0-0.dll")]
static extern IntPtr g_cclosure_new (Delegate cb, IntPtr data, IntPtr notify);
[DllImport("libgobject-2.0-0.dll")]
static extern IntPtr g_signal_get_invocation_hint (IntPtr instance);
[DllImport("libgobject-2.0-0.dll")]
static extern void g_signal_emitv (IntPtr instance_and_params, uint signal_id, uint gquark_detail, ref GLib.Value return_value);
[DllImport("libgobject-2.0-0.dll")]
static extern void g_signal_emitv (IntPtr instance_and_params, uint signal_id, uint gquark_detail, IntPtr return_value);
[DllImport("libgobject-2.0-0.dll")]
static extern uint g_signal_lookup (IntPtr name, IntPtr itype);
[DllImport("libgobject-2.0-0.dll")]
static extern void g_signal_override_class_closure (uint id, IntPtr gtype, IntPtr closure);
[DllImport("libgobject-2.0-0.dll")]
static extern void g_signal_query (uint signal_id, out Query query);
//better not to expose g_quark_from_static_string () due to memory allocation issues
[DllImport("libglib-2.0-0.dll")]
static extern uint g_quark_from_string (IntPtr str);
[DllImport("libgobject-2.0-0.dll")]
static extern ulong g_signal_add_emission_hook (uint signal_id, uint gquark_detail, EmissionHookNative hook_func, IntPtr hook_data, IntPtr data_destroy);
}
}