/*
* Greenshot - a free and open source screenshot tool
* Copyright (C) 2007-2013 Thomas Braun, Jens Klingen, Robin Krom
*
* For more information see: http://getgreenshot.org/
* The Greenshot project is hosted on Sourceforge: http://sourceforge.net/projects/greenshot/
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 1 of the License, or
* (at your option) any later version.
*
* 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see .
*/
using GreenshotPlugin;
using GreenshotPlugin.Core;
using System;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Runtime.Remoting;
using System.Runtime.Remoting.Messaging;
using System.Runtime.Remoting.Proxies;
using System.Windows.Forms;
namespace Greenshot.Interop
{
///
/// Wraps a late-bound COM server.
///
public sealed class COMWrapper : RealProxy, IDisposable, IRemotingTypeInfo
{
private const int MK_E_UNAVAILABLE = -2147221021;
private const int CO_E_CLASSSTRING = -2147221005;
public const int RPC_E_CALL_REJECTED = unchecked((int)0x80010001);
public const int RPC_E_FAIL = unchecked((int)0x80004005);
#region Private Data
///
/// Holds reference to the actual COM object which is wrapped by this proxy
///
private object _COMObject;
///
/// Type of the COM object, set on constructor after getting the COM reference
///
private Type _COMType;
///
/// The type of which method calls are intercepted and executed on the COM object.
///
private Type _InterceptType;
///
/// The humanly readable target name
///
private string _TargetName;
#endregion Private Data
[DllImport("ole32.dll")]
private static extern int ProgIDFromCLSID([In] ref Guid clsid, [MarshalAs(UnmanagedType.LPWStr)] out string lplpszProgID);
// Converts failure HRESULTs to exceptions:
[DllImport("oleaut32", PreserveSig = false)]
private static extern void GetActiveObject(ref Guid rclsid, IntPtr pvReserved, [MarshalAs(UnmanagedType.IUnknown)] out Object ppunk);
#region Construction
///
/// Gets a COM object and returns the transparent proxy which intercepts all calls to the object
///
/// Interface which defines the method and properties to intercept
/// Transparent proxy to the real proxy for the object
/// The must be an interface decorated with the attribute.
public static T GetInstance()
{
Type type = typeof(T);
if (null == type)
{
throw new ArgumentNullException("type");
}
if (!type.IsInterface)
{
throw new ArgumentException("The specified type must be an interface.", "type");
}
ComProgIdAttribute progIDAttribute = ComProgIdAttribute.GetAttribute(type);
if (null == progIDAttribute || null == progIDAttribute.Value || 0 == progIDAttribute.Value.Length)
{
throw new ArgumentException("The specified type must define a ComProgId attribute.", "type");
}
string progId = progIDAttribute.Value;
object comObject = null;
// Convert from clsid to Prog ID, if needed
if (progId.StartsWith("clsid:"))
{
Guid guid = new Guid(progId.Substring(6));
int result = ProgIDFromCLSID(ref guid, out progId);
if (result != 0)
{
// Restore progId, as it's overwritten
progId = progIDAttribute.Value;
try
{
GetActiveObject(ref guid, IntPtr.Zero, out comObject);
}
catch (Exception)
{
LOG.WarnFormat("Error {0} getting instance for class id {1}", result, progIDAttribute.Value);
}
if (comObject == null)
{
LOG.WarnFormat("Error {0} getting progId {1}", result, progIDAttribute.Value);
}
}
else
{
LOG.InfoFormat("Mapped {0} to progId {1}", progIDAttribute.Value, progId);
}
}
if (comObject == null)
{
try
{
comObject = Marshal.GetActiveObject(progId);
}
catch (COMException comE)
{
if (comE.ErrorCode == MK_E_UNAVAILABLE)
{
LOG.DebugFormat("No current instance of {0} object available.", progId);
}
else if (comE.ErrorCode == CO_E_CLASSSTRING)
{
LOG.WarnFormat("Unknown progId {0}", progId);
}
else
{
LOG.Warn("Error getting active object for " + progIDAttribute.Value, comE);
}
}
catch (Exception e)
{
LOG.Warn("Error getting active object for " + progIDAttribute.Value, e);
}
}
if (comObject != null)
{
if (comObject is IDispatch)
{
COMWrapper wrapper = new COMWrapper(comObject, type, progIDAttribute.Value);
return (T)wrapper.GetTransparentProxy();
}
else
{
return (T)comObject;
}
}
return default(T);
}
///
/// A simple create instance, doesn't create a wrapper!!
///
/// T
public static T CreateInstance()
{
Type type = typeof(T);
if (null == type)
{
throw new ArgumentNullException("type");
}
if (!type.IsInterface)
{
throw new ArgumentException("The specified type must be an interface.", "type");
}
ComProgIdAttribute progIDAttribute = ComProgIdAttribute.GetAttribute(type);
if (null == progIDAttribute || null == progIDAttribute.Value || 0 == progIDAttribute.Value.Length)
{
throw new ArgumentException("The specified type must define a ComProgId attribute.", "type");
}
string progId = progIDAttribute.Value;
Type comType = null;
if (progId.StartsWith("clsid:"))
{
Guid guid = new Guid(progId.Substring(6));
try
{
comType = Type.GetTypeFromCLSID(guid);
}
catch (Exception ex)
{
LOG.WarnFormat("Error {1} type for {0}", progId, ex.Message);
}
}
else
{
try
{
comType = Type.GetTypeFromProgID(progId, true);
}
catch (Exception ex)
{
LOG.WarnFormat("Error {1} type for {0}", progId, ex.Message);
}
}
object comObject = null;
if (comType != null)
{
try
{
comObject = Activator.CreateInstance(comType);
if (comObject != null)
{
LOG.DebugFormat("Created new instance of {0} object.", progId);
}
}
catch (Exception e)
{
LOG.WarnFormat("Error {1} creating object for {0}", progId, e.Message);
}
}
if (comObject != null)
{
return (T)comObject;
}
return default(T);
}
///
/// Gets or creates a COM object and returns the transparent proxy which intercepts all calls to the object
/// The ComProgId can be a normal ComProgId or a GUID prefixed with "clsid:"
///
/// Interface which defines the method and properties to intercept
/// Transparent proxy to the real proxy for the object
/// The must be an interface decorated with the attribute.
public static T GetOrCreateInstance()
{
Type type = typeof(T);
if (null == type)
{
throw new ArgumentNullException("type");
}
if (!type.IsInterface)
{
throw new ArgumentException("The specified type must be an interface.", "type");
}
ComProgIdAttribute progIDAttribute = ComProgIdAttribute.GetAttribute(type);
if (null == progIDAttribute || null == progIDAttribute.Value || 0 == progIDAttribute.Value.Length)
{
throw new ArgumentException("The specified type must define a ComProgId attribute.", "type");
}
object comObject = null;
Type comType = null;
string progId = progIDAttribute.Value;
Guid guid = Guid.Empty;
// Convert from clsid to Prog ID, if needed
if (progId.StartsWith("clsid:"))
{
guid = new Guid(progId.Substring(6));
int result = ProgIDFromCLSID(ref guid, out progId);
if (result != 0)
{
// Restore progId, as it's overwritten
progId = progIDAttribute.Value;
try
{
GetActiveObject(ref guid, IntPtr.Zero, out comObject);
}
catch (Exception)
{
LOG.WarnFormat("Error {0} getting instance for class id {1}", result, progIDAttribute.Value);
}
if (comObject == null)
{
LOG.WarnFormat("Error {0} getting progId {1}", result, progIDAttribute.Value);
}
}
else
{
LOG.InfoFormat("Mapped {0} to progId {1}", progIDAttribute.Value, progId);
}
}
if (comObject == null)
{
if (!progId.StartsWith("clsid:"))
{
try
{
comObject = Marshal.GetActiveObject(progId);
}
catch (COMException comE)
{
if (comE.ErrorCode == MK_E_UNAVAILABLE)
{
LOG.DebugFormat("No current instance of {0} object available.", progId);
}
else if (comE.ErrorCode == CO_E_CLASSSTRING)
{
LOG.WarnFormat("Unknown progId {0} (application not installed)", progId);
return default(T);
}
else
{
LOG.Warn("Error getting active object for " + progId, comE);
}
}
catch (Exception e)
{
LOG.Warn("Error getting active object for " + progId, e);
}
}
}
// Did we get the current instance? If not, try to create a new
if (comObject == null)
{
try
{
comType = Type.GetTypeFromProgID(progId, true);
}
catch (Exception ex)
{
if (Guid.Empty != guid)
{
comType = Type.GetTypeFromCLSID(guid);
}
else
{
LOG.Warn("Error type for " + progId, ex);
}
}
if (comType != null)
{
try
{
comObject = Activator.CreateInstance(comType);
if (comObject != null)
{
LOG.DebugFormat("Created new instance of {0} object.", progId);
}
}
catch (Exception e)
{
LOG.Warn("Error creating object for " + progId, e);
}
}
}
if (comObject != null)
{
if (comObject is IDispatch)
{
COMWrapper wrapper = new COMWrapper(comObject, type, progIDAttribute.Value);
return (T)wrapper.GetTransparentProxy();
}
else
{
return (T)comObject;
}
}
return default(T);
}
///
/// Wrap an object and return the transparent proxy which intercepts all calls to the object
///
/// An object to intercept
/// Interface which defines the method and properties to intercept
/// Transparent proxy to the real proxy for the object
private static object Wrap(object comObject, Type type, string targetName)
{
if (null == comObject)
{
throw new ArgumentNullException("comObject");
}
if (null == type)
{
throw new ArgumentNullException("type");
}
COMWrapper wrapper = new COMWrapper(comObject, type, targetName);
return wrapper.GetTransparentProxy();
}
///
/// Constructor
///
///
/// The COM object to wrap.
///
///
/// The interface type to impersonate.
///
private COMWrapper(object comObject, Type type, string targetName)
: base(type)
{
_COMObject = comObject;
_COMType = comObject.GetType();
_InterceptType = type;
_TargetName = targetName;
}
#endregion Construction
#region Clean up
///
/// If is not called, we need to make
/// sure that the COM object is still cleaned up.
///
~COMWrapper()
{
LOG.DebugFormat("Finalize {0}", _InterceptType.ToString());
Dispose(false);
}
///
/// Cleans up the COM object.
///
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
///
/// Release the COM reference
///
///
/// if this was called from the
/// interface.
///
private void Dispose(bool disposing)
{
if (null != _COMObject)
{
LOG.DebugFormat("Disposing {0}", _InterceptType.ToString());
if (Marshal.IsComObject(_COMObject))
{
try
{
while (Marshal.ReleaseComObject(_COMObject) > 0) ;
}
catch (Exception ex)
{
LOG.WarnFormat("Problem releasing {0}", _COMType);
LOG.Warn("Error: ", ex);
}
}
_COMObject = null;
}
}
#endregion Clean up
#region Object methods
///
/// Returns a string representing the wrapped object.
///
///
/// The full name of the intercepted type.
///
public override string ToString()
{
return _InterceptType.FullName;
}
///
/// Returns the hash code of the wrapped object.
///
///
/// The hash code of the wrapped object.
///
public override int GetHashCode()
{
return _COMObject.GetHashCode();
}
///
/// Compares this object to another.
///
///
/// The value to compare to.
///
///
/// if the objects are equal.
///
public override bool Equals(object value)
{
if (null != value && RemotingServices.IsTransparentProxy(value))
{
COMWrapper wrapper = RemotingServices.GetRealProxy(value) as COMWrapper;
if (null != wrapper)
{
return _COMObject == wrapper._COMObject;
}
}
return base.Equals(value);
}
///
/// Returns the base type for a reference type.
///
///
/// The reference type.
///
///
/// The base value type.
///
///
/// is .
///
private static Type GetByValType(Type byRefType)
{
if (null == byRefType)
{
throw new ArgumentNullException("byRefType");
}
if (byRefType.IsByRef)
{
string name = byRefType.FullName;
name = name.Substring(0, name.Length - 1);
byRefType = byRefType.Assembly.GetType(name, true);
}
return byRefType;
}
#endregion Object methods
///
/// Use this static method to cast a wrapped proxy to a new wrapper proxy of the supplied type.
/// In English, use this to cast you base "COM" interface to a specialized interface.
/// E.G. Outlook Item -> MailItem
///
/// the type you want to cast to
/// The wrapper interface, e.g. something you got back from calling GetItem
/// A new wrapper proxy for the specified type
public static T Cast(object wrapperProxy)
{
if (wrapperProxy == null)
{
return default(T);
}
Type newType = typeof(T);
COMWrapper oldWrapper = RemotingServices.GetRealProxy(wrapperProxy) as COMWrapper;
if (oldWrapper == null)
{
throw new ArgumentException("wrapper proxy was no COMWrapper");
}
if (oldWrapper._InterceptType.IsAssignableFrom(newType))
{
COMWrapper newWrapper = new COMWrapper(oldWrapper._COMObject, newType, oldWrapper._TargetName);
return (T)newWrapper.GetTransparentProxy();
}
throw new InvalidCastException(string.Format("{0} is not assignable from {1}", oldWrapper._InterceptType, newType));
}
///
/// Returns the "com" type of the wrapperproxy, making it possible to perform reflection on it.
///
/// wrapperProxy to get the type from
/// Type
public static Type GetUnderlyingTypeForWrapper(object wrapperProxy)
{
Type returnType = null;
COMWrapper wrapper = RemotingServices.GetRealProxy(wrapperProxy) as COMWrapper;
if (wrapper != null)
{
IDispatch dispatch = wrapper._COMObject as IDispatch;
if (dispatch != null)
{
int result = dispatch.GetTypeInfo(0, 0, out returnType);
if (result != 0)
{
LOG.DebugFormat("GetTypeInfo : 0x{0} ({1})", result.ToString("X"), result);
}
}
}
return returnType;
}
///
/// Return the Type of a IDispatch
///
/// IDispatch to get the type object for
/// Type of the IDispatch
public static Type GetUnderlyingType(IDispatch dispatch)
{
Type returnType = null;
if (dispatch != null)
{
int result = dispatch.GetTypeInfo(0, 0, out returnType);
if (result != 0)
{
LOG.DebugFormat("GetTypeInfo : 0x{0} ({1})", result.ToString("X"), result);
}
}
return returnType;
}
///
/// Dump the Type-Information for the Type to the log, this uses reflection
///
/// Type to inspect
public static void DumpTypeInfo(Type type)
{
LOG.InfoFormat("Type information for Type with name: {0}", type.Name);
try
{
foreach (MemberInfo memberInfo in type.GetMembers())
{
LOG.InfoFormat("Member: {0};", memberInfo.ToString());
}
}
catch (Exception memberException)
{
LOG.Error(memberException);
}
try
{
foreach (PropertyInfo propertyInfo in type.GetProperties())
{
LOG.InfoFormat("Property: {0};", propertyInfo.ToString());
}
}
catch (Exception propertyException)
{
LOG.Error(propertyException);
}
try
{
foreach (FieldInfo fieldInfo in type.GetFields())
{
LOG.InfoFormat("Field: {0};", fieldInfo.ToString());
}
}
catch (Exception fieldException)
{
LOG.Error(fieldException);
}
LOG.InfoFormat("Type information end.");
}
///
/// Intercept method calls
///
///
/// Contains information about the method being called
///
///
/// A .
///
public override IMessage Invoke(IMessage myMessage)
{
IMethodCallMessage callMessage = myMessage as IMethodCallMessage;
if (null == callMessage)
{
LOG.DebugFormat("Message type not implemented: {0}", myMessage.GetType().ToString());
return null;
}
MethodInfo method = callMessage.MethodBase as MethodInfo;
if (null == method)
{
LOG.DebugFormat("Unrecognized Invoke call: {0}", callMessage.MethodBase.ToString());
return null;
}
object returnValue = null;
object[] outArgs = null;
int outArgsCount = 0;
string methodName = method.Name;
Type returnType = method.ReturnType;
BindingFlags flags = BindingFlags.InvokeMethod;
int argCount = callMessage.ArgCount;
object invokeObject;
Type invokeType;
Type byValType;
object[] args;
object arg;
COMWrapper[] originalArgs;
COMWrapper wrapper;
ParameterModifier[] argModifiers = null;
ParameterInfo[] parameters = null;
ParameterInfo parameter;
if ("Dispose" == methodName && 0 == argCount && typeof(void) == returnType)
{
Dispose();
}
else if ("ToString" == methodName && 0 == argCount && typeof(string) == returnType)
{
returnValue = ToString();
}
else if ("GetType" == methodName && 0 == argCount && typeof(Type) == returnType)
{
returnValue = _InterceptType;
}
else if ("GetHashCode" == methodName && 0 == argCount && typeof(int) == returnType)
{
returnValue = GetHashCode();
}
else if ("Equals" == methodName && 1 == argCount && typeof(bool) == returnType)
{
returnValue = Equals(callMessage.Args[0]);
}
else if (1 == argCount && typeof(void) == returnType && (methodName.StartsWith("add_") || methodName.StartsWith("remove_")))
{
bool removeHandler = methodName.StartsWith("remove_");
methodName = methodName.Substring(removeHandler ? 7 : 4);
Delegate handler = callMessage.InArgs[0] as Delegate;
if (null == handler)
{
return new ReturnMessage(new ArgumentNullException("handler"), callMessage);
}
}
else
{
invokeObject = _COMObject;
invokeType = _COMType;
if (methodName.StartsWith("get_"))
{
// Property Get
methodName = methodName.Substring(4);
flags = BindingFlags.GetProperty;
args = callMessage.InArgs;
}
else if (methodName.StartsWith("set_"))
{
// Property Set
methodName = methodName.Substring(4);
flags = BindingFlags.SetProperty;
args = callMessage.InArgs;
}
else
{
args = callMessage.Args;
if (null != args && 0 != args.Length)
{
// Modifiers for ref / out parameters
argModifiers = new ParameterModifier[1];
argModifiers[0] = new ParameterModifier(args.Length);
parameters = method.GetParameters();
for (int i = 0; i < parameters.Length; i++)
{
parameter = parameters[i];
if (parameter.IsOut || parameter.ParameterType.IsByRef)
{
argModifiers[0][i] = true;
outArgsCount++;
}
}
if (0 == outArgsCount)
{
argModifiers = null;
}
}
}
// Un-wrap wrapped COM objects before passing to the method
if (null == args || 0 == args.Length)
{
originalArgs = null;
}
else
{
originalArgs = new COMWrapper[args.Length];
for (int i = 0; i < args.Length; i++)
{
if (null != args[i] && RemotingServices.IsTransparentProxy(args[i]))
{
wrapper = RemotingServices.GetRealProxy(args[i]) as COMWrapper;
if (null != wrapper)
{
originalArgs[i] = wrapper;
args[i] = wrapper._COMObject;
}
}
else if (0 != outArgsCount && argModifiers[0][i])
{
byValType = GetByValType(parameters[i].ParameterType);
if (byValType.IsInterface)
{
// If we're passing a COM object by reference, and
// the parameter is null, we need to pass a
// DispatchWrapper to avoid a type mismatch exception.
if (null == args[i])
{
args[i] = new DispatchWrapper(null);
}
}
else if (typeof(Decimal) == byValType)
{
// If we're passing a decimal value by reference,
// we need to pass a CurrencyWrapper to avoid a
// type mismatch exception.
// http://support.microsoft.com/?kbid=837378
args[i] = new CurrencyWrapper(args[i]);
}
}
}
}
do
{
try
{
returnValue = invokeType.InvokeMember(methodName, flags, null, invokeObject, args, argModifiers, null, null);
break;
}
catch (Exception ex)
{
// Test for rejected
COMException comEx = ex as COMException;
if (comEx == null)
{
comEx = ex.InnerException as COMException;
}
if (comEx != null && (comEx.ErrorCode == RPC_E_CALL_REJECTED || comEx.ErrorCode == RPC_E_FAIL))
{
string destinationName = _TargetName;
// Try to find a "catchy" name for the rejecting application
if (destinationName != null && destinationName.Contains("."))
{
destinationName = destinationName.Substring(0, destinationName.IndexOf("."));
}
if (destinationName == null)
{
destinationName = _InterceptType.FullName;
}
DialogResult result = MessageBox.Show(string.Format("The destination {0} rejected Greenshot access, probably a dialog is open. Close the dialog and try again.",
destinationName), "Greenshot access rejected", MessageBoxButtons.OKCancel, MessageBoxIcon.Exclamation);
if (result == DialogResult.OK)
{
continue;
}
}
// Not rejected OR pressed cancel
return new ReturnMessage(ex, callMessage);
}
} while (true);
// Handle enum and interface return types
if (null != returnValue)
{
if (returnType.IsInterface)
{
// Wrap the returned value in an intercepting COM wrapper
if (Marshal.IsComObject(returnValue))
{
returnValue = Wrap(returnValue, returnType, _TargetName);
}
}
else if (returnType.IsEnum)
{
// Convert to proper Enum type
returnValue = Enum.Parse(returnType, returnValue.ToString());
}
}
// Handle out args
if (0 != outArgsCount)
{
outArgs = new object[args.Length];
for (int i = 0; i < parameters.Length; i++)
{
if (!argModifiers[0][i])
{
continue;
}
arg = args[i];
if (null == arg)
{
continue;
}
parameter = parameters[i];
wrapper = null;
byValType = GetByValType(parameter.ParameterType);
if (typeof(Decimal) == byValType)
{
if (arg is CurrencyWrapper)
{
arg = ((CurrencyWrapper)arg).WrappedObject;
}
}
else if (byValType.IsEnum)
{
arg = Enum.Parse(byValType, arg.ToString());
}
else if (byValType.IsInterface)
{
if (Marshal.IsComObject(arg))
{
wrapper = originalArgs[i];
if (null != wrapper && wrapper._COMObject != arg)
{
wrapper.Dispose();
wrapper = null;
}
if (null == wrapper)
{
wrapper = new COMWrapper(arg, byValType, _TargetName);
}
arg = wrapper.GetTransparentProxy();
}
}
outArgs[i] = arg;
}
}
}
return new ReturnMessage(returnValue, outArgs, outArgsCount, callMessage.LogicalCallContext, callMessage);
}
///
/// Implementation for the interface IRemotingTypeInfo
/// This makes it possible to cast the COMWrapper
///
/// Type to cast to
/// object to cast
///
public bool CanCastTo(Type toType, object o)
{
bool returnValue = _InterceptType.IsAssignableFrom(toType);
return returnValue;
}
///
/// Implementation for the interface IRemotingTypeInfo
///
public string TypeName
{
get
{
throw new NotSupportedException();
}
set
{
throw new NotSupportedException();
}
}
}
}