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TVirtualQConnection.h
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1 // @(#)root/base:$Id$
2 // Author: Vassil Vassilev 23/01/2017
3 
4 /*************************************************************************
5  * Copyright (C) 1995-2017, Rene Brun and Fons Rademakers. *
6  * All rights reserved. *
7  * *
8  * For the licensing terms see $ROOTSYS/LICENSE. *
9  * For the list of contributors see $ROOTSYS/README/CREDITS. *
10  *************************************************************************/
11 
12 #ifndef ROOT_TVirtualQConnection
13 #define ROOT_TVirtualQConnection
14 
15 #include "TList.h"
16 #include "TInterpreter.h"
17 
18 /// Mediates the link between the signal and the slot. It decouples the setting of
19 /// arguments and sending a signal.
20 ///
21 /// There are three different modes in argument setting required by TQObject's Emit/EmitVA:
22 /// setting integral types, setting array types and setting const char*.
23 class TVirtualQConnection : public TList {
24 protected:
25  virtual CallFunc_t *GetSlotCallFunc() const = 0;
26  virtual void SetArg(Long_t) = 0;
27  virtual void SetArg(ULong_t) = 0;
28  virtual void SetArg(Float_t) = 0;
29  virtual void SetArg(Double_t) = 0;
30  virtual void SetArg(Long64_t) = 0;
31  virtual void SetArg(ULong64_t) = 0;
32 
33  // Note: sets argument list (for potentially more than one arg).
34  virtual void SetArg(const Long_t *, Int_t = -1) = 0;
35  virtual void SetArg(const char *) = 0;
36  void SetArg(const void *ptr) { SetArg((Long_t)ptr); };
37 
38  // We should 'widen' all types to one of the SetArg overloads.
39  template <class T, class = typename std::enable_if<std::is_integral<T>::value>::type>
40  void SetArg(const T& val)
41  {
42  if (std::is_signed<T>::value)
43  SetArg((Long_t)val);
44  else
45  SetArg((ULong_t)val);
46  }
47 
48  // We pass arrays as Lont_t*. In the template instance we can deduce their
49  // size, too.
50  template <class T, class = typename std::enable_if<std::is_array<T>::value>::type>
51  void SetArg(const T* val)
52  {
53  constexpr size_t size = sizeof(val)/sizeof(val[0]);
54  static_assert(size > 0, "The array must have at least one element!");
55  SetArg((Long_t*)val, size);
56  }
57 
58  void SetArgsImpl() {} // SetArgsImpl terminator
59  template <typename T, typename... Ts> void SetArgsImpl(const T& arg, const Ts&... tail)
60  {
61  SetArg(arg);
62  SetArgsImpl(tail...);
63  }
64 public:
65  virtual void SendSignal() = 0;
66 
67  /// Unpacks the template parameter type and sets arguments of integral and array (scalar) type.
68  ///
69  template <typename... T> void SetArgs(const T&... args)
70  {
71  // Do not reset the arguments if we have no arguments to reset with.
72  // This is essential in order to support cases like:
73  // void f(int) {}; TQObject::Connect (... "f(int=12");
74  // The implementation will see we create a slot which has a 'default'
75  // argument and create a CallFunc with preset argument values to later call.
76  if (!sizeof...(args)) return;
77  gInterpreter->CallFunc_ResetArg(GetSlotCallFunc());
78  SetArgsImpl(args...);
79  }
80 
81  /// Sets an array of arguments passed as a pointer type and size. If nargs is not specified
82  /// the number of arguments expected by the slot is used.
83  ///
84  void SetArgs(const Long_t* argArray, Int_t nargs = -1)
85  {
86  SetArg(argArray, nargs);
87  }
88 };
89 
90 #endif
TVirtualQConnection::SetArg
virtual void SetArg(const char *)=0
TVirtualQConnection::SetArg
virtual void SetArg(Float_t)=0
TVirtualQConnection::SetArg
virtual void SetArg(ULong_t)=0
TVirtualQConnection::SetArg
virtual void SetArg(ULong64_t)=0
Long64_t
long long Long64_t
Definition: RtypesCore.h:73
gInterpreter
#define gInterpreter
Definition: TInterpreter.h:560
Float_t
float Float_t
Definition: RtypesCore.h:57
TVirtualQConnection::SetArg
virtual void SetArg(const Long_t *, Int_t=-1)=0
TList.h
TVirtualQConnection::SetArg
void SetArg(const void *ptr)
Definition: TVirtualQConnection.h:36
TVirtualQConnection::SetArgs
void SetArgs(const T &... args)
Unpacks the template parameter type and sets arguments of integral and array (scalar) type.
Definition: TVirtualQConnection.h:69
TVirtualQConnection::GetSlotCallFunc
virtual CallFunc_t * GetSlotCallFunc() const =0
TVirtualQConnection::SetArgsImpl
void SetArgsImpl()
Definition: TVirtualQConnection.h:58
TVirtualQConnection::SetArg
void SetArg(const T &val)
Definition: TVirtualQConnection.h:40
TVirtualQConnection::SetArg
virtual void SetArg(Double_t)=0
TVirtualQConnection::SetArg
virtual void SetArg(Long64_t)=0
Long_t
long Long_t
Definition: RtypesCore.h:54
TVirtualQConnection::SetArg
virtual void SetArg(Long_t)=0
TVirtualQConnection::SetArgsImpl
void SetArgsImpl(const T &arg, const Ts &... tail)
Definition: TVirtualQConnection.h:59
TVirtualQConnection::SendSignal
virtual void SendSignal()=0
TVirtualQConnection::SetArg
void SetArg(const T *val)
Definition: TVirtualQConnection.h:51
ULong_t
unsigned long ULong_t
Definition: RtypesCore.h:55
ULong64_t
unsigned long long ULong64_t
Definition: RtypesCore.h:74
Double_t
double Double_t
Definition: RtypesCore.h:59
TInterpreter.h
ROOT::Math::Chebyshev::T
double T(double x)
Definition: ChebyshevPol.h:34
TVirtualQConnection
Mediates the link between the signal and the slot.
Definition: TVirtualQConnection.h:23
TVirtualQConnection::SetArgs
void SetArgs(const Long_t *argArray, Int_t nargs=-1)
Sets an array of arguments passed as a pointer type and size.
Definition: TVirtualQConnection.h:84
type
int type
Definition: TGX11.cxx:121
TList
A doubly linked list.
Definition: TList.h:44
int