/usr/include/sigc++-2.0/sigc++/functors/slot_base.h is in libsigc++-2.0-dev 2.4.0-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 | /*
* Copyright 2003, The libsigc++ Development Team
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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 library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#ifndef _SIGC_SLOT_BASE_HPP_
#define _SIGC_SLOT_BASE_HPP_
#include <sigc++config.h>
#include <sigc++/trackable.h>
#include <sigc++/functors/functor_trait.h>
namespace sigc
{
namespace internal {
typedef void* (*hook)(void*);
/** Internal representation of a slot.
* Derivations of this class can be considered as a link
* between a slot and the functor that the slot should
* execute in operator(). This link is needed because in
* libsigc++2 the slot doesn't necessarily have exactly the
* same function signature as the functor thus allowing for
* implicit conversions.
* The base class slot_rep serves the purpose to
* - form a common pointer type (slot_rep*),
* - offer the possibility to create duplicates (dup()),
* - offer a notification callback (notify()),
* - implement some of slot_base's interface that depends
* on the notification callback, i.e.
* -# the possibility to set a single parent with a callback
* (set_parent()) that is executed from notify(),
* -# a generic function pointer, call_, that is simply
* set to zero in notify() to invalidate the slot.
* slot_rep inherits trackable so that connection objects can
* refer to the slot and are notified when the slot is destroyed.
*/
struct SIGC_API slot_rep : public trackable
{
/* NB: Instead of slot_rep we could inherit slot_base from trackable.
* However, a simple benchmark seems to indicate that this slows
* down dereferencing of slot list iterators. Martin. */
/// Callback that invokes the contained functor.
/* This can't be a virtual function since number of arguments
* must be flexible. We use function pointers to slot_call::call_it()
* instead. call_ is set to zero to indicate that the slot is invalid.
*/
hook call_;
/// Callback that detaches the slot_rep object from referred trackables and destroys it.
/* This could be a replaced by a virtual dtor. However since this struct is
* crucual for the efficiency of the whole library we want to avoid this.
*/
hook destroy_;
/** Callback that makes a deep copy of the slot_rep object.
* @return A deep copy of the slot_rep object.
*/
hook dup_;
/** Callback of parent_. */
hook cleanup_;
/** Parent object whose callback cleanup_ is executed on notification. */
void* parent_;
inline slot_rep(hook call__, hook destroy__, hook dup__)
: call_(call__), destroy_(destroy__), dup_(dup__), cleanup_(0), parent_(0) {}
inline ~slot_rep()
{ destroy(); }
// only MSVC needs this to guarantee that all new/delete are executed from the DLL module
#ifdef SIGC_NEW_DELETE_IN_LIBRARY_ONLY
void* operator new(size_t size_);
void operator delete(void* p);
#endif
/** Destroys the slot_rep object (but doesn't delete it).
*/
inline void destroy()
{ if (destroy_) (*destroy_)(this); }
/** Makes a deep copy of the slot_rep object.
* @return A deep copy of the slot_rep object.
*/
inline slot_rep* dup() const
{ return reinterpret_cast<slot_rep*>((*dup_)(const_cast<slot_rep*>(this))); }
/** Set the parent with a callback.
* slots have one parent exclusively.
* @param parent The new parent.
* @param cleanup The callback to execute from notify().
*/
inline void set_parent(void* parent, hook cleanup)
{
parent_ = parent;
cleanup_ = cleanup;
}
/// Invalidates the slot and executes the parent's cleanup callback.
void disconnect();
/** Callback that invalidates the slot.
* This callback is registered in every object of a trackable
* inherited type that is referred by this slot_rep object.
* It is executed when the slot becomes invalid because of some
* referred object dying.
* @param data The slot_rep object that is becoming invalid (@p this).
*/
static void* notify(void* data);
};
/** Functor used to add a dependency to a trackable.
* Consequently slot_rep::notify() gets executed when the
* trackable is destroyed or overwritten.
*/
struct SIGC_API slot_do_bind
{
/** The slot_rep object trackables should notify on destruction. */
slot_rep* rep_;
/** Construct a slot_do_bind functor.
* @param rep The slot_rep object trackables should notify on destruction.
*/
inline slot_do_bind(slot_rep* rep) : rep_(rep) {}
/** Adds a dependency to @p t.
* @param t The trackable object to add a callback to.
*/
inline void operator()(const trackable* t) const
{ t->add_destroy_notify_callback(rep_, &slot_rep::notify); }
};
/// Functor used to remove a dependency from a trackable.
struct SIGC_API slot_do_unbind
{
/** The slot_rep object trackables don't need to notify on destruction any more. */
slot_rep* rep_;
/** Construct a slot_do_unbind functor.
* @param rep The slot_rep object trackables don't need to notify on destruction any more.
*/
inline slot_do_unbind(slot_rep* rep) : rep_(rep) {}
/** Removes a dependency from @p t.
* @param t The trackable object to remove the callback from.
*/
inline void operator()(const trackable* t) const
{ t->remove_destroy_notify_callback(rep_); }
};
} //namespace internal
/** @defgroup slot Slots
* Slots are type-safe representations of callback methods and functions.
* A Slot can be constructed from any function object or function, regardless of
* whether it is a global function, a member method, static, or virtual.
*
* Use the sigc::mem_fun() and sigc::ptr_fun() template functions to get a sigc::slot, like so:
*
* @code
* sigc::slot<void, int> sl = sigc::mem_fun(someobj, &SomeClass::somemethod);
* @endcode
*
* or
*
* @code
* sigc::slot<void, int> sl = sigc::ptr_fun(&somefunction);
* @endcode
*
* or
*
* @code
* m_Button.signal_clicked().connect( sigc::mem_fun(*this, &MyWindow::on_button_clicked) );
* @endcode
*
* The compiler will complain if SomeClass::somemethod, etc. have the wrong signature.
*
* You can also pass slots as method parameters where you might normally pass a function pointer.
*
* A C++11 lambda expression is a functor (function object). It is automatically
* wrapped in a slot, if it is connected to a signal.
* @code
* auto on_response = [&someobj] (int response_id)
* {
* someobj.somemethod(response_id);
* somefunction(response_id);
* };
* m_Dialog.signal_response().connect(on_response);
* @endcode
*
* If you connect a C++11 lambda expression or a std::function<> instance to
* a signal or assign it to a slot,
* - if the return type is not void, you must use the #SIGC_FUNCTORS_DEDUCE_RESULT_TYPE_WITH_DECLTYPE macro,
* - if your functor contains references to sigc::trackable derived objects,
* those objects will not be tracked, unless you also use sigc::track_obj().
*
* @ingroup sigcfunctors
*/
/** Base type for slots.
* slot_base integrates most of the interface of the derived
* sigc::slot templates. slots
* can be connected to signals, be disconnected at some later point
* (disconnect()) and temporarily be blocked (block(), unblock()).
* The validity of a slot can be tested with empty().
*
* The internal representation of a sigc::internal::slot_rep derived
* type is built from slot_base's derivations. set_parent() is used to
* register a notification callback that is executed when the slot gets
* invalid. add_destroy_notify_callback() is used by connection objects
* to add a notification callback that is executed on destruction.
*
* @ingroup slot
*/
class SIGC_API slot_base : public functor_base
{
typedef internal::slot_rep rep_type;
public:
/// Constructs an empty slot.
slot_base();
/** Constructs a slot from an existing slot_rep object.
* @param rep The slot_rep object this slot should contain.
*/
explicit slot_base(rep_type* rep);
/** Constructs a slot, copying an existing one.
* @param src The existing slot to copy.
*/
slot_base(const slot_base& src);
~slot_base();
/** Tests whether a slot is null, because the default constructor was used.
* Test a slot for null like so:
* @code
* if(slot)
* do_something()
* @endcode
*/
operator bool() const;
/** Sets the parent of this slot.
* This function is used by signals to register a notification callback.
* This notification callback is executed when the slot becomes invalid
* because of some referred object dying.
* @param parent The new parent.
* @param cleanup The notification callback.
*/
void set_parent(void* parent, void* (*cleanup)(void*)) const;
typedef trackable::func_destroy_notify func_destroy_notify;
/** Add a callback that is executed (notified) when the slot is detroyed.
* This function is used internally by connection objects.
* @param data Passed into func upon notification.
* @param func Callback executed upon destruction of the object.
*/
void add_destroy_notify_callback(void* data, func_destroy_notify func) const;
/** Remove a callback previously installed with add_destroy_notify_callback().
* The callback is not executed.
* @param data Parameter passed into previous call to add_destroy_notify_callback().
*/
void remove_destroy_notify_callback(void* data) const;
/** Returns whether the slot is invalid.
* @return @p true if the slot is invalid (empty).
*/
inline bool empty() const
{ return (!rep_ || !rep_->call_); }
/** Returns whether the slot is blocked.
* @return @p true if the slot is blocked.
*/
inline bool blocked() const
{ return blocked_; }
/** Sets the blocking state.
* If @e should_block is @p true then the blocking state is set.
* Subsequent calls to slot::operator()() don't invoke the functor
* contained by this slot until unblock() or block() with
* @e should_block = @p false is called.
* @param should_block Indicates whether the blocking state should be set or unset.
* @return @p true if the slot was in blocking state before.
*/
bool block(bool should_block = true);
/** Unsets the blocking state.
* @return @p true if the slot was in blocking state before.
*/
bool unblock();
/** Disconnects the slot.
* Invalidates the slot and notifies the parent.
*/
void disconnect();
//The Tru64 and Solaris Forte 5.5 compilers needs this operator=() to be public. I'm not sure why, or why it needs to be protected usually. murrayc.
//See bug #168265.
//protected:
/** Overrides this slot making a copy from another slot.
* @param src The slot from which to make a copy.
* @return @p this.
*/
slot_base& operator=(const slot_base& src);
public: // public to avoid template friend declarations
/** Typed slot_rep object that contains a functor. */
mutable rep_type *rep_;
/** Indicates whether the slot is blocked. */
bool blocked_;
};
} //namespace sigc
#endif //_SIGC_SLOT_BASE_HPP_
|