LUMIERA.clone/src/proc/control/command.cpp

416 lines
11 KiB
C++

/*
Command - Key abstraction for proc/edit operations and UNDO management
Copyright (C) Lumiera.org
2009, Hermann Vosseler <Ichthyostega@web.de>
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 2 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, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
* *****************************************************/
/** @file command.cpp
** Implementation of the command frontend.
** Within this file, the implementation level of the command frontend
** is linked to the implementation of the command registry. Client code
** is shielded from those implementation classes and need only include
** command.hpp
**
** More specifically, the actual number and type of arguments and the
** concrete functions implementing the command operation are known only
** at the time of the command definition; this detailed type information
** is erased afterwards, allowing client code to use a simple frontend.
**
** @see command.hpp
** @see command-registry.hpp
**
*/
#include "lib/util.hpp"
#include "lib/error.hpp"
#include "lib/symbol.hpp"
#include "include/logging.h"
#include "proc/control/command.hpp"
#include "proc/control/command-def.hpp"
#include "proc/control/command-impl.hpp"
#include "proc/control/command-registry.hpp"
#include "proc/control/command-impl-clone-builder.hpp"
#include "proc/control/handling-pattern.hpp"
#include <boost/format.hpp>
#include <sstream>
#include <string>
using std::ostringstream;
using std::string;
using boost::format;
using boost::str;
using util::cStr;
namespace proc {
namespace control {
namespace error = lumiera::error;
LUMIERA_ERROR_DEFINE (INVALID_COMMAND, "Unknown or insufficiently defined command");
LUMIERA_ERROR_DEFINE (DUPLICATE_COMMAND, "Attempt to redefine an already existing command definition");
LUMIERA_ERROR_DEFINE (INVALID_ARGUMENTS, "Arguments provided for binding doesn't match stored command function parameters");
LUMIERA_ERROR_DEFINE (UNBOUND_ARGUMENTS, "Command mutation functor not yet usable, because arguments aren't bound");
LUMIERA_ERROR_DEFINE (MISSING_MEMENTO, "Undo functor not yet usable, because no undo state has been captured");
namespace { // some common error checks...
void
___check_notBottom (const Command *handle, lib::Literal operation_descr)
{
REQUIRE (handle);
if (!handle->isValid())
throw error::Invalid (operation_descr+" an undefined command"
, LUMIERA_ERROR_INVALID_COMMAND);
}
void
___check_isBound (const Command *handle)
{
REQUIRE (handle);
if (!handle->canExec())
throw error::State ("Lifecycle error: command arguments not bound"
, LUMIERA_ERROR_UNBOUND_ARGUMENTS);
}
}
/** storage for the singleton factory used to access CommandRegistry */
lib::Singleton<CommandRegistry> CommandRegistry::instance;
Command::~Command() { }
/** Access existing command for use.
* @throw error::Invalid if command not
* registered or incompletely defined.
*/
Command
Command::get (Symbol cmdID)
{
Command cmd = CommandRegistry::instance().queryIndex (cmdID);
static format fmt("Command \"%s\" not found");
if (!cmd)
throw error::Invalid(str(fmt % cmdID), LUMIERA_ERROR_INVALID_COMMAND);
ENSURE (cmdID == CommandRegistry::instance().findDefinition(cmd));
return cmd;
}
/** @todo this is a "nice-to-have"; it would allow to call a function as a command,
* almost as if it was a normal function. But this function needs to be defined
* as a command previously, together with a suitable UNDO function. Moreover
* this would probably require to build an additional index;
* thus this feature is unimplemented for the time being.
*/
Command
Command::get (FuncPtr)
{
UNIMPLEMENTED ("find a command definition which was based on the given function (ptr)");
}
/** @internal just query an existing instance, if any. */
Command
Command::fetchDef (Symbol cmdID)
{
return CommandRegistry::instance().queryIndex (cmdID);
}
/** @internal make a command ready for use. Typically to be invoked
* through CommandDef during the definition stage, but also used
* for activating clone instances.
* @param cmdID new ID for creating a separate command registration when provided
* @throw error::Logic when \c this is already activated. */
void
Command::activate (shared_ptr<CommandImpl> const& implFrame, Symbol cmdID)
{
REQUIRE (implFrame);
static format fmt("Command \"%s\" already defined");
if (this->isValid())
duplicate_detected (cmdID);
_Handle::activate (implFrame);
if (cmdID)
CommandRegistry::instance().track (cmdID, *this);
INFO (command, "Command \"%s\" defined OK", cStr(*this));
}
/** create an independent clone copy of this command
* and register it as new command definition under a different ID */
Command
Command::storeDef (Symbol newCmdID) const
{
CommandRegistry& registry = CommandRegistry::instance();
___check_notBottom (this,"Cloning");
if (registry.queryIndex (newCmdID))
duplicate_detected (newCmdID);
Command cloneDefinition;
cloneDefinition.activate (registry.createCloneImpl(this->impl()), newCmdID);
ENSURE (cloneDefinition);
return cloneDefinition;
}
/** create independent clone copy of this command */
Command
Command::newInstance () const
{
___check_notBottom (this,"Cloning");
CommandRegistry& registry = CommandRegistry::instance();
shared_ptr<CommandImpl> cloneImpl = registry.createCloneImpl(this->impl());
Command clone;
clone.activate (cloneImpl);
ENSURE (clone);
return clone;
}
/** @note this bit of implementation from CommandRegistry rather
* heavily relies on implementation details from CommandImpl and
* the help of CommandImplCloneBuilder and ArgumentHolder. It's
* implemented within command.cpp to keep the includes of
* the handling patterns clean. */
shared_ptr<CommandImpl>
CommandRegistry::createCloneImpl (CommandImpl const& refObject)
{
CommandImplCloneBuilder cloneBuilder(allocator_);
refObject.prepareClone(cloneBuilder);
return allocator_.create<CommandImpl> (refObject, cloneBuilder.clonedUndoMutation()
, cloneBuilder.clonedClosuere());
}
void
Command::duplicate_detected (Symbol newCmdID) const
{
static format fmt("Unable to store %s as new command. ID \"%s\" is already in use");
throw error::Logic (str (fmt % *this % newCmdID), LUMIERA_ERROR_DUPLICATE_COMMAND);
}
bool
Command::remove (Symbol cmdID)
{
return CommandRegistry::instance().remove (cmdID);
}
/** @internal pass a new argument tuple to the
* CommandImpl without exposing implementation.
*/
void
Command::setArguments (Arguments& args)
{
___check_notBottom (this, "Binding arguments of");
_Handle::impl().setArguments(args);
}
/** @return the number of command \em definitions currently registered */
size_t
Command::definition_count()
{
return CommandRegistry::instance().index_size();
}
/** @return number of distinguishable registered command \em instances */
size_t
Command::instance_count()
{
return CommandRegistry::instance().instance_count();
}
namespace {
inline bool
was_activated (Command const& com)
{
return com.isValid();
}
inline Command
registered_for (Symbol id)
{
return CommandRegistry::instance().queryIndex (id);
}
}
/** when starting a CommandDef, we immediately place a yet empty
* Command object into the index, just assuming it will be defined
* properly and consequently get valid at some point. But in case
* this doesn't happen (e.g. because the definition is aborted),
* we need to clean up this empty pre-registration...
*/
CommandDef::~CommandDef()
{
if (!was_activated (prototype_))
CommandRegistry::instance().remove (this->id_);
}
/** is this a valid command definition? especially..
* - the prototype command is initialised properly
* - there is a command definition registered for our command ID
* - and the registered command uses the same underlying command impl
* record than our prototype
*/
bool
CommandDef::isValid() const
{
return (was_activated (prototype_))
&& (prototype_ == registered_for (this->id_))
;
}
bool
Command::canExec() const
{
return isValid()
&& impl().canExec();
}
bool
Command::canUndo() const
{
return isValid()
&& impl().canUndo();
}
bool
Command::equivalentImpl (Command const& c1, Command const& c2)
{
return c1.impl() == c2.impl();
}
/** diagnostics: shows the commandID, if any,
* and the degree of definition of this command */
Command::operator string() const
{
ostringstream repr;
repr << "Command";
////////////////////////////////////////////////////////////////////TODO do we need no-throw guarantee here?
Symbol id = CommandRegistry::instance().findDefinition (*this);
if (id)
repr << "(\""<<id<<"\") ";
else
repr << "(_xxx_) ";
if (!isValid())
repr << "NIL";
else
if (canUndo())
repr << "{undo}";
else
if (canExec())
repr << "{exec}";
else
repr << "{def}";
return repr.str();
}
ExecResult
Command::undo ()
{
___check_notBottom (this,"Un-doing");
HandlingPattern const& defaultPattern
= HandlingPattern::get (getDefaultHandlingPattern());
return exec (defaultPattern.howtoUNDO());
}
ExecResult
Command::exec (HandlingPattern const& execPattern)
{
___check_notBottom (this,"Invoking");
___check_isBound (this);
CommandImpl& thisCommand (_Handle::impl());
return execPattern.invoke (thisCommand, cStr(*this));
}
ExecResult
Command::exec (HandlingPattern::ID pattID)
{
return exec (HandlingPattern::get(pattID));
}
ExecResult
Command::execSync ()
{
return exec (HandlingPattern::get(HandlingPattern::DUMMY)); ///////////TICKET #211 : should be ID::SYNC_THROW
}
HandlingPattern::ID
Command::getDefaultHandlingPattern() const
{
___check_notBottom (this,"Accessing");
return impl().getDefaultHandlingPattern();
}
HandlingPattern::ID
Command::setHandlingPattern (HandlingPattern::ID pattID)
{
___check_notBottom (this, "Configuring");
return impl().setHandlingPattern(pattID);
}
}} // namespace proc::control