LUMIERA.clone/tests/core/steam/control/memento-tie-test.cpp

143 lines
4.3 KiB
C++

/*
MementoTie(Test) - check the mechanism for capturing and providing undo-state
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 memento-tie-test.cpp
** unit test \ref MementoTie_test
*/
#include "lib/test/run.hpp"
#include "lib/test/test-helper.hpp"
#include "steam/control/memento-tie.hpp"
#include <functional>
#include <cstdlib>
using std::function;
using std::bind;
using std::rand;
namespace steam {
namespace control {
namespace test {
namespace {
int testVal=0; ///< used to verify the effect of testFunc
void
undo (short param, int memento) ///< simulates "Undo" of the command operation
{
testVal += param-memento;
}
int
capture (short param) ///< simulates capturing the undo state
{
return testVal+param;
}
/** maximum additional storage maybe wasted due
* to alignment of the memento value within MementoTie
*/
const size_t ALIGNMENT = sizeof(size_t);
}
/*************************************************************************************//**
* @test Verify the state capturing mechanism (memento), which is used to implement
* the Undo() functionality for Steam-Layer commands. Bind an undo function and a state
* capturing function and wire up both to store and retrieve a memento value.
* Verify that after closing the functions, actually state is captured by each invocation.
*
* @see control::Command
* @see control::CmdClosure
* @see control::UndoMutation
* @see command-mutation-test.hpp
*/
class MementoTie_test : public Test
{
virtual void
run (Arg)
{
checkStateCapturingMechanism();
}
/// assumed signature of the Command "Operation"
typedef void OpSIG(short);
typedef MementoTie<OpSIG,int> MemHolder;
void
checkStateCapturingMechanism ()
{
function<void(short,int)> undo_func = undo;
function< int(short)> cap_func = capture;
MemHolder mementoHolder (undo_func,cap_func);
CHECK (sizeof(MemHolder) <= sizeof(int) // storage for the memento
+ 2 * sizeof(function<void()>) // storage for the 2 undecorated functors
+ ALIGNMENT);
function<OpSIG> bound_undo_func = mementoHolder.tieUndoFunc();
function<OpSIG> bound_cap_func = mementoHolder.tieCaptureFunc();
VERIFY_ERROR (MISSING_MEMENTO, bound_undo_func(123) );
VERIFY_ERROR (MISSING_MEMENTO, mementoHolder.getState() );
short rr (rand() %100);
testVal = 0;
bound_cap_func(rr); // invoke state capturing
CHECK (rr == mementoHolder.getState());
testVal = 10; // meanwhile "somehow" mutate the state
bound_undo_func(0); // invoking the undo() feeds back the memento
CHECK (testVal == 10-rr);
// this cycle can be repeated with different state values
rr = (rand() %100);
testVal = rr;
bound_cap_func(5); // capture new state
CHECK (5+rr == mementoHolder.getState());
testVal = -20;
bound_undo_func(3*rr);
CHECK (testVal == -20 + 3*rr - (5+rr));
}
};
/** Register this test class... */
LAUNCHER (MementoTie_test, "unit controller");
}}} // namespace steam::control::test