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// Copyright (C) 2008-2018 Lorenzo Caminiti
// Distributed under the Boost Software License, Version 1.0 (see accompanying
// file LICENSE_1_0.txt or a copy at http://www.boost.org/LICENSE_1_0.txt).
// See: http://www.boost.org/doc/libs/release/libs/contract/doc/html/index.html
//[mitchell02_push_button
#ifndef PUSH_BUTTON_HPP_
#define PUSH_BUTTON_HPP_
#include <boost/contract.hpp>
#include <cassert>
class push_button {
public:
// No inv and no bases so contracts optional if no pre, post, and override.
/* Creation */
// Create an enabled button.
push_button() : enabled_(true) {
boost::contract::check c = boost::contract::constructor(this)
.postcondition([&] {
BOOST_CONTRACT_ASSERT(enabled()); // Enabled.
})
;
}
// Destroy button.
virtual ~push_button() {
// Could have omitted contracts here (nothing to check).
boost::contract::check c = boost::contract::destructor(this);
}
/* Queries */
// If button is enabled.
bool enabled() const {
// Could have omitted contracts here (nothing to check).
boost::contract::check c = boost::contract::public_function(this);
return enabled_;
}
/* Commands */
// Enable button.
void enable() {
boost::contract::check c = boost::contract::public_function(this)
.postcondition([&] {
BOOST_CONTRACT_ASSERT(enabled()); // Enabled.
})
;
enabled_ = true;
}
// Disable button.
void disable() {
boost::contract::check c = boost::contract::public_function(this)
.postcondition([&] {
BOOST_CONTRACT_ASSERT(!enabled()); // Disabled.
})
;
enabled_ = false;
}
// Invoke externally when button clicked.
virtual void on_bn_clicked(boost::contract::virtual_* v = 0) = 0;
private:
bool enabled_;
};
void push_button::on_bn_clicked(boost::contract::virtual_* v) {
boost::contract::check c = boost::contract::public_function(v, this)
.precondition([&] {
BOOST_CONTRACT_ASSERT(enabled()); // Enabled.
})
;
assert(false);
}
#endif // #include guard
//]
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