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#include <glib.h>
#include <glibmm/binding.h>
#include <glibmm/init.h>
#include <glibmm/object.h>
#include <glibmm/property.h>
#include <glibmm/propertyproxy.h>
#include <algorithm>
#include <limits>
namespace {
class StringSource final: public Glib::Object {
public:
StringSource(): Glib::ObjectBase{"StringSource"} {}
auto property_string() { return m_property_string.get_proxy(); }
private:
Glib::Property<Glib::ustring> m_property_string{*this, "string"};
};
class IntTarget final: public Glib::Object {
public:
IntTarget(): Glib::ObjectBase{"IntTarget"} {}
auto property_int() { return m_property_int.get_proxy(); }
private:
Glib::Property<int> m_property_int{*this, "int"};
};
auto
transform_string_to_int(const Glib::ustring& source) -> std::optional<int>
{
char* str_end{};
auto long_int = std::strtol(source.c_str(), &str_end, 10);
if (str_end == source.c_str())
return std::nullopt;
using IntLimits = std::numeric_limits<int>;
auto constexpr min = long{IntLimits::min()};
auto constexpr max = long{IntLimits::max()};
auto const clamped_int = std::clamp(long_int, min, max);
if (clamped_int != long_int)
return std::nullopt;
return static_cast<int>(clamped_int);
}
void
test()
{
Glib::init();
auto source = StringSource{};
auto target = IntTarget{};
// We should obviously not change the target before it has been bound!
target.property_int() = 7;
source.property_string() = "42";
g_assert_cmpint(target.property_int(), ==, 7);
{
auto binding = Glib::Binding::bind_property(
source.property_string(), target.property_int(),
Glib::Binding::Flags::DEFAULT, &transform_string_to_int);
// Without SYNC_CREATE, only changes after bound will be synced
g_assert_cmpint(target.property_int(), ==, 7);
// An empty string is not a zero
source.property_string() = "";
g_assert_cmpint(target.property_int(), ==, 7);
// Ensure the change is synced
source.property_string() = "47";
g_assert_cmpint(target.property_int(), ==, 47);
// Ensure no change when invalid source results in false return
source.property_string() = "six six six";
g_assert_cmpint(target.property_int(), ==, 47);
// Ensure the binding is broken when unbind() is called
binding->unbind();
source.property_string() = "89";
g_assert_cmpint(target.property_int(), ==, 47);
}
{
auto binding = Glib::Binding::bind_property(
source.property_string(), target.property_int(),
Glib::Binding::Flags::SYNC_CREATE, &transform_string_to_int);
// With SYNC_CREATE, value of source must sync to target on bind
g_assert_cmpint(target.property_int(), ==, 89);
}
// Ensure the binding was not broken when its RefPtr went out of scope
source.property_string() = "90";
g_assert_cmpint(target.property_int(), ==, 90);
}
} // namespace
auto
main() -> int
{
test();
return 0;
}
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