listbox_inline_widget.cpp

#include <nana/gui.hpp>
#include <nana/gui/widgets/listbox.hpp>
#include <nana/gui/widgets/button.hpp>
#include <nana/gui/widgets/textbox.hpp>

using namespace nana;

//Creates a textbox and button
//textbox shows the value of the sub item
//button is used to delete the item.
class inline_widget : public listbox::inline_notifier_interface
{
        inline_indicator * indicator_{ nullptr };
        index_type  pos_ ;
        textbox     txt_ ;
        button      btn_ ;

private:
        //Creates inline widget
        //listbox calls this method to create the widget
        //The position and size of widget can be ignored in this process
        void create(window wd) override
        {
                //Create listbox
                txt_.create(wd);
                txt_.events().click([this]
                {
                        //Select the item when clicks the textbox
                        indicator_->selected(pos_);
                });

                txt_.events().mouse_move([this]
                {
                        //Highlight the item when hovers the textbox
                        indicator_->hovered(pos_);
                });

                txt_.events().key_char([this](const arg_keyboard& arg)
                {
                        if (arg.key == keyboard::enter)
                        {
                                //Modify the item when enter is pressed
                                arg.ignore = true;
                                indicator_->modify(pos_, txt_.caption());
                        }
                });

                //Create button
                btn_.create(wd);
                btn_.caption("Delete");
                btn_.events().click([this]
                {
                        //Delete the item when button is clicked
                        auto & lsbox = dynamic_cast<listbox&>(indicator_->host());
                        lsbox.erase(lsbox.at(pos_));
                });

                btn_.events().mouse_move([this]
                {
                        //Highlight the item when hovers the button
                        indicator_->hovered(pos_);
                });
        }

        //Activates the inline widget, bound to a certain item of the listbox
        //The inline_indicator is an object to operate the listbox item,
        //pos is an index object refers to the item of listbox
        void activate(inline_indicator& ind, index_type pos) override
        {
                indicator_ = &ind;
                pos_ = pos;
        }

        //Notify the item status
        //This method is introduced since 1.4.1
        void notify_status(status_type status, bool status_on) /*override*/ 
        {
                switch(status)
                {
                case status_type::selecting:
                        //If status_on is true, the item is selecting.
                        //If status on is false, the item is unselecting
                        break;
                case status_type::checking:
                        //If status_on is true, the item is checking
                        //If status_on is false, the item is unchecking
                        break;
                }
        }

        //Sets the inline widget size
        //dimension represents the max size can be set
        //The coordinate of inline widget is a logical coordinate to the sub item of listbox
        void resize(const size& dimension) override
        {
                auto sz = dimension;
                sz.width -= 50;
                txt_.size(sz);

                rectangle r(sz.width + 5, 0, 45, sz.height);
                btn_.move(r);
        }

        //Sets the value of inline widget with the value of the sub item
        void set(const value_type& value) override
        {
                txt_.caption(value);
        }

        //Determines whether to draw the value of sub item
        //e.g, when the inline widgets covers the whole background of the sub item,
        //it should return false to avoid listbox useless drawing
        bool whether_to_draw() const override
        {
                return false;
        }
private:
};

int main()
{
        using namespace nana;

        form fm;
        listbox lsbox(fm, rectangle{ 10, 10, 300, 200 });

        //Create two columns
        lsbox.append_header("column 0");
        lsbox.append_header("column 1");

        //Then append items
        lsbox.at(0).append({ std::string("Hello0"), std::string("World0") });
        lsbox.at(0).append({ std::string("Hello1"), std::string("World1") });
        lsbox.at(0).append({ std::string("Hello2"), std::string("World2") });
        lsbox.at(0).append({ std::string("Hello3"), std::string("World3") });

        //Create a new category
        lsbox.append("Category 1");

        //Append items for category 1
        lsbox.at(1).append({ std::string("Hello4"), std::string("World4") });
        lsbox.at(1).append({ std::string("Hello5"), std::string("World5") });
        lsbox.at(1).append({ std::string("Hello6"), std::string("World6") });
        lsbox.at(1).append({ std::string("Hello7"), std::string("World7") });

        //Set the inline_widget, the first column of category 0, the second column of category 1
        lsbox.at(0).inline_factory(0, pat::make_factory<inline_widget>());
        lsbox.at(1).inline_factory(1, pat::make_factory<inline_widget>());

        fm.show();
        exec();
}