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A Simple Example

Here is a simple example of using a TreeView widget in context of the other widgets. It simply creates a simple model and view, and puts them together. The model is populated with the data from  the section: "Creating a Model". More information can be found on this in The TreeModel Interface section.

TreeView

The header file for TreeView Example is treeview.h:

#include<inti/main.h>
#include <inti/gtk/window.h>
#include <inti/gtk/treestore.h>
#include <inti/gtk/treeview.h>

using namespace Inti;

class TreeViewWindow : public Gtk::Window
{
    Pointer<Gtk::TreeStore> model;
    Gtk::TreeView *tree_view;

protected:
    void on_selection();
    void on_toggled(const char *path_str);

public:
    TreeViewWindow();
    virtual ~TreeViewWindow();
};

and the source file is treeview.cc:

#include"treeview.h"
#include <inti/gtk/cellrenderer.h>
#include <iostream>

enum
{
   TITLE_COLUMN,
   AUTHOR_COLUMN,
   CHECKED_COLUMN,
   N_COLUMNS
};

TreeViewWindow::TreeViewWindow()
{
    set_title("TreeView Example");

    // We'll create a TreeStore model but this could be any model. The model pointer
    // is a smart pointer because we own the initial reference and it must be freed.
    model = new Gtk::TreeStore(N_COLUMNS, G_TYPE_STRING, G_TYPE_STRING, G_TYPE_BOOLEAN);

    // Populate the model with data. First acquire a top-level iterator.
    Gtk::TreeIter parent_iter = model->append();

    // Then, set the cell values
    model->set_value(parent_iter, TITLE_COLUMN, "The Art of Computer Programming");
    model->set_value(parent_iter, AUTHOR_COLUMN, "Donald E. Knuth");
    model->set_value(parent_iter, CHECKED_COLUMN, false);

    // Then, acquire a child iterator and set the values for the child cells
    Gtk::TreeIter child_iter = model->append(&parent_iter);
    model->set_value(child_iter, TITLE_COLUMN, "Volume 1: Fundamental Algorithms");
    model->set_value(child_iter, CHECKED_COLUMN, false);

    child_iter = model->append(&parent_iter);
    model->set_value(child_iter, TITLE_COLUMN, "Volume 2: Seminumerical Algorithms");
    model->set_value(child_iter, CHECKED_COLUMN, false);

    child_iter = model->append(&parent_iter);
    model->set_value(child_iter, TITLE_COLUMN, "Volume 3: Sorting and Searching");
    model->set_value(child_iter, CHECKED_COLUMN, false);

    // Create a TreeView
    tree_view = new Gtk::TreeView(*model);

    // You can't create a TreeSelection, you have to retrieve it from the TreeView.
    Gtk::TreeSelection *selection = tree_view->get_selection();
    selection->set_mode (Gtk::SELECTION_SINGLE);
    selection->sig_changed().connect(slot(this, &TreeViewWindow::on_selection));

    // Create a text cell render and arbitrarily make it red for demonstration purposes.
    Gtk::CellRendererText *renderer = new Gtk::CellRendererText;
    renderer->prop_foreground().set("red");

    // Create first column, associating the "text" attribute of the cell_renderer with the first column of the model
    Gtk::TreeViewColumn *column = new Gtk::TreeViewColumn("Author", renderer, "text", AUTHOR_COLUMN, 0);

    // Add the column to the view.
    tree_view->append_column(*column);

    // Create second column. The title of the book.
    renderer = new Gtk::CellRendererText;
    column = new Gtk::TreeViewColumn("Title", renderer, "text", TITLE_COLUMN, 0);
    tree_view->append_column(*column);

    // Create last column. Whether a book is checked out.
    Gtk::CellRendererToggle *toggle_renderer = new Gtk::CellRendererToggle;
    toggle_renderer->sig_toggled().connect(slot(this, &TreeViewWindow::on_toggled));
    column = new Gtk::TreeViewColumn("Check out", toggle_renderer, "active", CHECKED_COLUMN, 0);
    tree_view->append_column(*column);

    // Now we can manipulate the view just like any other widget
    add(*tree_view);
    tree_view->show_all();
}


TreeViewWindow::~TreeViewWindow()
{
}

void
TreeViewWindow::on_selection()
{
    Gtk::TreeIter iter;
    Gtk::TreeSelection *selection = tree_view->get_selection();

    if (selection->get_selected(&iter))
    {
        String title;
        model->get_value(iter, TITLE_COLUMN, title);
        std::cout << "You selected a book with the title \"" << title << "\"" << std::endl;
    }
}

void
TreeViewWindow::on_toggled(const char *path_str)
{
    Gtk::TreeIter iter;
    Pointer<Gtk::TreePath> path = new Gtk::TreePath(path_str);

    // Get toggled iter
    model->get_iter(iter, *path);
    bool checked;
    model->get_value(iter, CHECKED_COLUMN, checked);

    // Do something with the value
    checked ^= 1;

    // Set new value for the CHECKED_COLUMN
    model->set_value(iter, CHECKED_COLUMN, checked);
}

int main (int argc, char *argv[])
{
    using namespace Main;

    init(&argc, &argv);

    TreeViewWindow window;
    window.sig_destroy().connect(slot(&Inti::Main::quit));
    window.show();

    run();
    return 0;
}


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