Xfce Foundation Classes
« Main Page | Index

Tables


Apart from boxes, the other container commonly used to pack widgets is a table. Tables, like boxes are 'no window' widgets so they are invisible. You can use a table to arrange widgets in rows and columns, making it easy to align many widgets next to each other, horizontally and vertically.

An instance of Gtk::Table can be created with the following constructor:

Table(unsigned int rows, unsigned int columns, bool homogeneous = false);

The 'rows' argument is the number of rows the new table should have and 'columns' is the number of columns. The 'homogeneous' argument sets whether all cells in the table should be resized to the size of the largest cell. The default value is false.

The rows and columns are laid out from 0 to n, where n was the number specified in the Gtk::Table constructor. So, if you specify rows = 2 and columns = 2, the layout would look like this:

0          1          2
0+----------+----------+
 |          |          |
1+----------+----------+
 |          |          |
2+----------+----------+

Note that the coordinate system starts in the upper left hand corner. Widgets can be placed in a table using the table's attach method:

void attach
(
    Widget& child,
    unsigned int left_attach,
    unsigned int right_attach,
    unsigned int top_attach,
    unsigned int bottom_attach,
    AttachOptionsField xoptions = EXPAND | FILL,
    AttachOptionsField yoptions = EXPAND | FILL,
    unsigned int xpadding = 0,
    unsigned int ypadding = 0
);

The 'child' argument is a widget to add to the table. The 'left_attach' and 'right_attach' arguments are the column numbers to attach to the left and right side of the widget respectively. The 'top_attach' and 'bottom_attach' arguments are the column numbers to attach to the top and bottom of the widget respectively. The 'xoptions' and 'yoptions' arguments specify how the widget is resized, horizontally and vertically respectively,  when the table is resized. They can be one or more values from the Gtk::AttachOptions enum:
  • Gtk::EXPAND - the widget should expand to take up any extra space allocated to its table.
  • Gtk::SHRINK - the widget should shrink with the table when possible.
  • Gtk::FILL - if the table is larger than the widget the widget should expand to use all the room available.
The default values are Gtk::EXPAND and Gtk::FILL. The 'xpadding' argument is an integer value that specifies the padding on the left and right side of the widget being added to the table. The 'ypadding' argument is an integer value that specifies the padding above and below the widget being added to the table. The default value for both is zero.

Table Example

This example creates a window with three buttons in a 2x2 table. The first two buttons are placed in the upper row. The third, a quit button, is placed in the lower row, spanning both columns.

The header file for the Table example is <table.hh>:

#include <xfc/main.hh>
#include <xfc/gtk/window.hh>

using namespace Xfc;

class TableWindow : public Gtk::Window
{
protected:
    void on_button_clicked(const char *text);

public:
    TableWindow();
    ~TableWindow();
};

and the source file is <table.cc>:

#include "table.hh"
#include <xfc/gtk/box.hh>
#include <xfc/gtk/table.hh>
#include <xfc/gtk/button.hh>
#include <iostream>

TableWindow::TableWindow()
{
    // Set the window title
    set_title("Table");

    // Set the border width of the window.
    set_border_width( 20);

    // Create a 2x2 table
    Gtk::Table *table = new Gtk::Table(2, 2, true);

    // Put the table in the main window
    add(*table);

    // Create first button
    Gtk::Button *button = new Gtk::Button("button 1");
   
    // When the button is clicked, we call the "slot" function with a pointer to "button 1" as its argument.
    button->signal_clicked().connect(sigc::bind(sigc::mem_fun(this, &TableWindow::on_button_clicked), "button 1"));

    // Insert button 1 into the upper left quadrant of the table
    table->attach(*button, 0, 1, 0, 1);

    button->show();

    // Create second button
    button = new Gtk::Button("button 2");

    // When the button is clicked, we call the "slot" function with a pointer to "button 2" as its argument.
    button->signal_clicked().connect(sigc::bind(sigc::mem_fun(this, &TableWindow::on_button_clicked), "button 2"));

    // Insert button 2 into the upper right quadrant of the table
    table->attach(*button, 1, 2, 0, 1);

    button->show();

    // Create "Quit" button
    button = new Gtk::Button("Quit");

    // When the button is clicked, we call the main window's dispose() function and the program exits.
    button->signal_clicked().connect(sigc::mem_fun(this, &TableWindow::dispose));

    // Insert the quit button into the both lower quadrants of the table
    table->attach(*button, 0, 2, 1, 2);

    button->show();
    table->show();
}

TableWindow::~TableWindow()
{
}

void
TableWindow::on_button_clicked(const char *text)
{
    std::cout << "Hello again - " << text << " was pressed" << '\n';
}

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

    init(&argc, &argv);

    TableWindow window;
    window.signal_destroy().connect(sigc::ptr_fun(&Xfc::Main::quit));
    window.show();

    run();
    return 0;
}

Compiling Table

If you compiled and installed XFC yourself, you will find the source code for Table in the <examples/howto/table> source directory along with a Makefile. If XFC came pre-installed, or you installed it from an RPM package, you will find the source code in the </usr/share/doc/xfcui-X.X/examples/howto/table> subdirectory. In this case you will have to create the Makefile yourself (replace X.X with the version number of the libXFCui library you have installed).

To create a Makefile for Table, add the following lines to a new text file and save it using the name "Makefile":

CC = g++

CFLAGS = -Wall -O2

table: table.cc table.hh
    $(CC) table.cc -o table  $(CFLAGS) `pkg-config xfcui-X.X --cflags --libs`

clean:
    rm -f *.o table


If you cut and paste these lines make sure the whitespace before $(CC) and rm is a tab character. When you compile and run this program you will see the following window appear:




Copyright © 2004-2005 The XFC Development Team Top
XFC 4.4