gtk_tut.sgml

gtk是linux一款强大的夸平台的图形化开发工具

    GtkWidget *box;
    GtkWidget *button;
    char padstr[80];
    
    /* Create a new hbox with the appropriate homogeneous
     * and spacing settings */
    box = gtk_hbox_new (homogeneous, spacing);
    
    /* Create a series of buttons with the appropriate settings */
    button = gtk_button_new_with_label ("gtk_box_pack");
    gtk_box_pack_start (GTK_BOX (box), button, expand, fill, padding);
    gtk_widget_show (button);
    
    button = gtk_button_new_with_label ("(box,");
    gtk_box_pack_start (GTK_BOX (box), button, expand, fill, padding);
    gtk_widget_show (button);
    
    button = gtk_button_new_with_label ("button,");
    gtk_box_pack_start (GTK_BOX (box), button, expand, fill, padding);
    gtk_widget_show (button);
    
    /* Create a button with the label depending on the value of
     * expand. */
    if (expand == TRUE)
	    button = gtk_button_new_with_label ("TRUE,");
    else
	    button = gtk_button_new_with_label ("FALSE,");
    
    gtk_box_pack_start (GTK_BOX (box), button, expand, fill, padding);
    gtk_widget_show (button);
    
    /* This is the same as the button creation for "expand"
     * above, but uses the shorthand form. */
    button = gtk_button_new_with_label (fill ? "TRUE," : "FALSE,");
    gtk_box_pack_start (GTK_BOX (box), button, expand, fill, padding);
    gtk_widget_show (button);
    
    sprintf (padstr, "%d);", padding);
    
    button = gtk_button_new_with_label (padstr);
    gtk_box_pack_start (GTK_BOX (box), button, expand, fill, padding);
    gtk_widget_show (button);
    
    return box;
}

int main( int   argc,
          char *argv[]) 
{
    GtkWidget *window;
    GtkWidget *button;
    GtkWidget *box1;
    GtkWidget *box2;
    GtkWidget *separator;
    GtkWidget *label;
    GtkWidget *quitbox;
    int which;
    
    /* Our init, don't forget this! :) */
    gtk_init (&argc, &argv);
    
    if (argc != 2) {
	fprintf (stderr, "usage: packbox num, where num is 1, 2, or 3.\n");
	/* This just does cleanup in GTK and exits with an exit status of 1. */
	gtk_exit (1);
    }
    
    which = atoi (argv[1]);

    /* Create our window */
    window = gtk_window_new (GTK_WINDOW_TOPLEVEL);

    /* You should always remember to connect the destroy signal to the
     * main window. This is very important for proper intuitive
     * behavior */
    gtk_signal_connect (GTK_OBJECT (window), "delete_event",
			GTK_SIGNAL_FUNC (delete_event), NULL);
    gtk_container_set_border_width (GTK_CONTAINER (window), 10);
    
    /* We create a vertical box (vbox) to pack the horizontal boxes into.
     * This allows us to stack the horizontal boxes filled with buttons one
     * on top of the other in this vbox. */
    box1 = gtk_vbox_new (FALSE, 0);
    
    /* which example to show. These correspond to the pictures above. */
    switch (which) {
    case 1:
	/* create a new label. */
	label = gtk_label_new ("gtk_hbox_new (FALSE, 0);");
	
	/* Align the label to the left side.  We'll discuss this function and 
	 * others in the section on Widget Attributes. */
	gtk_misc_set_alignment (GTK_MISC (label), 0, 0);

	/* Pack the label into the vertical box (vbox box1).  Remember that 
	 * widgets added to a vbox will be packed one on top of the other in
	 * order. */
	gtk_box_pack_start (GTK_BOX (box1), label, FALSE, FALSE, 0);
	
	/* Show the label */
	gtk_widget_show (label);
	
	/* Call our make box function - homogeneous = FALSE, spacing = 0,
	 * expand = FALSE, fill = FALSE, padding = 0 */
	box2 = make_box (FALSE, 0, FALSE, FALSE, 0);
	gtk_box_pack_start (GTK_BOX (box1), box2, FALSE, FALSE, 0);
	gtk_widget_show (box2);

	/* Call our make box function - homogeneous = FALSE, spacing = 0,
	 * expand = FALSE, fill = FALSE, padding = 0 */
	box2 = make_box (FALSE, 0, TRUE, FALSE, 0);
	gtk_box_pack_start (GTK_BOX (box1), box2, FALSE, FALSE, 0);
	gtk_widget_show (box2);
	
	/* Args are: homogeneous, spacing, expand, fill, padding */
	box2 = make_box (FALSE, 0, TRUE, TRUE, 0);
	gtk_box_pack_start (GTK_BOX (box1), box2, FALSE, FALSE, 0);
	gtk_widget_show (box2);
	
	/* Creates a separator, we'll learn more about these later, 
	 * but they are quite simple. */
	separator = gtk_hseparator_new ();
	
	/* Cack the separator into the vbox. Remember each of these
	 * widgets are being packed into a vbox, so they'll be stacked
	 * vertically. */
	gtk_box_pack_start (GTK_BOX (box1), separator, FALSE, TRUE, 5);
	gtk_widget_show (separator);
	
	/* Create another new label, and show it. */
	label = gtk_label_new ("gtk_hbox_new (TRUE, 0);");
	gtk_misc_set_alignment (GTK_MISC (label), 0, 0);
	gtk_box_pack_start (GTK_BOX (box1), label, FALSE, FALSE, 0);
	gtk_widget_show (label);
	
	/* Args are: homogeneous, spacing, expand, fill, padding */
	box2 = make_box (TRUE, 0, TRUE, FALSE, 0);
	gtk_box_pack_start (GTK_BOX (box1), box2, FALSE, FALSE, 0);
	gtk_widget_show (box2);
	
	/* Args are: homogeneous, spacing, expand, fill, padding */
	box2 = make_box (TRUE, 0, TRUE, TRUE, 0);
	gtk_box_pack_start (GTK_BOX (box1), box2, FALSE, FALSE, 0);
	gtk_widget_show (box2);
	
	/* Another new separator. */
	separator = gtk_hseparator_new ();
	/* The last 3 arguments to gtk_box_pack_start are:
	 * expand, fill, padding. */
	gtk_box_pack_start (GTK_BOX (box1), separator, FALSE, TRUE, 5);
	gtk_widget_show (separator);
	
	break;

    case 2:

	/* Create a new label, remember box1 is a vbox as created 
	 * near the beginning of main() */
	label = gtk_label_new ("gtk_hbox_new (FALSE, 10);");
	gtk_misc_set_alignment (GTK_MISC (label), 0, 0);
	gtk_box_pack_start (GTK_BOX (box1), label, FALSE, FALSE, 0);
	gtk_widget_show (label);
	
	/* Args are: homogeneous, spacing, expand, fill, padding */
	box2 = make_box (FALSE, 10, TRUE, FALSE, 0);
	gtk_box_pack_start (GTK_BOX (box1), box2, FALSE, FALSE, 0);
	gtk_widget_show (box2);
	
	/* Args are: homogeneous, spacing, expand, fill, padding */
	box2 = make_box (FALSE, 10, TRUE, TRUE, 0);
	gtk_box_pack_start (GTK_BOX (box1), box2, FALSE, FALSE, 0);
	gtk_widget_show (box2);
	
	separator = gtk_hseparator_new ();
	/* The last 3 arguments to gtk_box_pack_start are:
	 * expand, fill, padding. */
	gtk_box_pack_start (GTK_BOX (box1), separator, FALSE, TRUE, 5);
	gtk_widget_show (separator);
	
	label = gtk_label_new ("gtk_hbox_new (FALSE, 0);");
	gtk_misc_set_alignment (GTK_MISC (label), 0, 0);
	gtk_box_pack_start (GTK_BOX (box1), label, FALSE, FALSE, 0);
	gtk_widget_show (label);
	
	/* Args are: homogeneous, spacing, expand, fill, padding */
	box2 = make_box (FALSE, 0, TRUE, FALSE, 10);
	gtk_box_pack_start (GTK_BOX (box1), box2, FALSE, FALSE, 0);
	gtk_widget_show (box2);
	
	/* Args are: homogeneous, spacing, expand, fill, padding */
	box2 = make_box (FALSE, 0, TRUE, TRUE, 10);
	gtk_box_pack_start (GTK_BOX (box1), box2, FALSE, FALSE, 0);
	gtk_widget_show (box2);
	
	separator = gtk_hseparator_new ();
	/* The last 3 arguments to gtk_box_pack_start are: expand, fill, padding. */
	gtk_box_pack_start (GTK_BOX (box1), separator, FALSE, TRUE, 5);
	gtk_widget_show (separator);
	break;
    
    case 3:

        /* This demonstrates the ability to use gtk_box_pack_end() to
	 * right justify widgets. First, we create a new box as before. */
	box2 = make_box (FALSE, 0, FALSE, FALSE, 0);

	/* Create the label that will be put at the end. */
	label = gtk_label_new ("end");
	/* Pack it using gtk_box_pack_end(), so it is put on the right
	 * side of the hbox created in the make_box() call. */
	gtk_box_pack_end (GTK_BOX (box2), label, FALSE, FALSE, 0);
	/* Show the label. */
	gtk_widget_show (label);
	
	/* Pack box2 into box1 (the vbox remember ? :) */
	gtk_box_pack_start (GTK_BOX (box1), box2, FALSE, FALSE, 0);
	gtk_widget_show (box2);
	
	/* A separator for the bottom. */
	separator = gtk_hseparator_new ();
	/* This explicitly sets the separator to 400 pixels wide by 5 pixels
	 * high. This is so the hbox we created will also be 400 pixels wide,
	 * and the "end" label will be separated from the other labels in the
	 * hbox. Otherwise, all the widgets in the hbox would be packed as
	 * close together as possible. */
	gtk_widget_set_usize (separator, 400, 5);
	/* pack the separator into the vbox (box1) created near the start 
	 * of main() */
	gtk_box_pack_start (GTK_BOX (box1), separator, FALSE, TRUE, 5);
	gtk_widget_show (separator);    
    }
    
    /* Create another new hbox.. remember we can use as many as we need! */
    quitbox = gtk_hbox_new (FALSE, 0);
    
    /* Our quit button. */
    button = gtk_button_new_with_label ("Quit");
    
    /* Setup the signal to destroy the window. Remember that this will send
     * the "destroy" signal to the window which will be caught by our signal
     * handler as defined above. */
    gtk_signal_connect_object (GTK_OBJECT (button), "clicked",
			       GTK_SIGNAL_FUNC (gtk_main_quit),
			       GTK_OBJECT (window));
    /* Pack the button into the quitbox.
     * The last 3 arguments to gtk_box_pack_start are:
     * expand, fill, padding. */
    gtk_box_pack_start (GTK_BOX (quitbox), button, TRUE, FALSE, 0);
    /* pack the quitbox into the vbox (box1) */
    gtk_box_pack_start (GTK_BOX (box1), quitbox, FALSE, FALSE, 0);
    
    /* Pack the vbox (box1) which now contains all our widgets, into the
     * main window. */
    gtk_container_add (GTK_CONTAINER (window), box1);
    
    /* And show everything left */
    gtk_widget_show (button);
    gtk_widget_show (quitbox);
    
    gtk_widget_show (box1);
    /* Showing the window last so everything pops up at once. */
    gtk_widget_show (window);
    
    /* And of course, our main function. */
    gtk_main ();

    /* Control returns here when gtk_main_quit() is called, but not when 
     * gtk_exit is used. */
    
    return(0);
}
/* example-end */
</verb></tscreen>

<!-- ----------------------------------------------------------------- -->
<sect1>Packing Using Tables
<p>
Let's take a look at another way of packing - Tables. These can be
extremely useful in certain situations.

Using tables, we create a grid that we can place widgets in. The
widgets may take up as many spaces as we specify.

The first thing to look at of course, is the gtk_table_new function:

<tscreen><verb>
GtkWidget *gtk_table_new( gint rows,
                          gint columns,
                          gint homogeneous );
</verb></tscreen>

The first argument is the number of rows to make in the table, while
the second, obviously, is the number of columns.

The homogeneous argument has to do with how the table's boxes are
sized. If homogeneous is TRUE, the table boxes are resized to the size
of the largest widget in the table. If homogeneous is FALSE, the size
of a table boxes is dictated by the tallest widget in its same row,
and the widest widget in its column.

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

<tscreen><verb>
 0          1          2
0+----------+----------+
 |          |          |
1+----------+----------+
 |          |          |
2+----------+----------+
</verb></tscreen>

Note that the coordinate system starts in the upper left hand corner.
To place a widget into a box, use the following function:

<tscreen><verb>
void gtk_table_attach( GtkTable  *table,
                       GtkWidget *child,
                       gint       left_attach,
                       gint       right_attach,
                       gint       top_attach,
                       gint       bottom_attach,
                       gint       xoptions,
                       gint       yoptions,
                       gint       xpadding,
                       gint       ypadding );
</verb></tscreen>				       

Where the first argument ("table") is the table you've created and the
second ("child") the widget you wish to place in the table.

The left and right attach arguments specify where to place the widget,
and how many boxes to use. If you want a button in the lower right
table entry of our 2x2 table, and want it to fill that entry ONLY,
left_attach would be = 1, right_attach = 2, top_attach = 1,
bottom_attach = 2.

Now, if you wanted a widget to take up the whole top row of our 2x2
table, you'd use left_attach = 0, right_attach = 2, top_attach = 0,
bottom_attach = 1.

The xoptions and yoptions are used to specify packing options and may
be bitwise OR'ed together to allow multiple options.

These options are:
<itemize>
<item>GTK_FILL - If the table box is larger than the widget, and
GTK_FILL is specified, the widget will expand to use all the room
available.

<item>GTK_SHRINK - If the table widget was allocated less space then
was requested (usually by the user resizing the window), then the
widgets would normally just be pushed off the bottom of the window and
disappear. If GTK_SHRINK is specified, the widgets will shrink with
the table.

<item>GTK_EXPAND - This will cause the table to expand to use up any
remaining space in the window.
</itemize>

Padding is just like in boxes, creating a clear area around the widget
specified in pixels.

gtk_table_attach() has a LOT of options.  So, there's a shortcut:

<tscreen><verb>
void gtk_table_attach_defaults( GtkTable  *table,
                                GtkWidget *widget,
                                gint       left_attach,
                                gint       right_attach,