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11.11. Toolbar

Toolbars are usually used to group some number of widgets in order to simplify customization of their look and layout. Typically a toolbar consists of buttons with icons, labels and tooltips, but any other widget can also be put inside a toolbar. Finally, items can be arranged horizontally or vertically and buttons can be displayed with icons, labels, or both.

Creating a toolbar is (as one may already suspect) done with the following function:

GtkWidget *gtk_toolbar_new( void );

After creating a toolbar one can append, prepend and insert items (that means simple text strings) or elements (that means any widget types) into the toolbar. To describe an item we need a label text, a tooltip text, a private tooltip text, an icon for the button and a callback function for it. For example, to append or prepend an item you may use the following functions:

GtkWidget *gtk_toolbar_append_item( GtkToolbar    *toolbar,
                                    const char    *text,
                                    const char    *tooltip_text,
                                    const char    *tooltip_private_text,
                                    GtkWidget     *icon,
                                    GtkSignalFunc  callback,
                                    gpointer       user_data );

GtkWidget *gtk_toolbar_prepend_item( GtkToolbar    *toolbar,
                                     const char    *text,
                                     const char    *tooltip_text,
                                     const char    *tooltip_private_text,
                                     GtkWidget     *icon,
                                     GtkSignalFunc  callback,
                                     gpointer       user_data );

If you want to use gtk_toolbar_insert_item(), the only additional parameter which must be specified is the position in which the item should be inserted, thus:

GtkWidget *gtk_toolbar_insert_item( GtkToolbar    *toolbar,
                                    const char    *text,
                                    const char    *tooltip_text,
                                    const char    *tooltip_private_text,
                                    GtkWidget     *icon,
                                    GtkSignalFunc  callback,
                                    gpointer       user_data,
                                    gint           position );

To simplify adding spaces between toolbar items, you may use the following functions:

void gtk_toolbar_append_space( GtkToolbar *toolbar );

void gtk_toolbar_prepend_space( GtkToolbar *toolbar );

void gtk_toolbar_insert_space( GtkToolbar *toolbar,
                               gint        position );

If it's required, the orientation of a toolbar and its style can be changed "on the fly" using the following functions:

void gtk_toolbar_set_orientation( GtkToolbar     *toolbar,
                                  GtkOrientation  orientation );

void gtk_toolbar_set_style( GtkToolbar      *toolbar,
                            GtkToolbarStyle  style );

void gtk_toolbar_set_tooltips( GtkToolbar *toolbar,
                               gint        enable );

Where orientation is one of GTK_ORIENTATION_HORIZONTAL or GTK_ORIENTATION_VERTICAL. The style is used to set appearance of the toolbar items by using one of GTK_TOOLBAR_ICONS, GTK_TOOLBAR_TEXT, or GTK_TOOLBAR_BOTH.

To show some other things that can be done with a toolbar, let's take the following program (we'll interrupt the listing with some additional explanations):

#include <gtk/gtk.h>

/* This function is connected to the Close button or
 * closing the window from the WM */
static gboolean delete_event( GtkWidget *widget,
                              GdkEvent *event,
                              gpointer data )
{
  gtk_main_quit ();
  return FALSE;
}

The above beginning seems for sure familiar to you if it's not your first GTK program. There is one additional thing though, we include a nice XPM picture to serve as an icon for all of the buttons.

GtkWidget* close_button; /* This button will emit signal to close
                          * application */
GtkWidget* tooltips_button; /* to enable/disable tooltips */
GtkWidget* text_button,
         * icon_button,
         * both_button; /* radio buttons for toolbar style */
GtkWidget* entry; /* a text entry to show packing any widget into
                   * toolbar */

In fact not all of the above widgets are needed here, but to make things clearer I put them all together.

/* that's easy... when one of the buttons is toggled, we just
 * check which one is active and set the style of the toolbar
 * accordingly
 * ATTENTION: our toolbar is passed as data to callback ! */
static void radio_event( GtkWidget *widget,
                         gpointer data )
{
  if (GTK_TOGGLE_BUTTON (text_button)->active) 
    gtk_toolbar_set_style (GTK_TOOLBAR (data), GTK_TOOLBAR_TEXT);
  else if (GTK_TOGGLE_BUTTON (icon_button)->active)
    gtk_toolbar_set_style (GTK_TOOLBAR (data), GTK_TOOLBAR_ICONS);
  else if (GTK_TOGGLE_BUTTON (both_button)->active)
    gtk_toolbar_set_style (GTK_TOOLBAR (data), GTK_TOOLBAR_BOTH);
}

/* even easier, just check given toggle button and enable/disable 
 * tooltips */
static void toggle_event( GtkWidget *widget,
                          gpointer   data )
{
  gtk_toolbar_set_tooltips (GTK_TOOLBAR (data),
                            GTK_TOGGLE_BUTTON (widget)->active );
}

The above are just two callback functions that will be called when one of the buttons on a toolbar is pressed. You should already be familiar with things like this if you've already used toggle buttons (and radio buttons).

int main (int argc, char *argv[])
{
  /* Here is our main window (a dialog) and a handle for the handlebox */
  GtkWidget* dialog;
  GtkWidget* handlebox;

  /* Ok, we need a toolbar, an icon with a mask (one for all of 
     the buttons) and an icon widget to put this icon in (but 
     we'll create a separate widget for each button) */
  GtkWidget * toolbar;
  GtkWidget * iconw;

  /* this is called in all GTK application. */
  gtk_init (&argc, &argv);
  
  /* create a new window with a given title, and nice size */
  dialog = gtk_dialog_new ();
  gtk_window_set_title (GTK_WINDOW (dialog), "GTKToolbar Tutorial");
  gtk_widget_set_size_request (GTK_WIDGET (dialog), 600, 300);
  GTK_WINDOW (dialog)->allow_shrink = TRUE;

  /* typically we quit if someone tries to close us */
  g_signal_connect (G_OBJECT (dialog), "delete_event",
                    G_CALLBACK (delete_event), NULL);

  /* we need to realize the window because we use pixmaps for 
   * items on the toolbar in the context of it */
  gtk_widget_realize (dialog);

  /* to make it nice we'll put the toolbar into the handle box, 
   * so that it can be detached from the main window */
  handlebox = gtk_handle_box_new ();
  gtk_box_pack_start (GTK_BOX (GTK_DIALOG (dialog)->vbox),
                      handlebox, FALSE, FALSE, 5);

The above should be similar to any other GTK application. Just initialization of GTK, creating the window, etc. There is only one thing that probably needs some explanation: a handle box. A handle box is just another box that can be used to pack widgets in to. The difference between it and typical boxes is that it can be detached from a parent window (or, in fact, the handle box remains in the parent, but it is reduced to a very small rectangle, while all of its contents are reparented to a new freely floating window). It is usually nice to have a detachable toolbar, so these two widgets occur together quite often.

  /* toolbar will be horizontal, with both icons and text, and
   * with 5pxl spaces between items and finally, 
   * we'll also put it into our handlebox */
  toolbar = gtk_toolbar_new ();
  gtk_toolbar_set_orientation (GTK_TOOLBAR (toolbar), GTK_ORIENTATION_HORIZONTAL);
  gtk_toolbar_set_style (GTK_TOOLBAR (toolbar), GTK_TOOLBAR_BOTH);
  gtk_container_set_border_width (GTK_CONTAINER (toolbar), 5);
  gtk_toolbar_set_space_size (GTK_TOOLBAR (toolbar), 5);
  gtk_container_add (GTK_CONTAINER (handlebox), toolbar);

Well, what we do above is just a straightforward initialization of the toolbar widget.

  /* our first item is <close> button */
  iconw = gtk_image_new_from_file ("gtk.xpm"); /* icon widget */
  close_button = 
    gtk_toolbar_append_item (GTK_TOOLBAR (toolbar), /* our toolbar */
                             "Close",               /* button label */
                             "Closes this app",     /* this button's tooltip */
                             "Private",             /* tooltip private info */
                             iconw,                 /* icon widget */
                             GTK_SIGNAL_FUNC (delete_event), /* a signal */
                             NULL);
  gtk_toolbar_append_space (GTK_TOOLBAR (toolbar)); /* space after item */

In the above code you see the simplest case: adding a button to toolbar. Just before appending a new item, we have to construct an image widget to serve as an icon for this item; this step will have to be repeated for each new item. Just after the item we also add a space, so the following items will not touch each other. As you see gtk_toolbar_append_item() returns a pointer to our newly created button widget, so that we can work with it in the normal way.

  /* now, let's make our radio buttons group... */
  iconw = gtk_image_new_from_file ("gtk.xpm");
  icon_button = gtk_toolbar_append_element (
                    GTK_TOOLBAR (toolbar),
                    GTK_TOOLBAR_CHILD_RADIOBUTTON, /* a type of element */
                    NULL,                          /* pointer to widget */
                    "Icon",                        /* label */
                    "Only icons in toolbar",       /* tooltip */
                    "Private",                     /* tooltip private string */
                    iconw,                         /* icon */
                    GTK_SIGNAL_FUNC (radio_event), /* signal */
                    toolbar);                      /* data for signal */
  gtk_toolbar_append_space (GTK_TOOLBAR (toolbar));

Here we begin creating a radio buttons group. To do this we use gtk_toolbar_append_element. In fact, using this function one can also +add simple items or even spaces (type = GTK_TOOLBAR_CHILD_SPACE or +GTK_TOOLBAR_CHILD_BUTTON). In the above case we start creating a radio group. In creating other radio buttons for this group a pointer to the previous button in the group is required, so that a list of buttons can be easily constructed (see the section on Radio Buttons earlier in this tutorial).

  /* following radio buttons refer to previous ones */
  iconw = gtk_image_new_from_file ("gtk.xpm");
  text_button = 
    gtk_toolbar_append_element (GTK_TOOLBAR (toolbar),
                                GTK_TOOLBAR_CHILD_RADIOBUTTON,
                                icon_button,
                                "Text",
                                "Only texts in toolbar",
                                "Private",
                                iconw,
                                GTK_SIGNAL_FUNC (radio_event),
                                toolbar);
  gtk_toolbar_append_space (GTK_TOOLBAR (toolbar));
                                          
  iconw = gtk_image_new_from_file ("gtk.xpm");
  both_button = 
    gtk_toolbar_append_element (GTK_TOOLBAR (toolbar),
                                GTK_TOOLBAR_CHILD_RADIOBUTTON,
                                text_button,
                                "Both",
                                "Icons and text in toolbar",
                                "Private",
                                iconw,
                                GTK_SIGNAL_FUNC (radio_event),
                                toolbar);
  gtk_toolbar_append_space (GTK_TOOLBAR (toolbar));
  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (both_button), TRUE);

In the end we have to set the state of one of the buttons manually (otherwise they all stay in active state, preventing us from switching between them).

  /* here we have just a simple toggle button */
  iconw = gtk_image_new_from_file ("gtk.xpm");
  tooltips_button = 
    gtk_toolbar_append_element (GTK_TOOLBAR (toolbar),
                                GTK_TOOLBAR_CHILD_TOGGLEBUTTON,
                                NULL,
                                "Tooltips",
                                "Toolbar with or without tips",
                                "Private",
                                iconw,
                                GTK_SIGNAL_FUNC (toggle_event),
                                toolbar);
  gtk_toolbar_append_space (GTK_TOOLBAR (toolbar));
  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (tooltips_button), TRUE);

A toggle button can be created in the obvious way (if one knows how to create radio buttons already).

  /* to pack a widget into toolbar, we only have to 
   * create it and append it with an appropriate tooltip */
  entry = gtk_entry_new ();
  gtk_toolbar_append_widget (GTK_TOOLBAR (toolbar), 
                             entry, 
                             "This is just an entry", 
                             "Private");

  /* well, it isn't created within the toolbar, so we must still show it */
  gtk_widget_show (entry);

As you see, adding any kind of widget to a toolbar is simple. The one thing you have to remember is that this widget must be shown manually (contrary to other items which will be shown together with the toolbar).

  /* that's it ! let's show everything. */
  gtk_widget_show (toolbar);
  gtk_widget_show (handlebox);
  gtk_widget_show (dialog);

  /* rest in gtk_main and wait for the fun to begin! */
  gtk_main ();
  
  return 0;
}

So, here we are at the end of toolbar tutorial. Of course, to appreciate it in full you need also this nice XPM icon, so here it is:

/* XPM */
static char * gtk_xpm[] = {
"32 39 5 1",
".      c none",
"+      c black",
"@      c #3070E0",
"#      c #F05050",
"$      c #35E035",
"................+...............",
"..............+++++.............",
"............+++++@@++...........",
"..........+++++@@@@@@++.........",
"........++++@@@@@@@@@@++........",
"......++++@@++++++++@@@++.......",
".....+++@@@+++++++++++@@@++.....",
"...+++@@@@+++@@@@@@++++@@@@+....",
"..+++@@@@+++@@@@@@@@+++@@@@@++..",
".++@@@@@@+++@@@@@@@@@@@@@@@@@@++",
".+#+@@@@@@++@@@@+++@@@@@@@@@@@@+",
".+##++@@@@+++@@@+++++@@@@@@@@$@.",
".+###++@@@@+++@@@+++@@@@@++$$$@.",
".+####+++@@@+++++++@@@@@+@$$$$@.",
".+#####+++@@@@+++@@@@++@$$$$$$+.",
".+######++++@@@@@@@++@$$$$$$$$+.",
".+#######+##+@@@@+++$$$$$$@@$$+.",
".+###+++##+##+@@++@$$$$$$++$$$+.",
".+###++++##+##+@@$$$$$$$@+@$$@+.",
".+###++++++#+++@$$@+@$$@++$$$@+.",
".+####+++++++#++$$@+@$$++$$$$+..",
".++####++++++#++$$@+@$++@$$$$+..",
".+#####+++++##++$$++@+++$$$$$+..",
".++####+++##+#++$$+++++@$$$$$+..",
".++####+++####++$$++++++@$$$@+..",
".+#####++#####++$$+++@++++@$@+..",
".+#####++#####++$$++@$$@+++$@@..",
".++####++#####++$$++$$$$$+@$@++.",
".++####++#####++$$++$$$$$$$$+++.",
".+++####+#####++$$++$$$$$$$@+++.",
"..+++#########+@$$+@$$$$$$+++...",
"...+++########+@$$$$$$$$@+++....",
".....+++######+@$$$$$$$+++......",
"......+++#####+@$$$$$@++........",
".......+++####+@$$$$+++.........",
".........++###+$$$@++...........",
"..........++##+$@+++............",
"...........+++++++..............",
".............++++..............."};