Xfce Foundation Classes

Gtk::Alignment
Gtk::Arrow
Gtk::AspectFrame
Gtk::Bin
Gtk::Box
Gtk::Button

Gtk::CheckButton
Gtk::Fixed
Gtk::Frame
Gtk::Image
Gtk::Label
Gtk::MenuItem

Gtk::Notebook
Gtk::Paned
Gtk::RadioButton
Gtk::Range
Gtk::ScrolledWindow
Gtk::Separator

Gtk::Table
Gtk::Toolbar
Gtk::VBox
Gtk::HBox
Gtk::VSeparator
Gtk::HSeparator

Widgets with no GDK window

Not having an X window saves memory and improves performance, but also has some drawbacks. A widget without an X window cannot receive events, and does not perform any clipping on its contents. Although the name EventBox emphasizes the event-handling function, the widget can also be used for clipping. (and more, see the example below).

To create a new EventBox widget use the following constructor:

EventBox();

A child widget can then be added to this EventBox:

eventbox->add(*child_widget);

You will need to call the following Gtk::Widget method to set which events the EventBox should receive:

 void
set_events(Gdk::EventMaskField events);

The 'events' argument is a mask that determines which events the EventBox will receive. It can be one or more values from the Gdk::EventMask enum:

EXPOSURE_MASK - maps to the expose-event.
POINTER_MOTION_MASK - maps to the motion-notify-event.
POINTER_MOTION_HINT_MASK - decreases the number of motion-notify events.
BUTTON_MOTION_MASK - maps to the motion-notify-event.
BUTTON1_MOTION_MASK - maps to the motion-notify-event.
BUTTON2_MOTION_MASK - maps to the motion-notify-event.
BUTTON3_MOTION_MASK - maps to the motion-notify-event.
BUTTON_PRESS_MASK - maps to the button-press-event.
BUTTON_RELEASE_MASK - maps to the button-press-event.
KEY_PRESS_MASK - maps to the key-press-event.
KEY_RELEASE_MASK - maps to the key-release-event.
ENTER_NOTIFY_MASK - maps to the enter-notify-event.
LEAVE_NOTIFY_MASK - maps to the leave-notify-event.
FOCUS_CHANGE_MASK - maps to the focus-change-event.
STRUCTURE_MASK- Allows map, unmap, destroy and configure events to be captured.
PROPERTY_CHANGE_MASK - maps to the property-notify-event.
VISIBILITY_NOTIFY_MASK - maps to the visibilty-notify-event.
PROXIMITY_IN_MASK - maps to the proximity-in-event.
PROXIMITY_OUT_MASK - maps to the proximity-out-event.
SUBSTRUCTURE_MASK - allows a window to receive STRUCTURE_MASK events on any child windows.
SCROLL_MASK - Maps to the scroll-event
ALL_EVENTS_MASK - Maps to the all events.

EventBox Example

The following example demonstrates both uses of an EventBox. A label is created that is clipped to a small box, and set up so that a mouse-click on the label causes the program to exit. Resizing the window reveals varying amounts of the label.

The header file for the Event Box example is <eventbox.hh>:

#include <xfc/main.hh>

#include <xfc/gtk/window.hh>

#include <xfc/gdk/cursor.hh>

      

using namespace Inti;

      

class EventBoxWindow : public Gtk::Window

{

    Pointer<Gdk::Cursor> hand_cursor;

      

protected:

    bool
on_button_press_event(const
Gdk::EventButton&);

      

public:

    EventBoxWindow();

    virtual
~EventBoxWindow();

};

and the source file is <eventbox.cc>:

#include "eventbox.hh"

#include <xfc/gtk/eventbox.hh>

#include <xfc/gtk/label.hh>

#include <xfc/gdk/window.hh>

      

EventBoxWindow::EventBoxWindow()

{

    set_title("Event Box");

    set_border_width(10);

      

    // Create an
EventBox
and add it to our toplevel window

    Gtk::EventBox *event_box = new Gtk::EventBox;

    add(*event_box);

    event_box->show();

      

    // Create a long
label

    Gtk::Label *label = new Gtk::Label("Click here to
quit, quit, quit,
quit, quit");

    event_box->add(*label);

    label->show();

      

    // Clip it short

    label->set_size_request(110,
20);

      

    // And bind an
action to
it

   
event_box->set_events(Gdk::BUTTON_PRESS_MASK);

   
event_box->signal_button_press_event().connect(sigc::mem_fun(this,
&EventBoxWindow::on_button_press_event));

      

    // Yet one more
thing
you need an X window for ...

    event_box->realize();

    hand_cursor = new
Gdk::Cursor(GDK_HAND1);

   
event_box->get_window()->set_cursor(*hand_cursor);

    show();

}

      

EventBoxWindow::~EventBoxWindow()

{

}

      

bool

EventBoxWindow::on_button_press_event(const Gdk::EventButton&)

{

    dispose();

    return true;

}

      

int main (int
argc, char *argv[])

{

    using namespace Main;

      

    init(&argc, &argv);

      

    EventBoxWindow window;

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

      

    run();

    return 0;

}

Compiling EventBox

If you compiled and installed XFC yourself, you will find the source code for EventBox in the <examples/eventbox> 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/eventbox> 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 EventBox, add the following lines to a new text file and save it using the name "Makefile":

CC = g++

      

CFLAGS = -Wall -O2

      

eventbox: eventbox.cc eventbox.hh

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

      

clean: 

    rm -f *.o eventbox

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:

If you click on the label the window will be destroyed.