Image
Object Hierarchy:
Description:
The Image widget displays an image.
Various kinds of object can be displayed as an image; most typically, you would load a Pixbuf ("pixel buffer") from a file, and then display that. There’s a convenience function to do this, Image.from_file, used as follows:
GtkWidget *image;
image = gtk_image_new_from_file ("myfile.png");The image file may contain an animation, if so the Image will display an animation ( PixbufAnimation) instead of a static image.
Image is a subclass of Misc, which implies that you can align it (center, left, right) and add padding to it, using Misc methods.
Image is a “no window” widget (has no Window of its own), so by default does not receive events. If you want to receive events on the image, such as button clicks, place the image inside a EventBox, then connect to the event signals on the event box.
Handling button press events on a Image.
static gboolean
button_press_callback (GtkWidget *event_box,
GdkEventButton *event,
gpointer data)
{
g_print ("Event box clicked at coordinates %f,%f\n",
event->x, event->y);
// Returning TRUE means we handled the event, so the signal
// emission should be stopped (don’t call any further callbacks
// that may be connected). Return FALSE to continue invoking callbacks.
return TRUE;
}
static GtkWidget*
create_image (void)
{
GtkWidget *image;
GtkWidget *event_box;
image = gtk_image_new_from_file ("myfile.png");
event_box = gtk_event_box_new ();
gtk_container_add (GTK_CONTAINER (event_box), image);
g_signal_connect (G_OBJECT (event_box),
"button_press_event",
G_CALLBACK (button_press_callback),
image);
return image;
}Sometimes an application will want to avoid depending on external data files, such as image files. GTK+ comes with a program to avoid this, called “gdk-pixbuf-csource”. This library allows you to convert an image into a C variable declaration, which can then be loaded into a Pixbuf using Pixbuf.from_inline.
CSS nodes
GtkImage has a single CSS node with the name image. The style classes may appear on image CSS nodes: .icon-dropshadow, .lowres-icon.
Example: Image:
public class Application : Gtk.Window {
public Application (string img_path) {
// Prepare Gtk.Window:
this.title = "My Gtk.Image";
this.window_position = Gtk.WindowPosition.CENTER;
this.destroy.connect (Gtk.main_quit);
this.set_default_size (350, 70);
// The image:
Gtk.Image image = new Gtk.Image ();
image.set_from_file (img_path);
this.add (image);
}
public static int main (string[] args) {
Gtk.init (ref args);
string img_path = "";
if (args[1] != null) {
img_path = args[1];
}
Application app = new Application (img_path);
app.show_all ();
Gtk.main ();
return 0;
}
}valac --pkg gtk+-3.0 Gtk.Image.vala