Description
The GtkImage widget displays an image. Various kinds of object
can be displayed as an image; most typically, you would load a
GdkPixbuf ("pixel buffer") from a file, and then display that.
There's a convenience function to do this, gtk_image_new_from_file(),
used as follows:
If the file isn't loaded successfully, the image will contain a
"broken image" icon similar to that used in many web browsers.
If you want to handle errors in loading the file yourself,
for example by displaying an error message, then load the image with
gdk_pixbuf_new_from_file(), then create the
GtkImage with
gtk_image_new_from_pixbuf().
The image file may contain an animation, if so the GtkImage will
display an animation (GdkPixbufAnimation) instead of a static image.
GtkImage is a subclass of GtkMisc, which implies that you can
align it (center, left, right) and add padding to it, using
GtkMisc methods.
GtkImage is a "no window" widget (has no GdkWindow 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
GtkEventBox, then connect to the event signals on the event box.
Example 1. Handling button press events on a
GtkImage.
static void
button_press_callback (GtkWidget *event_box,
GdkEventButton *event,
gpointer data)
{
g_print ("Event box clicked at coordinates d,d\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;
} |
When handling events on the event box, keep in mind that coordinates
in the image may be different from event box coordinates due to
the alignment and padding settings on the image (see GtkMisc).
The simplest way to solve this is to set the alignment to 0.0
(left/top), and set the padding to zero. Then the origin of
the image will be the same as the origin of the event box.
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 program
allows you to convert an image into a C variable declaration, which
can then be loaded into a GdkPixbuf using
gdk_pixbuf_new_from_inline().
Details
struct GtkImage
This struct contain private data only and should be accessed by the functions
below.
enum GtkImageType
typedef enum
{
GTK_IMAGE_EMPTY,
GTK_IMAGE_PIXMAP,
GTK_IMAGE_IMAGE,
GTK_IMAGE_PIXBUF,
GTK_IMAGE_STOCK,
GTK_IMAGE_ICON_SET,
GTK_IMAGE_ANIMATION
} GtkImageType; |
Describes the image data representation used by a GtkImage. If you
want to get the image from the widget, you can only get the
currently-stored representation. e.g. if the
gtk_image_get_storage_type() returns GTK_IMAGE_PIXBUF, then you can
call gtk_image_get_pixbuf() but not gtk_image_get_stock(). For empty
images, you can request any storage type (call any of the "get"
functions), but they will all return NULL values.
gtk_image_get_icon_set ()
Gets the icon set and size being displayed by the GtkImage.
The storage type of the image must be GTK_IMAGE_EMPTY or
GTK_IMAGE_ICON_SET (see gtk_image_get_storage_type()).
gtk_image_get_image ()
Gets the GdkImage and mask being displayed by the GtkImage.
The storage type of the image must be GTK_IMAGE_EMPTY or
GTK_IMAGE_IMAGE (see gtk_image_get_storage_type()).
The caller of this function does not own a reference to the
returned image and mask.
gtk_image_get_pixbuf ()
GdkPixbuf* gtk_image_get_pixbuf (GtkImage *image); |
Gets the GdkPixbuf being displayed by the GtkImage.
The storage type of the image must be GTK_IMAGE_EMPTY or
GTK_IMAGE_PIXBUF (see gtk_image_get_storage_type()).
The caller of this function does not own a reference to the
returned pixbuf.
gtk_image_get_pixmap ()
Gets the pixmap and mask being displayed by the GtkImage.
The storage type of the image must be GTK_IMAGE_EMPTY or
GTK_IMAGE_PIXMAP (see gtk_image_get_storage_type()).
The caller of this function does not own a reference to the
returned pixmap and mask.
gtk_image_get_stock ()
Gets the stock icon name and size being displayed by the GtkImage.
The storage type of the image must be GTK_IMAGE_EMPTY or
GTK_IMAGE_STOCK (see gtk_image_get_storage_type()).
The returned string is owned by the GtkImage and should not
be freed.
gtk_image_get_animation ()
GdkPixbufAnimation* gtk_image_get_animation (GtkImage *image); |
Gets the GdkPixbufAnimation being displayed by the GtkImage.
The storage type of the image must be GTK_IMAGE_EMPTY or
GTK_IMAGE_ANIMATION (see gtk_image_get_storage_type()).
The caller of this function does not own a reference to the
returned animation.
gtk_image_get_storage_type ()
Gets the type of representation being used by the GtkImage
to store image data. If the GtkImage has no image data,
the return value will be GTK_IMAGE_EMPTY.
gtk_image_new_from_file ()
GtkWidget* gtk_image_new_from_file (const gchar *filename); |
Creates a new GtkImage displaying the file filename. If the file
isn't found or can't be loaded, the resulting GtkImage will
display a "broken image" icon. This function never returns NULL,
it always returns a valid GtkImage widget.
If the file contains an animation, the image will contain an
animation.
If you need to detect failures to load the file, use
gdk_pixbuf_new_from_file() to load the file yourself, then create
the GtkImage from the pixbuf. (Or for animations, use
gdk_pixbuf_animation_new_from_file()).
The storage type (gtk_image_get_storage_type()) of the returned
image is not defined, it will be whatever is appropriate for
displaying the file.
gtk_image_new_from_icon_set ()
Creates a GtkImage displaying an icon set. Sample stock sizes are
GTK_ICON_SIZE_MENU, GTK_ICON_SIZE_SMALL_TOOLBAR. Instead of using
this function, usually it's better to create a GtkIconFactory, put
your icon sets in the icon factory, add the icon factory to the
list of default factories with gtk_icon_factory_add_default(), and
then use gtk_image_new_from_stock(). This will allow themes to
override the icon you ship with your application.
The GtkImage does not assume a reference to the
icon set; you still need to unref it if you own references.
GtkImage will add its own reference rather than adopting yours.
gtk_image_new_from_image ()
Creates a GtkImage widget displaying a image with a mask.
A GdkImage is a client-side image buffer in the pixel format of the
current display.
The GtkImage does not assume a reference to the
image or mask; you still need to unref them if you own references.
GtkImage will add its own reference rather than adopting yours.
gtk_image_new_from_pixbuf ()
GtkWidget* gtk_image_new_from_pixbuf (GdkPixbuf *pixbuf); |
Creates a new GtkImage displaying pixbuf.
The GtkImage does not assume a reference to the
pixbuf; you still need to unref it if you own references.
GtkImage will add its own reference rather than adopting yours.
Note that this function just creates an GtkImage from the pixbuf. The
GtkImage created will not react to state changes. Should you want that, you
should use gtk_image_new_from_icon_set().
gtk_image_new_from_pixmap ()
Creates a GtkImage widget displaying pixmap with a mask.
A GdkImage is a server-side image buffer in the pixel format of the
current display. The GtkImage does not assume a reference to the
pixmap or mask; you still need to unref them if you own references.
GtkImage will add its own reference rather than adopting yours.
gtk_image_new_from_stock ()
Creates a GtkImage displaying a stock icon. Sample stock icon
names are GTK_STOCK_OPEN, GTK_STOCK_EXIT. Sample stock sizes
are GTK_ICON_SIZE_MENU, GTK_ICON_SIZE_SMALL_TOOLBAR. If the stock
icon name isn't known, a "broken image" icon will be displayed instead.
You can register your own stock icon names, see
gtk_icon_factory_add_default() and gtk_icon_factory_add().
gtk_image_new_from_animation ()
GtkWidget* gtk_image_new_from_animation (GdkPixbufAnimation *animation); |
Creates a GtkImage displaying the given animation.
The GtkImage does not assume a reference to the
animation; you still need to unref it if you own references.
GtkImage will add its own reference rather than adopting yours.
gtk_image_set_from_animation ()
void gtk_image_set_from_animation (GtkImage *image,
GdkPixbufAnimation *animation); |
Causes the GtkImage to display the given animation (or display
nothing, if you set the animation to NULL).
gtk_image_new ()
Creates a new empty GtkImage widget.
gtk_image_set ()
Warning |
gtk_image_set is deprecated and should not be used in newly-written code. |
Sets the GtkImage.
gtk_image_get ()
Warning |
gtk_image_get is deprecated and should not be used in newly-written code. |
Gets the GtkImage.