Commit 00e738c1 authored by Havoc Pennington's avatar Havoc Pennington Committed by Havoc Pennington

fix GtkImage overview

2001-10-04  Havoc Pennington  <hp@pobox.com>

	* gtk/tmpl/gtkimage.sgml: fix GtkImage overview
parent ced7a5fd
2001-10-04 Havoc Pennington <hp@pobox.com>
* gtk/tmpl/gtkimage.sgml: fix GtkImage overview
Wed Oct 3 15:09:18 2001 Jonathan Blandford <jrb@redhat.com>
* gtk/gtk.types: remove gtk_cell_editable_get_type
......
......@@ -2,23 +2,101 @@
GtkImage
<!-- ##### SECTION Short_Description ##### -->
A widget displaying a graphical image
A widget displaying an image
<!-- ##### SECTION Long_Description ##### -->
<para>
The #GtkImage widget displays a graphical image. The image is typically created
using gdk_image_new.
</para>
<para>
The pixels in a #GtkImage may be manipulated by the application after creation,
as #GtkImage store the pixel data on the client side. If you wish to store the
pixel data on the server side (thus not allowing manipulation of the data after
creation) you should use #GtkPixmap.
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:
<programlisting>
GtkWidget *image;
image = gtk_image_new_from_file ("myfile.png");
</programlisting>
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().
</para>
<para>
The image file may contain an animation, if so the #GtkImage will
display an animation (#GdkPixbufAnimation) instead of a static image.
</para>
<para>
#GtkImage is a subclass of #GtkMisc, which implies that you can
align it (center, left, right) and add padding to it, using
#GtkMisc methods.
</para>
<para>
#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.
For example, here is some code that handles button press events
on a #GtkImage:
<programlisting>
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;
}
</programlisting>
</para>
<para>
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.
</para>
<para>
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 <application>gdk-pixbuf-csource</application>. 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().
</para>
<!-- ##### SECTION See_Also ##### -->
<para>
#GtkPixmap, #GdkRgb
#GdkPixbuf
</para>
<!-- ##### STRUCT GtkImage ##### -->
......@@ -30,12 +108,13 @@ below.
<!-- ##### ENUM GtkImageType ##### -->
<para>
Describes the representation stored 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.
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.
</para>
@GTK_IMAGE_EMPTY: there is no image displayed by the widget
......@@ -44,7 +123,7 @@ return %NULL values.
@GTK_IMAGE_PIXBUF: the widget contains a #GdkPixbuf
@GTK_IMAGE_STOCK: the widget contains a stock icon name
@GTK_IMAGE_ICON_SET: the widget contains a #GtkIconSet
@GTK_IMAGE_ANIMATION:
@GTK_IMAGE_ANIMATION: the widget contains a #GdkPixbufAnimation
<!-- ##### FUNCTION gtk_image_get_icon_set ##### -->
<para>
......
......@@ -191,12 +191,12 @@ GtkSettings
</para>
<!-- ##### ARG GtkSettings:gtk-color-palette ##### -->
<!-- ##### ARG GtkSettings:gtk-menu-bar-accel ##### -->
<para>
</para>
<!-- ##### ARG GtkSettings:gtk-menu-bar-accel ##### -->
<!-- ##### ARG GtkSettings:gtk-color-palette ##### -->
<para>
</para>
......
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