callisto-debian/gtk3
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Note that a widget must be focusable for the menu keybindings to work.

Browse Source 
2004-01-23  Federico Mena Quintero  <federico@ximian.com>

	* gtk/migrating-checklist.sgml: Note that a widget must be
	focusable for the menu keybindings to work.

2004-01-22  Federico Mena Quintero  <federico@ximian.com>

	* gtk/migrating-checklist.sgml: Mention when it is useful to use
	GdkEventExpose.region rather than GdkEventExpose.area.
This commit is contained in:
Federico Mena Quintero
2004-01-23 16:43:27 +00:00
committed by Federico Mena Quintero
parent e133455aa7
commit b930d25be2
2 changed files with 88 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
docs/reference/ChangeLog
View File

@ -1,3 +1,13 @@
2004-01-23 Federico Mena Quintero <federico@ximian.com>
* gtk/migrating-checklist.sgml: Note that a widget must be
focusable for the menu keybindings to work.
2004-01-22 Federico Mena Quintero <federico@ximian.com>
* gtk/migrating-checklist.sgml: Mention when it is useful to use
GdkEventExpose.region rather than GdkEventExpose.area.
2004-01-22 Federico Mena Quintero <federico@ximian.com>
* gtk/migrating-checklist.sgml: Point to GtkEntry as an example of

78
docs/reference/gtk/migrating-checklist.sgml
View File

@ -131,6 +131,84 @@ my_widget_popup_menu_handler (GtkWidget *widget)
top edge of its popup menu with the bottom edge of the entry.
</para>
</note>
<note>
<para>
For the standard key bindings to work, your widget must be
able to take the keyboard focus. In general, widgets should
be fully usable through the keyboard and not just the mouse.
The very first step of this is to ensure that your widget
turns on the <link
linkend="gtkwidgetflags"><constant>GTK_CAN_FOCUS</constant></link>
FLAG.
</para>
</note>
</section>
<section id="checklist-gdkeventexpose-region">
<title>Use GdkEventExpose.region</title>
<formalpara>
<title>Why</title>
<para>
The <structfield>region</structfield> field of
<structname>GdkEventExpose</structname> allows you to redraw
less than the traditional
<structfield>GdkEventRegion.area</structfield>.
</para>
</formalpara>
<para>
In GTK+ 1.x, the <structname>GdkEventExpose</structname>
structure only had an <structfield>area</structfield> field to
let you determine the region that you needed to redraw. In GTK+
2.x, this field exists for compatibility and as a simple
interface. However, there is also a
<structfield>region</structfield> field which contains a
fine-grained region. The <structfield>area</structfield> field
is simply the bounding rectangle of the
<structfield>region</structfield>.
</para>
<para>
Widgets that are very expensive to re-render, such as an image
editor, may prefer to use the
<structfield>GdkEventExpose.region</structfield> field to paint
as little as possible. Widgets that just use a few drawing
primitives, such as labels and buttons, may prefer to use the
traditional <structfield>GdkEventExpose.area</structfield> field
for simplicity.
</para>
<para>
Regions have an internal representation that is accessible as a
list of rectangles. To turn the
<structfield>GdkEventExpose.region</structfield> field into such
a list, use gdk_region_get_rectangles():
</para>
<programlisting id="gdkregion-get-rectangles">
static gboolean
my_widget_expose_event_handler (GtkWidget *widget, GdkEventExpose *event)
{
GdkRectangle *rects;
int n_rects;
int i;
gdk_region_get_rectangles (event-&gt;region, &amp;rects, &amp;n_rects);
for (i = 0; i &lt; n_rects; i++)
{
/* Repaint rectangle: (rects[i].x, rects[i].y),
* (rects[i].width, rects[i].height)
*/
}
g_free (rects);
return FALSE;
}
</programlisting>
</section>
</chapter>