Maximum height of line of text in Pango
Hi, how can I efficiently obtain the minimum height in pixels which is guaranteed to cover a text line in a given font? Basically, I need something like (metrics.get_ascent() + metrics.get_descent()) / pango.SCALE where metrics is a pango.FontMetrics. Unfotunately, the operation given above takes ages to compute and is thus not feasible in the context of drawing a widget to the screen. Any ideas? Thank you in advance Dominique ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
Re: scrolledview
Selon James Scott Jr [EMAIL PROTECTED]:
An idle handler would be a good fit here. I assumed that you are
creating and filling textviews during the startup of your program and
possibly before you enter the main_loop or gtk_main. Or possibly in a
routine that does everything at once. Here is the potential problem:
your create and populate actions require some additional gtk messages to
be processed, which are waiting to get serviced by the gtk_main() loop.
So thing s will not appear to settle down until after the gtk_main has
been allowed to run. Using an idle handler puts your call to a
Position/Size routine at the back of the waiting queue of needed
messages, so by the time it's processed the other messages have done
their job and all the textviews/scrollbars/gtkvboxes, and scrolled
windows have settled down. -- wait, this assumes you issued a
gtk_widget_show{_all} on the main window containing all this stuff! Its
the gtk_widget_show that starts the cascade of messages which includes
the size and realize messages.
g_idle_add() or g_timeout_add(250,...) show do the trick.
Thank you... you seem to be right.
Due to the nature of Gtk I should wait all events/messages to be consumed before
trying to do anything with widgets.
Mehmet
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Re: GObject docs improvements
On Fri, Feb 09, 2007 at 01:42:19PM +0100, Stefan Kost wrote:
Deriving from classes that implement interfaces and changing
the implementation would worth an explanation and example.
Huh, sounds scary.
...
Do you have pointers to an example?
I must admit while I do this in some real world code and it
works, I have never verified I do it right by analysing the
gtype.c code (too scary). That's one of the reasons why
I suggested it...
A testing (non-real world) example is attached, of which
only MyPrintable, MyParent and MyChild2 are interesting
(MyChild does not change the implementation). If I attempt
to summarize it:
1. Implement the interface *again* in the subclass (this is
the controversial point):
G_DEFINE_TYPE_EXTENDED
(MyChild2, my_child2, MY_TYPE_PARENT, 0,
G_IMPLEMENT_INTERFACE(MY_TYPE_PRINTABLE, my_child2_printable_init))
2. Get the parent interface in the interface init function
with g_type_interface_peek_parent() and override methods:
static void
my_child2_printable_init(MyPrintableIface *iface)
{
my_child2_parent_printable = g_type_interface_peek_parent(iface);
iface-print = my_child2_print;
}
3. Use thus obtained parent implementation to call it in
the overriden method (if suitable):
my_child2_parent_printable-print(printable);
While checking for an example, just noticed that the Implemented
Interfaces stuff in Gtkdoc seems quite borked. Need to fix that.
In what sense? It seems to work for me -- though I should
note I use svn trunk gtk-doc.
Yeti
--
Whatever.
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Re: GObject docs improvements
On Sat, Feb 10, 2007 at 10:38:11PM +0100, David Nečas (Yeti) wrote:
A testing (non-real world) example is attached
Maybe this time I won't forget?
Yeti
--
Whatever.
===
#include glib-object.h
//
/* */
/* Interface*/
/* */
/* Consists of one virtual method: print(). */
/* */
//
#define MY_TYPE_PRINTABLE (my_printable_get_type())
#define MY_PRINTABLE(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj),
MY_TYPE_PRINTABLE, MyPrintable))
#define MY_PRINTABLE_CLASS(obj) (G_TYPE_CHECK_CLASS_CAST((obj),
MY_TYPE_PRINTABLE, MyPrintableIface))
#define MY_IS_PRINTABLE(obj)(G_TYPE_CHECK_INSTANCE_TYPE((obj),
MY_TYPE_PRINTABLE))
#define MY_PRINTABLE_GET_IFACE(obj) (G_TYPE_INSTANCE_GET_INTERFACE((obj),
MY_TYPE_PRINTABLE, MyPrintableIface))
typedef struct _MyPrintable MyPrintable; /* Dummy typedef */
typedef struct _MyPrintableIface MyPrintableIface;
struct _MyPrintableIface
{
GTypeInterface g_iface;
void (*print)(MyPrintable *printable);
};
GType my_printable_get_type (void) G_GNUC_CONST;
void my_printable_print(MyPrintable *printable);
//
GType
my_printable_get_type(void)
{
static GType printable_type = 0;
if (!printable_type) {
static const GTypeInfo printable_info = {
sizeof(MyPrintableIface), NULL, NULL, NULL, NULL, NULL, 0, 0, NULL
};
printable_type =
g_type_register_static(G_TYPE_INTERFACE, MyPrintable,
printable_info, 0);
g_type_interface_add_prerequisite(printable_type, G_TYPE_OBJECT);
}
return printable_type;
}
void
my_printable_print(MyPrintable *printable)
{
g_return_if_fail(MY_IS_PRINTABLE(printable));
g_return_if_fail(MY_PRINTABLE_GET_IFACE(printable)-print != NULL);
MY_PRINTABLE_GET_IFACE(printable)-print(printable);
}
//
/* */
/* Parent class */
/* */
/* Implements MyPrintable. */
/* */
//
#define MY_TYPE_PARENT(my_parent_get_type())
#define MY_PARENT(obj)(G_TYPE_CHECK_INSTANCE_CAST((obj),
MY_TYPE_PARENT, MyParent))
#define MY_PARENT_CLASS(klass)(G_TYPE_CHECK_CLASS_CAST((klass),
MY_TYPE_PARENT, MyParentClass))
#define MY_IS_PARENT(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj),
MY_TYPE_PARENT))
#define MY_IS_PARENT_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),
MY_TYPE_PARENT))
#define MY_PARENT_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS((obj),
MY_TYPE_PARENT, MyParentClass))
typedef struct _MyParent MyParent;
typedef struct _MyParentClass MyParentClass;
struct _MyParent {
GObject object;
gint data;
};
struct _MyParentClass {
GObjectClass object_class;
};
GType my_parent_get_type (void) G_GNUC_CONST;
MyParent* my_parent_new (gint i);
void my_parent_set_data (MyParent *parent,
gint i);
//
static void my_parent_printable_init(MyPrintableIface *iface);
static void my_parent_print (MyPrintable *printable);
G_DEFINE_TYPE_EXTENDED
(MyParent, my_parent, G_TYPE_OBJECT, 0,
G_IMPLEMENT_INTERFACE(MY_TYPE_PRINTABLE, my_parent_printable_init))
static void
my_parent_printable_init(MyPrintableIface *iface)
{
iface-print = my_parent_print;
}
static void
my_parent_class_init(MyParentClass *klass)
{
}
static void
my_parent_init(MyParent *parent)
{
}
static void
my_parent_print(MyPrintable *printable)
{
MyParent *parent = MY_PARENT(printable);
g_print(%p: data=%d\n, parent, parent-data);
}
MyParent*
my_parent_new(gint i)
{
MyParent *instance;
instance = g_object_new(MY_TYPE_PARENT, NULL);
instance-data = i;
return instance;
}
void
my_parent_set_data(MyParent *parent,
gint i)
{
parent-data = i;
}
//
/*
Re: how to make an animation ;)
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Fri, Feb 09, 2007 at 01:39:17PM +0100, Enrico Sardi wrote: [EMAIL PROTECTED] pronuncio' le seguenti parole il 09/02/2007 10:19: Hi Tomas! [...] Even better: pixbufs know about animations and do it for you! [...] I saw gdk_pixbuf_animation_new_from_file but it only works with an animated file as input while I need to build the animation from a series of indipendent files...thanks for the help! Yes. Well, either you go Olivier's path (concoct an animated GIF with all your images -- you can even embed timing info in that), or you start with gdk_pixbuf_simple_anim_new() -- Creates a new, empty animation. and add frame by frame with: gdk_pixbuf_simple_anim_add_frame() -- Adds a new frame to animation. In a timeout function (or possibly in an idle handler) you might have to call gdk_pixbuf_animation_iter_advance() (I don't know if that's done for you). The whole page http://developer.gnome.org/doc/API/2.0/gdk-pixbuf/gdk-pixbuf-animation.html is worth a read. Regards - -- tomás -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.1 (GNU/Linux) iD8DBQFFzq6hBcgs9XrR2kYRAmE1AJ97E0EFY5IhTWerRPFCiCjJm/GmgQCfSDY6 fYb3nfhBh0DKznBgv2lazu0= =FGBc -END PGP SIGNATURE- ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
