GTK+ Reference Manual | ||||
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#include <gtk/gtk.h> gchar* gtk_set_locale (void); void gtk_disable_setlocale (void); PangoLanguage* gtk_get_default_language (void); gboolean gtk_parse_args (int *argc, char ***argv); void gtk_init (int *argc, char ***argv); gboolean gtk_init_check (int *argc, char ***argv); gboolean gtk_init_with_args (int *argc, char ***argv, char *parameter_string, GOptionEntry *entries, char *translation_domain, GError **error); GOptionGroup* gtk_get_option_group (gboolean open_default_display); void gtk_exit (gint error_code); gboolean gtk_events_pending (void); void gtk_main (void); guint gtk_main_level (void); void gtk_main_quit (void); gboolean gtk_main_iteration (void); gboolean gtk_main_iteration_do (gboolean blocking); void gtk_main_do_event (GdkEvent *event); void (*GtkModuleInitFunc) (gint *argc, gchar ***argv); void (*GtkModuleDisplayInitFunc) (GdkDisplay *display); gboolean gtk_true (void); gboolean gtk_false (void); void gtk_grab_add (GtkWidget *widget); GtkWidget* gtk_grab_get_current (void); void gtk_grab_remove (GtkWidget *widget); void gtk_init_add (GtkFunction function, gpointer data); void gtk_quit_add_destroy (guint main_level, GtkObject *object); guint gtk_quit_add (guint main_level, GtkFunction function, gpointer data); guint gtk_quit_add_full (guint main_level, GtkFunction function, GtkCallbackMarshal marshal, gpointer data, GtkDestroyNotify destroy); void gtk_quit_remove (guint quit_handler_id); void gtk_quit_remove_by_data (gpointer data); guint gtk_timeout_add_full (guint32 interval, GtkFunction function, GtkCallbackMarshal marshal, gpointer data, GtkDestroyNotify destroy); guint gtk_timeout_add (guint32 interval, GtkFunction function, gpointer data); void gtk_timeout_remove (guint timeout_handler_id); guint gtk_idle_add (GtkFunction function, gpointer data); guint gtk_idle_add_priority (gint priority, GtkFunction function, gpointer data); guint gtk_idle_add_full (gint priority, GtkFunction function, GtkCallbackMarshal marshal, gpointer data, GtkDestroyNotify destroy); void gtk_idle_remove (guint idle_handler_id); void gtk_idle_remove_by_data (gpointer data); guint gtk_input_add_full (gint source, GdkInputCondition condition, GdkInputFunction function, GtkCallbackMarshal marshal, gpointer data, GtkDestroyNotify destroy); void gtk_input_remove (guint input_handler_id); #define GTK_PRIORITY_REDRAW #define GTK_PRIORITY_RESIZE #define GTK_PRIORITY_HIGH #define GTK_PRIORITY_INTERNAL #define GTK_PRIORITY_DEFAULT #define GTK_PRIORITY_LOW guint gtk_key_snooper_install (GtkKeySnoopFunc snooper, gpointer func_data); gint (*GtkKeySnoopFunc) (GtkWidget *grab_widget, GdkEventKey *event, gpointer func_data); void gtk_key_snooper_remove (guint snooper_handler_id); GdkEvent* gtk_get_current_event (void); guint32 gtk_get_current_event_time (void); gboolean gtk_get_current_event_state (GdkModifierType *state); GtkWidget* gtk_get_event_widget (GdkEvent *event); void gtk_propagate_event (GtkWidget *widget, GdkEvent *event);
Before using GTK+, you need to initialize it; initialization connects
to the window system display, and parses some standard command line
arguments. The gtk_init()
function initializes GTK+. gtk_init()
exits
the application if errors occur; to avoid this, use gtk_init_check()
.
gtk_init_check()
allows you to recover from a failed GTK+
initialization - you might start up your application in text mode instead.
Like all GUI toolkits, GTK+ uses an event-driven programming model. When the user is doing nothing, GTK+ sits in the main loop and waits for input. If the user performs some action - say, a mouse click - then the main loop "wakes up" and delivers an event to GTK+. GTK+ forwards the event to one or more widgets.
When widgets receive an event, they frequently emit one or more
signals. Signals notify your program that
"something interesting happened" by invoking functions you've
connected to the signal with g_signal_connect()
. Functions connected
to a signal are often termed callbacks.
When your callbacks are invoked, you would typically take some action - for example, when an Open button is clicked you might display a GtkFileSelectionDialog. After a callback finishes, GTK+ will return to the main loop and await more user input.
Example 1. Typical main
function for a GTK+ application
int main (int argc, char **argv) { /* Initialize i18n support */ gtk_set_locale (); /* Initialize the widget set */ gtk_init (&argc, &argv); /* Create the main window */ mainwin = gtk_window_new (GTK_WINDOW_TOPLEVEL); /* Set up our GUI elements */ ... /* Show the application window */ gtk_widget_show_all (mainwin); /* Enter the main event loop, and wait for user interaction */ gtk_main (); /* The user lost interest */ return 0; }
It's OK to use the GLib main loop directly instead of gtk_main()
,
though it involves slightly more typing. See GMainLoop in the GLib
documentation.
gchar* gtk_set_locale (void);
Initializes internationalization support for GTK+. gtk_init()
automatically does this, so there is typically no point
in calling this function.
If you are calling this function because you changed the locale after GTK+ is was initialized, then calling this function may help a bit. (Note, however, that changing the locale after GTK+ is initialized may produce inconsistent results and is not really supported.)
In detail - sets the current locale according to the
program environment. This is the same as calling the C library function
setlocale (LC_ALL, "")
but also takes care of the
locale specific setup of the windowing system used by GDK.
Returns : | a string corresponding to the locale set, typically in the
form lang_COUNTRY, where lang is an ISO-639 language code, and
COUNTRY is an ISO-3166 country code. On Unix, this form matches the
result of the setlocale() ; it is also used on other machines, such as
Windows, where the C library returns a different result. The string is
owned by GTK+ and should not be modified or freed.
|
void gtk_disable_setlocale (void);
Prevents gtk_init()
, gtk_init_check()
, gtk_init_with_args()
and
gtk_parse_args()
from automatically
calling setlocale (LC_ALL, "")
. You would
want to use this function if you wanted to set the locale for
your program to something other than the user's locale, or if
you wanted to set different values for different locale categories.
Most programs should not need to call this function.
PangoLanguage* gtk_get_default_language (void);
Returns the PangoLanguage for the default language currently in
effect. (Note that this can change over the life of an
application.) The default language is derived from the current
locale. It determines, for example, whether GTK+ uses the
right-to-left or left-to-right text direction. See
_gtk_get_lc_ctype()
for notes on behaviour on Windows.
Returns : | the default language as a PangoLanguage, must not be freed |
gboolean gtk_parse_args (int *argc, char ***argv);
Parses command line arguments, and initializes global
attributes of GTK+, but does not actually open a connection
to a display. (See gdk_display_open()
, gdk_get_display_arg_name()
)
Any arguments used by GTK+ or GDK are removed from the array and
argc
and argv
are updated accordingly.
You shouldn't call this function explicitely if you are using
gtk_init()
, or gtk_init_check()
.
argc : |
a pointer to the number of command line arguments. |
argv : |
a pointer to the array of command line arguments. |
Returns : | TRUE if initialization succeeded, otherwise FALSE .
|
void gtk_init (int *argc, char ***argv);
Call this function before using any other GTK+ functions in your GUI
applications. It will initialize everything needed to operate the
toolkit and parses some standard command line options. argc
and
argv
are adjusted accordingly so your own code will
never see those standard arguments.
Note that there are some alternative ways to initialize GTK+:
if you are calling gtk_parse_args()
, gtk_init_check()
,
gtk_init_with_args()
or g_option_context_parse()
with
the option group returned by gtk_get_option_group()
, you
don't have to call gtk_init()
.
This function will terminate your program if it was unable to initialize
the GUI for some reason. If you want your program to fall back to a
textual interface you want to call gtk_init_check()
instead.
argc : |
Address of the argc parameter of your
main() function. Changed if any arguments were handled.
|
argv : |
Address of the argv parameter of main() .
Any parameters understood by gtk_init() are stripped before return.
|
gboolean gtk_init_check (int *argc, char ***argv);
This function does the same work as gtk_init()
with only
a single change: It does not terminate the program if the GUI can't be
initialized. Instead it returns FALSE
on failure.
This way the application can fall back to some other means of communication with the user - for example a curses or command line interface.
argc : |
Address of the argc parameter of your
main() function. Changed if any arguments were handled.
|
argv : |
Address of the argv parameter of main() .
Any parameters understood by gtk_init() are stripped before return.
|
Returns : | TRUE if the GUI has been successfully initialized,
FALSE otherwise.
|
gboolean gtk_init_with_args (int *argc, char ***argv, char *parameter_string, GOptionEntry *entries, char *translation_domain, GError **error);
This function does the same work as gtk_init_check()
.
Additionally, it allows you to add your own commandline options,
and it automatically generates nicely formatted
--help
output. Note that your program will
be terminated after writing out the help output.
argc : |
a pointer to the number of command line arguments. |
argv : |
a pointer to the array of command line arguments. |
parameter_string : |
a string which is displayed in
the first line of --help output, after
|
entries : |
a NULL -terminated array of GOptionEntrys
describing the options of your program
|
translation_domain : |
a translation domain to use for translating
the --help output for the options in entries
with gettext() , or NULL
|
error : |
a return location for errors |
Returns : | TRUE if the GUI has been successfully initialized,
FALSE otherwise.
|
Since 2.6
GOptionGroup* gtk_get_option_group (gboolean open_default_display);
Returns a GOptionGroup for the commandline arguments recognized
by GTK+ and GDK. You should add this group to your GOptionContext
with g_option_context_add_group()
, if you are using
g_option_context_parse()
to parse your commandline arguments.
open_default_display : |
whether to open the default display when parsing the commandline arguments |
Returns : | a GOptionGroup for the commandline arguments recognized by GTK+ |
Since 2.6
void gtk_exit (gint error_code);
gtk_exit
is deprecated and should not be used in newly-written code. Use the standard exit()
function instead.
Terminates the program and returns the given exit code to the caller. This function will shut down the GUI and free all resources allocated for GTK+.
error_code : |
Return value to pass to the caller. This is dependent on the
target system but at least on Unix systems 0 means success.
|
gboolean gtk_events_pending (void);
Checks if any events are pending. This can be used to update the GUI and invoke timeouts etc. while doing some time intensive computation.
Example 2. Updating the GUI during a long computation.
/* computation going on */ ... while (gtk_events_pending ()) gtk_main_iteration (); ... /* computation continued */
Returns : |
TRUE if any events are pending, FALSE otherwise.
|
void gtk_main (void);
Runs the main loop until gtk_main_quit()
is called. You can nest calls to
gtk_main()
. In that case gtk_main_quit()
will make the innermost invocation
of the main loop return.
guint gtk_main_level (void);
Asks for the current nesting level of the main loop. This can be useful
when calling gtk_quit_add()
.
Returns : | the nesting level of the current invocation of the main loop. |
void gtk_main_quit (void);
Makes the innermost invocation of the main loop return when it regains control.
gboolean gtk_main_iteration (void);
Runs a single iteration of the mainloop. If no events are waiting to be
processed GTK+ will block until the next event is noticed. If you don't
want to block look at gtk_main_iteration_do()
or check if any events are
pending with gtk_events_pending()
first.
Returns : |
TRUE if gtk_main_quit() has been called for the innermost mainloop.
|
gboolean gtk_main_iteration_do (gboolean blocking);
Runs a single iteration of the mainloop. If no events are available either
return or block dependent on the value of blocking
.
blocking : |
TRUE if you want GTK+ to block if no events are pending.
|
Returns : |
TRUE if gtk_main_quit() has been called for the innermost mainloop.
|
void gtk_main_do_event (GdkEvent *event);
Processes a single GDK event. This is public only to allow filtering of events between GDK and GTK+. You will not usually need to call this function directly.
While you should not call this function directly, you might want to know how exactly events are handled. So here is what this function does with the event:
Compress enter/leave notify events. If the event passed build an enter/leave pair together with the next event (peeked from GDK) both events are thrown away. This is to avoid a backlog of (de-)highlighting widgets crossed by the pointer.
Find the widget which got the event. If the widget can't be determined
the event is thrown away unless it belongs to a INCR transaction. In that
case it is passed to gtk_selection_incr_event()
.
Then the event is passed on a stack so you can query the currently handled
event with gtk_get_current_event()
.
The event is sent to a widget. If a grab is active all events for widgets that are not in the contained in the grab widget are sent to the latter with a few exceptions:
Deletion and destruction events are still sent to the event widget for obvious reasons.
Events which directly relate to the visual representation of the event widget.
Leave events are delivered to the event widget if there was an enter event delivered to it before without the paired leave event.
Drag events are not redirected because it is unclear what the semantics of that would be.
Another point of interest might be that all key events are first passed
through the key snooper functions if there are any. Read the description
of gtk_key_snooper_install()
if you need this feature.
After finishing the delivery the event is popped from the event stack.
event : |
An event to process (normally) passed by GDK. |
void (*GtkModuleInitFunc) (gint *argc, gchar ***argv);
Each GTK+ module must have a function gtk_module_init()
with this prototype.
This function is called after loading the module with the argc
and argv
cleaned from any arguments that GTK+ handles itself.
argc : |
Pointer to the number of arguments remaining after gtk_init() .
|
argv : |
Points to the argument vector. |
void (*GtkModuleDisplayInitFunc) (GdkDisplay *display);
display : |
Since 2.2
gboolean gtk_true (void);
All this function does it to return TRUE
. This can be useful for example
if you want to inhibit the deletion of a window. Of course you should
not do this as the user expects a reaction from clicking the close
icon of the window...
Example 3. A persistent window
##include <gtk/gtk.h> int main (int argc, char **argv) { GtkWidget *win, *but; gtk_init( &argc, &argv ); win = gtk_window_new (GTK_WINDOW_TOPLEVEL); g_signal_connect (win, "delete-event", G_CALLBACK (gtk_true), NULL); g_signal_connect (win, "destroy", G_CALLBACK (gtk_main_quit), NULL); but = gtk_button_new_with_label ("Close yourself. I mean it!"); g_signal_connect_swapped (but, "clicked", G_CALLBACK (gtk_object_destroy), win); gtk_container_add (GTK_CONTAINER (win), but); gtk_widget_show_all (win); gtk_main (); return 0; }
Returns : |
TRUE
|
gboolean gtk_false (void);
Analogical to gtk_true()
this function does nothing
but always returns FALSE
.
Returns : |
FALSE
|
void gtk_grab_add (GtkWidget *widget);
Makes widget
the current grabbed widget. This means that interaction with
other widgets in the same application is blocked and mouse as well as
keyboard events are delivered to this widget.
widget : |
The widget that grabs keyboard and pointer events. |
GtkWidget* gtk_grab_get_current (void);
Queries the current grab of the default window group.
Returns : | The widget which currently has the grab or NULL if no grab is active.
|
void gtk_grab_remove (GtkWidget *widget);
Removes the grab from the given widget. You have to pair calls to gtk_grab_add()
and gtk_grab_remove()
.
widget : |
The widget which gives up the grab. |
void gtk_init_add (GtkFunction function, gpointer data);
Registers a function to be called when the mainloop is started.
function : |
Function to invoke when gtk_main() is called next.
|
data : |
Data to pass to that function. |
void gtk_quit_add_destroy (guint main_level, GtkObject *object);
Trigger destruction of object
in case the mainloop at level main_level
is quit.
main_level : |
Level of the mainloop which shall trigger the destruction. |
object : |
Object to be destroyed. |
guint gtk_quit_add (guint main_level, GtkFunction function, gpointer data);
Registers a function to be called when an instance of the mainloop is left.
main_level : |
Level at which termination the function shall be called. You can pass 0 here to have the function run at the termination of the current mainloop. |
function : |
The function to call. This should return 0 to be removed from the list of quit handlers. Otherwise the function might be called again. |
data : |
Pointer to pass when calling function .
|
Returns : | A handle for this quit handler (you need this for gtk_quit_remove() )
or 0 if you passed a NULL pointer in function .
|
guint gtk_quit_add_full (guint main_level, GtkFunction function, GtkCallbackMarshal marshal, gpointer data, GtkDestroyNotify destroy);
Registers a function to be called when an instance of the mainloop is left.
In comparison to gtk_quit_add()
this function adds the possibility to
pass a marshaller and a function to be called when the quit handler is freed.
The former can be used to run interpreted code instead of a compiled function
while the latter can be used to free the information stored in data
(while
you can do this in function
as well)... So this function will mostly be
used by GTK+ wrappers for languages other than C.
main_level : |
Level at which termination the function shall be called. You can pass 0 here to have the function run at the termination of the current mainloop. |
function : |
The function to call. This should return 0 to be removed from the list of quit handlers. Otherwise the function might be called again. |
marshal : |
The marshaller to be used. If this is non-NULL , function is
ignored.
|
data : |
Pointer to pass when calling function .
|
destroy : |
Function to call to destruct data . Gets data as argument.
|
Returns : | A handle for this quit handler (you need this for gtk_quit_remove() )
or 0 if you passed a NULL pointer in function .
|
void gtk_quit_remove (guint quit_handler_id);
Removes a quit handler by its identifier.
quit_handler_id : |
Identifier for the handler returned when installing it. |
void gtk_quit_remove_by_data (gpointer data);
Removes a quit handler identified by its data
field.
data : |
The pointer passed as data to gtk_quit_add() or gtk_quit_add_full() .
|
guint gtk_timeout_add_full (guint32 interval, GtkFunction function, GtkCallbackMarshal marshal, gpointer data, GtkDestroyNotify destroy);
gtk_timeout_add_full
has been deprecated since version 2.4 and should not be used in newly-written code. Use g_timeout_add_full()
instead.
Registers a function to be called periodically. The function will be called
repeatedly after interval
milliseconds until it returns FALSE
at which
point the timeout is destroyed and will not be called again.
interval : |
The time between calls to the function, in milliseconds (1/1000ths of a second.) |
function : |
The function to call periodically. |
marshal : |
The marshaller to use instead of the function (if non-NULL ).
|
data : |
The data to pass to the function. |
destroy : |
Function to call when the timeout is destroyed or NULL .
|
Returns : | A unique id for the event source. |
guint gtk_timeout_add (guint32 interval, GtkFunction function, gpointer data);
gtk_timeout_add
has been deprecated since version 2.4 and should not be used in newly-written code. Use g_timeout_add()
instead.
Registers a function to be called periodically. The function will be called
repeatedly after interval
milliseconds until it returns FALSE
at which
point the timeout is destroyed and will not be called again.
interval : |
The time between calls to the function, in milliseconds (1/1000ths of a second.) |
function : |
The function to call periodically. |
data : |
The data to pass to the function. |
Returns : | A unique id for the event source. |
void gtk_timeout_remove (guint timeout_handler_id);
gtk_timeout_remove
has been deprecated since version 2.4 and should not be used in newly-written code. Use g_source_remove()
instead.
Removes the given timeout destroying all information about it.
timeout_handler_id : |
The identifier returned when installing the timeout. |
guint gtk_idle_add (GtkFunction function, gpointer data);
gtk_idle_add
has been deprecated since version 2.4 and should not be used in newly-written code. Use g_idle_add()
instead.
Causes the mainloop to call the given function whenever no events with
higher priority are to be processed. The default priority is
GTK_PRIORITY_DEFAULT
, which is rather low.
function : |
The function to call. |
data : |
The information to pass to the function. |
Returns : | a unique handle for this registration. |
guint gtk_idle_add_priority (gint priority, GtkFunction function, gpointer data);
gtk_idle_add_priority
has been deprecated since version 2.4 and should not be used in newly-written code. Use g_idle_add_full()
instead.
Like gtk_idle_add()
this function allows you to have a function called
when the event loop is idle. The difference is that you can give a
priority different from GTK_PRIORITY_DEFAULT
to the idle function.
priority : |
The priority which should not be above G_PRIORITY_HIGH_IDLE .
Note that you will interfere with GTK+ if you use a priority above
GTK_PRIORITY_RESIZE .
|
function : |
The function to call. |
data : |
Data to pass to that function. |
Returns : | A unique id for the event source. |
guint gtk_idle_add_full (gint priority, GtkFunction function, GtkCallbackMarshal marshal, gpointer data, GtkDestroyNotify destroy);
gtk_idle_add_full
has been deprecated since version 2.4 and should not be used in newly-written code. Use g_idle_add_full()
instead.
Like gtk_idle_add()
this function allows you to have a function called
when the event loop is idle. The difference is that you can give a
priority different from GTK_PRIORITY_DEFAULT
to the idle function.
priority : |
The priority which should not be above G_PRIORITY_HIGH_IDLE .
Note that you will interfere with GTK+ if you use a priority above
GTK_PRIORITY_RESIZE .
|
function : |
The function to call. |
marshal : |
The marshaller to use instead of the function (if non-NULL ).
|
data : |
Data to pass to that function. |
destroy : |
Function to call when the timeout is destroyed or NULL .
|
Returns : | A unique id for the event source. |
void gtk_idle_remove (guint idle_handler_id);
gtk_idle_remove
has been deprecated since version 2.4 and should not be used in newly-written code. Use g_source_remove()
instead.
Removes the idle function with the given id.
idle_handler_id : |
Identifies the idle function to remove. |
void gtk_idle_remove_by_data (gpointer data);
gtk_idle_remove_by_data
has been deprecated since version 2.4 and should not be used in newly-written code. Use g_idle_remove_by_data()
instead.
Removes the idle function identified by the user data.
data : |
remove the idle function which was registered with this user data. |
guint gtk_input_add_full (gint source, GdkInputCondition condition, GdkInputFunction function, GtkCallbackMarshal marshal, gpointer data, GtkDestroyNotify destroy);
gtk_input_add_full
has been deprecated since version 2.4 and should not be used in newly-written code. Use g_io_add_watch_full()
instead.
Registers a function to be called when a condition becomes true on a file descriptor.
source : |
a file descriptor. |
condition : |
the condition. |
function : |
The function to call. |
marshal : |
The marshaller to use instead of the function (if non-NULL ).
|
data : |
callback data passed to function .
|
destroy : |
callback function to call with data when the input
handler is removed, or NULL .
|
Returns : | A unique id for the event source; to be used with gtk_input_remove() .
|
void gtk_input_remove (guint input_handler_id);
gtk_input_remove
has been deprecated since version 2.4 and should not be used in newly-written code. Use g_source_remove()
instead.
Removes the function with the given id.
input_handler_id : |
Identifies the function to remove. |
#define GTK_PRIORITY_REDRAW (G_PRIORITY_HIGH_IDLE + 20)
GTK_PRIORITY_REDRAW
has been deprecated since version 2.4 and should not be used in newly-written code. This macro is deprecated. You should use GDK_PRIORITY_REDRAW
instead.
Use this priority for redrawing related stuff. It is used internally by
GTK+ to do pending redraws. This priority is lower than GTK_PRIORITY_RESIZE
to avoid redrawing a widget just before resizing (and therefore redrawing
it again).
#define GTK_PRIORITY_RESIZE (G_PRIORITY_HIGH_IDLE + 10)
Use this priority for resizing related stuff. It is used internally by
GTK+ to compute the sizes of widgets. This priority is higher than
GTK_PRIORITY_REDRAW
to avoid resizing a widget which was just redrawn.
#define GTK_PRIORITY_HIGH G_PRIORITY_HIGH
GTK_PRIORITY_HIGH
has been deprecated since version 2.4 and should not be used in newly-written code. This macro is deprecated. You should use G_PRIORITY_HIGH
instead.
Use this for high priority timeouts. This priority is never used inside GTK+ so everything running at this priority will be running before anything inside the toolkit.
#define GTK_PRIORITY_INTERNAL GTK_PRIORITY_REDRAW
GTK_PRIORITY_INTERNAL
is deprecated and should not be used in newly-written code.
This priority is for GTK+ internal stuff. Don't use it in your applications.
#define GTK_PRIORITY_DEFAULT G_PRIORITY_DEFAULT_IDLE
GTK_PRIORITY_DEFAULT
has been deprecated since version 2.4 and should not be used in newly-written code. This macro is deprecated. You should use G_PRIORITY_DEFAULT_IDLE
instead.
Default priority for idle functions.
#define GTK_PRIORITY_LOW G_PRIORITY_LOW
GTK_PRIORITY_LOW
has been deprecated since version 2.4 and should not be used in newly-written code. This macro is deprecated. You should use G_PRIORITY_LOW
instead.
Priority for very unimportant background tasks.
guint gtk_key_snooper_install (GtkKeySnoopFunc snooper, gpointer func_data);
Installs a key snooper function, which will get called on all key events before delivering them normally.
snooper : |
a GtkKeySnoopFunc. |
func_data : |
data to pass to snooper .
|
Returns : | a unique id for this key snooper for use with gtk_key_snooper_remove() .
|
gint (*GtkKeySnoopFunc) (GtkWidget *grab_widget, GdkEventKey *event, gpointer func_data);
Key snooper functions are called before normal event delivery. They can be used to implement custom key event handling.
grab_widget : |
the widget to which the event will be delivered. |
event : |
the key event. |
func_data : |
the func_data supplied to gtk_key_snooper_install() .
|
Returns : |
TRUE to stop further processing of event , FALSE to continue.
|
void gtk_key_snooper_remove (guint snooper_handler_id);
Removes the key snooper function with the given id.
snooper_handler_id : |
Identifies the key snooper to remove. |
GdkEvent* gtk_get_current_event (void);
Obtains a copy of the event currently being processed by GTK+. For
example, if you get a "clicked" signal from GtkButton, the current
event will be the GdkEventButton that triggered the "clicked"
signal. The returned event must be freed with gdk_event_free()
.
If there is no current event, the function returns NULL
.
Returns : | a copy of the current event, or NULL if no current event.
|
guint32 gtk_get_current_event_time (void);
If there is a current event and it has a timestamp, return that
timestamp, otherwise return GDK_CURRENT_TIME
.
Returns : | the timestamp from the current event, or GDK_CURRENT_TIME .
|
gboolean gtk_get_current_event_state (GdkModifierType *state);
If there is a current event and it has a state field, place
that state field in state
and return TRUE
, otherwise return
FALSE
.
state : |
a location to store the state of the current event |
Returns : | TRUE if there was a current event and it had a state field
|
GtkWidget* gtk_get_event_widget (GdkEvent *event);
If event
is NULL
or the event was not associated with any widget,
returns NULL
, otherwise returns the widget that received the event
originally.
void gtk_propagate_event (GtkWidget *widget, GdkEvent *event);
Sends an event to a widget, propagating the event to parent widgets
if the event remains unhandled. Events received by GTK+ from GDK
normally begin in gtk_main_do_event()
. Depending on the type of
event, existence of modal dialogs, grabs, etc., the event may be
propagated; if so, this function is used. gtk_propagate_event()
calls gtk_widget_event()
on each widget it decides to send the
event to. So gtk_widget_event()
is the lowest-level function; it
simply emits the "event" and possibly an event-specific signal on a
widget. gtk_propagate_event()
is a bit higher-level, and
gtk_main_do_event()
is the highest level.
All that said, you most likely don't want to use any of these
functions; synthesizing events is rarely needed. Consider asking on
the mailing list for better ways to achieve your goals. For
example, use gdk_window_invalidate_rect()
or
gtk_widget_queue_draw()
instead of making up expose events.
widget : |
a GtkWidget |
event : |
an event |