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GDK Reference Manual | ![]() |
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#include <gdk/gdk.h> GdkDisplay; GdkDisplay* gdk_display_open (const gchar *display_name); GdkDisplay* gdk_display_get_default (void); const gchar* gdk_display_get_name (GdkDisplay *display); gint gdk_display_get_n_screens (GdkDisplay *display); GdkScreen* gdk_display_get_screen (GdkDisplay *display, gint screen_num); GdkScreen* gdk_display_get_default_screen (GdkDisplay *display); void gdk_display_pointer_ungrab (GdkDisplay *display, guint32 time_); void gdk_display_keyboard_ungrab (GdkDisplay *display, guint32 time_); gboolean gdk_display_pointer_is_grabbed (GdkDisplay *display); void gdk_display_beep (GdkDisplay *display); void gdk_display_sync (GdkDisplay *display); void gdk_display_flush (GdkDisplay *display); void gdk_display_close (GdkDisplay *display); GList* gdk_display_list_devices (GdkDisplay *display); GdkEvent* gdk_display_get_event (GdkDisplay *display); GdkEvent* gdk_display_peek_event (GdkDisplay *display); void gdk_display_put_event (GdkDisplay *display, const GdkEvent *event); void gdk_display_add_client_message_filter (GdkDisplay *display, GdkAtom message_type, GdkFilterFunc func, gpointer data); void gdk_display_set_double_click_time (GdkDisplay *display, guint msec); void gdk_display_set_double_click_distance (GdkDisplay *display, guint distance); void gdk_display_get_pointer (GdkDisplay *display, GdkScreen **screen, gint *x, gint *y, GdkModifierType *mask); GdkWindow* gdk_display_get_window_at_pointer (GdkDisplay *display, gint *win_x, gint *win_y); GdkDisplayPointerHooks; GdkDisplayPointerHooks* gdk_display_set_pointer_hooks (GdkDisplay *display, const GdkDisplayPointerHooks *new_hooks); void gdk_display_warp_pointer (GdkDisplay *display, GdkScreen *screen, gint x, gint y); gboolean gdk_display_supports_cursor_color (GdkDisplay *display); gboolean gdk_display_supports_cursor_alpha (GdkDisplay *display); guint gdk_display_get_default_cursor_size (GdkDisplay *display); void gdk_display_get_maximal_cursor_size (GdkDisplay *display, guint *width, guint *height); GdkWindow* gdk_display_get_default_group (GdkDisplay *display); gboolean gdk_display_supports_selection_notification (GdkDisplay *display); gboolean gdk_display_request_selection_notification (GdkDisplay *display, GdkAtom selection); gboolean gdk_display_supports_clipboard_persistence (GdkDisplay *display); void gdk_display_store_clipboard (GdkDisplay *display, GdkWindow *clipboard_window, guint32 time_, const GdkAtom *targets, gint n_targets); gboolean gdk_display_supports_shapes (GdkDisplay *display); gboolean gdk_display_supports_input_shapes (GdkDisplay *display); gboolean gdk_display_supports_composite (GdkDisplay *display);
GdkDisplay objects purpose are two fold:
To grab/ungrab keyboard focus and mouse pointer
To manage and provide information about the GdkScreen(s) available for this GdkDisplay
GdkDisplay objects are the GDK representation of the X Display which can be described as a workstation consisting of a keyboard a pointing device (such as a mouse) and one or more screens. It is used to open and keep track of various GdkScreen objects currently instanciated by the application. It is also used to grab and release the keyboard and the mouse pointer.
typedef struct _GdkDisplay GdkDisplay;
The GdkDisplay struct is the GDK representation of an X display. All its fields are private and should not be accessed directly.
Since 2.2
GdkDisplay* gdk_display_open (const gchar *display_name);
Opens a display.
display_name : |
the name of the display to open |
Returns : | a GdkDisplay, or NULL if the display
could not be opened.
|
Since 2.2
GdkDisplay* gdk_display_get_default (void);
Gets the default GdkDisplay. This is a convenience
function for
gdk_display_manager_get_default_display (
.gdk_display_manager_get()
)
Returns : | a GdkDisplay, or NULL if there is no default
display.
|
Since 2.2
const gchar* gdk_display_get_name (GdkDisplay *display);
Gets the name of the display.
display : |
a GdkDisplay |
Returns : | a string representing the display name. This string is owned by GDK and should not be modified or freed. |
Since 2.2
gint gdk_display_get_n_screens (GdkDisplay *display);
Gets the number of screen managed by the display
.
display : |
a GdkDisplay |
Returns : | number of screens. |
Since 2.2
GdkScreen* gdk_display_get_screen (GdkDisplay *display, gint screen_num);
Returns a screen object for one of the screens of the display.
display : |
a GdkDisplay |
screen_num : |
the screen number |
Returns : | the GdkScreen object |
Since 2.2
GdkScreen* gdk_display_get_default_screen (GdkDisplay *display);
Get the default GdkScreen for display
.
display : |
a GdkDisplay |
Returns : | the default GdkScreen object for display
|
Since 2.2
void gdk_display_pointer_ungrab (GdkDisplay *display, guint32 time_);
Release any pointer grab.
display : |
a GdkDisplay. |
time_ : |
a timestap (e.g. GDK_CURRENT_TIME ).
|
Since 2.2
void gdk_display_keyboard_ungrab (GdkDisplay *display, guint32 time_);
Release any keyboard grab
display : |
a GdkDisplay. |
time_ : |
a timestap (e.g GDK_CURRENT_TIME). |
Since 2.2
gboolean gdk_display_pointer_is_grabbed (GdkDisplay *display);
Test if the pointer is grabbed.
display : |
a GdkDisplay |
Returns : | TRUE if an active X pointer grab is in effect
|
Since 2.2
void gdk_display_beep (GdkDisplay *display);
Emits a short beep on display
display : |
a GdkDisplay |
Since 2.2
void gdk_display_sync (GdkDisplay *display);
Flushes any requests queued for the windowing system and waits until all
requests have been handled. This is often used for making sure that the
display is synchronized with the current state of the program. Calling
gdk_display_sync()
before gdk_error_trap_pop()
makes sure that any errors
generated from earlier requests are handled before the error trap is
removed.
This is most useful for X11. On windowing systems where requests are handled synchronously, this function will do nothing.
display : |
a GdkDisplay |
Since 2.2
void gdk_display_flush (GdkDisplay *display);
Flushes any requests queued for the windowing system; this happens automatically when the main loop blocks waiting for new events, but if your application is drawing without returning control to the main loop, you may need to call this function explicitely. A common case where this function needs to be called is when an application is executing drawing commands from a thread other than the thread where the main loop is running.
This is most useful for X11. On windowing systems where requests are handled synchronously, this function will do nothing.
display : |
a GdkDisplay |
Since 2.4
void gdk_display_close (GdkDisplay *display);
Closes the connection to the windowing system for the given display, and cleans up associated resources.
display : |
a GdkDisplay |
Since 2.2
GList* gdk_display_list_devices (GdkDisplay *display);
Returns the list of available input devices attached to display
.
The list is statically allocated and should not be freed.
display : |
a GdkDisplay |
Returns : | a list of GdkDevice |
Since 2.2
GdkEvent* gdk_display_get_event (GdkDisplay *display);
Gets the next GdkEvent to be processed for display
, fetching events from the
windowing system if necessary.
display : |
a GdkDisplay |
Returns : | the next GdkEvent to be processed, or NULL if no events
are pending. The returned GdkEvent should be freed with gdk_event_free() .
|
Since 2.2
GdkEvent* gdk_display_peek_event (GdkDisplay *display);
Gets a copy of the first GdkEvent in the display
's event queue, without
removing the event from the queue. (Note that this function will
not get more events from the windowing system. It only checks the events
that have already been moved to the GDK event queue.)
display : |
a GdkDisplay |
Returns : | a copy of the first GdkEvent on the event queue, or NULL
if no events are in the queue. The returned GdkEvent should be freed with
gdk_event_free() .
|
Since 2.2
void gdk_display_put_event (GdkDisplay *display, const GdkEvent *event);
Appends a copy of the given event onto the front of the event
queue for display
.
display : |
a GdkDisplay |
event : |
a GdkEvent. |
Since 2.2
void gdk_display_add_client_message_filter (GdkDisplay *display, GdkAtom message_type, GdkFilterFunc func, gpointer data);
Adds a filter to be called when X ClientMessage events are received.
See gdk_window_add_filter()
if you are interested in filtering other
types of events.
display : |
a GdkDisplay for which this message filter applies |
message_type : |
the type of ClientMessage events to receive.
This will be checked against the message_type field
of the XClientMessage event struct.
|
func : |
the function to call to process the event. |
data : |
user data to pass to func .
|
Since 2.2
void gdk_display_set_double_click_time (GdkDisplay *display, guint msec);
Sets the double click time (two clicks within this time interval count as a double click and result in a GDK_2BUTTON_PRESS event). Applications should not set this, it is a global user-configured setting.
display : |
a GdkDisplay |
msec : |
double click time in milliseconds (thousandths of a second) |
Since 2.2
void gdk_display_set_double_click_distance (GdkDisplay *display, guint distance);
Sets the double click distance (two clicks within this distance
count as a double click and result in a GDK_2BUTTON_PRESS event).
See also gdk_display_set_double_click_time()
.
Applications should not set this, it is a global
user-configured setting.
display : |
a GdkDisplay |
distance : |
distance in pixels |
Since 2.4
void gdk_display_get_pointer (GdkDisplay *display, GdkScreen **screen, gint *x, gint *y, GdkModifierType *mask);
Gets the current location of the pointer and the current modifier mask for a given display.
display : |
a GdkDisplay |
screen : |
location to store the screen that the
cursor is on, or NULL .
|
x : |
location to store root window X coordinate of pointer, or NULL .
|
y : |
location to store root window Y coordinate of pointer, or NULL .
|
mask : |
location to store current modifier mask, or NULL
|
Since 2.2
GdkWindow* gdk_display_get_window_at_pointer (GdkDisplay *display, gint *win_x, gint *win_y);
Obtains the window underneath the mouse pointer, returning the location
of that window in win_x
, win_y
for screen
. Returns NULL
if the window
under the mouse pointer is not known to GDK (for example, belongs to
another application).
display : |
a GdkDisplay |
win_x : |
return location for origin of the window under the pointer |
win_y : |
return location for origin of the window under the pointer |
Returns : | the window under the mouse pointer, or NULL
|
Since 2.2
typedef struct { void (*get_pointer) (GdkDisplay *display, GdkScreen **screen, gint *x, gint *y, GdkModifierType *mask); GdkWindow* (*window_get_pointer) (GdkDisplay *display, GdkWindow *window, gint *x, gint *y, GdkModifierType *mask); GdkWindow* (*window_at_pointer) (GdkDisplay *display, gint *win_x, gint *win_y); } GdkDisplayPointerHooks;
A table of pointers to functions for getting quantities related to
the current pointer position. Each GdkDisplay has a table of this type,
which can be set using gdk_display_set_pointer_hooks()
.
This is only useful for such low-level tools as an event recorder. Applications should never have any reason to use this facility
get_pointer () |
Obtains the current pointer position and modifier state.
The position is given in coordinates relative to the window containing
the pointer, which is returned in window .
|
window_get_pointer () |
Obtains the window underneath the mouse pointer.
Current pointer position and modifier state are returned in x , y and
mask . The position is given in coordinates relative to window .
|
window_at_pointer () |
Obtains the window underneath the mouse pointer,
returning the location of that window in win_x , win_y . Returns NULL
if the window under the mouse pointer is not known to GDK (for example,
belongs to another application).
|
Since 2.2
GdkDisplayPointerHooks* gdk_display_set_pointer_hooks (GdkDisplay *display, const GdkDisplayPointerHooks *new_hooks);
This function allows for hooking into the operation of getting the current location of the pointer on a particular display. This is only useful for such low-level tools as an event recorder. Applications should never have any reason to use this facility.
display : |
a GdkDisplay |
new_hooks : |
a table of pointers to functions for getting
quantities related to the current pointer position,
or NULL to restore the default table.
|
Returns : | the previous pointer hook table |
Since 2.2
void gdk_display_warp_pointer (GdkDisplay *display, GdkScreen *screen, gint x, gint y);
Warps the pointer of display
to the point x
,y
on
the screen screen
, unless the pointer is confined
to a window by a grab, in which case it will be moved
as far as allowed by the grab. Warping the pointer
creates events as if the user had moved the mouse
instantaneously to the destination.
Note that the pointer should normally be under the control of the user. This function was added to cover some rare use cases like keyboard navigation support for the color picker in the GtkColorSelectionDialog.
display : |
a GdkDisplay |
screen : |
the screen of display to warp the pointer to
|
x : |
the x coordinate of the destination |
y : |
the y coordinate of the destination |
Since 2.8
gboolean gdk_display_supports_cursor_color (GdkDisplay *display);
Returns TRUE
if multicolored cursors are supported
on display
. Otherwise, cursors have only a forground
and a background color.
display : |
a GdkDisplay |
Returns : | whether cursors can have multiple colors. |
Since 2.4
gboolean gdk_display_supports_cursor_alpha (GdkDisplay *display);
Returns TRUE
if cursors can use an 8bit alpha channel
on display
. Otherwise, cursors are restricted to bilevel
alpha (i.e. a mask).
display : |
a GdkDisplay |
Returns : | whether cursors can have alpha channels. |
Since 2.4
guint gdk_display_get_default_cursor_size (GdkDisplay *display);
Returns the default size to use for cursors on display
.
display : |
a GdkDisplay |
Returns : | the default cursor size. |
Since 2.4
void gdk_display_get_maximal_cursor_size (GdkDisplay *display, guint *width, guint *height);
Gets the maximal size to use for cursors on display
.
display : |
a GdkDisplay |
width : |
the return location for the maximal cursor width |
height : |
the return location for the maximal cursor height |
Since 2.4
GdkWindow* gdk_display_get_default_group (GdkDisplay *display);
Returns the default group leader window for all toplevel windows
on display
. This window is implicitly created by GDK.
See gdk_window_set_group()
.
display : |
a GdkDisplay |
Returns : | The default group leader window for display
|
Since 2.4
gboolean gdk_display_supports_selection_notification (GdkDisplay *display);
Returns whether GdkEventOwnerChange events will be sent when the owner of a selection changes.
display : |
a GdkDisplay |
Returns : | whether GdkEventOwnerChange events will be sent. |
Since 2.6
gboolean gdk_display_request_selection_notification (GdkDisplay *display, GdkAtom selection);
Request GdkEventOwnerChange events for ownership changes of the selection named by the given atom.
display : |
a GdkDisplay |
selection : |
the GdkAtom naming the selection for which ownership change notification is requested |
Returns : | whether GdkEventOwnerChange events will be sent. |
Since 2.6
gboolean gdk_display_supports_clipboard_persistence (GdkDisplay *display);
Returns whether the speicifed display supports clipboard persistance; i.e. if it's possible to store the clipboard data after an application has quit. On X11 this checks if a clipboard daemon is running.
display : |
a GdkDisplay |
Returns : | TRUE if the display supports clipboard persistance.
|
Since 2.6
void gdk_display_store_clipboard (GdkDisplay *display, GdkWindow *clipboard_window, guint32 time_, const GdkAtom *targets, gint n_targets);
Issues a request to the clipboard manager to store the clipboard data. On X11, this is a special program that works according to the freedesktop clipboard specification, available at http://www.freedesktop.org/Standards/clipboard-manager-spec.
display : |
a GdkDisplay |
clipboard_window : |
a GdkWindow belonging to the clipboard owner |
time_ : |
a timestamp |
targets : |
an array of targets that should be saved, or NULL
if all available targets should be saved.
|
n_targets : |
length of the targets array
|
Since 2.6
gboolean gdk_display_supports_shapes (GdkDisplay *display);
Returns TRUE
if gdk_window_shape_combine_mask()
can
be used to create shaped windows on display
.
display : |
a GdkDisplay |
Returns : | TRUE if shaped windows are supported
|
Since 2.10
gboolean gdk_display_supports_input_shapes (GdkDisplay *display);
Returns TRUE
if gdk_window_input_shape_combine_mask()
can
be used to modify the input shape of windows on display
.
display : |
a GdkDisplay |
Returns : | TRUE if windows with modified input shape are supported
|
Since 2.10
gboolean gdk_display_supports_composite (GdkDisplay *display);
Returns TRUE
if gdk_window_set_composited()
can be used
to redirect drawing on the window using compositing.
Currently this only works on X11 with XComposite and XDamage extensions available.
display : |
a GdkDisplay |
Returns : | TRUE if windows may be composited.
|
Since 2.12
"closed"
signalvoid user_function (GdkDisplay *display, gboolean is_error, gpointer user_data) : Run Last
The ::closed signal is emitted when the connection to the windowing
system for display
is closed.
display : |
the object on which the signal is emitted |
is_error : |
TRUE if the display was closed due to an error
|
user_data : |
user data set when the signal handler was connected. |
Since 2.2