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GdkDisplay

GdkDisplay — Controls the keyboard/mouse pointer grabs and a set of GdkScreens

Synopsis


#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,
                                             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);
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_,
                                             GdkAtom *targets,
                                             gint n_targets);


Object Hierarchy


  GObject
   +----GdkDisplay

Signal Prototypes


"closed"    void        user_function      (GdkDisplay *display,
                                            gboolean is_error,
                                            gpointer user_data);

Description

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.

Details

GdkDisplay

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


gdk_display_open ()

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


gdk_display_get_default ()

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


gdk_display_get_name ()

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


gdk_display_get_n_screens ()

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


gdk_display_get_screen ()

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


gdk_display_get_default_screen ()

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


gdk_display_pointer_ungrab ()

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


gdk_display_keyboard_ungrab ()

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


gdk_display_pointer_is_grabbed ()

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


gdk_display_beep ()

void        gdk_display_beep                (GdkDisplay *display);

Emits a short beep on display

display : a GdkDisplay

Since 2.2


gdk_display_sync ()

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


gdk_display_flush ()

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


gdk_display_close ()

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


gdk_display_list_devices ()

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


gdk_display_get_event ()

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


gdk_display_peek_event ()

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


gdk_display_put_event ()

void        gdk_display_put_event           (GdkDisplay *display,
                                             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


gdk_display_add_client_message_filter ()

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.

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


gdk_display_set_double_click_time ()

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


gdk_display_set_double_click_distance ()

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


gdk_display_get_pointer ()

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


gdk_display_get_window_at_pointer ()

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


GdkDisplayPointerHooks

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


gdk_display_set_pointer_hooks ()

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


gdk_display_supports_cursor_color ()

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


gdk_display_supports_cursor_alpha ()

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


gdk_display_get_default_cursor_size ()

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


gdk_display_get_maximal_cursor_size ()

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


gdk_display_get_default_group ()

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


gdk_display_supports_selection_notification ()

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


gdk_display_request_selection_notification ()

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


gdk_display_supports_clipboard_persistence ()

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


gdk_display_store_clipboard ()

void        gdk_display_store_clipboard     (GdkDisplay *display,
                                             GdkWindow *clipboard_window,
                                             guint32 time_,
                                             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

Signals

The "closed" signal

void        user_function                  (GdkDisplay *display,
                                            gboolean is_error,
                                            gpointer user_data);

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