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GdkScreen

GdkScreen — Object representing a physical screen

Synopsis


#include <gdk/gdk.h>


            GdkScreen;
GdkScreen*  gdk_screen_get_default          (void);
GdkColormap* gdk_screen_get_default_colormap
                                            (GdkScreen *screen);
void        gdk_screen_set_default_colormap (GdkScreen *screen,
                                             GdkColormap *colormap);
GdkColormap* gdk_screen_get_system_colormap (GdkScreen *screen);
GdkVisual*  gdk_screen_get_system_visual    (GdkScreen *screen);
GdkColormap* gdk_screen_get_rgb_colormap    (GdkScreen *screen);
GdkVisual*  gdk_screen_get_rgb_visual       (GdkScreen *screen);
GdkWindow*  gdk_screen_get_root_window      (GdkScreen *screen);
GdkDisplay* gdk_screen_get_display          (GdkScreen *screen);
gint        gdk_screen_get_number           (GdkScreen *screen);
gint        gdk_screen_get_width            (GdkScreen *screen);
gint        gdk_screen_get_height           (GdkScreen *screen);
gint        gdk_screen_get_width_mm         (GdkScreen *screen);
gint        gdk_screen_get_height_mm        (GdkScreen *screen);
GList*      gdk_screen_list_visuals         (GdkScreen *screen);
GList*      gdk_screen_get_toplevel_windows (GdkScreen *screen);
gchar*      gdk_screen_make_display_name    (GdkScreen *screen);
gint        gdk_screen_get_n_monitors       (GdkScreen *screen);
void        gdk_screen_get_monitor_geometry (GdkScreen *screen,
                                             gint monitor_num,
                                             GdkRectangle *dest);
gint        gdk_screen_get_monitor_at_point (GdkScreen *screen,
                                             gint x,
                                             gint y);
gint        gdk_screen_get_monitor_at_window
                                            (GdkScreen *screen,
                                             GdkWindow *window);
void        gdk_screen_broadcast_client_message
                                            (GdkScreen *screen,
                                             GdkEvent *event);
gboolean    gdk_screen_get_setting          (GdkScreen *screen,
                                             const gchar *name,
                                             GValue *value);

gboolean    gdk_spawn_on_screen             (GdkScreen *screen,
                                             const gchar *working_directory,
                                             gchar **argv,
                                             gchar **envp,
                                             GSpawnFlags flags,
                                             GSpawnChildSetupFunc child_setup,
                                             gpointer user_data,
                                             gint *child_pid,
                                             GError **error);
gboolean    gdk_spawn_on_screen_with_pipes  (GdkScreen *screen,
                                             const gchar *working_directory,
                                             gchar **argv,
                                             gchar **envp,
                                             GSpawnFlags flags,
                                             GSpawnChildSetupFunc child_setup,
                                             gpointer user_data,
                                             gint *child_pid,
                                             gint *standard_input,
                                             gint *standard_output,
                                             gint *standard_error,
                                             GError **error);
gboolean    gdk_spawn_command_line_on_screen
                                            (GdkScreen *screen,
                                             const gchar *command_line,
                                             GError **error);


Object Hierarchy


  GObject
   +----GdkScreen

Signal Prototypes


"size-changed"
            void        user_function      (GdkScreen *screen,
                                            gpointer user_data);

Description

GdkScreen objects are the GDK representation of a physical screen. It is used throughout GDK and GTK+ to specify which screen the top level windows are to be displayed on. It is also used to query the screen specification and default settings such as the default colormap (gdk_screen_get_default_colormap()), the screen width (gdk_screen_get_width()), etc.

Note that a screen may consist of multiple monitors which are merged to form a large screen area.

Details

GdkScreen

typedef struct _GdkScreen GdkScreen;

This is a currently just a placeholder typedef for the first argument of the window_at_pointer function in GdkPointerHooks. It will be used when GDK gets multihead support.

Since 2.2


gdk_screen_get_default ()

GdkScreen*  gdk_screen_get_default          (void);

Gets the default screen for the default display. (See gdk_display_get_default()).

Returns : a GdkScreen, or NULL if there is no default display.

Since 2.2


gdk_screen_get_default_colormap ()

GdkColormap* gdk_screen_get_default_colormap
                                            (GdkScreen *screen);

Gets the default colormap for screen.

screen : a GdkScreen
Returns : the default GdkColormap.

Since 2.2


gdk_screen_set_default_colormap ()

void        gdk_screen_set_default_colormap (GdkScreen *screen,
                                             GdkColormap *colormap);

Sets the default colormap for screen.

screen : a GdkScreen
colormap : a GdkColormap

Since 2.2


gdk_screen_get_system_colormap ()

GdkColormap* gdk_screen_get_system_colormap (GdkScreen *screen);

Gets the system's default colormap for screen

screen : a GdkScreen
Returns : the default colormap for screen.

Since 2.2


gdk_screen_get_system_visual ()

GdkVisual*  gdk_screen_get_system_visual    (GdkScreen *screen);

Get the system's default visual for screen. This is the visual for the root window of the display. The return value should not be freed.

screen : a GdkScreen.
Returns : the system visual

Since 2.2


gdk_screen_get_rgb_colormap ()

GdkColormap* gdk_screen_get_rgb_colormap    (GdkScreen *screen);

Gets the preferred colormap for rendering image data on screen. Not a very useful function; historically, GDK could only render RGB image data to one colormap and visual, but in the current version it can render to any colormap and visual. So there's no need to call this function.

screen : a GdkScreen.
Returns : the preferred colormap

Since 2.2


gdk_screen_get_rgb_visual ()

GdkVisual*  gdk_screen_get_rgb_visual       (GdkScreen *screen);

Gets a "preferred visual" chosen by GdkRGB for rendering image data on screen. In previous versions of GDK, this was the only visual GdkRGB could use for rendering. In current versions, it's simply the visual GdkRGB would have chosen as the optimal one in those previous versions. GdkRGB can now render to drawables with any visual.

screen : a GdkScreen
Returns : The GdkVisual chosen by GdkRGB.

Since 2.2


gdk_screen_get_root_window ()

GdkWindow*  gdk_screen_get_root_window      (GdkScreen *screen);

Gets the root window of screen.

screen : a GdkScreen
Returns : the root window

Since 2.2


gdk_screen_get_display ()

GdkDisplay* gdk_screen_get_display          (GdkScreen *screen);

Gets the display to which the screen belongs.

screen : a GdkScreen
Returns : the display to which screen belongs

Since 2.2


gdk_screen_get_number ()

gint        gdk_screen_get_number           (GdkScreen *screen);

Gets the index of screen among the screens in the display to which it belongs. (See gdk_screen_get_display())

screen : a GdkScreen
Returns : the index

Since 2.2


gdk_screen_get_width ()

gint        gdk_screen_get_width            (GdkScreen *screen);

Gets the width of screen in pixels

screen : a GdkScreen
Returns : the width of screen in pixels.

Since 2.2


gdk_screen_get_height ()

gint        gdk_screen_get_height           (GdkScreen *screen);

Gets the height of screen in pixels

screen : a GdkScreen
Returns : the height of screen in pixels.

Since 2.2


gdk_screen_get_width_mm ()

gint        gdk_screen_get_width_mm         (GdkScreen *screen);

Gets the width of screen in millimeters. Note that on some X servers this value will not be correct.

screen : a GdkScreen
Returns : the width of screen in pixels.

Since 2.2


gdk_screen_get_height_mm ()

gint        gdk_screen_get_height_mm        (GdkScreen *screen);

Returns the height of screen in millimeters. Note that on some X servers this value will not be correct.

screen : a GdkScreen
Returns : the heigth of screen in pixels.

Since 2.2


gdk_screen_list_visuals ()

GList*      gdk_screen_list_visuals         (GdkScreen *screen);

Lists the available visuals for the specified screen. A visual describes a hardware image data format. For example, a visual might support 24-bit color, or 8-bit color, and might expect pixels to be in a certain format.

Call g_list_free() on the return value when you're finished with it.

screen : the relevant GdkScreen.
Returns : a list of visuals; the list must be freed, but not its contents

Since 2.2


gdk_screen_get_toplevel_windows ()

GList*      gdk_screen_get_toplevel_windows (GdkScreen *screen);

Obtains a list of all toplevel windows known to GDK on the screen screen. A toplevel window is a child of the root window (see gdk_get_default_root_window()).

The returned list should be freed with g_list_free(), but its elements need not be freed.

screen : The GdkScreen where the toplevels are located.
Returns : list of toplevel windows, free with g_list_free()

Since 2.2


gdk_screen_make_display_name ()

gchar*      gdk_screen_make_display_name    (GdkScreen *screen);

Determines the name to pass to gdk_display_open() to get a GdkDisplay with this screen as the default screen.

screen : a GdkScreen
Returns : a newly allocated string, free with g_free()

Since 2.2


gdk_screen_get_n_monitors ()

gint        gdk_screen_get_n_monitors       (GdkScreen *screen);

Returns the number of monitors which screen consists of.

screen : a GdkScreen.
Returns : number of monitors which screen consists of.

Since 2.2


gdk_screen_get_monitor_geometry ()

void        gdk_screen_get_monitor_geometry (GdkScreen *screen,
                                             gint monitor_num,
                                             GdkRectangle *dest);

Retrieves the GdkRectangle representing the size and position of the individual monitor within the entire screen area.

Note that the size of the entire screen area can be retrieved via gdk_screen_get_width() and gdk_screen_get_height().

screen : a GdkScreen.
monitor_num : the monitor number.
dest : a GdkRectangle to be filled with the monitor geometry

Since 2.2


gdk_screen_get_monitor_at_point ()

gint        gdk_screen_get_monitor_at_point (GdkScreen *screen,
                                             gint x,
                                             gint y);

Returns the monitor number in which the point (x,y) is located.

screen : a GdkScreen.
x : the x coordinate in the virtual screen.
y : the y coordinate in the virtual screen.
Returns : the monitor number in which the point (x,y) lies, or a monitor close to (x,y) if the point is not in any monitor.

Since 2.2


gdk_screen_get_monitor_at_window ()

gint        gdk_screen_get_monitor_at_window
                                            (GdkScreen *screen,
                                             GdkWindow *window);

Returns the number of the monitor in which the largest area of the bounding rectangle of window resides.

screen : a GdkScreen.
window : a GdkWindow
Returns : the monitor number in which most of window is located, or if window does not intersect any monitors, a monitor, close to window.

Since 2.2


gdk_screen_broadcast_client_message ()

void        gdk_screen_broadcast_client_message
                                            (GdkScreen *screen,
                                             GdkEvent *event);

On X11, sends an X ClientMessage event to all toplevel windows on screen.

Toplevel windows are determined by checking for the WM_STATE property, as described in the Inter-Client Communication Conventions Manual (ICCCM). If no windows are found with the WM_STATE property set, the message is sent to all children of the root window.

On Windows, broadcasts a message registered with the name GDK_WIN32_CLIENT_MESSAGE to all top-level windows. The amount of data is limited to one long, i.e. four bytes.

screen : the GdkScreen where the event will be broadcasted.
event : the GdkEvent.

Since 2.2


gdk_screen_get_setting ()

gboolean    gdk_screen_get_setting          (GdkScreen *screen,
                                             const gchar *name,
                                             GValue *value);

Retrieves a desktop-wide setting such as double-click time for the GdkScreen screen.

FIXME needs a list of valid settings here, or a link to more information.

screen : the GdkScreen where the setting is located
name : the name of the setting
value : location to store the value of the setting
Returns : TRUE if the setting existed and a value was stored in value, FALSE otherwise.

Since 2.2


gdk_spawn_on_screen ()

gboolean    gdk_spawn_on_screen             (GdkScreen *screen,
                                             const gchar *working_directory,
                                             gchar **argv,
                                             gchar **envp,
                                             GSpawnFlags flags,
                                             GSpawnChildSetupFunc child_setup,
                                             gpointer user_data,
                                             gint *child_pid,
                                             GError **error);

Like g_spawn_async(), except the child process is spawned in such an environment that on calling gdk_display_open() it would be returned a GdkDisplay with screen as the default screen.

This is useful for applications which wish to launch an application on a specific screen.

screen : a GdkScreen
working_directory : child's current working directory, or NULL to inherit parent's
argv : child's argument vector
envp : child's environment, or NULL to inherit parent's
flags : flags from GSpawnFlags
child_setup : function to run in the child just before exec()
user_data : user data for child_setup
child_pid : return location for child process ID, or NULL
error : return location for error
Returns : TRUE on success, FALSE if error is set

Since 2.4


gdk_spawn_on_screen_with_pipes ()

gboolean    gdk_spawn_on_screen_with_pipes  (GdkScreen *screen,
                                             const gchar *working_directory,
                                             gchar **argv,
                                             gchar **envp,
                                             GSpawnFlags flags,
                                             GSpawnChildSetupFunc child_setup,
                                             gpointer user_data,
                                             gint *child_pid,
                                             gint *standard_input,
                                             gint *standard_output,
                                             gint *standard_error,
                                             GError **error);

Like g_spawn_async_with_pipes(), except the child process is spawned in such an environment that on calling gdk_display_open() it would be returned a GdkDisplay with screen as the default screen.

This is useful for applications which wish to launch an application on a specific screen.

screen : a GdkScreen
working_directory : child's current working directory, or NULL to inherit parent's
argv : child's argument vector
envp : child's environment, or NULL to inherit parent's
flags : flags from GSpawnFlags
child_setup : function to run in the child just before exec()
user_data : user data for child_setup
child_pid : return location for child process ID, or NULL
standard_input : return location for file descriptor to write to child's stdin, or NULL
standard_output : return location for file descriptor to read child's stdout, or NULL
standard_error : return location for file descriptor to read child's stderr, or NULL
error : return location for error
Returns : TRUE on success, FALSE if an error was set

Since 2.4


gdk_spawn_command_line_on_screen ()

gboolean    gdk_spawn_command_line_on_screen
                                            (GdkScreen *screen,
                                             const gchar *command_line,
                                             GError **error);

Like g_spawn_command_line_async(), except the child process is spawned in such an environment that on calling gdk_display_open() it would be returned a GdkDisplay with screen as the default screen.

This is useful for applications which wish to launch an application on a specific screen.

screen : a GdkScreen
command_line : a command line
error : return location for errors
Returns : TRUE on success, FALSE if error is set.

Since 2.4

Signals

The "size-changed" signal

void        user_function                  (GdkScreen *screen,
                                            gpointer user_data);

The ::size_changed signal is emitted when the pixel width or height of a screen changes.

screen : the object on which the signal is emitted
user_data :user data set when the signal handler was connected.

Since 2.2