The Python X Library: 6.1 Display

6.1 Display

Display information retrieval methods:

Method on Display: get_display_name ( ): Returns the name used to connect to the server, either provided when creating the Display object, or fetched from the environmental variable $DISPLAY.

Method on Display: fileno ( ): Returns the file descriptor number of the underlying socket. This method is provided to allow Display objects to be passed select.select().

Method on Display: close ( ): Close the display, freeing the resources that it holds.

Method on Display: set_error_handler ( handler )

Set the default error handler which will be called for all unhandled errors. handler should take two arguments as a normal request error handler, but the second argument (the request) will be None.

See section Error Handling.

Method on Display: flush ( ): Flush the request queue, building and sending the queued requests. This can be necessary in applications that never wait for events, and in threaded applications.

Method on Display: sync ( ): Flush the queue and wait until the server has processed all the queued requests. Use this e.g. when it is important that errors caused by a certain request is trapped.

Method on Display: next_event ( ): Return the next event. If there are no events queued, it will block until the next event is fetched from the server.

Method on Display: pending_events ( ): Return the number of events queued, i.e. the number of times that Display.next_event() can be called without blocking.

Method on Display: has_extension ( extension ): Check if both the server and the client library support the X extension named extension.

Method on Display: create_resource_object ( type, id )

Create a resource object of type for the integer id. type should be one of the following strings:

resource
drawable
window
pixmap
fontable
font
gc
colormap
cursor

This function can be used when a resource ID has been fetched e.g. from an resource or a command line argument. Resource objects should never be created by instantiating the appropriate class directly, since any X extensions dynamically added by the library will not be available.

Method on Display: screen ( sno = None )

Return the information about screen number sno, or the default screen if sno is None.

The return object has the following attributes:

root

The screen root window.

default_colormap

The default colormap for the root window and its children.

white_pixel

black_pixel

The pixel values for white and black, respectively, in the default colormap.

current_input_mask

The event mask of the root window at the time the connection was set up.

width_in_pixels

height_in_pixels

The size of the root window in pixels, i.e. the size of the entire screen.

width_in_mms

height_in_mms

The physical size of the screen, in millimeters.

min_installed_maps

max_installed_maps

The minimum and maximum number of colormaps that can be installed at the same time.

root_visual

The visual type of the root window.

backing_store

Whether the screen supports backing store, one of the values X.WhenMapped, X.NotUseful, or X.Always.

save_unders

True if the screen supports save unders.

root_depth

The depth of the root window.

allowed_depths

A list of the pixmap and windows depths that this screen supports. The list items have the following attributes:

depth

This depth is supported by the screen.

visuals

A list of visual types that is valid for this depth. If this list is empty, this depth is only valid for pixmaps and not for windows. The list items have the following attributes:

visual_id: The ID of this visual.
visual_class: One of X.StaticGray, X.StaticColor, X.TrueColor, X.GrayScale, X.PseudoColor, or X.DirectColor.
bits_per_rgb_value: The number of bits used to represent an entire RGB-value, allowing a total of 2^bits_per_rgb_value distinct colors.
colormap_entries: The number of free entries in a newly created colormap.
red_mask
blue_mask
green_mask: Bitmasks selecting the three color components from the entire RGB value.

Method on Display: screen_count ( ): Return the total number of screens on the display.

Method on Display: get_default_screen ( ): Return the number of the default screen, extracted from the display name.

Method on Display: keycode_to_keysym ( keycode, index ): Convert a keycode to a keysym, looking in entry index. Normally index 0 is unshifted, 1 is shifted, 2 is alt grid, and 3 is shift+alt grid. If that key entry is not bound, X.NoSymbol is returned.

Method on Display: keysym_to_keycode ( keysym ): Look up the primary keycode that is bound to keysym. If several keycodes are found, the one with the lowest index and lowest code is returned. If keysym is not bound to any key, 0 is returned.

Method on Display: keysym_to_keycodes ( keysym ): Look up all the keycodes that is bound to keysym. A list of tuples (keycode, index) is returned, sorted primarily on the lowest index and secondarily on the lowest keycode.

Method on Display: refresh_keyboard_mapping ( evt ): This method should be called once when a MappingNotify event is received, to update the keymap cache. evt should be the event object.

Method on Display: lookup_string ( keysym ): Attempt to convert keysym into a single character or a string. If no translation is found, None is returned.

Method on Display: rebind_string ( keysym, newstring ): Set the string representation of keysym to newstring, so that it will be returned by Display.lookup_string().

X requests methods:

Method on Display: intern_atom ( name, only_if_exists = 0 ): Intern the string name, returning its atom number. If only_if_exists is true and the atom does not already exist, it will not be created and X.NONE is returned.

Method on Display: get_atom_name ( atom ): Look up the name of atom, returning it as a string. Will raise BadAtom if atom does not exist.

Method on Display: get_selection_owner ( selection ): Return the window that owns selection (an atom), or X.NONE if there is no owner for the selection. Can raise BadAtom.

Method on Display: send_event ( destination, event, event_mask = 0, propagate = 0, onerror = None )

Send a synthetic event to the window destination which can be a window object, or X.PointerWindow or X.InputFocus. event is the event object to send, instantiated from one of the classes in protocol.events. See XSendEvent(3X11) for details.

There is also a Window.send_event() method.

Method on Display: ungrab_pointer ( time, onerror = None ): Release a grabbed pointer and any queued events. See XUngrabPointer(3X11).

Method on Display: change_active_pointer_grab ( event_mask, cursor, time, onerror = None ): Change the dynamic parameters of a pointer grab. See XChangeActivePointerGrab(3X11).

Method on Display: ungrab_keyboard ( time, onerror = None ): Ungrab a grabbed keyboard and any queued events. See XUngrabKeyboard(3X11).

Method on Display: allow_events ( mode, time, onerror = None ): Release some queued events. mode should be one of X.AsyncPointer, X.SyncPointer, X.AsyncKeyboard, X.SyncKeyboard, X.ReplayPointer, X.ReplayKeyboard, X.AsyncBoth, or X.SyncBoth. time should be a timestamp or X.CurrentTime.

Method on Display: grab_server ( onerror = None ): Disable processing of requests on all other client connections until the server is ungrabbed. Server grabbing should be avoided as much as possible.

Method on Display: ungrab_server ( onerror = None ): Release the server if it was previously grabbed by this client.

Method on Display: warp_pointer ( x, y, src_window = X.NONE, src_x = 0, src_y = 0, src_width = 0, src_height = 0, onerror = None )

Move the pointer relative its current position by the offsets (x, y). However, if src_window is a window the pointer is only moved if the specified rectangle in src_window contains it. If src_width is 0 it will be replaced with the width of src_window - src_x. src_height is treated in a similar way.

To move the pointer to absolute coordinates, use Window.warp_pointer().

Method on Display: set_input_focus ( focus, revert_to, time, onerror = None )

Set input focus to focus, which should be a window, X.PointerRoot or X.NONE. revert_to specifies where the focus reverts to if the focused window becomes not visible, and should be X.RevertToParent, RevertToPointerRoot, or RevertToNone. See XSetInputFocus(3X11) for details.

There is also a Window.set_input_focus().

Method on Display: get_input_focus ( )

Return an object with the following attributes:

focus: The window which currently holds the input focus, X.NONE or X.PointerRoot.
revert_to: Where the focus will revert, one of X.RevertToParent, RevertToPointerRoot, or RevertToNone.

Method on Display: query_keymap ( ): Return a bit vector for the logical state of the keyboard, where each bit set to 1 indicates that the corresponding key is currently pressed down. The vector is represented as a list of 32 integers. List item N contains the bits for keys 8N to 8N + 7 with the least significant bit in the byte representing key 8N.

Method on Display: open_font ( name ): Open the font identifed by the pattern name and return its font object. If name does not match any font, None is returned.

Method on Display: list_fonts ( pattern, max_names ): Return a list of font names matching pattern. No more than max_names will be returned.

Method on Display: list_fonts_with_info ( pattern, max_names )

Return a list of fonts matching pattern. No more than max_names will be returned. Each list item represents one font and has the following properties:

name

The name of the font.

min_bounds

max_bounds

min_char_or_byte2

max_char_or_byte2

default_char

draw_direction

min_byte1

max_byte1

all_chars_exist

font_ascent

font_descent

replies_hint

See the description of XFontStruct in XGetFontProperty(3X11) for details on these values.

properties

A list of properties. Each entry has two attributes:

name: The atom identifying this property.
value: A 32-bit unsigned value.

Method on Display: set_font_path ( path, onerror = None ): Set the font path to path, which should be a list of strings. If path is empty, the default font path of the server will be restored.

Method on Display: get_font_path ( ): Return the current font path as a list of strings.

Method on Display: query_extension ( name )

Ask the server if it supports the extension name. If it is supported an object with the following attributes is returned:

major_opcode: The major opcode that the requests of this extension uses.
first_event: The base event code if the extension have additional events, or 0.
first_error: The base error code if the extension have additional errors, or 0.

If the extension is not supported, None is returned.

Method on Display: list_extensions ( ): Return a list of all the extensions provided by the server.

Method on Display: change_keyboard_mapping ( first_keycode, keysyms, onerror = None ): Modify the keyboard mapping, starting with first_keycode. keysyms is a list of tuples of keysyms. keysyms[n][i] will be assigned to keycode first_keycode+n at index i.

Method on Display: get_keyboard_mapping ( first_keycode, count ): Return the current keyboard mapping as a list of tuples, starting at first_keycount and no more than count.

Method on Display: change_keyboard_control ( onerror = None, **keys )

Change the parameters provided as keyword arguments:

key_click_percent: The volume of key clicks between 0 (off) and 100 (load). -1 will restore default setting.
bell_percent: The base volume of the bell, coded as above.
bell_pitch: The pitch of the bell in Hz, -1 restores the default.
bell_duration: The duration of the bell in milliseconds, -1 restores the default.
led
led_mode: led_mode should be X.LedModeOff or X.LedModeOn. If led is provided, it should be a 32-bit mask listing the LEDs that should change. If led is not provided, all LEDs are changed.
key
auto_repeat_mode: auto_repeat_mode should be one of X.AutoRepeatModeOff, X.AutoRepeatModeOn, or X.AutoRepeatModeDefault. If key is provided, that key will be modified, otherwise the global state for the entire keyboard will be modified.

Method on Display: get_keyboard_control ( )

Return an object with the following attributes:

global_auto_repeat: X.AutoRepeatModeOn or X.AutoRepeatModeOff.
auto_repeats: A list of 32 integers. List item N contains the bits for keys 8N to 8N + 7 with the least significant bit in the byte representing key 8N. If a bit is on, autorepeat is enabled for the corresponding key.
led_mask: A 32-bit mask indicating which LEDs are on.
key_click_percent: The volume of key click, from 0 to 100.
bell_percent
bell_pitch
bell_duration: The volume, pitch and duration of the bell.

Method on Display: bell ( percent = 0, onerror = None ): Ring the bell at the volume percent which is relative the base volume. See XBell(3X11).

Method on Display: change_pointer_control ( accel = None, threshold = None, onerror = None ): To change the pointer acceleration, set accel to a tuple (num, denum). The pointer will then move num/denum times the normal speed if it moves beyond the threshold number of pixels at once. To change the threshold, set it to the number of pixels. -1 restores the default.

Method on Display: get_pointer_control ( )

Return an object with the following attributes:

accel_num
accel_denom: The acceleration as numerator/denumerator.
threshold: The number of pixels the pointer must move before the acceleration kicks in.

Method on Display: set_screen_saver ( timeout, interval, prefer_blank, allow_exposures, onerror = None ): See XSetScreenSaver(3X11).

Method on Display: get_screen_saver ( ): Return an object with the attributes timeout, interval, prefer_blanking, allow_exposures. See XGetScreenSaver(3X11) for details.

Method on Display: change_hosts ( mode, host_family, host, onerror = None )

mode is either X.HostInsert or X.HostDelete. host_family is one of X.FamilyInternet, X.FamilyDECnet or X.FamilyChaos.

host is a list of bytes. For the Internet family, it should be the four bytes of an IPv4 address.

Method on Display: list_hosts ( )

Return an object with the following attributes:

mode

X.EnableAccess if the access control list is used, X.DisableAccess otherwise.

hosts

The hosts on the access list. Each entry has the following attributes:

family: X.FamilyInternet, X.FamilyDECnet, or X.FamilyChaos.
name: A list of byte values, the coding depends on family. For the Internet family, it is the 4 bytes of an IPv4 address.

Method on Display: set_access_control ( mode, onerror = None ): Enable use of access control lists at connection setup if mode is X.EnableAccess, disable if it is X.DisableAccess.

Method on Display: set_close_down_mode ( mode, onerror = None ): Control what will happen with the client’s resources at connection close. The default is X.DestroyAll, the other values are X.RetainPermanent and X.RetainTemporary.

Method on Display: force_screen_saver ( mode, onerror = None ): If mode is X.ScreenSaverActive the screen saver is activated. If it is X.ScreenSaverReset, the screen saver is deactivated as if device input had been received.

Method on Display: set_pointer_mapping ( map )

Set the mapping of the pointer buttons. map is a list of logical button numbers. map must be of the same length as the list returned by Display.get_pointer_mapping().

map[n] sets the logical number for the physical button n+1. Logical number 0 disables the button. Two physical buttons cannot be mapped to the same logical number.

If one of the buttons to be altered are logically in the down state, X.MappingBusy is returned and the mapping is not changed. Otherwise the mapping is changed and X.MappingSuccess is returned.

Method on Display: get_pointer_mapping ( ): Return a list of the pointer button mappings. Entry N in the list sets the logical button number for the physical button N+1.

Method on Display: set_modifier_mapping ( keycodes )

Set the keycodes for the eight modifiers X.Shift, X.Lock, X.Control, X.Mod1, X.Mod2, X.Mod3, X.Mod4 and X.Mod5. keycodes should be a eight-element list where each entry is a list of the keycodes that should be bound to that modifier.

If any changed key is logically in the down state, X.MappingBusy is returned and the mapping is not changed. If the mapping violates some server restriction, X.MappingFailed is returned. Otherwise the mapping is changed and X.MappingSuccess is returned.

Method on Display: get_modifier_mapping ( ): Return a list of eight lists, one for each modifier. The list can be indexed using X.ShiftMapIndex, X.Mod1MapIndex, and so on. The sublists list the keycodes bound to that modifier.

Method on Display: no_operation ( onerror = None ): Do nothing but send a request to the server.

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