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xdisplay(x) Xlib xdisplay(x)

NAME

xdisplay - a connection to an X display

DESCRIPTION

The xdisplay object opens a connection to an X server. This server can have one or more screens attached.

Since all X objects need a display connection, the xdisplay

class is used as a default.

SUPERCLASS

object

INSTANCE VARIABLES

display is the name of the X display. The format of this string is hostname:server or hostname:server.screen. For example, my_machine:0.1 would specify screen 1 of server 0 on the machine my_machine. The default value is "", which will cause the value of the DISPLAY environment variable to be used.

id is a pointer to the X Display structure.

MESSAGES

bell: volume rings the display bell. Volume can range from -100 (off) through 0 (base volume) to 100 (loudest).

bell! rings the display bell using the base volume.

bitmap_bit_order? returns bitmap bit order for the display. With each bitmap unit, the leftmost bit in the bitmap as displayed on the screen is either the least or most significant bit in the unit. Possible values are 0 (LSBFirst) or 1 (MSBFirst).

bitmap_pad? returns bitmap pad. Each scan line must be padded with a number of bits that is a multiple of this pad.

bitmap_unit? returns bitmap unit. Each scan line is calculated in multiples of this value.

close! disconnects the client from the X server.

default_colormap? returns a pointer to the X Colormap structure for default colormap. This pointer can be used to set

the id of an xcolormap object.

default_root_window? returns a pointer to a X Window structure for the default root window. This can be used to set the id of an xwindow object.

default_depth? returns the depth of the default root window.

default_screen? returns the number of the default screen.

default_screen_of_display? returns a pointer to the X Screen structure for default screen.

display= display_name sets the display instance variable.

display? returns the value of the display instance variable on the argument stack.

extensions? returns the list of extensions understood by the X server managing the current display.

black_pixel? returns the black pixel value for this display.

white_pixel? returns the white pixel value for this display.

flush! flushes the ouput buffer (display all queued X requests). Flushing is automatically done when input is read or a call is made that gets information from the server. In OSCAR, the buffer will be flushed periodically if ui has been started.

id? returns the value of the id instance variable as a pointer on the argument stack.

id_as_int? returns the value of the id instance variable as an integer on the argument stack.

image_byte_order? returns the required byte order for images for each scan line unit in XYFORMAT (bitmap) or for each pixel value in ZFORMAT. Possible values are 0 (LSBFirst) or 1 (MSBFirst).

last_known_request_processed? returns the serial ID of the last known protocol request that was issued. This can be useful when processing errors since the serial number of the failing requests are provided in the XErrorEvent structure.

next_request? returns the serial ID of the next protocol request to be issued.

open! connects the client to the X server specified by the display instance variable. If the display string is equal to the NULL string, the contents of the DISPLAY environment varaible will be used.

open? returns 1 if the display is open and 0 if it is not open.

protocol_version? returns the version of the X protocol associated with the connected display.

q_length? returns the number of events that an be queued by the display.

screen_count? returns the number of available screens.

sync! flushes the output buffer and waits for all events and errors to be processed. No events are discarded.

synchronize! enables synchronization for debugging. When events are synchronized, errors are reported as they occur instead of at some later time. Server performance is many times slower in synchronization mode.

synchronize_off! disables event synchronization.

EXAMPLE

/* create a display for my_machine:0.0 and open it */ xdisplay new: the_display display= "my_machine:0.0" open!;

SEE ALSO

xscreen, xdrawable, xgc, xcolormap, xvisual, xprivate_cells, xshared_cell, xshared_cells, ximage, xfont, xcursor, motif, motif_display


Last Updated On: Fri Mar 10 15:38:44 1995

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