OMERO(4) OMERO(4)
NAME
omero - octopus window system
SYNOPSIS
o/mero [ -abcdi ] [ -m mnt ]
DESCRIPTION
O/mero is the Octopus window system, as introduced in
olive(1). Here we describe the file system interface.
By default, o/mero mounts itself at /mnt/ui. Flags -abc are
similar to the bind(2) flags of the same name. Option -m can
be used to select mnt as the mount point instead of the
default /mnt/ui. Under flag -i the standard input is used
as a connection to the client.
O/mero provides GUI components known as panels, like rows,
columns, buttons, sliders, and others described below. Per-
haps surprisingly, o/mero does not draw and does not inter-
act with the mouse or keyboard. O/live is a viewer for
o/mero that does it, as said in olive(1).
The root directory contains a directory named appl where
applications create their panel hierarchies, one extra
directory per screen or session, and a file named olive used
by the viewer to receive updates from the window system and
to send requests to it.
Each panel is represented by a directory that contains some
files, the most important are files named ctl, and a data.
Panels can be created and deleted by making and removing
such directories. Rows and columns have one extra subdirec-
tory for each one of the panels they contain, and do not
contain a data file. The file system can be used to move,
copy (i.e. replicate), and delete panels. The applications
affected are usually unaware of this fact.
The name of a directory determines the type of panel it rep-
resents. A name is of the form type:name (eg.
text:ox.3442). Usually, name is a string randomized by the
application to permit any two names to cohexist within the
same directory (i.e., within the same container panel).
Type is any of the following:
row A container panel arranging children in a row.
col A container panel arranging children in a table.
image An image in Plan 9 format.
text An editable text panel.
tbl An editable text panel that insists on tabulating the
words contained.
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label A single line (small) read-only text panel.
button A single line (small) read-only text panel customized
to behave as a button.
tag A single line editable text panel. Usually to inform
the user of sibling panels and to provide a place to
type some text.
gauge A meter to show a value between 0 and 100.
slider An editable meter to show a value between 0 and 100
and let the user adjust it.
page An image in Plan 9 format supporting paning. To view
large images.
draw A vector graphics device. Used to draw geometrical
figures.
O/mero (or rather, o/live) uses the file /dev/snarf as the
clipboard, to put there the bytes when a cut operation
snarfs them. The file /mnt/snarf/sel is updated with the
file system path for the last text panel where some text was
selected. This does not consider tag lines and is a conve-
nience for executing commands that operate on selected text.
Panel Files
Panel directories contain a data and a ctl file. The data
file contains a portable representation of the graphical
panel, text for most panels and Plan 9 images for images.
The ctl file contains a textual representation of the panel
attributes. Some attributes are common to all panels and are
described together later. The textual representation for an
attribute may be issued as a control request by writing it
to the control file of a panel. Each control request is ter-
minated by a newline character.
Both files are complete descriptions (i.e. they are not
streams), which means that tools like tar(1) can be used to
take a snapshot of a hierarchy of panels.
Applications are expected to read, write, create, and remove
panel files using the /mnt/ui/appl file tree. Panels found
there are not shown by default at any screen. Instead, a
panel can be replicated at other places under /mnt/ui by
issuing control requests. A panel replicated at a directory
/mnt/ui/dir has a mirror of its file tree at that directory.
Operations made to the files at /mnt/ui/appl affect all the
replicas (the panel itself). Operations made to the files at
/mnt/ui/dir (ususally done by viewers) are made to that
replica. Most of the operations also update the panel (and
any other replicas), but some (eg., hidding the panel) do
not.
Attributes and control requests
These are both attributes and control requests common to all
panels. Depending on the panel type, additional attributes
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and/or control requests may exist as described later.
tag Activates a tag for the panel. This permits
using the mouse and keyboard commands described
in olive(1) for tags.
notag Ceactivates it.
hide Hides the panel,
show Makes a hidden panel visible.
appl id pid Sets the panel as an application panel, identi-
fied by id (reported back along with events for
the panel), handled by the process with the
given pid. If a pid is set to -1 the panel is
not associated to any process. Otherwise, an
interrupt request causes o/mero to try to
interrupt that process.
layout The counterpart of appl. It flags the panel as
one used just for layout purposes.
copyto dir[pos]
Informs of a replica of the panel (or estab-
lishes a new one when issued as a control
request). The destination dir should be an
absolute path starting from the o/mero root
directory (eg. /mnt/ui) and showing where to
``copy'' the panel. The optional pos argument
is a number indicating the position for the
panel in the target container ( `1' for the
first, `2' for the second, etc.)
The following control requests may be issued but do not cor-
respond to panel attributes:
moveto dir[pos]
Is similar to copyto but it is meant only as a control
request at a replica. It relocates the replica to a
different path. It is equivalent of a copyto request
followed by a close request for the original replica.
top Makes the panel full-screen (by zooming to it).
pos n
Sets the position of the panel to n in its container.
hold Prevents o/mero from sending events notifying of
changes to the panel (and its children) until the
moment when the control file is closed or the next
request is issued.
release
Makes o/mero release the hold on the panel (and inner
ones).
look what
OMERO(4) OMERO(4)
Causes the panel to post an event to the application to
look for what. The argument is terminated by a newline
character. It may be more than a single line of text,
and the convention is to replace ew lines within the
argument with the SOH character (ASCII `1').
exec cmd
Causes the panel to post an event to the application to
execute cmd. The argument is handled as in look regard-
ing newline characters.
By default, container panels have the attributes tag, show,
and appl 0 -1; and all other panels have the attributes
notag, show, and appl 0 -1.
Panels
What follows documents the list of panels along with the
format of their data files and their specific control
requests.
Row and col are the two container panels. They contain the
order
attribute (also a control request). Its arguments are the
names for the panels contained in the container. The order
of the arguments corresponds to the order of the panels on
the viewer. New panels created inside the container are
added to the end of this attribute.
Image panels hold Plan 9 images as data. The size of the
panel is that of the image. Its ctl file contains
size nx ny
besides other attributes, to report the size of the image
measured in pixels.
Page is like image but grows depending on available space
and allows mouse interaction to see images bigger than the
space available.
Text is a text panel that permits edition. The content of
the data file is the text being edited. See olive(1), for a
description of the user interaction for this panel. The
following attributes and control requests are specific of
text panels:
dirty Flags the panel to indicate edits not sent to the
application (i.e., unsaved changes).
clean The opposite of dirty.
sel n m Indicates (or sets) the selection to include runes
from the n-th to the m-th. When both values are the
same the selection is null and corresponds to the
insertion point for the panel.
font F Sets the font for the panel to F. Where F may be
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any of B, I, L, R S and T (bold, italics, large,
roman, small, and fixed-width).
tab wid Sets the tab width to wid.
usel permits the panel to update /mnt/snarf/sel to record
the path of the panel with the last selection. This
is the default (but note that none of tags, tables,
buttons or labes update that file).
nousel prevents the panel from updating the last selection
file.
scroll puts the panel in scroll mode (the frame shows the
last text added and it keeps at most 16Kbytes of
text).
noscroll
puts the panel in no-scroll mode (the default, keep-
ing all the text placed in the panel and preserving
the position shown by the frame despite appends of
new text).
temp prevents the panel from becoming dirty. The panel is
considered as scratch space.
The following requests are understood for text panels but
are not attributes:
ins tag vers pos text
Inserts text at position pos in the panel, but only
the the Qid.vers for the data file matches vers. Tag
is a user chosen identifier sent along with any
insert event resulting from the control request (so
that the sender may identify the operation as its
own one).
del tag vers pos n
Deletes n runes starting at position pos in the
text. Tag and vers are similar to those of the ins
request.
Tbl, label, tag, and button panels are similar to text.
Gauge and slider contain in their data files a numeric value
between 0 and 100 corresponding to a graphical representa-
tion of a gauge.
Draw is a graphical panel for vector graphics. The data file
contains a textual representation of drawing commands (one
per line). The following commands are understood:
ellipse cx cy rx ry[w col]
Draws a ellipse with center (cx,cy) and rx and ry as
radiuses. The width of the line is w and the color is
col (which is a string naming a color; most of the typ-
ical ones are available. See the implementation for a
full list.)
ellipse cx cy rx ry[col]
is similar but draws a filled ellipse.
line ax ay bx by[ea eb r col]
draws a line from (ax,ay) to (bx,by). Arguments ea and
eb are small integers that select a line ending at the
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former and the latter point. The width of the line is
given by r and col selects the color for the line.
rect ax ay bx by[col]
Draws a rectangle with opposite corners at (ax,ay) and
(bx,by). Col selects the color for the lines.
poly x0 y0 x1 y1...xn yn e0 en w col
draws a polygon. Arguments indicate the points, E0 and
en indicate endings, w the line width and col the
color.
bezspline x0 y0 x1 y1...xn yn e0 en w col
is similar but draws a spline curve.
fillpoly x0 y0 x1 y1...xn yn w col
is like poly but fills the polygon.
fillbezspline x0 y0 x1 y1...xn yn w col
is like bezspline but fills the region delimited by the
spline.
Events
Events are sent using ports(4). All events are terminated on
a newline character (not considered part of the event data).
By convention, newlines part of the event data are escaped
by replacing them with ASCII `01'. All events start with
the string `omero:', followed by the panel id (as set using
the appl control request) and the panel path (eg.
/appl/draw:clock).
The following events are sent from o/mero to the applica-
tion, in response to user interaction or to operations on
the file system.
o/mero: id path look arg
o/mero: id path exec arg
o/mero: id path close
o/mero: id path click buttons x y time
o/mero: id path keys str
o/mero: id path interrupt
o/mero: id path clean
o/mero: id path dirty
Look and exec notify that the user is looking for arg or
tries to execute arg. Close notifies that a panel is no
longer being viewed. This event is posted when the last
replica is closed (also when the panel files at /appl are
removed).
Click and keys report mouse and keyboard activity. This is
only done for vector graphics panels. Keyboard is also
reported for non-editable text panels.
Interrupt notifies the application that the user wants to
inerrupt it.
OMERO(4) OMERO(4)
Clean and dirty report that panel does not have (or does)
unsaved changes.
SOURCE
/usr/octopus/port/live
/usr/octopus/port/mero
SEE ALSO
panels(2), olive(1), and ox(1).