1038 lines
34 KiB
Plaintext
1038 lines
34 KiB
Plaintext
IPC interface (interprocess communication)
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==========================================
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Michael Stapelberg <michael@i3wm.org>
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September 2017
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This document describes how to interface with i3 from a separate process. This
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is useful for example to remote-control i3 (to write test cases for example) or
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to get various information like the current workspaces to implement an external
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workspace bar.
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The method of choice for IPC in our case is a unix socket because it has very
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little overhead on both sides and is usually available without headaches in
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most languages. In the default configuration file, the ipc-socket gets created
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in +/tmp/i3-%u.XXXXXX/ipc-socket.%p+ where +%u+ is your UNIX username, +%p+ is
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the PID of i3 and XXXXXX is a string of random characters from the portable
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filename character set (see mkdtemp(3)). You can get the socketpath from i3 by
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calling +i3 --get-socketpath+.
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All i3 utilities, like +i3-msg+ and +i3-input+ will read the +I3_SOCKET_PATH+
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X11 property, stored on the X11 root window.
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[WARNING]
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.Use an existing library!
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There are existing libraries for many languages. You can have a look at
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<<libraries>> or search the web if your language of choice is not mentioned.
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Usually, it is not necessary to implement low-level communication with i3
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directly.
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== Establishing a connection
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To establish a connection, simply open the IPC socket. The following code
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snippet illustrates this in Perl:
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-------------------------------------------------------------
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use IO::Socket::UNIX;
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chomp(my $path = qx(i3 --get-socketpath));
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my $sock = IO::Socket::UNIX->new(Peer => $path);
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-------------------------------------------------------------
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== Sending messages to i3
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To send a message to i3, you have to format in the binary message format which
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i3 expects. This format specifies a magic string in the beginning to ensure
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the integrity of messages (to prevent follow-up errors). Following the magic
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string comes the length of the payload of the message as 32-bit integer, and
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the type of the message as 32-bit integer (the integers are not converted, so
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they are in native byte order).
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The magic string currently is "i3-ipc" and will only be changed when a change
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in the IPC API is done which breaks compatibility (we hope that we don’t need
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to do that).
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.Currently implemented message types
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[options="header",cols="^10%,^20%,^20%,^50%"]
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|======================================================
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| Type (numeric) | Type (name) | Reply type | Purpose
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| 0 | +RUN_COMMAND+ | <<_command_reply,COMMAND>> | Run the payload as an i3 command (like the commands you can bind to keys).
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| 1 | +GET_WORKSPACES+ | <<_workspaces_reply,WORKSPACES>> | Get the list of current workspaces.
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| 2 | +SUBSCRIBE+ | <<_subscribe_reply,SUBSCRIBE>> | Subscribe this IPC connection to the event types specified in the message payload. See <<events>>.
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| 3 | +GET_OUTPUTS+ | <<_outputs_reply,OUTPUTS>> | Get the list of current outputs.
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| 4 | +GET_TREE+ | <<_tree_reply,TREE>> | Get the i3 layout tree.
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| 5 | +GET_MARKS+ | <<_marks_reply,MARKS>> | Gets the names of all currently set marks.
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| 6 | +GET_BAR_CONFIG+ | <<_bar_config_reply,BAR_CONFIG>> | Gets the specified bar configuration or the names of all bar configurations if payload is empty.
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| 7 | +GET_VERSION+ | <<_version_reply,VERSION>> | Gets the i3 version.
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| 8 | +GET_BINDING_MODES+ | <<_binding_modes_reply,BINDING_MODES>> | Gets the names of all currently configured binding modes.
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| 9 | +GET_CONFIG+ | <<_config_reply,CONFIG>> | Returns the last loaded i3 config.
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| 10 | +SEND_TICK+ | <<_tick_reply,TICK>> | Sends a tick event with the specified payload.
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| 11 | +SYNC+ | <<_sync_reply,SYNC>> | Sends an i3 sync event with the specified random value to the specified window.
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|======================================================
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So, a typical message could look like this:
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--------------------------------------------------
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"i3-ipc" <message length> <message type> <payload>
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--------------------------------------------------
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Or, as a hexdump:
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------------------------------------------------------------------------------
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00000000 69 33 2d 69 70 63 04 00 00 00 00 00 00 00 65 78 |i3-ipc........ex|
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00000010 69 74 |it|
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------------------------------------------------------------------------------
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To generate and send such a message, you could use the following code in Perl:
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------------------------------------------------------------
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sub format_ipc_command {
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my ($msg) = @_;
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my $len;
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# Get the real byte count (vs. amount of characters)
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{ use bytes; $len = length($msg); }
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return "i3-ipc" . pack("LL", $len, 0) . $msg;
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}
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$sock->write(format_ipc_command("exit"));
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------------------------------------------------------------------------------
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== Receiving replies from i3
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Replies from i3 usually consist of a simple string (the length of the string
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is the message_length, so you can consider them length-prefixed) which in turn
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contain the JSON serialization of a data structure. For example, the
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GET_WORKSPACES message returns an array of workspaces (each workspace is a map
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with certain attributes).
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=== Reply format
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The reply format is identical to the normal message format. There also is
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the magic string, then the message length, then the message type and the
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payload.
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The following reply types are implemented:
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COMMAND (0)::
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Confirmation/Error code for the RUN_COMMAND message.
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WORKSPACES (1)::
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Reply to the GET_WORKSPACES message.
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SUBSCRIBE (2)::
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Confirmation/Error code for the SUBSCRIBE message.
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OUTPUTS (3)::
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Reply to the GET_OUTPUTS message.
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TREE (4)::
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Reply to the GET_TREE message.
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MARKS (5)::
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Reply to the GET_MARKS message.
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BAR_CONFIG (6)::
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Reply to the GET_BAR_CONFIG message.
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VERSION (7)::
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Reply to the GET_VERSION message.
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BINDING_MODES (8)::
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Reply to the GET_BINDING_MODES message.
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GET_CONFIG (9)::
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Reply to the GET_CONFIG message.
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TICK (10)::
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Reply to the SEND_TICK message.
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[[_command_reply]]
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=== COMMAND reply
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The reply consists of a list of serialized maps for each command that was
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parsed. Each has the property +success (bool)+ and may also include a
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human-readable error message in the property +error (string)+.
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*Example:*
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-------------------
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[{ "success": true }]
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-------------------
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[[_workspaces_reply]]
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=== WORKSPACES reply
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The reply consists of a serialized list of workspaces. Each workspace has the
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following properties:
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num (integer)::
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The logical number of the workspace. Corresponds to the command
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to switch to this workspace. For named workspaces, this will be -1.
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name (string)::
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The name of this workspace (by default num+1), as changed by the
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user. Encoded in UTF-8.
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visible (boolean)::
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Whether this workspace is currently visible on an output (multiple
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workspaces can be visible at the same time).
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focused (boolean)::
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Whether this workspace currently has the focus (only one workspace
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can have the focus at the same time).
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urgent (boolean)::
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Whether a window on this workspace has the "urgent" flag set.
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rect (map)::
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The rectangle of this workspace (equals the rect of the output it
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is on), consists of x, y, width, height.
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output (string)::
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The video output this workspace is on (LVDS1, VGA1, …).
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*Example:*
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-------------------
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[
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{
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"num": 0,
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"name": "1",
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"visible": true,
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"focused": true,
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"urgent": false,
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"rect": {
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"x": 0,
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"y": 0,
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"width": 1280,
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"height": 800
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},
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"output": "LVDS1"
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},
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{
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"num": 1,
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"name": "2",
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"visible": false,
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"focused": false,
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"urgent": false,
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"rect": {
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"x": 0,
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"y": 0,
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"width": 1280,
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"height": 800
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},
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"output": "LVDS1"
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}
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]
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-------------------
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[[_subscribe_reply]]
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=== SUBSCRIBE reply
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The reply consists of a single serialized map. The only property is
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+success (bool)+, indicating whether the subscription was successful (the
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default) or whether a JSON parse error occurred.
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*Example:*
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-------------------
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{ "success": true }
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-------------------
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[[_outputs_reply]]
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=== OUTPUTS reply
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The reply consists of a serialized list of outputs. Each output has the
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following properties:
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name (string)::
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The name of this output (as seen in +xrandr(1)+). Encoded in UTF-8.
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active (boolean)::
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Whether this output is currently active (has a valid mode).
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primary (boolean)::
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Whether this output is currently the primary output.
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current_workspace (string)::
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The name of the current workspace that is visible on this output. +null+ if
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the output is not active.
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rect (map)::
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The rectangle of this output (equals the rect of the output it
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is on), consists of x, y, width, height.
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*Example:*
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-------------------
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[
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{
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"name": "LVDS1",
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"active": true,
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"current_workspace": "4",
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"rect": {
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"x": 0,
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"y": 0,
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"width": 1280,
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"height": 800
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}
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},
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{
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"name": "VGA1",
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"active": true,
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"current_workspace": "1",
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"rect": {
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"x": 1280,
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"y": 0,
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"width": 1280,
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"height": 1024
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}
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}
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]
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-------------------
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[[_tree_reply]]
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=== TREE reply
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The reply consists of a serialized tree. Each node in the tree (representing
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one container) has at least the properties listed below. While the nodes might
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have more properties, please do not use any properties which are not documented
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here. They are not yet finalized and will probably change!
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id (integer)::
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The internal ID (actually a C pointer value) of this container. Do not
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make any assumptions about it. You can use it to (re-)identify and
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address containers when talking to i3.
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name (string)::
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The internal name of this container. For all containers which are part
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of the tree structure down to the workspace contents, this is set to a
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nice human-readable name of the container.
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For containers that have an X11 window, the content is the title
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(_NET_WM_NAME property) of that window.
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For all other containers, the content is not defined (yet).
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type (string)::
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Type of this container. Can be one of "root", "output", "con",
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"floating_con", "workspace" or "dockarea".
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border (string)::
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Can be either "normal", "none" or "pixel", depending on the
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container’s border style.
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current_border_width (integer)::
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Number of pixels of the border width.
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layout (string)::
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Can be either "splith", "splitv", "stacked", "tabbed", "dockarea" or
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"output".
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Other values might be possible in the future, should we add new
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layouts.
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orientation (string)::
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Can be either "none" (for non-split containers), "horizontal" or
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"vertical".
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THIS FIELD IS OBSOLETE. It is still present, but your code should not
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use it. Instead, rely on the layout field.
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percent (float)::
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The percentage which this container takes in its parent. A value of
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+null+ means that the percent property does not make sense for this
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container, for example for the root container.
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rect (map)::
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The absolute display coordinates for this container. Display
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coordinates means that when you have two 1600x1200 monitors on a single
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X11 Display (the standard way), the coordinates of the first window on
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the second monitor are +{ "x": 1600, "y": 0, "width": 1600, "height":
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1200 }+.
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window_rect (map)::
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The coordinates of the *actual client window* inside its container.
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These coordinates are relative to the container and do not include the
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window decoration (which is actually rendered on the parent container).
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So, when using the +default+ layout, you will have a 2 pixel border on
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each side, making the window_rect +{ "x": 2, "y": 0, "width": 632,
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"height": 366 }+ (for example).
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deco_rect (map)::
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The coordinates of the *window decoration* inside its container. These
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coordinates are relative to the container and do not include the actual
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client window.
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geometry (map)::
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The original geometry the window specified when i3 mapped it. Used when
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switching a window to floating mode, for example.
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window (integer)::
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The X11 window ID of the *actual client window* inside this container.
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This field is set to null for split containers or otherwise empty
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containers. This ID corresponds to what xwininfo(1) and other
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X11-related tools display (usually in hex).
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window_properties (map)::
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X11 window properties title, instance, class, window_role and transient_for.
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urgent (bool)::
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Whether this container (window, split container, floating container or
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workspace) has the urgency hint set, directly or indirectly. All parent
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containers up until the workspace container will be marked urgent if they
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have at least one urgent child.
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focused (bool)::
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Whether this container is currently focused.
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focus (array of integer)::
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List of child node IDs (see +nodes+, +floating_nodes+ and +id+) in focus
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order. Traversing the tree by following the first entry in this array
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will result in eventually reaching the one node with +focused+ set to
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true.
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nodes (array of node)::
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The tiling (i.e. non-floating) child containers of this node.
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floating_nodes (array of node)::
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The floating child containers of this node. Only non-empty on nodes with
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type +workspace+.
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Please note that in the following example, I have left out some keys/values
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which are not relevant for the type of the node. Otherwise, the example would
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be by far too long (it already is quite long, despite showing only 1 window and
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one dock window).
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It is useful to have an overview of the structure before taking a look at the
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JSON dump:
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* root
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** LVDS1
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*** topdock
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*** content
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**** workspace 1
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***** window 1
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*** bottomdock
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**** dock window 1
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** VGA1
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*Example:*
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-----------------------
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{
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"id": 6875648,
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"name": "root",
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"rect": {
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"x": 0,
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"y": 0,
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"width": 1280,
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"height": 800
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},
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"nodes": [
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{
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"id": 6878320,
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"name": "LVDS1",
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"layout": "output",
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"rect": {
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"x": 0,
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"y": 0,
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"width": 1280,
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"height": 800
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},
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"nodes": [
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{
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"id": 6878784,
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"name": "topdock",
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"layout": "dockarea",
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"orientation": "vertical",
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"rect": {
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"x": 0,
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"y": 0,
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"width": 1280,
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"height": 0
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}
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},
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{
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"id": 6879344,
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"name": "content",
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"rect": {
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"x": 0,
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"y": 0,
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"width": 1280,
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"height": 782
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},
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"nodes": [
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{
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"id": 6880464,
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"name": "1",
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"orientation": "horizontal",
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"rect": {
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"x": 0,
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"y": 0,
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"width": 1280,
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"height": 782
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},
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"window_properties": {
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"class": "Evince",
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"instance": "evince",
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"title": "Properties",
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"transient_for": 52428808
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},
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"floating_nodes": [],
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"nodes": [
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{
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"id": 6929968,
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"name": "#aa0000",
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"border": "normal",
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"percent": 1,
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"rect": {
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"x": 0,
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"y": 18,
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"width": 1280,
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"height": 782
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}
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}
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]
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}
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]
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},
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{
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"id": 6880208,
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"name": "bottomdock",
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"layout": "dockarea",
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"orientation": "vertical",
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"rect": {
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"x": 0,
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"y": 782,
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"width": 1280,
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"height": 18
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},
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"nodes": [
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{
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"id": 6931312,
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"name": "#00aa00",
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"percent": 1,
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"rect": {
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"x": 0,
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"y": 782,
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"width": 1280,
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"height": 18
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}
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}
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]
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}
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]
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}
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]
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}
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------------------------
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[[_marks_reply]]
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=== MARKS reply
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The reply consists of a single array of strings for each container that has a
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mark. A mark can only be set on one container, so the array is unique.
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The order of that array is undefined.
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If no window has a mark the response will be the empty array [].
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[[_bar_config_reply]]
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=== BAR_CONFIG reply
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This can be used by third-party workspace bars (especially i3bar, but others
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are free to implement compatible alternatives) to get the +bar+ block
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configuration from i3.
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Depending on the input, the reply is either:
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empty input::
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An array of configured bar IDs
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Bar ID::
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A JSON map containing the configuration for the specified bar.
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Each bar configuration has the following properties:
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id (string)::
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The ID for this bar. Included in case you request multiple
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configurations and want to differentiate the different replies.
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mode (string)::
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Either +dock+ (the bar sets the dock window type) or +hide+ (the bar
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does not show unless a specific key is pressed).
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position (string)::
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Either +bottom+ or +top+ at the moment.
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status_command (string)::
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Command which will be run to generate a statusline. Each line on stdout
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of this command will be displayed in the bar. At the moment, no
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formatting is supported.
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font (string)::
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The font to use for text on the bar.
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workspace_buttons (boolean)::
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Display workspace buttons or not? Defaults to true.
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binding_mode_indicator (boolean)::
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Display the mode indicator or not? Defaults to true.
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verbose (boolean)::
|
||
Should the bar enable verbose output for debugging? Defaults to false.
|
||
colors (map)::
|
||
Contains key/value pairs of colors. Each value is a color code in hex,
|
||
formatted #rrggbb (like in HTML).
|
||
|
||
The following colors can be configured at the moment:
|
||
|
||
background::
|
||
Background color of the bar.
|
||
statusline::
|
||
Text color to be used for the statusline.
|
||
separator::
|
||
Text color to be used for the separator.
|
||
focused_background::
|
||
Background color of the bar on the currently focused monitor output.
|
||
focused_statusline::
|
||
Text color to be used for the statusline on the currently focused
|
||
monitor output.
|
||
focused_separator::
|
||
Text color to be used for the separator on the currently focused
|
||
monitor output.
|
||
focused_workspace_text/focused_workspace_bg/focused_workspace_border::
|
||
Text/background/border color for a workspace button when the workspace
|
||
has focus.
|
||
active_workspace_text/active_workspace_bg/active_workspace_border::
|
||
Text/background/border color for a workspace button when the workspace
|
||
is active (visible) on some output, but the focus is on another one.
|
||
You can only tell this apart from the focused workspace when you are
|
||
using multiple monitors.
|
||
inactive_workspace_text/inactive_workspace_bg/inactive_workspace_border::
|
||
Text/background/border color for a workspace button when the workspace
|
||
does not have focus and is not active (visible) on any output. This
|
||
will be the case for most workspaces.
|
||
urgent_workspace_text/urgent_workspace_bg/urgent_workspace_border::
|
||
Text/background/border color for workspaces which contain at least one
|
||
window with the urgency hint set.
|
||
binding_mode_text/binding_mode_bg/binding_mode_border::
|
||
Text/background/border color for the binding mode indicator.
|
||
|
||
|
||
*Example of configured bars:*
|
||
--------------
|
||
["bar-bxuqzf"]
|
||
--------------
|
||
|
||
*Example of bar configuration:*
|
||
--------------
|
||
{
|
||
"id": "bar-bxuqzf",
|
||
"mode": "dock",
|
||
"position": "bottom",
|
||
"status_command": "i3status",
|
||
"font": "-misc-fixed-medium-r-normal--13-120-75-75-C-70-iso10646-1",
|
||
"workspace_buttons": true,
|
||
"binding_mode_indicator": true,
|
||
"verbose": false,
|
||
"colors": {
|
||
"background": "#c0c0c0",
|
||
"statusline": "#00ff00",
|
||
"focused_workspace_text": "#ffffff",
|
||
"focused_workspace_bg": "#000000"
|
||
}
|
||
}
|
||
--------------
|
||
|
||
[[_version_reply]]
|
||
=== VERSION reply
|
||
|
||
The reply consists of a single JSON dictionary with the following keys:
|
||
|
||
major (integer)::
|
||
The major version of i3, such as +4+.
|
||
minor (integer)::
|
||
The minor version of i3, such as +2+. Changes in the IPC interface (new
|
||
features) will only occur with new minor (or major) releases. However,
|
||
bugfixes might be introduced in patch releases, too.
|
||
patch (integer)::
|
||
The patch version of i3, such as +1+ (when the complete version is
|
||
+4.2.1+). For versions such as +4.2+, patch will be set to +0+.
|
||
human_readable (string)::
|
||
A human-readable version of i3 containing the precise git version,
|
||
build date and branch name. When you need to display the i3 version to
|
||
your users, use the human-readable version whenever possible (since
|
||
this is what +i3 --version+ displays, too).
|
||
loaded_config_file_name (string)::
|
||
The current config path.
|
||
|
||
*Example:*
|
||
-------------------
|
||
{
|
||
"human_readable" : "4.2-169-gf80b877 (2012-08-05, branch \"next\")",
|
||
"loaded_config_file_name" : "/home/hwangcc23/.i3/config",
|
||
"minor" : 2,
|
||
"patch" : 0,
|
||
"major" : 4
|
||
}
|
||
-------------------
|
||
|
||
[[_binding_modes_reply]]
|
||
=== BINDING_MODES reply
|
||
|
||
The reply consists of an array of all currently configured binding modes.
|
||
|
||
*Example:*
|
||
---------------------
|
||
["default", "resize"]
|
||
---------------------
|
||
|
||
[[_config_reply]]
|
||
=== CONFIG reply
|
||
|
||
The config reply is a map which currently only contains the "config" member,
|
||
which is a string containing the config file as loaded by i3 most recently.
|
||
|
||
*Example:*
|
||
-------------------
|
||
{ "config": "font pango:monospace 8\nbindsym Mod4+q exit\n" }
|
||
-------------------
|
||
|
||
[[_tick_reply]]
|
||
=== TICK reply
|
||
|
||
The reply is a map containing the "success" member. After the reply was
|
||
received, the tick event has been written to all IPC connections which subscribe
|
||
to tick events. UNIX sockets are usually buffered, but you can be certain that
|
||
once you receive the tick event you just triggered, you must have received all
|
||
events generated prior to the +SEND_TICK+ message (happened-before relation).
|
||
|
||
*Example:*
|
||
-------------------
|
||
{ "success": true }
|
||
-------------------
|
||
|
||
[[_sync_reply]]
|
||
=== SYNC reply
|
||
|
||
The reply is a map containing the "success" member. After the reply was
|
||
received, the https://i3wm.org/docs/testsuite.html#i3_sync[i3 sync message] was
|
||
responded to.
|
||
|
||
*Example:*
|
||
-------------------
|
||
{ "success": true }
|
||
-------------------
|
||
|
||
== Events
|
||
|
||
[[events]]
|
||
|
||
To get informed when certain things happen in i3, clients can subscribe to
|
||
events. Events consist of a name (like "workspace") and an event reply type
|
||
(like I3_IPC_EVENT_WORKSPACE). Events sent by i3 follow a format similar to
|
||
replies but with the highest bit of the message type set to 1 to indicate an
|
||
event reply instead of a normal reply. Note that event types and reply types
|
||
do not follow the same enumeration scheme (e.g. event type 0 corresponds to the
|
||
workspace event however reply type 0 corresponds to the COMMAND reply).
|
||
|
||
Caveat: As soon as you subscribe to an event, it is not guaranteed any longer
|
||
that the requests to i3 are processed in order. This means, the following
|
||
situation can happen: You send a GET_WORKSPACES request but you receive a
|
||
"workspace" event before receiving the reply to GET_WORKSPACES. If your
|
||
program does not want to cope which such kinds of race conditions (an
|
||
event based library may not have a problem here), I suggest you create a
|
||
separate connection to receive events.
|
||
|
||
If an event message needs to be sent and the socket is not writeable (write
|
||
returns EAGAIN, happens when the socket doesn't have enough buffer space for
|
||
writing new data) then i3 uses a queue system to store outgoing messages for
|
||
each client. This is combined with a timer: if the message queue for a client is
|
||
not empty and no data where successfully written in the past 10 seconds, the
|
||
connection is killed. Practically, this means that your client should try to
|
||
always read events from the socket to avoid having its connection closed.
|
||
|
||
=== Subscribing to events
|
||
|
||
By sending a message of type SUBSCRIBE with a JSON-encoded array as payload
|
||
you can register to an event.
|
||
|
||
*Example:*
|
||
---------------------------------
|
||
type: SUBSCRIBE
|
||
payload: [ "workspace", "output" ]
|
||
---------------------------------
|
||
|
||
|
||
=== Available events
|
||
|
||
The numbers in parenthesis is the event type (keep in mind that you need to
|
||
strip the highest bit first).
|
||
|
||
workspace (0)::
|
||
Sent when the user switches to a different workspace, when a new
|
||
workspace is initialized or when a workspace is removed (because the
|
||
last client vanished).
|
||
output (1)::
|
||
Sent when RandR issues a change notification (of either screens,
|
||
outputs, CRTCs or output properties).
|
||
mode (2)::
|
||
Sent whenever i3 changes its binding mode.
|
||
window (3)::
|
||
Sent when a client's window is successfully reparented (that is when i3
|
||
has finished fitting it into a container), when a window received input
|
||
focus or when certain properties of the window have changed.
|
||
barconfig_update (4)::
|
||
Sent when the hidden_state or mode field in the barconfig of any bar
|
||
instance was updated and when the config is reloaded.
|
||
binding (5)::
|
||
Sent when a configured command binding is triggered with the keyboard or
|
||
mouse
|
||
shutdown (6)::
|
||
Sent when the ipc shuts down because of a restart or exit by user command
|
||
tick (7)::
|
||
Sent when the ipc client subscribes to the tick event (with +"first":
|
||
true+) or when any ipc client sends a SEND_TICK message (with +"first":
|
||
false+).
|
||
|
||
*Example:*
|
||
--------------------------------------------------------------------
|
||
# the appropriate 4 bytes read from the socket are stored in $input
|
||
|
||
# unpack a 32-bit unsigned integer
|
||
my $message_type = unpack("L", $input);
|
||
|
||
# check if the highest bit is 1
|
||
my $is_event = (($message_type >> 31) == 1);
|
||
|
||
# use the other bits
|
||
my $event_type = ($message_type & 0x7F);
|
||
|
||
if ($is_event) {
|
||
say "Received event of type $event_type";
|
||
}
|
||
--------------------------------------------------------------------
|
||
|
||
=== workspace event
|
||
|
||
This event consists of a single serialized map containing a property
|
||
+change (string)+ which indicates the type of the change ("focus", "init",
|
||
"empty", "urgent", "reload", "rename", "restored", "move"). A
|
||
+current (object)+ property will be present with the affected workspace
|
||
whenever the type of event affects a workspace (otherwise, it will be +null).
|
||
|
||
When the change is "focus", an +old (object)+ property will be present with the
|
||
previous workspace. When the first switch occurs (when i3 focuses the
|
||
workspace visible at the beginning) there is no previous workspace, and the
|
||
+old+ property will be set to +null+. Also note that if the previous is empty
|
||
it will get destroyed when switching, but will still be present in the "old"
|
||
property.
|
||
|
||
*Example:*
|
||
---------------------
|
||
{
|
||
"change": "focus",
|
||
"current": {
|
||
"id": 28489712,
|
||
"type": "workspace",
|
||
...
|
||
}
|
||
"old": {
|
||
"id": 28489715,
|
||
"type": "workspace",
|
||
...
|
||
}
|
||
}
|
||
---------------------
|
||
|
||
=== output event
|
||
|
||
This event consists of a single serialized map containing a property
|
||
+change (string)+ which indicates the type of the change (currently only
|
||
"unspecified").
|
||
|
||
*Example:*
|
||
---------------------------
|
||
{ "change": "unspecified" }
|
||
---------------------------
|
||
|
||
=== mode event
|
||
|
||
This event consists of a single serialized map containing a property
|
||
+change (string)+ which holds the name of current mode in use. The name
|
||
is the same as specified in config when creating a mode. The default
|
||
mode is simply named default. It contains a second property, +pango_markup+, which
|
||
defines whether pango markup shall be used for displaying this mode.
|
||
|
||
*Example:*
|
||
---------------------------
|
||
{
|
||
"change": "default",
|
||
"pango_markup": true
|
||
}
|
||
---------------------------
|
||
|
||
=== window event
|
||
|
||
This event consists of a single serialized map containing a property
|
||
+change (string)+ which indicates the type of the change
|
||
|
||
* +new+ – the window has become managed by i3
|
||
* +close+ – the window has closed
|
||
* +focus+ – the window has received input focus
|
||
* +title+ – the window's title has changed
|
||
* +fullscreen_mode+ – the window has entered or exited fullscreen mode
|
||
* +move+ – the window has changed its position in the tree
|
||
* +floating+ – the window has transitioned to or from floating
|
||
* +urgent+ – the window has become urgent or lost its urgent status
|
||
* +mark+ – a mark has been added to or removed from the window
|
||
|
||
Additionally a +container (object)+ field will be present, which consists
|
||
of the window's parent container. Be aware that for the "new" event, the
|
||
container will hold the initial name of the newly reparented window (e.g.
|
||
if you run urxvt with a shell that changes the title, you will still at
|
||
this point get the window title as "urxvt").
|
||
|
||
*Example:*
|
||
---------------------------
|
||
{
|
||
"change": "new",
|
||
"container": {
|
||
"id": 35569536,
|
||
"type": "con",
|
||
...
|
||
}
|
||
}
|
||
---------------------------
|
||
|
||
=== barconfig_update event
|
||
|
||
This event consists of a single serialized map reporting on options from the
|
||
barconfig of the specified bar_id that were updated in i3. This event is the
|
||
same as a +GET_BAR_CONFIG+ reply for the bar with the given id.
|
||
|
||
=== binding event
|
||
|
||
This event consists of a single serialized map reporting on the details of a
|
||
binding that ran a command because of user input. The +change (string)+ field
|
||
indicates what sort of binding event was triggered (right now it will always be
|
||
+"run"+ but may be expanded in the future).
|
||
|
||
The +binding (object)+ field contains details about the binding that was run:
|
||
|
||
command (string)::
|
||
The i3 command that is configured to run for this binding.
|
||
event_state_mask (array of strings)::
|
||
The group and modifier keys that were configured with this binding.
|
||
input_code (integer)::
|
||
If the binding was configured with +bindcode+, this will be the key code
|
||
that was given for the binding. If the binding is a mouse binding, it will be
|
||
the number of the mouse button that was pressed. Otherwise it will be 0.
|
||
symbol (string or null)::
|
||
If this is a keyboard binding that was configured with +bindsym+, this
|
||
field will contain the given symbol. Otherwise it will be +null+.
|
||
input_type (string)::
|
||
This will be +"keyboard"+ or +"mouse"+ depending on whether or not this was
|
||
a keyboard or a mouse binding.
|
||
|
||
*Example:*
|
||
---------------------------
|
||
{
|
||
"change": "run",
|
||
"binding": {
|
||
"command": "nop",
|
||
"event_state_mask": [
|
||
"shift",
|
||
"ctrl"
|
||
],
|
||
"input_code": 0,
|
||
"symbol": "t",
|
||
"input_type": "keyboard"
|
||
}
|
||
}
|
||
---------------------------
|
||
|
||
=== shutdown event
|
||
|
||
This event is triggered when the connection to the ipc is about to shutdown
|
||
because of a user action such as a +restart+ or +exit+ command. The +change
|
||
(string)+ field indicates why the ipc is shutting down. It can be either
|
||
+"restart"+ or +"exit"+.
|
||
|
||
*Example:*
|
||
---------------------------
|
||
{
|
||
"change": "restart"
|
||
}
|
||
---------------------------
|
||
|
||
=== tick event
|
||
|
||
This event is triggered by a subscription to tick events or by a +SEND_TICK+
|
||
message.
|
||
|
||
*Example (upon subscription):*
|
||
--------------------------------------------------------------------------------
|
||
{
|
||
"first": true,
|
||
"payload": ""
|
||
}
|
||
--------------------------------------------------------------------------------
|
||
|
||
*Example (upon +SEND_TICK+ with a payload of +arbitrary string+):*
|
||
--------------------------------------------------------------------------------
|
||
{
|
||
"first": false,
|
||
"payload": "arbitrary string"
|
||
}
|
||
--------------------------------------------------------------------------------
|
||
|
||
== See also (existing libraries)
|
||
|
||
[[libraries]]
|
||
|
||
For some languages, libraries are available (so you don’t have to implement
|
||
all this on your own). This list names some (if you wrote one, please let me
|
||
know):
|
||
|
||
C::
|
||
* i3 includes a headerfile +i3/ipc.h+ which provides you all constants.
|
||
* https://github.com/acrisci/i3ipc-glib
|
||
C++::
|
||
* https://github.com/Iskustvo/i3-ipcpp[i3-ipc++]
|
||
* https://github.com/drmgc/i3ipcpp
|
||
Go::
|
||
* https://github.com/mdirkse/i3ipc-go
|
||
* https://github.com/i3/go-i3
|
||
JavaScript::
|
||
* https://github.com/acrisci/i3ipc-gjs
|
||
Lua::
|
||
* https://github.com/acrisci/i3ipc-lua
|
||
Perl::
|
||
* https://metacpan.org/module/AnyEvent::I3
|
||
Python::
|
||
* https://github.com/acrisci/i3ipc-python
|
||
* https://github.com/whitelynx/i3ipc (not maintained)
|
||
* https://github.com/ziberna/i3-py (not maintained)
|
||
Ruby::
|
||
* https://github.com/veelenga/i3ipc-ruby
|
||
* https://github.com/badboy/i3-ipc (not maintained)
|
||
Rust::
|
||
* https://github.com/tmerr/i3ipc-rs
|
||
OCaml::
|
||
* https://github.com/Armael/ocaml-i3ipc
|
||
|
||
== Appendix A: Detecting byte order in memory-safe languages
|
||
|
||
Some programming languages such as Go don’t offer a way to serialize data in the
|
||
native byte order of the machine they’re running on without resorting to tricks
|
||
involving the +unsafe+ package.
|
||
|
||
The following technique can be used (and will not be broken by changes to i3) to
|
||
detect the byte order i3 is using:
|
||
|
||
1. The byte order dependent fields of an IPC message are message type and
|
||
payload length.
|
||
|
||
* The message type +RUN_COMMAND+ (0) is the same in big and little endian, so
|
||
we can use it in either byte order to elicit a reply from i3.
|
||
|
||
* The payload length 65536 + 256 (+0x00 01 01 00+) is the same in big and
|
||
little endian, and also small enough to not worry about memory allocations
|
||
of that size. We must use payloads of length 65536 + 256 in every message
|
||
we send, so that i3 will be able to read the entire message regardless of
|
||
the byte order it uses.
|
||
|
||
2. Send a big endian encoded message of type +SUBSCRIBE+ (2) with payload `[]`
|
||
followed by 65536 + 256 - 2 +SPACE+ (ASCII 0x20) bytes.
|
||
|
||
* If i3 is running in big endian, this message is treated as a noop,
|
||
resulting in a +SUBSCRIBE+ reply with payload `{"success":true}`
|
||
footnote:[A small payload is important: that way, we circumvent dealing
|
||
with UNIX domain socket buffer sizes, whose size depends on the
|
||
implementation/operating system. Exhausting such a buffer results in an i3
|
||
deadlock unless you concurrently read and write, which — depending on the
|
||
programming language — makes the technique much more complicated.].
|
||
|
||
* If i3 is running in little endian, this message is read in its entirety due
|
||
to the byte order independent payload length, then
|
||
https://github.com/i3/i3/blob/d726d09d496577d1c337a4b97486f2c9fbc914f1/src/ipc.c#L1188[silently
|
||
discarded] due to the unknown message type.
|
||
|
||
3. Send a byte order independent message, i.e. type +RUN_COMMAND+ (0) with
|
||
payload +nop byte order detection. padding:+, padded to 65536 + 256 bytes
|
||
with +a+ (ASCII 0x61) bytes. i3 will reply to this message with a reply of
|
||
type +COMMAND+ (0).
|
||
|
||
* The human-readable prefix is in there to not confuse readers of the i3 log.
|
||
|
||
* This messages serves as a synchronization primitive so that we know whether
|
||
i3 discarded the +SUBSCRIBE+ message or didn’t answer it yet.
|
||
|
||
4. Receive a message header from i3, decoding the message type as big endian.
|
||
|
||
* If the message’s reply type is +COMMAND+ (0), i3 is running in little
|
||
endian (because the +SUBSCRIBE+ message was discarded). Decode the message
|
||
payload length as little endian, receive the message payload.
|
||
|
||
* If the message’s reply type is anything else, i3 is running in big endian
|
||
(because our big endian encoded +SUBSCRIBE+ message was answered). Decode
|
||
the message payload length in big endian, receive the message
|
||
payload. Then, receive the pending +COMMAND+ message reply in big endian.
|
||
|
||
5. From here on out, send/receive all messages using the detected byte order.
|
||
|
||
Find an example implementation of this technique in
|
||
https://github.com/i3/go-i3/blob/master/byteorder.go
|