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827 lines
31 KiB
EmacsLisp
827 lines
31 KiB
EmacsLisp
;;; dbus.el --- Elisp bindings for D-Bus.
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;; Copyright (C) 2007, 2008 Free Software Foundation, Inc.
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;; Author: Michael Albinus <michael.albinus@gmx.de>
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;; Keywords: comm, hardware
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;; This file is part of GNU Emacs.
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;; GNU Emacs is free software: you can redistribute it and/or modify
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;; it under the terms of the GNU General Public License as published by
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;; the Free Software Foundation, either version 3 of the License, or
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;; (at your option) any later version.
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;; GNU Emacs is distributed in the hope that it will be useful,
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;; but WITHOUT ANY WARRANTY; without even the implied warranty of
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;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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;; GNU General Public License for more details.
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;; You should have received a copy of the GNU General Public License
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;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
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;;; Commentary:
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;; This package provides language bindings for the D-Bus API. D-Bus
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;; is a message bus system, a simple way for applications to talk to
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;; one another. See <http://dbus.freedesktop.org/> for details.
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;; Low-level language bindings are implemented in src/dbusbind.c.
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;;; Code:
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;; D-Bus support in the Emacs core can be disabled with configuration
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;; option "--without-dbus". Declare used subroutines and variables.
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(declare-function dbus-call-method "dbusbind.c")
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(declare-function dbus-call-method-asynchronously "dbusbind.c")
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(declare-function dbus-method-return-internal "dbusbind.c")
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(declare-function dbus-method-error-internal "dbusbind.c")
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(declare-function dbus-register-signal "dbusbind.c")
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(defvar dbus-debug)
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(defvar dbus-registered-functions-table)
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;; Pacify byte compiler.
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(eval-when-compile
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(require 'cl))
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(require 'xml)
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(defconst dbus-service-dbus "org.freedesktop.DBus"
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"The bus name used to talk to the bus itself.")
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(defconst dbus-path-dbus "/org/freedesktop/DBus"
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"The object path used to talk to the bus itself.")
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(defconst dbus-interface-dbus "org.freedesktop.DBus"
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"The interface exported by the object with `dbus-service-dbus' and `dbus-path-dbus'.")
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(defconst dbus-interface-peer (concat dbus-interface-dbus ".Peer")
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"The interface for peer objects.")
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(defconst dbus-interface-introspectable
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(concat dbus-interface-dbus ".Introspectable")
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"The interface supported by introspectable objects.")
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(defconst dbus-interface-properties (concat dbus-interface-dbus ".Properties")
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"The interface for property objects.")
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(defconst dbus-service-emacs "org.gnu.Emacs"
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"The well known service name of Emacs.")
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(defconst dbus-path-emacs "/org/gnu/Emacs"
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"The object path head used by Emacs.")
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(defconst dbus-message-type-invalid 0
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"This value is never a valid message type.")
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(defconst dbus-message-type-method-call 1
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"Message type of a method call message.")
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(defconst dbus-message-type-method-return 2
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"Message type of a method return message.")
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(defconst dbus-message-type-error 3
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"Message type of an error reply message.")
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(defconst dbus-message-type-signal 4
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"Message type of a signal message.")
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(defmacro dbus-ignore-errors (&rest body)
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"Execute BODY; signal D-Bus error when `dbus-debug' is non-nil.
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Otherwise, return result of last form in BODY, or all other errors."
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`(condition-case err
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(progn ,@body)
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(dbus-error (when dbus-debug (signal (car err) (cdr err))))))
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(put 'dbus-ignore-errors 'lisp-indent-function 0)
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(put 'dbus-ignore-errors 'edebug-form-spec '(form body))
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(font-lock-add-keywords 'emacs-lisp-mode '("\\<dbus-ignore-errors\\>"))
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;;; Hash table of registered functions.
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;; We create it here. So we have a simple test in dbusbind.c, whether
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;; the Lisp code has been loaded.
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(setq dbus-registered-functions-table (make-hash-table :test 'equal))
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(defvar dbus-return-values-table (make-hash-table :test 'equal)
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"Hash table for temporary storing arguments of reply messages.
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A key in this hash table is a list (BUS SERIAL). BUS is either the
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symbol `:system' or the symbol `:session'. SERIAL is the serial number
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of the reply message. See `dbus-call-method-non-blocking-handler' and
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`dbus-call-method-non-blocking'.")
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(defun dbus-list-hash-table ()
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"Returns all registered member registrations to D-Bus.
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The return value is a list, with elements of kind (KEY . VALUE).
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See `dbus-registered-functions-table' for a description of the
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hash table."
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(let (result)
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(maphash
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'(lambda (key value) (add-to-list 'result (cons key value) 'append))
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dbus-registered-functions-table)
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result))
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(defun dbus-unregister-object (object)
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"Unregister OBJECT from D-Bus.
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OBJECT must be the result of a preceding `dbus-register-method'
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or `dbus-register-signal' call. It returns `t' if OBJECT has
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been unregistered, `nil' otherwise."
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;; Check parameter.
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(unless (and (consp object) (not (null (car object))) (consp (cdr object)))
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(signal 'wrong-type-argument (list 'D-Bus object)))
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;; Find the corresponding entry in the hash table.
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(let* ((key (car object))
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(value (gethash key dbus-registered-functions-table)))
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;; Loop over the registered functions.
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(while (consp value)
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;; (car value) has the structure (UNAME SERVICE PATH HANDLER).
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;; (cdr object) has the structure ((SERVICE PATH HANDLER) ...).
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(if (not (equal (cdr (car value)) (car (cdr object))))
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(setq value (cdr value))
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;; Compute new hash value. If it is empty, remove it from
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;; hash table.
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(unless
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(puthash
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key
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(delete (car value) (gethash key dbus-registered-functions-table))
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dbus-registered-functions-table)
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(remhash key dbus-registered-functions-table))
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(setq value t)))
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value))
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(defun dbus-call-method-non-blocking-handler (&rest args)
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"Handler for reply messages of asynchronous D-Bus message calls.
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It calls the function stored in `dbus-registered-functions-table'.
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The result will be made available in `dbus-return-values-table'."
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(puthash (list (dbus-event-bus-name last-input-event)
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(dbus-event-serial-number last-input-event))
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(if (= (length args) 1) (car args) args)
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dbus-return-values-table))
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(defun dbus-call-method-non-blocking
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(bus service path interface method &rest args)
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"Call METHOD on the D-Bus BUS, but don't block the event queue.
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This is necessary for communicating to registered D-Bus methods,
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which are running in the same Emacs process.
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The arguments are the same as in `dbus-call-method'.
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usage: (dbus-call-method-non-blocking
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BUS SERVICE PATH INTERFACE METHOD
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&optional :timeout TIMEOUT &rest ARGS)"
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(let ((key
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(apply
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'dbus-call-method-asynchronously
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bus service path interface method
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'dbus-call-method-non-blocking-handler args)))
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;; Wait until `dbus-call-method-non-blocking-handler' has put the
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;; result into `dbus-return-values-table'.
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(while (not (gethash key dbus-return-values-table nil))
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(read-event nil nil 0.1))
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;; Cleanup `dbus-return-values-table'. Return the result.
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(prog1
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(gethash key dbus-return-values-table nil)
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(remhash key dbus-return-values-table))))
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(defun dbus-name-owner-changed-handler (&rest args)
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"Reapplies all member registrations to D-Bus.
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This handler is applied when a \"NameOwnerChanged\" signal has
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arrived. SERVICE is the object name for which the name owner has
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been changed. OLD-OWNER is the previous owner of SERVICE, or the
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empty string if SERVICE was not owned yet. NEW-OWNER is the new
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owner of SERVICE, or the empty string if SERVICE looses any name owner.
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usage: (dbus-name-owner-changed-handler service old-owner new-owner)"
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(save-match-data
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;; Check the arguments. We should silently ignore it when they
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;; are wrong.
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(if (and (= (length args) 3)
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(stringp (car args))
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(stringp (cadr args))
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(stringp (caddr args)))
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(let ((service (car args))
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(old-owner (cadr args))
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(new-owner (caddr args)))
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;; Check whether SERVICE is a known name.
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(when (not (string-match "^:" service))
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(maphash
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'(lambda (key value)
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(dolist (elt value)
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;; key has the structure (BUS INTERFACE MEMBER).
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;; elt has the structure (UNAME SERVICE PATH HANDLER).
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(when (string-equal old-owner (car elt))
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;; Remove old key, and add new entry with changed name.
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(dbus-unregister-object (list key (cdr elt)))
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;; Maybe we could arrange the lists a little bit better
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;; that we don't need to extract every single element?
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(dbus-register-signal
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;; BUS SERVICE PATH
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(nth 0 key) (nth 1 elt) (nth 2 elt)
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;; INTERFACE MEMBER HANDLER
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(nth 1 key) (nth 2 key) (nth 3 elt)))))
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(copy-hash-table dbus-registered-functions-table))))
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;; The error is reported only in debug mode.
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(when dbus-debug
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(signal
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'dbus-error
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(cons
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(format "Wrong arguments of %s.NameOwnerChanged" dbus-interface-dbus)
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args))))))
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;; Register the handler.
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(when nil ;ignore-errors
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(dbus-register-signal
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:system dbus-service-dbus dbus-path-dbus dbus-interface-dbus
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"NameOwnerChanged" 'dbus-name-owner-changed-handler)
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(dbus-register-signal
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:session dbus-service-dbus dbus-path-dbus dbus-interface-dbus
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"NameOwnerChanged" 'dbus-name-owner-changed-handler))
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;;; D-Bus type conversion.
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(defun dbus-string-to-byte-array (string)
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"Transforms STRING to list (:array :byte c1 :byte c2 ...).
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STRING shall be UTF8 coded."
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(let (result)
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(dolist (elt (string-to-list string) (append '(:array) result))
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(setq result (append result (list :byte elt))))))
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(defun dbus-byte-array-to-string (byte-array)
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"Transforms BYTE-ARRAY into UTF8 coded string.
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BYTE-ARRAY must be a list of structure (c1 c2 ...)."
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(apply 'string byte-array))
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(defun dbus-escape-as-identifier (string)
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"Escape an arbitrary STRING so it follows the rules for a C identifier.
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The escaped string can be used as object path component, interface element
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component, bus name component or member name in D-Bus.
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The escaping consists of replacing all non-alphanumerics, and the
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first character if it's a digit, with an underscore and two
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lower-case hex digits:
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\"0123abc_xyz\\x01\\xff\" -> \"_30123abc_5fxyz_01_ff\"
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i.e. similar to URI encoding, but with \"_\" taking the role of \"%\",
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and a smaller allowed set. As a special case, \"\" is escaped to
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\"_\".
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Returns the escaped string. Algorithm taken from
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telepathy-glib's `tp-escape-as-identifier'."
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(if (zerop (length string))
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"_"
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(replace-regexp-in-string
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"^[0-9]\\|[^A-Za-z0-9]"
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(lambda (x) (format "_%2x" (aref x 0)))
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string)))
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(defun dbus-unescape-from-identifier (string)
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"Retrieve the original string from the encoded STRING.
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STRING must have been coded with `dbus-escape-as-identifier'"
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(if (string-equal string "_")
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""
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(replace-regexp-in-string
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"_.."
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(lambda (x) (format "%c" (string-to-number (substring x 1) 16)))
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string)))
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;;; D-Bus events.
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(defun dbus-check-event (event)
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"Checks whether EVENT is a well formed D-Bus event.
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EVENT is a list which starts with symbol `dbus-event':
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(dbus-event BUS TYPE SERIAL SERVICE PATH INTERFACE MEMBER HANDLER &rest ARGS)
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BUS identifies the D-Bus the message is coming from. It is
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either the symbol `:system' or the symbol `:session'. TYPE is
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the D-Bus message type which has caused the event, SERIAL is the
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serial number of the received D-Bus message. SERVICE and PATH
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are the unique name and the object path of the D-Bus object
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emitting the message. INTERFACE and MEMBER denote the message
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which has been sent. HANDLER is the function which has been
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registered for this message. ARGS are the arguments passed to
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HANDLER, when it is called during event handling in
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`dbus-handle-event'.
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This function raises a `dbus-error' signal in case the event is
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not well formed."
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(when dbus-debug (message "DBus-Event %s" event))
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(unless (and (listp event)
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(eq (car event) 'dbus-event)
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;; Bus symbol.
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(symbolp (nth 1 event))
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;; Type.
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(and (natnump (nth 2 event))
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(< dbus-message-type-invalid (nth 2 event)))
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;; Serial.
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(natnump (nth 3 event))
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;; Service.
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(or (= dbus-message-type-method-return (nth 2 event))
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(= dbus-message-type-error (nth 2 event))
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(stringp (nth 4 event)))
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;; Object path.
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(or (= dbus-message-type-method-return (nth 2 event))
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(= dbus-message-type-error (nth 2 event))
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(stringp (nth 5 event)))
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;; Interface.
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(or (= dbus-message-type-method-return (nth 2 event))
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(= dbus-message-type-error (nth 2 event))
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(stringp (nth 6 event)))
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;; Member.
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(or (= dbus-message-type-method-return (nth 2 event))
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(= dbus-message-type-error (nth 2 event))
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(stringp (nth 7 event)))
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;; Handler.
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(functionp (nth 8 event)))
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(signal 'dbus-error (list "Not a valid D-Bus event" event))))
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;;;###autoload
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(defun dbus-handle-event (event)
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"Handle events from the D-Bus.
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EVENT is a D-Bus event, see `dbus-check-event'. HANDLER, being
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part of the event, is called with arguments ARGS.
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If the HANDLER returns an `dbus-error', it is propagated as return message."
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(interactive "e")
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(condition-case err
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(let (result)
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;; We ignore not well-formed events.
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(dbus-check-event event)
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;; Error messages must be propagated.
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(when (= dbus-message-type-error (nth 2 event))
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(signal 'dbus-error (nthcdr 9 event)))
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;; Apply the handler.
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(setq result (apply (nth 8 event) (nthcdr 9 event)))
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;; Return a message when it is a message call.
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(when (= dbus-message-type-method-call (nth 2 event))
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(dbus-ignore-errors
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(apply 'dbus-method-return-internal
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(nth 1 event) (nth 3 event) (nth 4 event)
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(if (consp result) result (list result))))))
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;; Error handling.
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(dbus-error
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;; Return an error message when it is a message call.
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(when (= dbus-message-type-method-call (nth 2 event))
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(dbus-ignore-errors
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(dbus-method-error-internal
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(nth 1 event) (nth 3 event) (nth 4 event) (cadr err))))
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;; Propagate D-Bus error messages.
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(when (or dbus-debug (= dbus-message-type-error (nth 2 event)))
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(signal (car err) (cdr err))))))
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(defun dbus-event-bus-name (event)
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"Return the bus name the event is coming from.
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The result is either the symbol `:system' or the symbol `:session'.
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EVENT is a D-Bus event, see `dbus-check-event'. This function
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raises a `dbus-error' signal in case the event is not well
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formed."
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(dbus-check-event event)
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(nth 1 event))
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(defun dbus-event-message-type (event)
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"Return the message type of the corresponding D-Bus message.
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The result is a number. EVENT is a D-Bus event, see
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`dbus-check-event'. This function raises a `dbus-error' signal
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in case the event is not well formed."
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(dbus-check-event event)
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(nth 2 event))
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(defun dbus-event-serial-number (event)
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"Return the serial number of the corresponding D-Bus message.
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The result is a number. The serial number is needed for
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generating a reply message. EVENT is a D-Bus event, see
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`dbus-check-event'. This function raises a `dbus-error' signal
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in case the event is not well formed."
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(dbus-check-event event)
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(nth 3 event))
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(defun dbus-event-service-name (event)
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"Return the name of the D-Bus object the event is coming from.
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The result is a string. EVENT is a D-Bus event, see `dbus-check-event'.
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This function raises a `dbus-error' signal in case the event is
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not well formed."
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(dbus-check-event event)
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(nth 4 event))
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(defun dbus-event-path-name (event)
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"Return the object path of the D-Bus object the event is coming from.
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The result is a string. EVENT is a D-Bus event, see `dbus-check-event'.
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This function raises a `dbus-error' signal in case the event is
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not well formed."
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(dbus-check-event event)
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(nth 5 event))
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(defun dbus-event-interface-name (event)
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"Return the interface name of the D-Bus object the event is coming from.
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The result is a string. EVENT is a D-Bus event, see `dbus-check-event'.
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This function raises a `dbus-error' signal in case the event is
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not well formed."
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(dbus-check-event event)
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(nth 6 event))
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(defun dbus-event-member-name (event)
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"Return the member name the event is coming from.
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It is either a signal name or a method name. The result is is a
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string. EVENT is a D-Bus event, see `dbus-check-event'. This
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function raises a `dbus-error' signal in case the event is not
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well formed."
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(dbus-check-event event)
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(nth 7 event))
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;;; D-Bus registered names.
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(defun dbus-list-activatable-names ()
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"Return the D-Bus service names which can be activated as list.
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The result is a list of strings, which is `nil' when there are no
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activatable service names at all."
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(dbus-ignore-errors
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(dbus-call-method
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:system dbus-service-dbus
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dbus-path-dbus dbus-interface-dbus "ListActivatableNames")))
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(defun dbus-list-names (bus)
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"Return the service names registered at D-Bus BUS.
|
||
The result is a list of strings, which is `nil' when there are no
|
||
registered service names at all. Well known names are strings
|
||
like \"org.freedesktop.DBus\". Names starting with \":\" are
|
||
unique names for services."
|
||
(dbus-ignore-errors
|
||
(dbus-call-method
|
||
bus dbus-service-dbus dbus-path-dbus dbus-interface-dbus "ListNames")))
|
||
|
||
(defun dbus-list-known-names (bus)
|
||
"Retrieve all services which correspond to a known name in BUS.
|
||
A service has a known name if it doesn't start with \":\"."
|
||
(let (result)
|
||
(dolist (name (dbus-list-names bus) result)
|
||
(unless (string-equal ":" (substring name 0 1))
|
||
(add-to-list 'result name 'append)))))
|
||
|
||
(defun dbus-list-queued-owners (bus service)
|
||
"Return the unique names registered at D-Bus BUS and queued for SERVICE.
|
||
The result is a list of strings, or `nil' when there are no
|
||
queued name owners service names at all."
|
||
(dbus-ignore-errors
|
||
(dbus-call-method
|
||
bus dbus-service-dbus dbus-path-dbus
|
||
dbus-interface-dbus "ListQueuedOwners" service)))
|
||
|
||
(defun dbus-get-name-owner (bus service)
|
||
"Return the name owner of SERVICE registered at D-Bus BUS.
|
||
The result is either a string, or `nil' if there is no name owner."
|
||
(dbus-ignore-errors
|
||
(dbus-call-method
|
||
bus dbus-service-dbus dbus-path-dbus
|
||
dbus-interface-dbus "GetNameOwner" service)))
|
||
|
||
(defun dbus-ping (bus service)
|
||
"Check whether SERVICE is registered for D-Bus BUS."
|
||
;; "Ping" raises a D-Bus error if SERVICE does not exist.
|
||
;; Otherwise, it returns silently with `nil'.
|
||
(condition-case nil
|
||
(not
|
||
(dbus-call-method bus service dbus-path-dbus dbus-interface-peer "Ping"))
|
||
(dbus-error nil)))
|
||
|
||
|
||
;;; D-Bus introspection.
|
||
|
||
(defun dbus-introspect (bus service path)
|
||
"This function returns all interfaces and sub-nodes of SERVICE,
|
||
registered at object path PATH at bus BUS.
|
||
|
||
BUS must be either the symbol `:system' or the symbol `:session'.
|
||
SERVICE must be a known service name, and PATH must be a valid
|
||
object path. The last two parameters are strings. The result,
|
||
the introspection data, is a string in XML format."
|
||
;; We don't want to raise errors. `dbus-call-method-non-blocking'
|
||
;; is used, because the handler can be registered in our Emacs
|
||
;; instance; caller an callee would block each other.
|
||
(dbus-ignore-errors
|
||
(dbus-call-method-non-blocking
|
||
bus service path dbus-interface-introspectable "Introspect")))
|
||
|
||
(defun dbus-introspect-xml (bus service path)
|
||
"Return the introspection data of SERVICE in D-Bus BUS at object path PATH.
|
||
The data are a parsed list. The root object is a \"node\",
|
||
representing the object path PATH. The root object can contain
|
||
\"interface\" and further \"node\" objects."
|
||
;; We don't want to raise errors.
|
||
(xml-node-name
|
||
(ignore-errors
|
||
(with-temp-buffer
|
||
(insert (dbus-introspect bus service path))
|
||
(xml-parse-region (point-min) (point-max))))))
|
||
|
||
(defun dbus-introspect-get-attribute (object attribute)
|
||
"Return the ATTRIBUTE value of D-Bus introspection OBJECT.
|
||
ATTRIBUTE must be a string according to the attribute names in
|
||
the D-Bus specification."
|
||
(xml-get-attribute-or-nil object (intern attribute)))
|
||
|
||
(defun dbus-introspect-get-node-names (bus service path)
|
||
"Return all node names of SERVICE in D-Bus BUS at object path PATH.
|
||
It returns a list of strings. The node names stand for further
|
||
object paths of the D-Bus service."
|
||
(let ((object (dbus-introspect-xml bus service path))
|
||
result)
|
||
(dolist (elt (xml-get-children object 'node) result)
|
||
(add-to-list
|
||
'result (dbus-introspect-get-attribute elt "name") 'append))))
|
||
|
||
(defun dbus-introspect-get-all-nodes (bus service path)
|
||
"Return all node names of SERVICE in D-Bus BUS at object path PATH.
|
||
It returns a list of strings, which are further object paths of SERVICE."
|
||
(let ((result (list path)))
|
||
(dolist (elt
|
||
(dbus-introspect-get-node-names bus service path)
|
||
result)
|
||
(setq elt (expand-file-name elt path))
|
||
(setq result
|
||
(append result (dbus-introspect-get-all-nodes bus service elt))))))
|
||
|
||
(defun dbus-introspect-get-interface-names (bus service path)
|
||
"Return all interface names of SERVICE in D-Bus BUS at object path PATH.
|
||
It returns a list of strings.
|
||
|
||
There will be always the default interface
|
||
\"org.freedesktop.DBus.Introspectable\". Another default
|
||
interface is \"org.freedesktop.DBus.Properties\". If present,
|
||
\"interface\" objects can also have \"property\" objects as
|
||
children, beside \"method\" and \"signal\" objects."
|
||
(let ((object (dbus-introspect-xml bus service path))
|
||
result)
|
||
(dolist (elt (xml-get-children object 'interface) result)
|
||
(add-to-list
|
||
'result (dbus-introspect-get-attribute elt "name") 'append))))
|
||
|
||
(defun dbus-introspect-get-interface (bus service path interface)
|
||
"Return the INTERFACE of SERVICE in D-Bus BUS at object path PATH.
|
||
The return value is an XML object. INTERFACE must be a string,
|
||
element of the list returned by
|
||
`dbus-introspect-get-interface-names'. The resulting
|
||
\"interface\" object can contain \"method\", \"signal\",
|
||
\"property\" and \"annotation\" children."
|
||
(let ((elt (xml-get-children
|
||
(dbus-introspect-xml bus service path) 'interface)))
|
||
(while (and elt
|
||
(not (string-equal
|
||
interface
|
||
(dbus-introspect-get-attribute (car elt) "name"))))
|
||
(setq elt (cdr elt)))
|
||
(car elt)))
|
||
|
||
(defun dbus-introspect-get-method-names (bus service path interface)
|
||
"Return a list of strings of all method names of INTERFACE.
|
||
SERVICE is a service of D-Bus BUS at object path PATH."
|
||
(let ((object (dbus-introspect-get-interface bus service path interface))
|
||
result)
|
||
(dolist (elt (xml-get-children object 'method) result)
|
||
(add-to-list
|
||
'result (dbus-introspect-get-attribute elt "name") 'append))))
|
||
|
||
(defun dbus-introspect-get-method (bus service path interface method)
|
||
"Return method METHOD of interface INTERFACE as XML object.
|
||
It must be located at SERVICE in D-Bus BUS at object path PATH.
|
||
METHOD must be a string, element of the list returned by
|
||
`dbus-introspect-get-method-names'. The resulting \"method\"
|
||
object can contain \"arg\" and \"annotation\" children."
|
||
(let ((elt (xml-get-children
|
||
(dbus-introspect-get-interface bus service path interface)
|
||
'method)))
|
||
(while (and elt
|
||
(not (string-equal
|
||
method (dbus-introspect-get-attribute (car elt) "name"))))
|
||
(setq elt (cdr elt)))
|
||
(car elt)))
|
||
|
||
(defun dbus-introspect-get-signal-names (bus service path interface)
|
||
"Return a list of strings of all signal names of INTERFACE.
|
||
SERVICE is a service of D-Bus BUS at object path PATH."
|
||
(let ((object (dbus-introspect-get-interface bus service path interface))
|
||
result)
|
||
(dolist (elt (xml-get-children object 'signal) result)
|
||
(add-to-list
|
||
'result (dbus-introspect-get-attribute elt "name") 'append))))
|
||
|
||
(defun dbus-introspect-get-signal (bus service path interface signal)
|
||
"Return signal SIGNAL of interface INTERFACE as XML object.
|
||
It must be located at SERVICE in D-Bus BUS at object path PATH.
|
||
SIGNAL must be a string, element of the list returned by
|
||
`dbus-introspect-get-signal-names'. The resulting \"signal\"
|
||
object can contain \"arg\" and \"annotation\" children."
|
||
(let ((elt (xml-get-children
|
||
(dbus-introspect-get-interface bus service path interface)
|
||
'signal)))
|
||
(while (and elt
|
||
(not (string-equal
|
||
signal (dbus-introspect-get-attribute (car elt) "name"))))
|
||
(setq elt (cdr elt)))
|
||
(car elt)))
|
||
|
||
(defun dbus-introspect-get-property-names (bus service path interface)
|
||
"Return a list of strings of all property names of INTERFACE.
|
||
SERVICE is a service of D-Bus BUS at object path PATH."
|
||
(let ((object (dbus-introspect-get-interface bus service path interface))
|
||
result)
|
||
(dolist (elt (xml-get-children object 'property) result)
|
||
(add-to-list
|
||
'result (dbus-introspect-get-attribute elt "name") 'append))))
|
||
|
||
(defun dbus-introspect-get-property (bus service path interface property)
|
||
"This function returns PROPERTY of INTERFACE as XML object.
|
||
It must be located at SERVICE in D-Bus BUS at object path PATH.
|
||
PROPERTY must be a string, element of the list returned by
|
||
`dbus-introspect-get-property-names'. The resulting PROPERTY
|
||
object can contain \"annotation\" children."
|
||
(let ((elt (xml-get-children
|
||
(dbus-introspect-get-interface bus service path interface)
|
||
'property)))
|
||
(while (and elt
|
||
(not (string-equal
|
||
property
|
||
(dbus-introspect-get-attribute (car elt) "name"))))
|
||
(setq elt (cdr elt)))
|
||
(car elt)))
|
||
|
||
(defun dbus-introspect-get-annotation-names
|
||
(bus service path interface &optional name)
|
||
"Return all annotation names as list of strings.
|
||
If NAME is `nil', the annotations are children of INTERFACE,
|
||
otherwise NAME must be a \"method\", \"signal\", or \"property\"
|
||
object, where the annotations belong to."
|
||
(let ((object
|
||
(if name
|
||
(or (dbus-introspect-get-method bus service path interface name)
|
||
(dbus-introspect-get-signal bus service path interface name)
|
||
(dbus-introspect-get-property bus service path interface name))
|
||
(dbus-introspect-get-interface bus service path interface)))
|
||
result)
|
||
(dolist (elt (xml-get-children object 'annotation) result)
|
||
(add-to-list
|
||
'result (dbus-introspect-get-attribute elt "name") 'append))))
|
||
|
||
(defun dbus-introspect-get-annotation
|
||
(bus service path interface name annotation)
|
||
"Return ANNOTATION as XML object.
|
||
If NAME is `nil', ANNOTATION is a child of INTERFACE, otherwise
|
||
NAME must be the name of a \"method\", \"signal\", or
|
||
\"property\" object, where the ANNOTATION belongs to."
|
||
(let ((elt (xml-get-children
|
||
(if name
|
||
(or (dbus-introspect-get-method
|
||
bus service path interface name)
|
||
(dbus-introspect-get-signal
|
||
bus service path interface name)
|
||
(dbus-introspect-get-property
|
||
bus service path interface name))
|
||
(dbus-introspect-get-interface bus service path interface))
|
||
'annotation)))
|
||
(while (and elt
|
||
(not (string-equal
|
||
annotation
|
||
(dbus-introspect-get-attribute (car elt) "name"))))
|
||
(setq elt (cdr elt)))
|
||
(car elt)))
|
||
|
||
(defun dbus-introspect-get-argument-names (bus service path interface name)
|
||
"Return a list of all argument names as list of strings.
|
||
NAME must be a \"method\" or \"signal\" object.
|
||
|
||
Argument names are optional, the function can return `nil'
|
||
therefore, even if the method or signal has arguments."
|
||
(let ((object
|
||
(or (dbus-introspect-get-method bus service path interface name)
|
||
(dbus-introspect-get-signal bus service path interface name)))
|
||
result)
|
||
(dolist (elt (xml-get-children object 'arg) result)
|
||
(add-to-list
|
||
'result (dbus-introspect-get-attribute elt "name") 'append))))
|
||
|
||
(defun dbus-introspect-get-argument (bus service path interface name arg)
|
||
"Return argument ARG as XML object.
|
||
NAME must be a \"method\" or \"signal\" object. ARG must be a
|
||
string, element of the list returned by `dbus-introspect-get-argument-names'."
|
||
(let ((elt (xml-get-children
|
||
(or (dbus-introspect-get-method bus service path interface name)
|
||
(dbus-introspect-get-signal bus service path interface name))
|
||
'arg)))
|
||
(while (and elt
|
||
(not (string-equal
|
||
arg (dbus-introspect-get-attribute (car elt) "name"))))
|
||
(setq elt (cdr elt)))
|
||
(car elt)))
|
||
|
||
(defun dbus-introspect-get-signature
|
||
(bus service path interface name &optional direction)
|
||
"Return signature of a `method' or `signal', represented by NAME, as string.
|
||
If NAME is a `method', DIRECTION can be either \"in\" or \"out\".
|
||
If DIRECTION is `nil', \"in\" is assumed.
|
||
|
||
If NAME is a `signal', and DIRECTION is non-`nil', DIRECTION must
|
||
be \"out\"."
|
||
;; For methods, we use "in" as default direction.
|
||
(let ((object (or (dbus-introspect-get-method
|
||
bus service path interface name)
|
||
(dbus-introspect-get-signal
|
||
bus service path interface name))))
|
||
(when (and (string-equal
|
||
"method" (dbus-introspect-get-attribute object "name"))
|
||
(not (stringp direction)))
|
||
(setq direction "in"))
|
||
;; In signals, no direction is given.
|
||
(when (string-equal "signal" (dbus-introspect-get-attribute object "name"))
|
||
(setq direction nil))
|
||
;; Collect the signatures.
|
||
(mapconcat
|
||
'(lambda (x)
|
||
(let ((arg (dbus-introspect-get-argument
|
||
bus service path interface name x)))
|
||
(if (or (not (stringp direction))
|
||
(string-equal
|
||
direction
|
||
(dbus-introspect-get-attribute arg "direction")))
|
||
(dbus-introspect-get-attribute arg "type")
|
||
"")))
|
||
(dbus-introspect-get-argument-names bus service path interface name)
|
||
"")))
|
||
|
||
|
||
;;; D-Bus properties.
|
||
|
||
(defun dbus-get-property (bus service path interface property)
|
||
"Return the value of PROPERTY of INTERFACE.
|
||
It will be checked at BUS, SERVICE, PATH. The result can be any
|
||
valid D-Bus value, or `nil' if there is no PROPERTY."
|
||
(dbus-ignore-errors
|
||
;; We must check, whether the "org.freedesktop.DBus.Properties"
|
||
;; interface is supported; otherwise the call blocks.
|
||
(when
|
||
(member
|
||
"Get"
|
||
(dbus-introspect-get-method-names
|
||
bus service path "org.freedesktop.DBus.Properties"))
|
||
;; "Get" returns a variant, so we must use the car.
|
||
(car
|
||
(dbus-call-method
|
||
bus service path dbus-interface-properties
|
||
"Get" interface property)))))
|
||
|
||
(defun dbus-set-property (bus service path interface property value)
|
||
"Set value of PROPERTY of INTERFACE to VALUE.
|
||
It will be checked at BUS, SERVICE, PATH. When the value has
|
||
been set successful, the result is VALUE. Otherwise, `nil' is
|
||
returned."
|
||
(dbus-ignore-errors
|
||
(when
|
||
(and
|
||
;; We must check, whether the
|
||
;; "org.freedesktop.DBus.Properties" interface is supported;
|
||
;; otherwise the call blocks.
|
||
(member
|
||
"Set"
|
||
(dbus-introspect-get-method-names
|
||
bus service path "org.freedesktop.DBus.Properties"))
|
||
;; PROPERTY must be writable.
|
||
(string-equal
|
||
"readwrite"
|
||
(dbus-introspect-get-attribute
|
||
(dbus-introspect-get-property bus service path interface property)
|
||
"access")))
|
||
;; "Set" requires a variant.
|
||
(dbus-call-method
|
||
bus service path dbus-interface-properties
|
||
"Set" interface property (list :variant value))
|
||
;; Return VALUE.
|
||
(dbus-get-property bus service path interface property))))
|
||
|
||
(defun dbus-get-all-properties (bus service path interface)
|
||
"Return all properties of INTERFACE at BUS, SERVICE, PATH.
|
||
The result is a list of entries. Every entry is a cons of the
|
||
name of the property, and its value. If there are no properties,
|
||
`nil' is returned."
|
||
;; "org.freedesktop.DBus.Properties.GetAll" is not supported at
|
||
;; all interfaces. Therefore, we do it ourselves.
|
||
(dbus-ignore-errors
|
||
(let (result)
|
||
(dolist (property
|
||
(dbus-introspect-get-property-names
|
||
bus service path interface)
|
||
result)
|
||
(add-to-list
|
||
'result
|
||
(cons property (dbus-get-property bus service path interface property))
|
||
'append)))))
|
||
|
||
(provide 'dbus)
|
||
|
||
;; arch-tag: a47caf84-9162-4811-90cc-5d388e37b9bd
|
||
;;; dbus.el ends here
|