lisp/dnd.el

   1 ;;; dnd.el --- drag and drop support.  -*- coding: utf-8 -*-
   2
   3 ;; Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011
   4 ;;   Free Software Foundation, Inc.
   5
   6 ;; Author: Jan Djärv <jan.h.d@swipnet.se>
   7 ;; Maintainer: FSF
   8 ;; Keywords: window, drag, drop
   9 ;; Package: emacs
  10
  11 ;; This file is part of GNU Emacs.
  12
  13 ;; GNU Emacs is free software: you can redistribute it and/or modify
  14 ;; it under the terms of the GNU General Public License as published by
  15 ;; the Free Software Foundation, either version 3 of the License, or
  16 ;; (at your option) any later version.
  17
  18 ;; GNU Emacs is distributed in the hope that it will be useful,
  19 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 ;; GNU General Public License for more details.
  22
  23 ;; You should have received a copy of the GNU General Public License
  24 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  25
  26 ;;; Commentary:
  27
  28 ;; This file provides the generic handling of the drop part only.
  29 ;; Different DND backends (X11, W32, etc.) that handle the platform
  30 ;; specific DND parts call the functions here to do final delivery of
  31 ;; a drop.
  32
  33 ;;; Code:
  34
  35 ;;; Customizable variables
  36
  37
  38 ;;;###autoload
  39 (defcustom dnd-protocol-alist
  40   `((,(purecopy "^file:///")  . dnd-open-local-file)    ; XDND format.
  41     (,(purecopy "^file://")   . dnd-open-file)          ; URL with host
  42     (,(purecopy "^file:")     . dnd-open-local-file)    ; Old KDE, Motif, Sun
  43     (,(purecopy "^\\(https?\\|ftp\\|file\\|nfs\\)://") . dnd-open-file)
  44    )
  45
  46   "The functions to call for different protocols when a drop is made.
  47 This variable is used by `dnd-handle-one-url' and `dnd-handle-file-name'.
  48 The list contains of (REGEXP . FUNCTION) pairs.
  49 The functions shall take two arguments, URL, which is the URL dropped and
  50 ACTION which is the action to be performed for the drop (move, copy, link,
  51 private or ask).
  52 If no match is found here, and the value of `browse-url-browser-function'
  53 is a pair of (REGEXP . FUNCTION), those regexps are tried for a match.
  54 If no match is found, the URL is inserted as text by calling `dnd-insert-text'.
  55 The function shall return the action done (move, copy, link or private)
  56 if some action was made, or nil if the URL is ignored."
  57   :version "22.1"
  58   :type '(repeat (cons (regexp) (function)))
  59   :group 'dnd)
  60
  61
  62 (defcustom dnd-open-remote-file-function
  63   (if (eq system-type 'windows-nt)
  64       'dnd-open-local-file
  65     'dnd-open-remote-url)
  66   "The function to call when opening a file on a remote machine.
  67 The function will be called with two arguments; URI and ACTION. See
  68 `dnd-open-file' for details.
  69 If nil, then dragging remote files into Emacs will result in an error.
  70 Predefined functions are `dnd-open-local-file' and `dnd-open-remote-url'.
  71 `dnd-open-local-file' attempts to open a remote file using its UNC name and
  72 is the  default on MS-Windows.  `dnd-open-remote-url' uses `url-handler-mode'
  73 and is the default except for MS-Windows."
  74   :version "22.1"
  75   :type 'function
  76   :group 'dnd)
  77
  78
  79 (defcustom dnd-open-file-other-window nil
  80   "If non-nil, always use find-file-other-window to open dropped files."
  81   :version "22.1"
  82   :type 'boolean
  83   :group 'dnd)
  84
  85
  86 ;; Functions
  87
  88 (defun dnd-handle-one-url (window action url)
  89   "Handle one dropped url by calling the appropriate handler.
  90 The handler is first located by looking at `dnd-protocol-alist'.
  91 If no match is found here, and the value of `browse-url-browser-function'
  92 is a pair of (REGEXP . FUNCTION), those regexps are tried for a match.
  93 If no match is found, just call `dnd-insert-text'.
  94 WINDOW is where the drop happened, ACTION is the action for the drop,
  95 URL is what has been dropped.
  96 Returns ACTION."
  97   (require 'browse-url)
  98   (let (ret)
  99     (or
 100      (catch 'done
 101        (dolist (bf dnd-protocol-alist)
 102          (when (string-match (car bf) url)
 103            (setq ret (funcall (cdr bf) url action))
 104            (throw 'done t)))
 105        nil)
 106      (when (not (functionp browse-url-browser-function))
 107        (catch 'done
 108          (dolist (bf browse-url-browser-function)
 109            (when (string-match (car bf) url)
 110              (setq ret 'private)
 111              (funcall (cdr bf) url action)
 112              (throw 'done t)))
 113          nil))
 114      (progn
 115        (dnd-insert-text window action url)
 116        (setq ret 'private)))
 117     ret))
 118
 119
 120 (defun dnd-get-local-file-uri (uri)
 121   "Return an uri converted to file:/// syntax if uri is a local file.
 122 Return nil if URI is not a local file."
 123
 124   ;; The hostname may be our hostname, in that case, convert to a local
 125   ;; file.  Otherwise return nil.  TODO:  How about an IP-address as hostname?
 126   (let ((hostname (when (string-match "^file://\\([^/]*\\)" uri)
 127                       (downcase (match-string 1 uri))))
 128         (system-name-no-dot
 129          (downcase (if (string-match "^[^\\.]+" system-name)
 130                        (match-string 0 system-name)
 131                      system-name))))
 132     (when (and hostname
 133              (or (string-equal "localhost" hostname)
 134                  (string-equal (downcase system-name) hostname)
 135                  (string-equal system-name-no-dot hostname)))
 136         (concat "file://" (substring uri (+ 7 (length hostname)))))))
 137
 138 (defsubst dnd-unescape-uri (uri)
 139   (replace-regexp-in-string
 140    "%[A-Fa-f0-9][A-Fa-f0-9]"
 141    (lambda (arg)
 142      (let ((str (make-string 1 0)))
 143        (aset str 0 (string-to-number (substring arg 1) 16))
 144        str))
 145    uri t t))
 146
 147 ;; http://lists.gnu.org/archive/html/emacs-devel/2006-05/msg01060.html
 148 (defun dnd-get-local-file-name (uri &optional must-exist)
 149   "Return file name converted from file:/// or file: syntax.
 150 URI is the uri for the file.  If MUST-EXIST is given and non-nil,
 151 only return non-nil if the file exists.
 152 Return nil if URI is not a local file."
 153   (let ((f (cond ((string-match "^file:///" uri)        ; XDND format.
 154                   (substring uri (1- (match-end 0))))
 155                  ((string-match "^file:" uri)           ; Old KDE, Motif, Sun
 156                   (substring uri (match-end 0))))))
 157     (and f (setq f (decode-coding-string (dnd-unescape-uri f)
 158                                          (or file-name-coding-system
 159                                              default-file-name-coding-system))))
 160     (when (and f must-exist (not (file-readable-p f)))
 161       (setq f nil))
 162     f))
 163
 164 (defun dnd-open-local-file (uri action)
 165   "Open a local file.
 166 The file is opened in the current window, or a new window if
 167 `dnd-open-file-other-window' is set.  URI is the url for the file,
 168 and must have the format file:file-name or file:///file-name.
 169 The last / in file:/// is part of the file name.  If the system
 170 natively supports unc file names, then remote urls of the form
 171 file://server-name/file-name will also be handled by this function.
 172 An alternative for systems that do not support unc file names is
 173 `dnd-open-remote-url'. ACTION is ignored."
 174
 175   (let* ((f (dnd-get-local-file-name uri t)))
 176     (if (and f (file-readable-p f))
 177         (progn
 178           (if dnd-open-file-other-window
 179               (find-file-other-window f)
 180             (find-file f))
 181           'private)
 182       (error "Can not read %s" uri))))
 183
 184 (defun dnd-open-remote-url (uri action)
 185   "Open a remote file with `find-file' and `url-handler-mode'.
 186 Turns `url-handler-mode' on if not on before.  The file is opened in the
 187 current window, or a new window if `dnd-open-file-other-window' is set.
 188 URI is the url for the file.  ACTION is ignored."
 189   (progn
 190     (require 'url-handlers)
 191     (or url-handler-mode (url-handler-mode))
 192     (if dnd-open-file-other-window
 193         (find-file-other-window uri)
 194       (find-file uri))
 195     'private))
 196
 197
 198 (defun dnd-open-file (uri action)
 199   "Open a local or remote file.
 200 The file is opened in the current window, or a new window if
 201 `dnd-open-file-other-window' is set.  URI is the url for the file,
 202 and must have the format file://hostname/file-name.  ACTION is ignored.
 203 The last / in file://hostname/ is part of the file name."
 204
 205   ;; The hostname may be our hostname, in that case, convert to a local
 206   ;; file.  Otherwise return nil.
 207   (let ((local-file (dnd-get-local-file-uri uri)))
 208     (if local-file (dnd-open-local-file local-file action)
 209       (if dnd-open-remote-file-function
 210           (funcall dnd-open-remote-file-function uri action)
 211         (error "Remote files not supported")))))
 212
 213
 214 (defun dnd-insert-text (window action text)
 215   "Insert text at point or push to the kill ring if buffer is read only.
 216 TEXT is the text as a string, WINDOW is the window where the drop happened."
 217   (if (or buffer-read-only
 218           (not (windowp window)))
 219       (progn
 220         (kill-new text)
 221         (message "%s"
 222          (substitute-command-keys
 223           "The dropped text can be accessed with \\[yank]")))
 224     (insert text))
 225   action)
 226
 227
 228 (provide 'dnd)
 229
 230 ;; arch-tag: 0472f6a5-2e8f-4304-9e44-1a0877c771b7
 231 ;;; dnd.el ends here