lisp/dnd.el

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