lisp/dnd.el

   1 ;;; dnd.el --- drag and drop support.
   2
   3 ;; Copyright (C) 2005, 2006 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 2, or (at your option)
  14 ;; 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; see the file COPYING.  If not, write to the
  23 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  24 ;; Boston, MA 02110-1301, USA.
  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   '(
  41     ("^file:///" . dnd-open-local-file) ; XDND format.
  42     ("^file://"  . dnd-open-file)       ; URL with host
  43     ("^file:"    . dnd-open-local-file) ; Old KDE, Motif, Sun
  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
  63 (defcustom dnd-open-file-other-window nil
  64   "If non-nil, always use find-file-other-window to open dropped files."
  65   :version "22.1"
  66   :type 'boolean
  67   :group 'dnd)
  68
  69
  70 ;; Functions
  71
  72 (defun dnd-handle-one-url (window action arg)
  73   "Handle one dropped url by calling the appropriate handler.
  74 The handler is first located by looking at `dnd-protocol-alist'.
  75 If no match is found here, and the value of `browse-url-browser-function'
  76 is a pair of (REGEXP . FUNCTION), those regexps are tried for a match.
  77 If no match is found, just call `dnd-insert-text'.
  78 WINDOW is where the drop happend, ACTION is the action for the drop,
  79 ARG is the URL that has been dropped.
  80 Returns ACTION."
  81   (require 'browse-url)
  82   (let* ((uri (replace-regexp-in-string
  83                "%[A-Z0-9][A-Z0-9]"
  84                (lambda (arg)
  85                  (format "%c" (string-to-number (substring arg 1) 16)))
  86                arg))
  87          ret)
  88     (or
  89      (catch 'done
  90        (dolist (bf dnd-protocol-alist)
  91          (when (string-match (car bf) uri)
  92            (setq ret (funcall (cdr bf) uri action))
  93            (throw 'done t)))
  94        nil)
  95      (when (not (functionp browse-url-browser-function))
  96        (catch 'done
  97          (dolist (bf browse-url-browser-function)
  98            (when (string-match (car bf) uri)
  99              (setq ret 'private)
 100              (funcall (cdr bf) uri action)
 101              (throw 'done t)))
 102          nil))
 103      (progn
 104        (dnd-insert-text window action uri)
 105        (setq ret 'private)))
 106     ret))
 107
 108
 109 (defun dnd-get-local-file-uri (uri)
 110   "Return an uri converted to file:/// syntax if uri is a local file.
 111 Return nil if URI is not a local file."
 112
 113   ;; The hostname may be our hostname, in that case, convert to a local
 114   ;; file.  Otherwise return nil.  TODO:  How about an IP-address as hostname?
 115   (let ((hostname (when (string-match "^file://\\([^/]*\\)" uri)
 116                       (downcase (match-string 1 uri))))
 117         (system-name-no-dot
 118          (downcase (if (string-match "^[^\\.]+" system-name)
 119                        (match-string 0 system-name)
 120                      system-name))))
 121     (when (and hostname
 122              (or (string-equal "localhost" hostname)
 123                  (string-equal (downcase system-name) hostname)
 124                  (string-equal system-name-no-dot hostname)))
 125         (concat "file://" (substring uri (+ 7 (length hostname)))))))
 126
 127 (defun dnd-get-local-file-name (uri &optional must-exist)
 128   "Return file name converted from file:/// or file: syntax.
 129 URI is the uri for the file.  If MUST-EXIST is given and non-nil,
 130 only return non-nil if the file exists.
 131 Return nil if URI is not a local file."
 132   (let ((f (cond ((string-match "^file:///" uri)        ; XDND format.
 133                   (substring uri (1- (match-end 0))))
 134                  ((string-match "^file:" uri)           ; Old KDE, Motif, Sun
 135                   (substring uri (match-end 0))))))
 136     (when (and f must-exist)
 137       (let* ((decoded-f (decode-coding-string
 138                          f
 139                          (or file-name-coding-system
 140                              default-file-name-coding-system)))
 141              (try-f (if (file-readable-p decoded-f) decoded-f f)))
 142         (when (file-readable-p try-f) try-f)))))
 143
 144
 145 (defun dnd-open-local-file (uri action)
 146   "Open a local file.
 147 The file is opened in the current window, or a new window if
 148 `dnd-open-file-other-window' is set.  URI is the url for the file,
 149 and must have the format file:file-name or file:///file-name.
 150 The last / in file:/// is part of the file name.  ACTION is ignored."
 151
 152   (let* ((f (dnd-get-local-file-name uri t)))
 153     (if (and f (file-readable-p f))
 154         (progn
 155           (if dnd-open-file-other-window
 156               (find-file-other-window f)
 157             (find-file f))
 158           'private)
 159       (error "Can not read %s" uri))))
 160
 161 (defun dnd-open-file (uri action)
 162   "Open a local or remote 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://hostname/file-name.  ACTION is ignored.
 166 The last / in file://hostname/ is part of the file name."
 167
 168   ;; The hostname may be our hostname, in that case, convert to a local
 169   ;; file.  Otherwise return nil.
 170   (let ((local-file (dnd-get-local-file-uri uri)))
 171     (if local-file (dnd-open-local-file local-file action)
 172       (error "Remote files not supported"))))
 173
 174
 175 (defun dnd-insert-text (window action text)
 176   "Insert text at point or push to the kill ring if buffer is read only.
 177 TEXT is the text as a string, WINDOW is the window where the drop happened."
 178   (if (or buffer-read-only
 179           (not (windowp window)))
 180       (progn
 181         (kill-new text)
 182         (message "%s"
 183          (substitute-command-keys
 184           "The dropped text can be accessed with \\[yank]")))
 185     (insert text))
 186   action)
 187
 188
 189 (provide 'dnd)
 190
 191 ;; arch-tag: 0472f6a5-2e8f-4304-9e44-1a0877c771b7
 192 ;;; dnd.el ends here