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aae56ea7 ER |
1 | ;;; levents.el --- emulate the Lucid event data type and associated functions. |
2 | ||
f448b834 RS |
3 | ;; Copyright (C) 1993 Free Software Foundation, Inc. |
4 | ||
5 | ;; This file is part of GNU Emacs. | |
6 | ||
7 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
8 | ;; it under the terms of the GNU General Public License as published by | |
9 | ;; the Free Software Foundation; either version 2, or (at your option) | |
10 | ;; any later version. | |
11 | ||
12 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
13 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | ;; GNU General Public License for more details. | |
16 | ||
17 | ;; You should have received a copy of the GNU General Public License | |
18 | ;; along with GNU Emacs; see the file COPYING. If not, write to | |
19 | ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. | |
20 | ||
aae56ea7 | 21 | ;;; Commentary: |
f448b834 RS |
22 | |
23 | ;; Things we cannot emulate in Lisp: | |
24 | ;; It is not possible to emulate current-mouse-event as a variable, | |
25 | ;; though it is not hard to obtain the data from (this-command-keys). | |
26 | ||
f448b834 RS |
27 | ;; We do not have a variable unread-command-event; |
28 | ;; instead, we have the more general unread-command-events. | |
29 | ||
ecc71b7f RS |
30 | ;; Our read-key-sequence and read-char are not precisely |
31 | ;; compatible with those in Lucid Emacs, but they should work ok. | |
f448b834 RS |
32 | |
33 | ;;; Code: | |
34 | ||
5f1d59f4 RS |
35 | (defun next-command-event (event) |
36 | (error "You must rewrite to use `read-command-event' instead of `next-command-event'")) | |
37 | ||
38 | (defun next-event (event) | |
39 | (error "You must rewrite to use `read-event' instead of `next-event'")) | |
40 | ||
41 | (defun dispatch-event (event) | |
42 | (error "`dispatch-event' not supported")) | |
43 | ||
f448b834 RS |
44 | ;; Make events of type eval, menu and timeout |
45 | ;; execute properly. | |
46 | ||
47 | (define-key global-map [menu] 'execute-eval-event) | |
48 | (define-key global-map [timeout] 'execute-eval-event) | |
49 | (define-key global-map [eval] 'execute-eval-event) | |
50 | ||
51 | (defun execute-eval-event (event) | |
52 | (interactive "e") | |
53 | (funcall (nth 1 event) (nth 2 event))) | |
54 | ||
55 | (put 'eval 'event-symbol-elements '(eval)) | |
56 | (put 'menu 'event-symbol-elements '(eval)) | |
57 | (put 'timeout 'event-symbol-elements '(eval)) | |
58 | ||
59 | (defsubst eventp (obj) | |
60 | "True if the argument is an event object." | |
61 | (or (integerp obj) | |
62 | (and (symbolp obj) | |
63 | (get obj 'event-symbol-elements)) | |
64 | (and (consp obj) | |
65 | (symbolp (car obj)) | |
66 | (get (car obj) 'event-symbol-elements)))) | |
67 | ||
68 | (defun allocate-event () | |
69 | "Returns an empty event structure. | |
70 | In this emulation, it returns nil." | |
71 | nil) | |
72 | ||
73 | (defun button-press-event-p (obj) | |
74 | "True if the argument is a mouse-button-press event object." | |
75 | (and (consp obj) (symbolp (car obj)) | |
76 | (memq 'down (get (car obj) 'event-symbol-elements)))) | |
77 | ||
78 | (defun button-release-event-p (obj) | |
79 | "True if the argument is a mouse-button-release event object." | |
80 | (and (consp obj) (symbolp (car obj)) | |
81 | (or (memq 'click (get (car obj) 'event-symbol-elements)) | |
82 | (memq 'drag (get (car obj) 'event-symbol-elements))))) | |
83 | ||
84 | (defun character-to-event (ch &optional event) | |
85 | "Converts a numeric ASCII value to an event structure, replete with | |
86 | bucky bits. The character is the first argument, and the event to fill | |
87 | in is the second. This function contains knowledge about what the codes | |
88 | mean -- for example, the number 9 is converted to the character Tab, | |
89 | not the distinct character Control-I. | |
90 | ||
91 | Beware that character-to-event and event-to-character are not strictly | |
92 | inverse functions, since events contain much more information than the | |
93 | ASCII character set can encode." | |
94 | ch) | |
95 | ||
96 | (defun copy-event (event1 &optional event2) | |
97 | "Make a copy of the given event object. | |
98 | In this emulation, `copy-event' just returns its argument." | |
99 | event1) | |
100 | ||
101 | (defun deallocate-event (event) | |
102 | "Allow the given event structure to be reused. | |
103 | In actual Lucid Emacs, you MUST NOT use this event object after | |
104 | calling this function with it. You will lose. It is not necessary to | |
105 | call this function, as event objects are garbage- collected like all | |
106 | other objects; however, it may be more efficient to explicitly | |
107 | deallocate events when you are sure that that is safe. | |
108 | ||
109 | This emulation does not actually deallocate or reuse events | |
110 | except via garbage collection and `cons'." | |
111 | nil) | |
112 | ||
f448b834 RS |
113 | (defun enqueue-eval-event: (function object) |
114 | "Add an eval event to the back of the queue. | |
115 | It will be the next event read after all pending events." | |
116 | (setq unread-command-events | |
117 | (nconc unread-command-events | |
118 | (list (list 'eval function object))))) | |
119 | ||
120 | (defun eval-event-p (obj) | |
121 | "True if the argument is an eval or menu event object." | |
122 | (eq (car-safe obj) 'eval)) | |
123 | ||
124 | (defun event-button (event) | |
125 | "Return the button-number of the given mouse-button-press event." | |
126 | (let ((sym (car (get (car event) 'event-symbol-elements)))) | |
127 | (cdr (assq sym '((mouse-1 . 1) (mouse-2 . 2) (mouse-3 . 3) | |
128 | (mouse-4 . 4) (mouse-5 . 5)))))) | |
129 | ||
130 | (defun event-function (event) | |
131 | "Return the callback function of the given timeout, menu, or eval event." | |
132 | (nth 1 event)) | |
133 | ||
134 | (defun event-key (event) | |
135 | "Returns the KeySym of the given key-press event. | |
136 | The value is an ASCII printing character (not upper case) or a symbol." | |
137 | (if (symbolp event) | |
138 | (car (get event 'event-symbol-elements)) | |
139 | (let ((base (logand event (1- (lsh 1 18))))) | |
140 | (downcase (if (< base 32) (logior base 64) base))))) | |
141 | ||
f448b834 RS |
142 | (defun event-object (event) |
143 | "Returns the function argument of the given timeout, menu, or eval event." | |
144 | (nth 2 event)) | |
145 | ||
146 | (defun event-point (event) | |
147 | "Returns the character position of the given mouse-related event. | |
148 | If the event did not occur over a window, or did | |
149 | not occur over text, then this returns nil. Otherwise, it returns an index | |
150 | into the buffer visible in the event's window." | |
151 | (posn-point (event-end event))) | |
152 | ||
153 | (defun event-process (event) | |
154 | "Returns the process of the given process-output event." | |
155 | (nth 1 event)) | |
156 | ||
157 | (defun event-timestamp (event) | |
158 | "Returns the timestamp of the given event object. | |
159 | In Lucid Emacs, this works for any kind of event. | |
160 | In this emulation, it returns nil for non-mouse-related events." | |
161 | (and (listp event) | |
162 | (posn-timestamp (event-end event)))) | |
163 | ||
164 | (defun event-to-character (event &optional lenient) | |
165 | "Returns the closest ASCII approximation to the given event object. | |
166 | If the event isn't a keypress, this returns nil. | |
167 | If the second argument is non-nil, then this is lenient in its | |
168 | translation; it will ignore modifier keys other than control and meta, | |
169 | and will ignore the shift modifier on those characters which have no | |
170 | shifted ASCII equivalent (Control-Shift-A for example, will be mapped to | |
171 | the same ASCII code as Control-A.) If the second arg is nil, then nil | |
172 | will be returned for events which have no direct ASCII equivalent." | |
173 | (if (symbolp event) | |
174 | (and lenient | |
175 | (cdr (assq event '((backspace . 8) (delete . 127) (tab . 9) | |
176 | (return . 10) (enter . 10))))) | |
177 | ;; Our interpretation is, ASCII means anything a number can represent. | |
178 | (if (integerp event) | |
179 | event nil))) | |
180 | ||
181 | (defun event-window (event) | |
182 | "Returns the window of the given mouse-related event object." | |
183 | (posn-window (event-end event))) | |
184 | ||
185 | (defun event-x (event) | |
186 | "Returns the X position in characters of the given mouse-related event." | |
187 | (/ (car (posn-col-row (event-end event))) | |
bb621b01 | 188 | (frame-char-width (window-frame (event-window event))))) |
f448b834 RS |
189 | |
190 | (defun event-x-pixel (event) | |
191 | "Returns the X position in pixels of the given mouse-related event." | |
192 | (car (posn-col-row (event-end event)))) | |
193 | ||
194 | (defun event-y (event) | |
195 | "Returns the Y position in characters of the given mouse-related event." | |
196 | (/ (cdr (posn-col-row (event-end event))) | |
bb621b01 | 197 | (frame-char-height (window-frame (event-window event))))) |
f448b834 RS |
198 | |
199 | (defun event-y-pixel (event) | |
200 | "Returns the Y position in pixels of the given mouse-related event." | |
201 | (cdr (posn-col-row (event-end event)))) | |
202 | ||
203 | (defun key-press-event-p (obj) | |
204 | "True if the argument is a keyboard event object." | |
205 | (or (integerp obj) | |
206 | (and (symbolp obj) | |
207 | (get obj 'event-symbol-elements)))) | |
208 | ||
209 | (defun menu-event-p (obj) | |
210 | "True if the argument is a menu event object." | |
211 | (eq (car-safe obj) 'menu)) | |
212 | ||
213 | (defun motion-event-p (obj) | |
214 | "True if the argument is a mouse-motion event object." | |
215 | (eq (car-safe obj) 'mouse-movement)) | |
216 | ||
5f1d59f4 RS |
217 | (defun read-command-event () |
218 | "Return the next keyboard or mouse event; execute other events. | |
219 | This is similar to the function `next-command-event' of Lucid Emacs, | |
220 | but different in that it returns the event rather than filling in | |
221 | an existing event object." | |
222 | (let (event) | |
223 | (while (progn | |
224 | (setq event (read-event)) | |
225 | (not (or (key-press-event-p event) | |
226 | (button-press-event-p event) | |
227 | (button-release-event-p event) | |
228 | (menu-event-p event)))) | |
229 | (let ((type (car-safe event))) | |
230 | (cond ((eq type 'eval) | |
231 | (funcall (nth 1 event) (nth 2 event))) | |
232 | ((eq type 'switch-frame) | |
e74865ee | 233 | (select-frame (nth 1 event)))))) |
5f1d59f4 | 234 | event)) |
f448b834 RS |
235 | |
236 | (defun process-event-p (obj) | |
237 | "True if the argument is a process-output event object. | |
238 | GNU Emacs 19 does not currently generate process-output events." | |
239 | (eq (car-safe obj) 'process)) | |
240 | ||
241 | (defun timeout-event-p (obj) | |
242 | "True if the argument is a timeout event object. | |
243 | GNU Emacs 19 does not currently generate timeout events." | |
244 | (eq (car-safe obj) 'timeout)) | |
245 | ||
246 | ;;; levents.el ends here |