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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 | |
b578f267 EN |
18 | ;; along with GNU Emacs; see the file COPYING. If not, write to the |
19 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
20 | ;; Boston, MA 02111-1307, USA. | |
f448b834 | 21 | |
aae56ea7 | 22 | ;;; Commentary: |
f448b834 RS |
23 | |
24 | ;; Things we cannot emulate in Lisp: | |
25 | ;; It is not possible to emulate current-mouse-event as a variable, | |
26 | ;; though it is not hard to obtain the data from (this-command-keys). | |
27 | ||
f448b834 RS |
28 | ;; We do not have a variable unread-command-event; |
29 | ;; instead, we have the more general unread-command-events. | |
30 | ||
ecc71b7f RS |
31 | ;; Our read-key-sequence and read-char are not precisely |
32 | ;; compatible with those in Lucid Emacs, but they should work ok. | |
f448b834 RS |
33 | |
34 | ;;; Code: | |
35 | ||
5f1d59f4 RS |
36 | (defun next-command-event (event) |
37 | (error "You must rewrite to use `read-command-event' instead of `next-command-event'")) | |
38 | ||
39 | (defun next-event (event) | |
40 | (error "You must rewrite to use `read-event' instead of `next-event'")) | |
41 | ||
42 | (defun dispatch-event (event) | |
43 | (error "`dispatch-event' not supported")) | |
44 | ||
f448b834 RS |
45 | ;; Make events of type eval, menu and timeout |
46 | ;; execute properly. | |
47 | ||
48 | (define-key global-map [menu] 'execute-eval-event) | |
49 | (define-key global-map [timeout] 'execute-eval-event) | |
50 | (define-key global-map [eval] 'execute-eval-event) | |
51 | ||
52 | (defun execute-eval-event (event) | |
53 | (interactive "e") | |
54 | (funcall (nth 1 event) (nth 2 event))) | |
55 | ||
56 | (put 'eval 'event-symbol-elements '(eval)) | |
57 | (put 'menu 'event-symbol-elements '(eval)) | |
58 | (put 'timeout 'event-symbol-elements '(eval)) | |
59 | ||
f448b834 RS |
60 | (defun allocate-event () |
61 | "Returns an empty event structure. | |
62 | In this emulation, it returns nil." | |
63 | nil) | |
64 | ||
65 | (defun button-press-event-p (obj) | |
66 | "True if the argument is a mouse-button-press event object." | |
67 | (and (consp obj) (symbolp (car obj)) | |
68 | (memq 'down (get (car obj) 'event-symbol-elements)))) | |
69 | ||
70 | (defun button-release-event-p (obj) | |
71 | "True if the argument is a mouse-button-release event object." | |
72 | (and (consp obj) (symbolp (car obj)) | |
73 | (or (memq 'click (get (car obj) 'event-symbol-elements)) | |
74 | (memq 'drag (get (car obj) 'event-symbol-elements))))) | |
75 | ||
76 | (defun character-to-event (ch &optional event) | |
77 | "Converts a numeric ASCII value to an event structure, replete with | |
78 | bucky bits. The character is the first argument, and the event to fill | |
79 | in is the second. This function contains knowledge about what the codes | |
80 | mean -- for example, the number 9 is converted to the character Tab, | |
81 | not the distinct character Control-I. | |
82 | ||
83 | Beware that character-to-event and event-to-character are not strictly | |
84 | inverse functions, since events contain much more information than the | |
85 | ASCII character set can encode." | |
86 | ch) | |
87 | ||
88 | (defun copy-event (event1 &optional event2) | |
89 | "Make a copy of the given event object. | |
90 | In this emulation, `copy-event' just returns its argument." | |
91 | event1) | |
92 | ||
93 | (defun deallocate-event (event) | |
94 | "Allow the given event structure to be reused. | |
95 | In actual Lucid Emacs, you MUST NOT use this event object after | |
96 | calling this function with it. You will lose. It is not necessary to | |
97 | call this function, as event objects are garbage- collected like all | |
98 | other objects; however, it may be more efficient to explicitly | |
99 | deallocate events when you are sure that that is safe. | |
100 | ||
101 | This emulation does not actually deallocate or reuse events | |
102 | except via garbage collection and `cons'." | |
103 | nil) | |
104 | ||
f448b834 RS |
105 | (defun enqueue-eval-event: (function object) |
106 | "Add an eval event to the back of the queue. | |
107 | It will be the next event read after all pending events." | |
108 | (setq unread-command-events | |
109 | (nconc unread-command-events | |
110 | (list (list 'eval function object))))) | |
111 | ||
112 | (defun eval-event-p (obj) | |
113 | "True if the argument is an eval or menu event object." | |
114 | (eq (car-safe obj) 'eval)) | |
115 | ||
116 | (defun event-button (event) | |
117 | "Return the button-number of the given mouse-button-press event." | |
118 | (let ((sym (car (get (car event) 'event-symbol-elements)))) | |
119 | (cdr (assq sym '((mouse-1 . 1) (mouse-2 . 2) (mouse-3 . 3) | |
120 | (mouse-4 . 4) (mouse-5 . 5)))))) | |
121 | ||
122 | (defun event-function (event) | |
123 | "Return the callback function of the given timeout, menu, or eval event." | |
124 | (nth 1 event)) | |
125 | ||
126 | (defun event-key (event) | |
127 | "Returns the KeySym of the given key-press event. | |
128 | The value is an ASCII printing character (not upper case) or a symbol." | |
129 | (if (symbolp event) | |
130 | (car (get event 'event-symbol-elements)) | |
131 | (let ((base (logand event (1- (lsh 1 18))))) | |
132 | (downcase (if (< base 32) (logior base 64) base))))) | |
133 | ||
f448b834 RS |
134 | (defun event-object (event) |
135 | "Returns the function argument of the given timeout, menu, or eval event." | |
136 | (nth 2 event)) | |
137 | ||
138 | (defun event-point (event) | |
139 | "Returns the character position of the given mouse-related event. | |
140 | If the event did not occur over a window, or did | |
141 | not occur over text, then this returns nil. Otherwise, it returns an index | |
142 | into the buffer visible in the event's window." | |
143 | (posn-point (event-end event))) | |
144 | ||
145 | (defun event-process (event) | |
146 | "Returns the process of the given process-output event." | |
147 | (nth 1 event)) | |
148 | ||
149 | (defun event-timestamp (event) | |
150 | "Returns the timestamp of the given event object. | |
151 | In Lucid Emacs, this works for any kind of event. | |
152 | In this emulation, it returns nil for non-mouse-related events." | |
153 | (and (listp event) | |
154 | (posn-timestamp (event-end event)))) | |
155 | ||
156 | (defun event-to-character (event &optional lenient) | |
157 | "Returns the closest ASCII approximation to the given event object. | |
158 | If the event isn't a keypress, this returns nil. | |
159 | If the second argument is non-nil, then this is lenient in its | |
160 | translation; it will ignore modifier keys other than control and meta, | |
161 | and will ignore the shift modifier on those characters which have no | |
162 | shifted ASCII equivalent (Control-Shift-A for example, will be mapped to | |
163 | the same ASCII code as Control-A.) If the second arg is nil, then nil | |
164 | will be returned for events which have no direct ASCII equivalent." | |
165 | (if (symbolp event) | |
166 | (and lenient | |
167 | (cdr (assq event '((backspace . 8) (delete . 127) (tab . 9) | |
168 | (return . 10) (enter . 10))))) | |
169 | ;; Our interpretation is, ASCII means anything a number can represent. | |
170 | (if (integerp event) | |
171 | event nil))) | |
172 | ||
173 | (defun event-window (event) | |
174 | "Returns the window of the given mouse-related event object." | |
175 | (posn-window (event-end event))) | |
176 | ||
177 | (defun event-x (event) | |
178 | "Returns the X position in characters of the given mouse-related event." | |
179 | (/ (car (posn-col-row (event-end event))) | |
bb621b01 | 180 | (frame-char-width (window-frame (event-window event))))) |
f448b834 RS |
181 | |
182 | (defun event-x-pixel (event) | |
183 | "Returns the X position in pixels of the given mouse-related event." | |
184 | (car (posn-col-row (event-end event)))) | |
185 | ||
186 | (defun event-y (event) | |
187 | "Returns the Y position in characters of the given mouse-related event." | |
188 | (/ (cdr (posn-col-row (event-end event))) | |
bb621b01 | 189 | (frame-char-height (window-frame (event-window event))))) |
f448b834 RS |
190 | |
191 | (defun event-y-pixel (event) | |
192 | "Returns the Y position in pixels of the given mouse-related event." | |
193 | (cdr (posn-col-row (event-end event)))) | |
194 | ||
195 | (defun key-press-event-p (obj) | |
196 | "True if the argument is a keyboard event object." | |
197 | (or (integerp obj) | |
198 | (and (symbolp obj) | |
199 | (get obj 'event-symbol-elements)))) | |
200 | ||
201 | (defun menu-event-p (obj) | |
202 | "True if the argument is a menu event object." | |
203 | (eq (car-safe obj) 'menu)) | |
204 | ||
205 | (defun motion-event-p (obj) | |
206 | "True if the argument is a mouse-motion event object." | |
207 | (eq (car-safe obj) 'mouse-movement)) | |
208 | ||
5f1d59f4 RS |
209 | (defun read-command-event () |
210 | "Return the next keyboard or mouse event; execute other events. | |
211 | This is similar to the function `next-command-event' of Lucid Emacs, | |
212 | but different in that it returns the event rather than filling in | |
213 | an existing event object." | |
214 | (let (event) | |
215 | (while (progn | |
216 | (setq event (read-event)) | |
217 | (not (or (key-press-event-p event) | |
218 | (button-press-event-p event) | |
219 | (button-release-event-p event) | |
220 | (menu-event-p event)))) | |
221 | (let ((type (car-safe event))) | |
222 | (cond ((eq type 'eval) | |
223 | (funcall (nth 1 event) (nth 2 event))) | |
224 | ((eq type 'switch-frame) | |
e74865ee | 225 | (select-frame (nth 1 event)))))) |
5f1d59f4 | 226 | event)) |
f448b834 RS |
227 | |
228 | (defun process-event-p (obj) | |
229 | "True if the argument is a process-output event object. | |
230 | GNU Emacs 19 does not currently generate process-output events." | |
231 | (eq (car-safe obj) 'process)) | |
232 | ||
233 | (defun timeout-event-p (obj) | |
234 | "True if the argument is a timeout event object. | |
235 | GNU Emacs 19 does not currently generate timeout events." | |
236 | (eq (car-safe obj) 'timeout)) | |
237 | ||
238 | ;;; levents.el ends here |