summaryrefslogtreecommitdiff
path: root/lisp/net/newst-ticker.el
blob: 275c91a36ea7bbb37f396796fbebed777afb8451 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
;; newst-ticker.el --- mode line ticker for newsticker.

;; Copyright (C) 2003-2021 Free Software Foundation, Inc.

;; Author:      Ulf Jasper <ulf.jasper@web.de>
;; Filename:    newst-ticker.el
;; URL:         http://www.nongnu.org/newsticker
;; Keywords:    News, RSS, Atom
;; Package:     newsticker

;; ======================================================================

;; This file is part of GNU Emacs.

;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.

;; ======================================================================

;;; Commentary:

;; See newsticker.el

;; ======================================================================
;;; Code:

(require 'newst-backend)

(defvar newsticker--item-list nil
  "List of newsticker items.")
(defvar newsticker--item-position 0
  "Actual position in list of newsticker items.")
(defvar newsticker--prev-message "There was no previous message yet!"
  "Last message that the newsticker displayed.")
(defvar newsticker--scrollable-text ""
  "The text which is scrolled smoothly in the echo area.")
(defvar newsticker--ticker-timer nil
  "Timer for newsticker ticker.")

;;;###autoload
(defun newsticker-ticker-running-p ()
  "Check whether newsticker's actual ticker is running.
Return t if ticker is running, nil otherwise.  Newsticker is
considered to be running if the newsticker timer list is not
empty."
  (timerp newsticker--ticker-timer))

;; customization group ticker
(defgroup newsticker-ticker nil
  "Settings for the headline ticker."
  :group 'newsticker)

(defun newsticker--set-customvar-ticker (symbol value)
  "Set newsticker-variable SYMBOL value to VALUE.
Calls all actions which are necessary in order to make the new
value effective."
  (if (or (not (boundp symbol))
          (equal (symbol-value symbol) value))
      (set symbol value)
    ;; something must have changed -- restart ticker
    (when (newsticker-running-p)
      (message "Restarting ticker")
      (newsticker-stop-ticker)
      (newsticker--ticker-text-setup)
      (newsticker-start-ticker)
      (message ""))))

(defcustom newsticker-ticker-interval
  0.3
  "Time interval for displaying news items in the echo area (seconds).
If equal or less than 0 no messages are shown in the echo area.  For
smooth display (see `newsticker-scroll-smoothly') a value of 0.3 seems
reasonable.  For non-smooth display a value of 10 is a good starting
point."
  :type 'number
  :set 'newsticker--set-customvar-ticker
  :group 'newsticker-ticker)

(defcustom newsticker-scroll-smoothly
  t
  "Decides whether to flash or scroll news items.
If t the news headlines are scrolled (more-or-less) smoothly in the echo
area.  If nil one headline after another is displayed in the echo area.
The variable `newsticker-ticker-interval' determines how fast this
display moves/changes and whether headlines are shown in the echo area
at all.  If you change `newsticker-scroll-smoothly' you should also change
`newsticker-ticker-interval'."
  :type 'boolean
  :group 'newsticker-ticker)

(defcustom newsticker-hide-immortal-items-in-echo-area
  t
  "Decides whether to show immortal/non-expiring news items in the ticker.
If t the echo area will not show immortal items.  See also
`newsticker-hide-old-items-in-echo-area'."
  :type 'boolean
  :set 'newsticker--set-customvar-ticker
  :group 'newsticker-ticker)

(defcustom newsticker-hide-old-items-in-echo-area
  t
  "Decides whether to show only the newest news items in the ticker.
If t the echo area will show only new items, i.e. only items which have
been added between the last two retrievals."
  :type 'boolean
  :set 'newsticker--set-customvar-ticker
  :group 'newsticker-ticker)

(defcustom newsticker-hide-obsolete-items-in-echo-area
  t
  "Decides whether to show obsolete items in the ticker.
If t the echo area will not show obsolete items.  See also
`newsticker-hide-old-items-in-echo-area'."
  :type 'boolean
  :set 'newsticker--set-customvar-ticker
  :group 'newsticker-ticker)

(defun newsticker--display-tick ()
  "Called from the display timer.
This function calls a display function, according to the variable
`newsticker-scroll-smoothly'."
  (if newsticker-scroll-smoothly
      (newsticker--display-scroll)
    (newsticker--display-jump)))

(defsubst newsticker--echo-area-clean-p ()
  "Check whether somebody is using the echo area / minibuffer.
Return t if echo area and minibuffer are unused."
  (not (or (active-minibuffer-window)
           (and (current-message)
                (not (string= (current-message)
                              newsticker--prev-message))))))

(defun newsticker--display-jump ()
  "Called from the display timer.
This function displays the next ticker item in the echo area, unless
there is another message displayed or the minibuffer is active."
  (let ((message-log-max nil));; prevents message text from being logged
    (when (newsticker--echo-area-clean-p)
      (setq newsticker--item-position (1+ newsticker--item-position))
      (when (>= newsticker--item-position (length newsticker--item-list))
        (setq newsticker--item-position 0))
      (setq newsticker--prev-message
            (nth newsticker--item-position newsticker--item-list))
      (message "%s" newsticker--prev-message))))

(defun newsticker--display-scroll ()
  "Called from the display timer.
This function scrolls the ticker items in the echo area, unless
there is another message displayed or the minibuffer is active."
  (when (newsticker--echo-area-clean-p)
    (let* ((width (- (frame-width) 1))
           (message-log-max nil);; prevents message text from being logged
           (i newsticker--item-position)
           subtext
           (s-text newsticker--scrollable-text)
           (l (length s-text)))
      ;; don't show anything if there is nothing to show
      (unless (< (length s-text) 1)
        ;; repeat the ticker string if it is shorter than frame width
        (while (< (length s-text) width)
          (setq s-text (concat s-text s-text)))
        ;; get the width of the printed string
        (setq l (length s-text))
        (cond ((< i (- l width))
               (setq subtext (substring s-text i (+ i width))))
              (t
               (setq subtext (concat
                              (substring s-text i l)
                              (substring s-text 0 (- width (- l i)))))))
        ;; Take care of multibyte strings, for which (string-width) is
        ;; larger than (length).
        ;; Actually, such strings may be smaller than (frame-width)
        ;; because return values of (string-width) are too large:
        ;; (string-width "<japanese character>") => 2
        (let ((t-width (1- (length subtext))))
          (while (> (string-width subtext) width)
            (setq subtext (substring subtext 0 t-width))
            (setq t-width (1- t-width))))
        ;; show the ticker text and save current position
        (message "%s" subtext)
        (setq newsticker--prev-message subtext)
        (setq newsticker--item-position (1+ i))
        (when (>= newsticker--item-position l)
          (setq newsticker--item-position 0))))))

;;;###autoload
(defun newsticker-start-ticker ()
  "Start newsticker's ticker (but not the news retrieval).
Start display timer for the actual ticker if wanted and not
running already."
  (interactive)
  (if (and (> newsticker-ticker-interval 0)
           (not newsticker--ticker-timer))
      (setq newsticker--ticker-timer
            (run-at-time newsticker-ticker-interval
                         newsticker-ticker-interval
                         'newsticker--display-tick))))

(defun newsticker-stop-ticker ()
  "Stop newsticker's ticker (but not the news retrieval)."
  (interactive)
  (when newsticker--ticker-timer
    (cancel-timer newsticker--ticker-timer)
    (setq newsticker--ticker-timer nil)))

;; ======================================================================
;;; Manipulation of ticker text
;; ======================================================================
(defun newsticker--ticker-text-setup ()
  "Build the ticker text which is scrolled or flashed in the echo area."
  ;; reset scrollable text
  (setq newsticker--scrollable-text "")
  (setq newsticker--item-list nil)
  (setq newsticker--item-position 0)
  ;; build scrollable text from cache data
  (let ((have-something nil))
    (mapc
     (lambda (feed)
       (let ((feed-name (symbol-name (car feed))))
         (let ((num-new (newsticker--stat-num-items (car feed) 'new))
               (num-old (newsticker--stat-num-items (car feed) 'old))
               (num-imm (newsticker--stat-num-items (car feed) 'immortal))
               (num-obs (newsticker--stat-num-items (car feed) 'obsolete)))
           (when (or (> num-new 0)
                     (and (> num-old 0)
                          (not newsticker-hide-old-items-in-echo-area))
                     (and (> num-imm 0)
                          (not newsticker-hide-immortal-items-in-echo-area))
                     (and (> num-obs 0)
                          (not newsticker-hide-obsolete-items-in-echo-area)))
             (setq have-something t)
             (mapc
              (lambda (item)
                (let ((title (replace-regexp-in-string
                              "[\r\n]+" " "
                              (newsticker--title item)))
                      (age (newsticker--age item)))
                  (unless (string= title newsticker--error-headline)
                    (when
                        (or (eq age 'new)
                            (and (eq age 'old)
                                 (not newsticker-hide-old-items-in-echo-area))
                            (and (eq age 'obsolete)
                                 (not
                                  newsticker-hide-obsolete-items-in-echo-area))
                            (and (eq age 'immortal)
                                 (not
                                  newsticker-hide-immortal-items-in-echo-area)))
                      (setq title (newsticker--remove-whitespace title))
                      ;; add to flash list
                      (add-to-list 'newsticker--item-list
                                   (concat feed-name ": " title) t)
                      ;; and to the scrollable text
                      (setq newsticker--scrollable-text
                            (concat newsticker--scrollable-text
                                    " " feed-name ": " title " +++"))))))
                (cdr feed))))))
     newsticker--cache)
    (when have-something
      (setq newsticker--scrollable-text
            (concat "+++ "
                    (format-time-string "%A, %H:%M"
                                        newsticker--latest-update-time)
                    " ++++++" newsticker--scrollable-text)))))

(defun newsticker--ticker-text-remove (feed title)
  "Remove the item of FEED with TITLE from the ticker text."
  ;; reset scrollable text
  (setq newsticker--item-position 0)
  (let ((feed-name (symbol-name feed))
        (t-title (replace-regexp-in-string "[\r\n]+" " " title)))
    ;; remove from flash list
    (setq newsticker--item-list (remove (concat feed-name ": " t-title)
                                        newsticker--item-list))
    ;; and from the scrollable text
    (setq newsticker--scrollable-text
          (replace-regexp-in-string
           (regexp-quote (concat " " feed-name ": " t-title " +++"))
           ""
           newsticker--scrollable-text))
    (if (string-match (concat "^\\+\\+\\+ [A-Z][a-z]+, "
                              "[012]?[0-9]:[0-9][0-9] \\+\\+\\+\\+\\+\\+$")
                              newsticker--scrollable-text)
        (setq newsticker--scrollable-text ""))))

(provide 'newst-ticker)

;;; newst-ticker.el ends here