modules/page-modes/reddit.js

   1 /**
   2  * (C) Copyright 2008 Martin Dybdal
   3  * (C) Copyright 2009-2010 John Foerch
   4  *
   5  * Use, modification, and distribution are subject to the terms specified in the
   6  * COPYING file.
   7 **/
   8
   9 require("content-buffer.js");
  10
  11 define_variable("reddit_end_behavior", "stop",
  12     "Controls the behavior of the commands reddit-next-link and "+
  13     "reddit-prev-link when at the last or first link, respectively. "+
  14     "Given as a string, the supported values are 'stop', 'wrap', "+
  15     "and 'page'.  'stop' means to not move the highlight in any "+
  16     "way.  'wrap' means to wrap around to the first (or last) "+
  17     "link.  'page' means to navigate the buffer to the next (or "+
  18     "previous) page on reddit.");
  19
  20 register_user_stylesheet(
  21     "data:text/css," +
  22         escape (
  23             "@-moz-document url-prefix(http://www.reddit.com/) {" +
  24                 ".last-clicked {" +
  25                 " background-color: #bfb !important;" +
  26                 " border: 0px !important;"+
  27                 "}}"));
  28
  29
  30 /* Scroll, if necessary, to make the given element visible */
  31 function reddit_scroll_into_view (window, element) {
  32     var rect = element.getBoundingClientRect();
  33     if (rect.top < 0 || rect.bottom > window.innerHeight)
  34         element.scrollIntoView();
  35 }
  36
  37
  38 /* Move select the next link down from the currently highlighted one.
  39  * When the end of the page is reached, the behavior is controlled by
  40  * the variable reddit_end_behavior.
  41  */
  42 function reddit_next (I) {
  43     var doc = I.buffer.document;
  44     // the behavior of this command depends on whether we have downloaded
  45     // enough of the page to include all of the article links.
  46     var complete = doc.getElementsByClassName('footer').length > 0;
  47     var links = doc.getElementsByClassName('link');
  48     var first = null;
  49     var current = null;
  50     var next = null;
  51     for (var i = 0, llen = links.length; i < llen; i++) {
  52         if (links[i].style.display == 'none')
  53             continue;
  54         if (! first)
  55             first = links[i];
  56         if (current) {
  57             next = links[i];
  58             break;
  59         }
  60         if (links[i].className.indexOf("last-clicked") >= 0)
  61             current = links[i];
  62     }
  63     // The following situations are null-ops:
  64     //  1) there are no links on the page.
  65     //  2) page is incomplete and the current link is the last link.
  66     if (!first || (current && !next && !complete))
  67         return;
  68     if (! next) {
  69         if (current) {
  70             if (reddit_end_behavior == 'stop')
  71                 return;
  72             if (reddit_end_behavior == 'wrap')
  73                 next = first;
  74             if (reddit_end_behavior == 'page') {
  75                 let (xpr = doc.evaluate(
  76                     '//p[@class="nextprev"]/a[text()="next"]', doc, null,
  77                     Ci.nsIDOMXPathResult.ORDERED_NODE_ITERATOR_TYPE, null))
  78                 {
  79                     let nextpage;
  80                     if (xpr && (nextpage = xpr.iterateNext())) {
  81                         dom_remove_class(current, "last-clicked");
  82                         browser_object_follow(I.buffer, FOLLOW_DEFAULT, nextpage);
  83                         return;
  84                     }
  85                 }
  86             }
  87         } else {
  88             // Page may or may not be complete.  If the page is not
  89             // complete, it is safe to assume that there is no current
  90             // link because a current link can only persist on a
  91             // cached page, which would load instantaneously, not
  92             // giving the user the opportunity to run this command.
  93             //
  94             next = first;
  95         }
  96     }
  97     // ordinaries (highlight new, maybe dehighlight old)
  98     if (current)
  99         dom_remove_class(current, "last-clicked");
 100     dom_add_class(next, "last-clicked");
 101     let (anchor = doc.evaluate(
 102         '//*[contains(@class,"last-clicked")]//a[contains(@class,"title")]',
 103         next, null, Ci.nsIDOMXPathResult.FIRST_ORDERED_NODE_TYPE, null))
 104     {
 105         browser_set_element_focus(I.buffer, anchor.singleNodeValue);
 106     }
 107     reddit_scroll_into_view(I.buffer.focused_frame, next);
 108 }
 109 interactive("reddit-next-link",
 110             "Move the 'cursor' to the next reddit entry.",
 111             reddit_next);
 112
 113
 114 /* Select the link before the currently highlighted one.  When the
 115  * beginning of the page is reached, behavior is controlled by the
 116  * variable reddit_end_behavior.
 117  */
 118 function reddit_prev (I) {
 119     var doc = I.buffer.document;
 120     // the behavior of this command depends on whether we have downloaded
 121     // enough of the page to include all of the article links.
 122     var complete = doc.getElementsByClassName('footer').length > 0;
 123     var links = doc.getElementsByClassName('link');
 124     var llen = links.length;
 125     var first = null;
 126     var prev = null;
 127     var current = null;
 128     for (var i = 0; i < llen; i++) {
 129         if (links[i].style.display == 'none')
 130             continue;
 131         if (! first)
 132             first = links[i];
 133         if (links[i].className.indexOf("last-clicked") >= 0) {
 134             current = links[i];
 135             break;
 136         }
 137         prev = links[i];
 138     }
 139     if (! first || // no links were found at all.
 140         (!current && !complete)) // don't know where current is.
 141         return;
 142     if (! prev) {
 143         // the first visible link is the `current' link.
 144         // dispatch on reddit_end_behavior.
 145         if (reddit_end_behavior == 'stop')
 146             return;
 147         else if (reddit_end_behavior == 'wrap') {
 148             // need to get last link on page.
 149             if (complete) {
 150                 for (var i = 0; i < llen; i++) {
 151                     if (links[i].style.display == 'none')
 152                         continue;
 153                     prev = links[i];
 154                 }
 155             }
 156         } else if (reddit_end_behavior == 'page') {
 157             let (xpr = doc.evaluate(
 158                 '//p[@class="nextprev"]/a[text()="prev"]', doc, null,
 159                 Ci.nsIDOMXPathResult.ORDERED_NODE_ITERATOR_TYPE, null))
 160             {
 161                 let prevpage;
 162                 if (xpr && (prevpage = xpr.iterateNext())) {
 163                     dom_remove_class(current, "last-clicked");
 164                     browser_object_follow(I.buffer, FOLLOW_DEFAULT, prevpage);
 165                     return;
 166                 }
 167             }
 168         }
 169     }
 170     // ordinaries (highlight new, maybe dehighlight old)
 171     if (current)
 172         dom_remove_class(current, "last-clicked");
 173     dom_add_class(prev, "last-clicked");
 174     let (anchor = doc.evaluate(
 175         '//*[contains(@class,"last-clicked")]//a[contains(@class,"title")]',
 176         prev, null, Ci.nsIDOMXPathResult.FIRST_ORDERED_NODE_TYPE, null))
 177     {
 178         browser_set_element_focus(I.buffer, anchor.singleNodeValue);
 179     }
 180     reddit_scroll_into_view(I.buffer.focused_frame, prev);
 181 }
 182 interactive("reddit-prev-link",
 183             "Move the 'cursor' to the previous reddit entry.",
 184             reddit_prev);
 185
 186
 187 function reddit_open_comments (I, target) {
 188     var xpr = I.buffer.document.evaluate(
 189         '//*[contains(@class,"last-clicked")]/descendant::a[@class="comments"]',
 190         I.buffer.document, null,
 191         Ci.nsIDOMXPathResult.ORDERED_NODE_ITERATOR_TYPE, null);
 192     let link;
 193     if (xpr && (link = xpr.iterateNext()))
 194         browser_object_follow(I.buffer, target || FOLLOW_DEFAULT, link);
 195 }
 196 function reddit_open_comments_new_buffer (I) {
 197     reddit_open_comments(I, OPEN_NEW_BUFFER);
 198 }
 199 function reddit_open_comments_new_window (I) {
 200     reddit_open_comments(I, OPEN_NEW_WINDOW);
 201 }
 202 interactive("reddit-open-comments",
 203             "Open the comments-page associated with the currently selected link.",
 204             alternates(reddit_open_comments,
 205                        reddit_open_comments_new_buffer,
 206                        reddit_open_comments_new_window));
 207
 208
 209 function reddit_vote_up (I) {
 210     // get the current article and send a click to its vote-up button.
 211     var xpr = I.buffer.document.evaluate(
 212         '//*[contains(@class,"last-clicked")]/div[contains(@class,"midcol")]/div[contains(@class,"up")]',
 213         I.buffer.document, null,
 214         Ci.nsIDOMXPathResult.ORDERED_NODE_ITERATOR_TYPE, null);
 215     let link;
 216     if (xpr && (link = xpr.iterateNext()))
 217         browser_object_follow(I.buffer, FOLLOW_DEFAULT, link);
 218 }
 219 interactive("reddit-vote-up",
 220             "Vote the currently selected link up.",
 221             reddit_vote_up);
 222
 223
 224 function reddit_vote_down (I) {
 225     // get the current article and send a click to its vote-down button.
 226     var xpr = I.buffer.document.evaluate(
 227         '//*[contains(@class,"last-clicked")]/div[contains(@class,"midcol")]/div[contains(@class,"down")]',
 228         I.buffer.document, null,
 229         Ci.nsIDOMXPathResult.ORDERED_NODE_ITERATOR_TYPE, null);
 230     let link;
 231     if (xpr && (link = xpr.iterateNext()))
 232         browser_object_follow(I.buffer, FOLLOW_DEFAULT, link);
 233 }
 234 interactive("reddit-vote-down",
 235             "Vote the currently selected link down.",
 236             reddit_vote_down);
 237
 238
 239 define_browser_object_class("reddit-current", null,
 240     function (I, prompt) {
 241         var xpr = I.buffer.document.evaluate(
 242             '//*[contains(@class,"last-clicked")]/*[contains(@class,"entry")]/p[@class="title"]/a',
 243             I.buffer.document, null,
 244             Ci.nsIDOMXPathResult.ORDERED_NODE_ITERATOR_TYPE, null);
 245         yield co_return(xpr.iterateNext());
 246     });
 247
 248
 249 define_keymap("reddit_keymap", $display_name = "reddit");
 250 define_key(reddit_keymap, "j", "reddit-next-link");
 251 define_key(reddit_keymap, "k", "reddit-prev-link");
 252 define_key(reddit_keymap, ",", "reddit-vote-up");
 253 define_key(reddit_keymap, ".", "reddit-vote-down");
 254 define_key(reddit_keymap, "h", "reddit-open-comments");
 255
 256
 257 var reddit_link_commands =
 258     ["follow-current", "follow-current-new-buffer",
 259      "follow-current-new-buffer-background",
 260      "follow-current-new-window", "copy"];
 261
 262
 263 var reddit_modality = {
 264     normal: reddit_keymap
 265 };
 266
 267
 268 define_page_mode("reddit-mode",
 269     build_url_regexp($domain = /([a-zA-Z0-9\-]*\.)*reddit/),
 270     function enable (buffer) {
 271         for each (var c in reddit_link_commands) {
 272             buffer.default_browser_object_classes[c] =
 273                 browser_object_reddit_current;
 274         }
 275         buffer.content_modalities.push(reddit_modality);
 276     },
 277     function disable (buffer) {
 278         for each (var c in reddit_link_commands) {
 279             delete buffer.default_browser_object_classes[c];
 280         }
 281         var i = buffer.content_modalities.indexOf(reddit_modality);
 282         if (i > -1)
 283             buffer.content_modalities.splice(i, 1);
 284     },
 285     $display_name = "reddit",
 286     $doc = "reddit page-mode: keyboard navigation for reddit.");
 287
 288 page_mode_activate(reddit_mode);
 289
 290 provide("reddit");