modules/mouse-wheel.js

   1 /**
   2  * (C) Copyright 2011 Peter Lunicks
   3  *
   4  * Use, modification, and distribution are subject to the terms specified in the
   5  * COPYING file.
   6 **/
   7
   8 define_variable("mouse_wheel_scroll_lines", null,
   9                 "How many lines to scroll when the mouse wheel is used. " +
  10                 "A null value causes mouse-wheel-mode to scroll by the " +
  11                 "number of lines specified in the DOMMouseScroll event.");
  12
  13 function mouse_wheel_scroll (event) {
  14     var lines;
  15     if (mouse_wheel_scroll_lines != null)
  16         lines = mouse_wheel_scroll_lines * (event.detail < 0 ? -1 : 1)
  17     else
  18         lines = event.detail;
  19
  20     // Scroll the frame under mouse, not necessarily the current/focused frame
  21     var window = this.ownerDocument.defaultView;
  22     var frame = event.target.ownerDocument.defaultView;
  23     do_repeatedly(attempt_builtin_command, lines,
  24                   [window, frame, "cmd_scrollLineDown"],
  25                   [window, frame, "cmd_scrollLineUp"]);
  26
  27     // Prevent the scrollbars from scrolling further (if visible)
  28     event.preventDefault();
  29 }
  30
  31 function mouse_wheel_add_listener (buffer) {
  32     buffer.browser.addEventListener("DOMMouseScroll",
  33                                     mouse_wheel_scroll,
  34                                     true);
  35 }
  36
  37 function mouse_wheel_remove_listener (buffer) {
  38     buffer.browser.removeEventListener("DOMMouseScroll",
  39                                        mouse_wheel_scroll,
  40                                        true);
  41 }
  42
  43 function mouse_wheel_mode_enable () {
  44     add_hook("create_buffer_hook", mouse_wheel_add_listener);
  45     for_each_buffer(mouse_wheel_add_listener);
  46 }
  47
  48 function mouse_wheel_mode_disable () {
  49     remove_hook("create_buffer_hook", mouse_wheel_remove_listener);
  50     for_each_buffer(mouse_wheel_remove_listener);
  51 }
  52
  53 define_global_mode("mouse_wheel_mode",
  54                    mouse_wheel_mode_enable,
  55                    mouse_wheel_mode_disable);
  56
  57 mouse_wheel_mode(true);
  58
  59 provide("mouse-wheel");