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Piazza History Keybindings

Use left and right arrows to navigate Piazza post history

  1. // ==UserScript==
  2. // @name         Piazza History Keybindings
  3. // @namespace    https://piazza.com
  4. // @version      0.2
  5. // @description  Use left and right arrows to navigate Piazza post history
  6. // @author       David Harris, Yuto Takano
  7. // @match        https://piazza.com/*
  8. // @grant        none
  9. // @require      https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js
  10. // ==/UserScript==
  11.  
  12. // Avoid conflicts
  13. this.$ = this.jQuery = jQuery.noConflict(true);
  14.  
  15. function moveHistorySlider(increment) {
  16.     // `P` is a Piazza internal variable
  17.     // I discovered this while exploring their scripts
  18.     var newVal = P.history_slider.slider.value[0] + increment;
  19.     if(newVal < P.history_slider.slider.min) newVal = P.history_slider.slider.min;
  20.     if(newVal > P.history_slider.slider.max) newVal = P.history_slider.slider.max;
  21.     P.history_slider.slider.element.slider("setValue", newVal).trigger("slide");
  22. }
  23.  
  24. $(document).ready(function () {
  25.     $(document).keydown(function(e) {
  26.         var element;
  27. 		if(e.target) element = e.target;
  28. 		else if(e.srcElement) element = e.srcElement;
  29. 		if(element.nodeType == 3) element = element.parentNode;
  30.  
  31.         if(element.tagName.toLowerCase() == "input" || element.tagName.toLowerCase() == "textarea") return;
  32.         
  33.         switch(e.which) {
  34.             case 37:
  35.                 moveHistorySlider(-1);
  36.                 break;
  37.             case 39:
  38.                 moveHistorySlider(1);
  39.                 break;
  40.  
  41.             default: return;
  42.         }
  43.         e.preventDefault();
  44.     });
  45. });
  46.