Issue 2100 - Fixed block element dialog moving outside viewport

include.postload.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2015 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 682 matching lines @@
           sendResponse({filters: clickHide_filters});
 
           clickHideFiltersDialog.style.width = msg.width + "px";
           clickHideFiltersDialog.style.height = msg.height + "px";
           clickHideFiltersDialog.style.visibility = "visible";
         }
         break;
       case "clickhide-move":
         if (clickHideFiltersDialog)
         {
-          clickHideFiltersDialog.style.left = (parseInt(clickHideFiltersDialog.style.left, 10) + msg.x) + "px";
-          clickHideFiltersDialog.style.top = (parseInt(clickHideFiltersDialog.style.top, 10) + msg.y) + "px";
+          var rect = clickHideFiltersDialog.getBoundingClientRect();
+          var x = Math.max(0, Math.min(rect.left + msg.x, window.innerWidth - rect.width));
+          var y = Math.max(0, Math.min(rect.top + msg.y, window.innerHeight - rect.height));
+          
+          clickHideFiltersDialog.style.left = x + "px";
+          clickHideFiltersDialog.style.top = y + "px";
         }
         break;
       case "clickhide-close":
         if (currentElement && msg.remove)
         {
           // Hide the selected element itself if an added blocking
           // filter is causing it to collapse. Note that this
           // behavior is incomplete, but the best we can do here,
           // e.g. if an added blocking filter matches other elements,
           // the effect won't be visible until the page is is reloaded.
@@ skipping 15 matching lines @@
           lastRightClickEventValid = false;
         else
           lastRightClickEvent = null;
         break;
     }
   });
 
   if (window == window.top)
     ext.backgroundPage.sendMessage({type: "report-html-page"});
 }