1 files changed, 167 insertions, 0 deletions
diff --git a/data/extensions/spyblock@gnu.org/chrome/content/elemHideEmulation.js b/data/extensions/spyblock@gnu.org/chrome/content/elemHideEmulation.js
new file mode 100644
index 0000000..ff824ae
--- /dev/null
+++ b/data/extensions/spyblock@gnu.org/chrome/content/elemHideEmulation.js
@@ -0,0 +1,167 @@
+// We are currently limited to ECMAScript 5 in this file, because it is being
+// used in the browser tests. See https://issues.adblockplus.org/ticket/4796
+
+var propertySelectorRegExp = /\[\-abp\-properties=(["'])([^"']+)\1\]/;
+
+function splitSelector(selector)
+{
+  if (selector.indexOf(",") == -1)
+    return [selector];
+
+  var selectors = [];
+  var start = 0;
+  var level = 0;
+  var sep = "";
+
+  for (var i = 0; i < selector.length; i++)
+  {
+    var chr = selector[i];
+
+    if (chr == "\\")        // ignore escaped characters
+      i++;
+    else if (chr == sep)    // don't split within quoted text
+      sep = "";             // e.g. [attr=","]
+    else if (sep == "")
+    {
+      if (chr == '"' || chr == "'")
+        sep = chr;
+      else if (chr == "(")  // don't split between parentheses
+        level++;            // e.g. :matches(div,span)
+      else if (chr == ")")
+        level = Math.max(0, level - 1);
+      else if (chr == "," && level == 0)
+      {
+        selectors.push(selector.substring(start, i));
+        start = i + 1;
+      }
+    }
+  }
+
+  selectors.push(selector.substring(start));
+  return selectors;
+}
+
+function ElemHideEmulation(window, getFiltersFunc, addSelectorsFunc)
+{
+  this.window = window;
+  this.getFiltersFunc = getFiltersFunc;
+  this.addSelectorsFunc = addSelectorsFunc;
+}
+
+ElemHideEmulation.prototype = {
+  stringifyStyle: function(style)
+  {
+    var styles = [];
+    for (var i = 0; i < style.length; i++)
+    {
+      var property = style.item(i);
+      var value    = style.getPropertyValue(property);
+      var priority = style.getPropertyPriority(property);
+      styles.push(property + ": " + value + (priority ? " !" + priority : "") + ";");
+    }
+    styles.sort();
+    return styles.join(" ");
+  },
+
+  isSameOrigin: function(stylesheet)
+  {
+    try
+    {
+      return new URL(stylesheet.href).origin == this.window.location.origin;
+    }
+    catch (e)
+    {
+      // Invalid URL, assume that it is first-party.
+      return true;
+    }
+  },
+
+  findSelectors: function(stylesheet, selectors, filters)
+  {
+    // Explicitly ignore third-party stylesheets to ensure consistent behavior
+    // between Firefox and Chrome.
+    if (!this.isSameOrigin(stylesheet))
+      return;
+
+    var rules = stylesheet.cssRules;
+    if (!rules)
+      return;
+
+    for (var i = 0; i < rules.length; i++)
+    {
+      var rule = rules[i];
+      if (rule.type != rule.STYLE_RULE)
+        continue;
+
+      var style = this.stringifyStyle(rule.style);
+      for (var j = 0; j < this.patterns.length; j++)
+      {
+        var pattern = this.patterns[j];
+        if (pattern.regexp.test(style))
+        {
+          var subSelectors = splitSelector(rule.selectorText);
+          for (var k = 0; k < subSelectors.length; k++)
+          {
+            var subSelector = subSelectors[k];
+            selectors.push(pattern.prefix + subSelector + pattern.suffix);
+            filters.push(pattern.text);
+          }
+        }
+      }
+    }
+  },
+
+  addSelectors: function(stylesheets)
+  {
+    var selectors = [];
+    var filters = [];
+    for (var i = 0; i < stylesheets.length; i++)
+      this.findSelectors(stylesheets[i], selectors, filters);
+    this.addSelectorsFunc(selectors, filters);
+  },
+
+  onLoad: function(event)
+  {
+    var stylesheet = event.target.sheet;
+    if (stylesheet)
+      this.addSelectors([stylesheet]);
+  },
+
+  apply: function()
+  {
+    this.getFiltersFunc(function(patterns)
+    {
+      this.patterns = [];
+      for (var i = 0; i < patterns.length; i++)
+      {
+        var pattern = patterns[i];
+        var match = propertySelectorRegExp.exec(pattern.selector);
+        if (!match)
+          continue;
+
+        var propertyExpression = match[2];
+        var regexpString;
+        if (propertyExpression.length >= 2 && propertyExpression[0] == "/" &&
+            propertyExpression[propertyExpression.length - 1] == "/")
+          regexpString = propertyExpression.slice(1, -1)
+              .replace("\\x7B ", "{").replace("\\x7D ", "}");
+        else
+          regexpString = filterToRegExp(propertyExpression);
+
+        this.patterns.push({
+          text: pattern.text,
+          regexp: new RegExp(regexpString, "i"),
+          prefix: pattern.selector.substr(0, match.index),
+          suffix: pattern.selector.substr(match.index + match[0].length)
+        });
+      }
+
+      if (this.patterns.length > 0)
+      {
+        var document = this.window.document;
+        this.addSelectors(document.styleSheets);
+        document.addEventListener("load", this.onLoad.bind(this), true);
+      }
+    }.bind(this));
+  }
+};