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WindowFeatures.h (4314B)

      1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
      2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
      3 /* This Source Code Form is subject to the terms of the Mozilla Public
      4 * License, v. 2.0. If a copy of the MPL was not distributed with this
      5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      6 
      7 #ifndef mozilla_dom_WindowFeatures_h
      8 #define mozilla_dom_WindowFeatures_h
      9 
     10 #include "mozilla/Assertions.h"  // MOZ_ASSERT
     11 #include "mozilla/HashTable.h"   // mozilla::HashMap
     12 #include "nsString.h"
     13 #include "nsStringFwd.h"  // nsCString, nsACString, nsAutoCString, nsLiteralCString
     14 #include "nsTStringHasher.h"  // mozilla::DefaultHasher<nsCString>
     15 
     16 namespace mozilla::dom {
     17 
     18 // Represents `tokenizedFeatures` in
     19 // https://html.spec.whatwg.org/multipage/window-object.html#concept-window-open-features-tokenize
     20 // with accessor methods for values.
     21 class WindowFeatures {
     22 public:
     23  WindowFeatures() = default;
     24 
     25  WindowFeatures(const WindowFeatures& aOther) = delete;
     26  WindowFeatures& operator=(const WindowFeatures& aOther) = delete;
     27 
     28  WindowFeatures(WindowFeatures&& aOther) = delete;
     29  WindowFeatures& operator=(WindowFeatures&& aOther) = delete;
     30 
     31  // Tokenizes `aFeatures` and stores the result map in member field.
     32  // This should be called at the begining, only once.
     33  //
     34  // Returns true if successfully tokenized, false otherwise.
     35  bool Tokenize(const nsACString& aFeatures);
     36 
     37  // Returns true if the `aName` feature is specified.
     38  template <size_t N>
     39  bool Exists(const char (&aName)[N]) const {
     40    MOZ_ASSERT(IsLowerCase(aName));
     41    nsLiteralCString name(aName);
     42    return tokenizedFeatures_.has(name);
     43  }
     44 
     45  // Returns string value of `aName` feature.
     46  // The feature must exist.
     47  template <size_t N>
     48  const nsCString& Get(const char (&aName)[N]) const {
     49    MOZ_ASSERT(IsLowerCase(aName));
     50    nsLiteralCString name(aName);
     51    auto p = tokenizedFeatures_.lookup(name);
     52    MOZ_ASSERT(p.found());
     53 
     54    return p->value();
     55  }
     56 
     57  // Returns integer value of `aName` feature.
     58  // The feature must exist.
     59  template <size_t N>
     60  int32_t GetInt(const char (&aName)[N]) const {
     61    const nsCString& value = Get(aName);
     62    return ParseIntegerWithFallback(value);
     63  }
     64 
     65  // Returns bool value of `aName` feature.
     66  // The feature must exist.
     67  template <size_t N>
     68  bool GetBool(const char (&aName)[N]) const {
     69    const nsCString& value = Get(aName);
     70    return ParseBool(value);
     71  }
     72 
     73  // Returns bool value of `aName` feature.
     74  // If the feature doesn't exist, returns `aDefault`.
     75  //
     76  // If `aPresenceFlag` is provided and the feature exists, it's set to `true`.
     77  // (note that the value isn't overwritten if the feature doesn't exist)
     78  template <size_t N>
     79  bool GetBoolWithDefault(const char (&aName)[N], bool aDefault,
     80                          bool* aPresenceFlag = nullptr) const {
     81    MOZ_ASSERT(IsLowerCase(aName));
     82    nsLiteralCString name(aName);
     83    auto p = tokenizedFeatures_.lookup(name);
     84    if (p.found()) {
     85      if (aPresenceFlag) {
     86        *aPresenceFlag = true;
     87      }
     88      return ParseBool(p->value());
     89    }
     90    return aDefault;
     91  }
     92 
     93  // Remove the feature from the map.
     94  template <size_t N>
     95  void Remove(const char (&aName)[N]) {
     96    MOZ_ASSERT(IsLowerCase(aName));
     97    nsLiteralCString name(aName);
     98    tokenizedFeatures_.remove(name);
     99  }
    100 
    101  // Returns true if there was no feature specified, or all features are
    102  // removed by `Remove`.
    103  //
    104  // Note that this can be true even if `aFeatures` parameter of `Tokenize`
    105  // is not empty, in case it contains no feature with non-empty name.
    106  bool IsEmpty() const { return tokenizedFeatures_.empty(); }
    107 
    108  // Stringify the map into `aOutput`.
    109  // The result can be parsed again with `Tokenize`.
    110  void Stringify(nsAutoCString& aOutput);
    111 
    112 private:
    113 #ifdef DEBUG
    114  // Returns true if `text` does not contain any character that gets modified by
    115  // `ToLowerCase`.
    116  static bool IsLowerCase(const char* text);
    117 #endif
    118 
    119  static int32_t ParseIntegerWithFallback(const nsCString& aValue);
    120  static bool ParseBool(const nsCString& aValue);
    121 
    122  // A map from feature name to feature value.
    123  // If value is not provided, it's empty string.
    124  mozilla::HashMap<nsCString, nsCString> tokenizedFeatures_;
    125 };
    126 
    127 }  // namespace mozilla::dom
    128 
    129 #endif  // #ifndef mozilla_dom_WindowFeatures_h