dom/base/WindowFeatures.h

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