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 {
  18 namespace dom {
  19
  20 // Represents `tokenizedFeatures` in
  21 // https://html.spec.whatwg.org/multipage/window-object.html#concept-window-open-features-tokenize
  22 // with accessor methods for values.
  23 class WindowFeatures {
  24  public:
  25   WindowFeatures() = default;
  26
  27   WindowFeatures(const WindowFeatures& aOther) = delete;
  28   WindowFeatures& operator=(const WindowFeatures& aOther) = delete;
  29
  30   WindowFeatures(WindowFeatures&& aOther) = delete;
  31   WindowFeatures& operator=(WindowFeatures&& aOther) = delete;
  32
  33   // Tokenizes `aFeatures` and stores the result map in member field.
  34   // This should be called at the begining, only once.
  35   //
  36   // Returns true if successfully tokenized, false otherwise.
  37   bool Tokenize(const nsACString& aFeatures);
  38
  39   // Returns true if the `aName` feature is specified.
  40   template <size_t N>
  41   bool Exists(const char (&aName)[N]) const {
  42     MOZ_ASSERT(IsLowerCase(aName));
  43     nsLiteralCString name(aName);
  44     return tokenizedFeatures_.has(name);
  45   }
  46
  47   // Returns string value of `aName` feature.
  48   // The feature must exist.
  49   template <size_t N>
  50   const nsCString& Get(const char (&aName)[N]) const {
  51     MOZ_ASSERT(IsLowerCase(aName));
  52     nsLiteralCString name(aName);
  53     auto p = tokenizedFeatures_.lookup(name);
  54     MOZ_ASSERT(p.found());
  55
  56     return p->value();
  57   }
  58
  59   // Returns integer value of `aName` feature.
  60   // The feature must exist.
  61   template <size_t N>
  62   int32_t GetInt(const char (&aName)[N]) const {
  63     const nsCString& value = Get(aName);
  64     return ParseIntegerWithFallback(value);
  65   }
  66
  67   // Returns bool value of `aName` feature.
  68   // The feature must exist.
  69   template <size_t N>
  70   bool GetBool(const char (&aName)[N]) const {
  71     const nsCString& value = Get(aName);
  72     return ParseBool(value);
  73   }
  74
  75   // Returns bool value of `aName` feature.
  76   // If the feature doesn't exist, returns `aDefault`.
  77   //
  78   // If `aPresenceFlag` is provided and the feature exists, it's set to `true`.
  79   // (note that the value isn't overwritten if the feature doesn't exist)
  80   template <size_t N>
  81   bool GetBoolWithDefault(const char (&aName)[N], bool aDefault,
  82                           bool* aPresenceFlag = nullptr) const {
  83     MOZ_ASSERT(IsLowerCase(aName));
  84     nsLiteralCString name(aName);
  85     auto p = tokenizedFeatures_.lookup(name);
  86     if (p.found()) {
  87       if (aPresenceFlag) {
  88         *aPresenceFlag = true;
  89       }
  90       return ParseBool(p->value());
  91     }
  92     return aDefault;
  93   }
  94
  95   // Remove the feature from the map.
  96   template <size_t N>
  97   void Remove(const char (&aName)[N]) {
  98     MOZ_ASSERT(IsLowerCase(aName));
  99     nsLiteralCString name(aName);
 100     tokenizedFeatures_.remove(name);
 101   }
 102
 103   // Returns true if there was no feature specified, or all features are
 104   // removed by `Remove`.
 105   //
 106   // Note that this can be true even if `aFeatures` parameter of `Tokenize`
 107   // is not empty, in case it contains no feature with non-empty name.
 108   bool IsEmpty() const { return tokenizedFeatures_.empty(); }
 109
 110   // Stringify the map into `aOutput`.
 111   // The result can be parsed again with `Tokenize`.
 112   void Stringify(nsAutoCString& aOutput);
 113
 114  private:
 115 #ifdef DEBUG
 116   // Returns true if `text` does not contain any character that gets modified by
 117   // `ToLowerCase`.
 118   static bool IsLowerCase(const char* text);
 119 #endif
 120
 121   static int32_t ParseIntegerWithFallback(const nsCString& aValue);
 122   static bool ParseBool(const nsCString& aValue);
 123
 124   // A map from feature name to feature value.
 125   // If value is not provided, it's empty string.
 126   mozilla::HashMap<nsCString, nsCString> tokenizedFeatures_;
 127 };
 128
 129 }  // namespace dom
 130 }  // namespace mozilla
 131
 132 #endif  // #ifndef mozilla_dom_WindowFeatures_h