editor/libeditor/ChangeStyleTransaction.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef ChangeStyleTransaction_h
   7 #define ChangeStyleTransaction_h
   8
   9 #include "EditTransactionBase.h"  // base class
  10
  11 #include "nsCOMPtr.h"                      // nsCOMPtr members
  12 #include "nsCycleCollectionParticipant.h"  // various macros
  13 #include "nsString.h"                      // nsString members
  14
  15 class nsAtom;
  16 class nsStyledElement;
  17
  18 namespace mozilla {
  19
  20 namespace dom {
  21 class Element;
  22 }  // namespace dom
  23
  24 /**
  25  * A transaction that changes the value of a CSS inline style of a content
  26  * node.  This transaction covers add, remove, and change a property's value.
  27  */
  28 class ChangeStyleTransaction final : public EditTransactionBase {
  29  protected:
  30   ChangeStyleTransaction(nsStyledElement& aStyledElement, nsAtom& aProperty,
  31                          const nsAString& aValue, bool aRemove);
  32
  33  public:
  34   /**
  35    * Creates a change style transaction.  This never returns nullptr.
  36    *
  37    * @param aStyledElement  The node whose style attribute will be changed.
  38    * @param aProperty       The name of the property to change.
  39    * @param aValue          New value for aProperty.
  40    */
  41   static already_AddRefed<ChangeStyleTransaction> Create(
  42       nsStyledElement& aStyledElement, nsAtom& aProperty,
  43       const nsAString& aValue);
  44
  45   /**
  46    * Creates a change style transaction.  This never returns nullptr.
  47    *
  48    * @param aStyledElement  The node whose style attribute will be changed.
  49    * @param aProperty       The name of the property to change.
  50    * @param aValue          The value to remove from aProperty.
  51    */
  52   static already_AddRefed<ChangeStyleTransaction> CreateToRemove(
  53       nsStyledElement& aStyledElement, nsAtom& aProperty,
  54       const nsAString& aValue);
  55
  56   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(ChangeStyleTransaction,
  57                                            EditTransactionBase)
  58
  59   NS_DECL_ISUPPORTS_INHERITED
  60
  61   NS_DECL_EDITTRANSACTIONBASE
  62   NS_DECL_EDITTRANSACTIONBASE_GETASMETHODS_OVERRIDE(ChangeStyleTransaction)
  63
  64   MOZ_CAN_RUN_SCRIPT NS_IMETHOD RedoTransaction() override;
  65
  66   /**
  67    * Returns true if the list of white-space separated values contains aValue
  68    *
  69    * @param aValueList      [IN] a list of white-space separated values
  70    * @param aValue          [IN] the value to look for in the list
  71    * @return                true if the value is in the list of values
  72    */
  73   static bool ValueIncludes(const nsACString& aValueList,
  74                             const nsACString& aValue);
  75
  76   friend std::ostream& operator<<(std::ostream& aStream,
  77                                   const ChangeStyleTransaction& aTransaction);
  78
  79  private:
  80   virtual ~ChangeStyleTransaction() = default;
  81
  82   /**
  83    * Build new text-decoration value to set/remove specific values to/from the
  84    * rule which already has aCurrentValues.
  85    */
  86   void BuildTextDecorationValueToSet(const nsACString& aCurrentValues,
  87                                      const nsACString& aAddingValues,
  88                                      nsACString& aOutValues);
  89   void BuildTextDecorationValueToRemove(const nsACString& aCurrentValues,
  90                                         const nsACString& aRemovingValues,
  91                                         nsACString& aOutValues);
  92
  93   /**
  94    * Helper method for above methods.
  95    */
  96   void BuildTextDecorationValue(bool aUnderline, bool aOverline,
  97                                 bool aLineThrough, nsACString& aOutValues);
  98
  99   /**
 100    * If the boolean is true and if the value is not the empty string,
 101    * set the property in the transaction to that value; if the value
 102    * is empty, remove the property from element's styles. If the boolean
 103    * is false, just remove the style attribute.
 104    */
 105   MOZ_CAN_RUN_SCRIPT nsresult SetStyle(bool aAttributeWasSet,
 106                                        nsACString& aValue);
 107
 108   // The element to operate upon.
 109   RefPtr<nsStyledElement> mStyledElement;
 110
 111   // The CSS property to change.
 112   RefPtr<nsAtom> mProperty;
 113
 114   // The value to set the property to (ignored if mRemoveProperty==true).
 115   nsCString mValue;
 116
 117   // The value to set the property to for undo.
 118   nsCString mUndoValue;
 119   // The value to set the property to for redo.
 120   nsCString mRedoValue;
 121
 122   // true if the operation is to remove mProperty from mElement.
 123   bool mRemoveProperty;
 124
 125   // True if the style attribute was present and not empty before DoTransaction.
 126   bool mUndoAttributeWasSet;
 127   // True if the style attribute is present and not empty after DoTransaction.
 128   bool mRedoAttributeWasSet;
 129 };
 130
 131 }  // namespace mozilla
 132
 133 #endif  // #ifndef ChangeStyleTransaction_h