editor/libeditor/ChangeStyleTxn.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 ChangeStyleTxn_h__
   7 #define ChangeStyleTxn_h__
   8
   9 #include "EditTxn.h"                      // base class
  10 #include "nsCOMPtr.h"                     // nsCOMPtr members
  11 #include "nsCycleCollectionParticipant.h" // various macros
  12 #include "nsString.h"                     // nsString members
  13
  14 class nsAString;
  15 class nsIAtom;
  16
  17 namespace mozilla {
  18 namespace dom {
  19 class Element;
  20
  21 /**
  22  * A transaction that changes the value of a CSS inline style of a content
  23  * node.  This transaction covers add, remove, and change a property's value.
  24  */
  25 class ChangeStyleTxn : public EditTxn
  26 {
  27 public:
  28   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(ChangeStyleTxn, EditTxn)
  29
  30   NS_DECL_ISUPPORTS_INHERITED
  31
  32   NS_DECL_EDITTXN
  33
  34   NS_IMETHOD RedoTransaction() MOZ_OVERRIDE;
  35
  36   enum EChangeType { eSet, eRemove };
  37
  38   /** @param aNode           [IN] the node whose style attribute will be changed
  39     * @param aProperty       [IN] the name of the property to change
  40     * @param aValue          [IN] new value for aProperty, or value to remove
  41     * @param aChangeType     [IN] whether to set or remove
  42     */
  43   ChangeStyleTxn(Element& aElement, nsIAtom& aProperty,
  44                  const nsAString& aValue, EChangeType aChangeType);
  45
  46   /** Returns true if the list of white-space separated values contains aValue
  47     *
  48     * @return                true if the value is in the list of values
  49     * @param aValueList      [IN] a list of white-space separated values
  50     * @param aValue          [IN] the value to look for in the list
  51     */
  52   static bool ValueIncludes(const nsAString& aValueList,
  53                             const nsAString& aValue);
  54
  55 private:
  56   ~ChangeStyleTxn();
  57
  58   /** Adds the value aNewValue to list of white-space separated values aValues
  59     *
  60     * @param aValues         [IN/OUT] a list of wite-space separated values
  61     * @param aNewValue       [IN] a value this code adds to aValues if it is not already in
  62     */
  63   void AddValueToMultivalueProperty(nsAString& aValues,
  64                                     const nsAString& aNewValue);
  65
  66   /** Returns true if the property accepts more than one value
  67     *
  68     * @return                true if the property accepts more than one value
  69     * @param aCSSProperty    [IN] the CSS property
  70     */
  71   bool AcceptsMoreThanOneValue(nsIAtom& aCSSProperty);
  72
  73   /** Remove a value from a list of white-space separated values
  74     * @param aValues         [IN] a list of white-space separated values
  75     * @param aRemoveValue    [IN] the value to remove from the list
  76     */
  77   void RemoveValueFromListOfValues(nsAString& aValues,
  78                                    const nsAString& aRemoveValue);
  79
  80   /** If the boolean is true and if the value is not the empty string,
  81     * set the property in the transaction to that value; if the value
  82     * is empty, remove the property from element's styles. If the boolean
  83     * is false, just remove the style attribute.
  84     */
  85   nsresult SetStyle(bool aAttributeWasSet, nsAString& aValue);
  86
  87   /** The element to operate upon */
  88   nsCOMPtr<Element> mElement;
  89
  90   /** The CSS property to change */
  91   nsCOMPtr<nsIAtom> mProperty;
  92
  93   /** The value to set the property to (ignored if mRemoveProperty==true) */
  94   nsString mValue;
  95
  96   /** true if the operation is to remove mProperty from mElement */
  97   bool mRemoveProperty;
  98
  99   /** The value to set the property to for undo */
 100   nsString mUndoValue;
 101   /** The value to set the property to for redo */
 102   nsString mRedoValue;
 103   /** True if the style attribute was present and not empty before DoTransaction */
 104   bool mUndoAttributeWasSet;
 105   /** True if the style attribute is present and not empty after DoTransaction */
 106   bool mRedoAttributeWasSet;
 107 };
 108
 109 }
 110 }
 111
 112 #endif