RetroZilla/editor/libeditor/base/ChangeCSSInlineStyleTxn.h

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 * Contributor(s):
 *   Original Author: Daniel Glazman <glazman@netscape.com>
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#ifndef ChangeCSSInlineStyleTxn_h__
#define ChangeCSSInlineStyleTxn_h__

#include "EditTxn.h"
#include "nsCOMPtr.h"
#include "nsIDOMElement.h"
#include "nsIEditor.h"

#define CHANGE_CSSINLINESTYLE_TXN_CID \
{/* a2185c9e-1dd1-11b2-88d6-d89704bf7a5a */ \
0xa2185c9e, 0x1dd1, 0x11b2, \
{0x88, 0xd6, 0xd8, 0x97, 0x04, 0xbf, 0x7a, 0x5a} }

/**
 * A transaction that changes the value of a CSS inline style of a content node. 
 * This transaction covers add, remove, and change a property's value.
 */
class ChangeCSSInlineStyleTxn : public EditTxn
{
public:

  static const nsIID& GetCID() { static const nsIID iid = CHANGE_CSSINLINESTYLE_TXN_CID; return iid; }

  virtual ~ChangeCSSInlineStyleTxn();

  /** Initialize the transaction.
    * @param aEditor         [IN] the object providing core editing operations
    * @param aNode           [IN] the node whose style attribute will be changed
    * @param aProperty       [IN] the name of the property to change
    * @param aValue          [IN] the new value for aProperty, if aRemoveProperty is false
    * @param aRemoveProperty [IN] if PR_TRUE, remove aProperty from style attribute
    */
  NS_IMETHOD Init(nsIEditor      * aEditor,
                  nsIDOMElement  * aElement,
                  nsIAtom        * aProperty,
                  const nsAString & aValue,
                  PRBool aRemoveProperty);

  /** returns true if the list of white-space separated values contains aValue
    *
    * @return                true if the value is in the list of values
    * @param aValueList      [IN] a list of white-space separated values
    * @param aValue          [IN] the value to look for in the list
    * @param aCaseSensitive  [IN] a boolean being true if a case-sensitive search is needed
    */
  static PRBool ValueIncludes(const nsAString & aValueList, const nsAString & aValue, PRBool aCaseSensitive);

  /** adds the value aNewValue to the list of white-space separated values aValues
    *
    * @param aValues         [IN/OUT] a list of wite-space separated values
    * @param aNewValue       [IN] a value this code adds to aValues if it is not already in
    */
  NS_IMETHOD AddValueToMultivalueProperty(nsAString & aValues, const nsAString  & aNewValue);

private:
  ChangeCSSInlineStyleTxn();

  /** returns true if the property accepts more than one value
    *
    * @return                true if the property accepts more than one value
    * @param aCSSProperty    [IN] the CSS property
    */
  PRBool AcceptsMoreThanOneValue(nsIAtom * aCSSProperty);

  /** remove a value from a list of white-space separated values
    * @param aValues         [IN] a list of white-space separated values
    * @param aRemoveValue    [IN] the value to remove from the list
    */
  void   RemoveValueFromListOfValues(nsAString & aValues, const nsAString  & aRemoveValue);

  /** appends 'property : value' to the string
    *
    * @param aOutputString   [IN/OUT] the string
    * @param aPropert        [IN] the css property string
    * @param aValues         [IN] the value string for the css property
    */
  void   AppendDeclaration(nsAString & aOutputString,
                           const nsAString & aProperty,
                           const nsAString & aValues);

  /** If the boolean is true and if the value is not the empty string,
    * set the property in the transaction to that value; if the value
    * is empty, remove the property from element's styles. If the boolean
    * is false, just remove the style attribute.
    */
  nsresult SetStyle(PRBool aAttributeWasSet, nsAString & aValue);

public:

  NS_IMETHOD DoTransaction(void);

  NS_IMETHOD UndoTransaction(void);

  NS_IMETHOD RedoTransaction(void);

  NS_IMETHOD Merge(nsITransaction *aTransaction, PRBool *aDidMerge);

  NS_IMETHOD GetTxnDescription(nsAString& aTxnDescription);

protected:

  /** the editor that created this transaction */
  nsIEditor *mEditor;
  
  /** the element to operate upon */
  nsCOMPtr<nsIDOMElement> mElement;
  
  /** the CSS property to change */
  nsIAtom *mProperty;

  /** the value to set the property to (ignored if mRemoveProperty==PR_TRUE) */
  nsString mValue;

  /** the value to set the property to for undo */
  nsString mUndoValue;
  /** the value to set the property to for redo */
  nsString mRedoValue;
  /** true if the style attribute was present and not empty before DoTransaction */
  PRBool   mUndoAttributeWasSet;
  /** true if the style attribute is present and not empty after DoTransaction */
  PRBool   mRedoAttributeWasSet;

  /** PR_TRUE if the operation is to remove mProperty from mElement */
  PRBool   mRemoveProperty;

  friend class TransactionFactory;
};

#endif