gecko-dev/content/base/public/nsIContent.h

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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 * Version 1.1 (the "License"); you may not use this file except in
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 *
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 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla Communicator client code.
 *
 * The Initial Developer of the Original Code is 
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 * the Initial Developer. All Rights Reserved.
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 * Contributor(s):
 *
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 * either the GNU General Public License Version 2 or later (the "GPL"), or
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#ifndef nsIContent_h___
#define nsIContent_h___

#include <stdio.h>
#include "nslayout.h"
#include "nsISupports.h"
#include "nsEvent.h"
#include "nsAWritableString.h"

// Forward declarations
class nsIAtom;
class nsIDocument;
class nsIPresContext;
class nsVoidArray;
class nsIDOMEvent;
class nsIContent;
class nsISupportsArray;
class nsIDOMRange;
class nsISizeOfHandler;
class nsINodeInfo;
class nsIEventListenerManager;

// IID for the nsIContent interface
#define NS_ICONTENT_IID       \
{ 0x78030220, 0x9447, 0x11d1, \
  {0x93, 0x23, 0x00, 0x80, 0x5f, 0x8a, 0xdd, 0x32} }

// A node of content in a documents content model. This interface
// is supported by all content objects.
class nsIContent : public nsISupports {
public:
  NS_DEFINE_STATIC_IID_ACCESSOR(NS_ICONTENT_IID)

  NS_IMETHOD GetDocument(nsIDocument*& aResult) const = 0;

  NS_IMETHOD SetDocument(nsIDocument* aDocument, PRBool aDeep, PRBool aCompileEventHandlers) = 0;

  NS_IMETHOD GetParent(nsIContent*& aResult) const = 0;

  NS_IMETHOD SetParent(nsIContent* aParent) = 0;

  /**
   * Get the namespace that this tag is defined in
   */
  NS_IMETHOD GetNameSpaceID(PRInt32& aResult) const = 0;

  NS_IMETHOD GetTag(nsIAtom*& aResult) const = 0;

  NS_IMETHOD GetNodeInfo(nsINodeInfo*& aResult) const = 0;

  NS_IMETHOD CanContainChildren(PRBool& aResult) const = 0;

  NS_IMETHOD ChildCount(PRInt32& aResult) const = 0;

  NS_IMETHOD ChildAt(PRInt32 aIndex, nsIContent*& aResult) const = 0;

  NS_IMETHOD IndexOf(nsIContent* aPossibleChild, PRInt32& aIndex) const = 0;

  NS_IMETHOD InsertChildAt(nsIContent* aKid, PRInt32 aIndex,
                           PRBool aNotify, PRBool aDeepSetDocument) = 0;

  NS_IMETHOD ReplaceChildAt(nsIContent* aKid, PRInt32 aIndex,
                            PRBool aNotify, PRBool aDeepSetDocument) = 0;

  NS_IMETHOD AppendChildTo(nsIContent* aKid, PRBool aNotify,
                           PRBool aDeepSetDocument) = 0;

  NS_IMETHOD RemoveChildAt(PRInt32 aIndex, PRBool aNotify) = 0;

  /**
   * Normalizes an attribute string into an atom that represents the
   * qualified attribute name of the attribute. This method is intended
   * for character case conversion if the content object is case
   * insensitive (e.g. HTML).
   *
   * @param aStr the unparsed attribute string
   * @param aName out parameter representing the complete name of the
   * attribute
   */
  NS_IMETHOD NormalizeAttrString(const nsAReadableString& aStr, 
                                 nsINodeInfo*& aNodeInfo) = 0;

  /**
   * Set attribute values. All attribute values are assumed to have a
   * canonical String representation that can be used for these
   * methods. The SetAttr method is assumed to perform a translation
   * of the canonical form into the underlying content specific
   * form.
   *
   * @param aName the name of the attribute

   * @param aValue may legitimately be the empty string.
   *
   * @param aUpdateMask specifies how whether or not the document should be
   * notified of the attribute change.
   */
  NS_IMETHOD SetAttr(PRInt32 aNameSpaceID, nsIAtom* aName,
                     const nsAReadableString& aValue,
                     PRBool aNotify) = 0;

  /**
   * Set attribute values. All attribute values are assumed to have a
   * canonical string representation that can be used for these
   * methods. The SetAttr method is assumed to perform a translation
   * of the canonical form into the underlying content specific
   * form.
   *
   * @param aNodeInfo the node info (name, prefix, namespace id) of the
   * attribute
   * @param aValue may legitimately be the empty string.
   *
   * @param aNotify specifies whether or not the document should be
   * notified of the attribute change.
   */
  NS_IMETHOD SetAttr(nsINodeInfo* aNodeInfo,
                     const nsAReadableString& aValue,
                     PRBool aNotify) = 0;

  /**
   * Get the current value of the attribute. This returns a form that is
   * suitable for passing back into SetAttr.
   *
   * <UL>
   *
   * <LI>If the attribute is not set and has no default value, return
   * NS_CONTENT_ATTR_NOT_THERE.
   *
   * <LI>If the attribute exists, but has no value, return
   * NS_CONTENT_ATTR_NO_VALUE.
   *
   * <LI>If the attribute has a non-empty value, set ret to
   * be the value, and return NS_CONTENT_ATTR_HAS_VALUE (== NS_OK).
   *
   * </UL>
   */
  NS_IMETHOD GetAttr(PRInt32 aNameSpaceID, nsIAtom* aName, 
                     nsAWritableString& aResult) const = 0;

  /**
   * Get the current value and prefix of the attribute. This returns a form
   * that is suitable for passing back into SetAttr.
   *
   * <UL>
   *
   * <LI>If the attribute is not set and has no default value, return
   * NS_CONTENT_ATTR_NOT_THERE.
   *
   * <LI>If the attribute exists, but has no value, return
   * NS_CONTENT_ATTR_NO_VALUE.
   *
   * <LI>If the attribute has a non-empty value, set ret to
   * be the value, and return NS_CONTENT_ATTR_HAS_VALUE (== NS_OK).
   *
   * </UL>
   *
   * NOTE! aPrefix is an OUT parameter.
   */

  NS_IMETHOD GetAttr(PRInt32 aNameSpaceID, nsIAtom* aName,
                     nsIAtom*& aPrefix, nsAWritableString& aResult) const = 0;

  /**
   * Remove an attribute so that it is no longer explicitly specified.
   *
   * @param aAttr the name of the attribute to unset
   * 
   * @param aNotify specifies whether or not the document should be
   * notified of the attribute change
   *
   */
  NS_IMETHOD UnsetAttr(PRInt32 aNameSpaceID, nsIAtom* aAttr, 
                       PRBool aNotify) = 0;


  /**
   * Get the namespace & name of a given attribute.
   * 
   * @param aIndex the index of the attribute name
   * @param aNameSpace an out param of the name space ID of the attribute name
   * @param aName an out param if the attribute name
   *
   */
  NS_IMETHOD GetAttrNameAt(PRInt32 aIndex,
                           PRInt32& aNameSpaceID, 
                           nsIAtom*& aName,
                           nsIAtom*& aPrefix) const = 0;

  /**
   * Get the number of all specified attributes.
   *
   * @param aCountResult an out parameter to be filled in with
   *        the number of attributes
   *
   */
  NS_IMETHOD GetAttrCount(PRInt32& aCountResult) const = 0;

  /**
   * Get the size of the content object. The size value should include
   * all subordinate data referenced by the content that is not
   * accounted for by child content. However, this value should not
   * include the frame objects, style contexts, views or other data
   * that lies logically outside the content model.
   *
   * If the implementation so chooses, instead of returning the total
   * subordinate data it may instead use the sizeof handler to store
   * away subordinate data under its own key so that the subordinate
   * data may be tabulated independently of the frame itself.
   *
   * The caller is responsible for recursing over all children that
   * the content contains.
   */
  NS_IMETHOD  SizeOf(nsISizeOfHandler* aSizer, PRUint32* aResult) const = 0;

  /**
   * List the content (and anything it contains) out to the given
   * file stream. Use aIndent as the base indent during formatting.
   * Returns NS_OK unless a file error occurs.
   */
  NS_IMETHOD List(FILE* out = stdout, PRInt32 aIndent = 0) const = 0;

  /**
   * Dump the content (and anything it contains) out to the given
   * file stream. Use aIndent as the base indent during formatting.
   * Returns NS_OK unless a file error occurs.
   */
  NS_IMETHOD DumpContent(FILE* out = stdout, PRInt32 aIndent = 0,PRBool aDumpAll=PR_TRUE) const = 0;

  /**
   * Inform content of range ownership changes.  This allows content
   * to do the right thing to ranges in the face of changes to the content
   * model.

   * RangeAdd -- informs content that it owns one or both range endpoints
   * RangeRemove -- informs content that it no longer owns a range endpoint
   * GetRangeList -- returns the list of ranges that have one or both endpoints
   *                 within this content item
   */
  NS_IMETHOD RangeAdd(nsIDOMRange& aRange) = 0;
  NS_IMETHOD RangeRemove(nsIDOMRange& aRange) = 0;
  NS_IMETHOD GetRangeList(nsVoidArray*& aResult) const = 0;
  
  /**
   * Handle a DOM event for this piece of content.
   */
  NS_IMETHOD HandleDOMEvent(nsIPresContext* aPresContext,
                            nsEvent* aEvent,
                            nsIDOMEvent** aDOMEvent,
                            PRUint32 aFlags,
                            nsEventStatus* aEventStatus) = 0;

  /**
   * Get and set a unique ID for this piece of content.
   * This ID is used as a key to store state information 
   * about this content object and its associated frame object.
   * The state information is stored in a dictionary that is
   * manipulated by the frame manager (nsIFrameManager) inside layout.
   * An opaque pointer to this dictionary is passed to the session
   * history as a handle associated with the current document's state
   */
  NS_IMETHOD GetContentID(PRUint32* aID) = 0;
  NS_IMETHOD SetContentID(PRUint32 aID) = 0;

  /**
   * All content elements are potentially focusable (according to CSS3).
   * These methods are used to set and remove the focus on the content
   * element.
   */
  NS_IMETHOD SetFocus(nsIPresContext* aPresContext) = 0;
  NS_IMETHOD RemoveFocus(nsIPresContext* aPresContext) = 0;

  /**
   * APIs for setting and obtaining the content node
   * with the binding responsible for our construction (and existence)
   * Used by anonymous content (XBL-generated). null for all explicit content.
   */
  NS_IMETHOD SetBindingParent(nsIContent* aContent) = 0;
  NS_IMETHOD GetBindingParent(nsIContent** aContent) = 0;

  /**
   * Bit-flags to pass (or'ed together) to IsContentOfType()
   */
  enum {
    eTEXT                = 0x00000001,
    eELEMENT             = 0x00000002,
    eHTML                = 0x00000004,
    eHTML_FORM_CONTROL   = 0x00000008,
    eXUL                 = 0x00000010
  };

  /**
   * API for doing a quick check if a content object is of a given
   * type, such as HTML, XUL, Text, ...
   */
  NS_IMETHOD_(PRBool) IsContentOfType(PRUint32 aFlags) = 0;

  NS_IMETHOD GetListenerManager(nsIEventListenerManager** aResult) = 0;
};

// nsresult codes for GetAttr
#define NS_CONTENT_ATTR_HAS_VALUE NS_OK

#define NS_CONTENT_ATTR_NO_VALUE \
  NS_ERROR_GENERATE_SUCCESS(NS_ERROR_MODULE_LAYOUT,0)

#define NS_CONTENT_ATTR_NOT_THERE \
  NS_ERROR_GENERATE_SUCCESS(NS_ERROR_MODULE_LAYOUT,1)

#endif /* nsIContent_h___ */