--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/textrendering/texthandling/inc/TXTLAYDC.H Tue Feb 02 02:02:46 2010 +0200
@@ -0,0 +1,180 @@
+/*
+* Copyright (c) 2003-2009 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description:
+*
+*/
+
+
+#ifndef __TXTLAYDC_H__
+#define __TXTLAYDC_H__
+
+#include <e32std.h>
+
+class CParaFormat;
+class TCharFormat;
+class CPicture;
+
+
+class MLayDoc
+/**
+Specifies the interface for providing the information needed by the text
+layout engine to lay out a text object.
+
+Examples of derived classes are CRichText and CGlobalText.
+
+At the heart of the interface are two interrogation functions; one gives the
+paragraph formatting for a document position, and the other gives a pointer
+descriptor to a series of contiguous characters with identical character
+formatting, and their character formatting. This information is sufficient
+for the layout engine to find the formatting and content of an entire document.
+
+The constructor for the layout engine (CTextLayout) is prototyped as:
+static CTextLayout *NewL(MLayDoc *aDoc,TInt aWrapWidth);
+By viewing the text object purely in terms of the MLayDoc interface, the layout
+engine is insulated from any editable text implementation issues.
+@see static CTextLayout *NewL(MLayDoc *aDoc,TInt aWrapWidth)
+@publishedAll
+@released
+*/
+ {
+ // Defines interface for extracting content & format information from text source.
+ // Designed to be 'mixed-in' with other classes.
+ //
+public:
+
+ /** Used as a parameter to the PictureHandleL() function to control whether
+ picture data should be loaded into memory or not. */
+ enum TForcePictureLoad
+ {
+ /** Do not load the picture data into memory. */
+ EForceLoadFalse,
+ /** Load the picture data into memory. */
+ EForceLoadTrue
+ };
+public:
+
+ /** Gets the the number of characters in the document.
+
+ @return The number of characters contained in the document. */
+ virtual TInt LdDocumentLength()const=0; // Does not include final document terminator
+
+ /** Gets the document position of the start of the paragraph containing a
+ specified position.
+
+ @param aCurrentPos A valid document position. On return contains the
+ document position of the first character in the paragraph.
+ @return The number of characters skipped in scanning to the start of the
+ paragraph. */
+ virtual TInt LdToParagraphStart(TInt& aCurrentPos)const=0;
+
+ /** Gets the effective paragraph formatting which applies to the paragraph
+ which contains a specified document position. On return, aFormat is filled
+ with values for all paragraph format attributes.
+
+ @param aFormat On return, filled with the paragraph's effective paragraph
+ formatting.
+ @param aPos Any document position within the paragraph of interest. */
+ virtual void GetParagraphFormatL(CParaFormat* aFormat,TInt aPos)const=0;
+
+ /** Gets a constant pointer descriptor to a portion of the text object with
+ constant character formatting. The view starts at the document position
+ specified, and ends at:
+
+ the last character which shares the same character formatting (rich text
+ only), or
+
+ the end of the document, or
+
+ the end of the segment, if segmented storage is being used
+
+ whichever occurs first.
+
+ Also fills a character format object with the character formatting of the
+ range of characters.
+
+ @param aView On return, a constant pointer to a portion of the text.
+ @param aFormat On return, contains the character formatting of the text.
+ @param aStartPos The start position for the view. Must be a valid document
+ position, or a panic occurs. */
+ virtual void GetChars(TPtrC& aView,TCharFormat& aFormat,TInt aStartPos)const=0;
+
+ /** Gets the size of a picture located at a specified document position.
+
+ Note: The global text implementation of this function always returns
+ KErrNotFound because global text does not support pictures.
+
+ @param aSize On return, contains the size of the picture located at aPos.
+ @param aPos Document position of the picture.
+ @return KErrNotFound if there is no picture at the specified document
+ position, KErrNone if there is. */
+ virtual TInt GetPictureSizeInTwips(TSize& aSize, TInt aPos)const=0;
+
+ /** Gets a pointer to the picture located at a specified document position,
+ if one exists. If the picture is not in memory, the function loads it (if
+ the second argument has a value of EForceLoadTrue).
+
+ Note: The global text implementation of this function always returns NULL
+ because global text does not support pictures.
+
+ @param aPos Document position of the picture character.
+ @param aForceLoad If the picture is not loaded into memory, EForceLoadTrue
+ loads it using the picture factory; EForceLoadFalse does not, and in this
+ case, the function returns NULL.
+ @return A pointer to the picture located at aPos. NULL if aPos does not
+ specify a picture character, or if there is a picture at aPos which is not
+ in memory, and the second argument is EForceLoadFalse. */
+ virtual CPicture* PictureHandleL(TInt aPos,TForcePictureLoad aForceLoad=EForceLoadTrue)const=0;
+
+ /** Tests whether a page break occurs within a range of characters. A page
+ table should have been set up first: see CPlainText::SetPageTable().
+
+ @param aPos The document position from which to begin searching for a page
+ break.
+ @param aLength The number of characters to search for a page break,
+ beginning at aPos. The default is zero.
+ @return ETrue if a page break occurs within the specified range, otherwise
+ EFalse. */
+ virtual TBool EnquirePageBreak(TInt aPos,TInt aLength=0)const=0;
+
+ /** This function should be implemented by text objects which support
+ paragraph labels. Each paragraph may have at most one label. By default,
+ the functions provided by MLayDoc apply to the main body of text. This
+ function is provided to change this so that the MLayDoc object is an
+ individual paragraph label, (each of which is treated as a separate
+ document). Paragraph labelling has not been implemented by global or rich
+ text.
+
+ This function should select the paragraph label associated with the
+ paragraph containing document position aPos (aPos is a document position
+ in the main document).
+
+ @param aPos A document position within a paragraph. This paragraph's label
+ should be set as the main MLayDoc document.
+ @return Should return EFalse if the paragraph has no label, in which case
+ the function has no effect, ETrue otherwise. */
+ virtual TBool SelectParagraphLabel(TInt aPos)=0;
+
+ /** Cancels a paragraph label selection made by a call to
+ SelectParagraphLabel() so that the main document reverts back to the main
+ body of text. */
+ virtual void CancelSelectLabel()=0;
+
+ /** This function is reserved for future purpose.
+ It should not be used externally for now.
+ @internalAll */
+ IMPORT_C virtual void MLayDoc_Reserved_1();
+ };
+
+#endif
+