1.1 --- a/epoc32/include/txtlaydc.h Tue Nov 24 13:55:44 2009 +0000
1.2 +++ b/epoc32/include/txtlaydc.h Tue Mar 16 16:12:26 2010 +0000
1.3 @@ -1,1 +1,177 @@
1.4 -txtlaydc.h
1.5 +// Copyright (c) 2003-2009 Nokia Corporation and/or its subsidiary(-ies).
1.6 +// All rights reserved.
1.7 +// This component and the accompanying materials are made available
1.8 +// under the terms of the License "Symbian Foundation License v1.0" to Symbian Foundation members and "Symbian Foundation End User License Agreement v1.0" to non-members
1.9 +// which accompanies this distribution, and is available
1.10 +// at the URL "http://www.symbianfoundation.org/legal/licencesv10.html".
1.11 +//
1.12 +// Initial Contributors:
1.13 +// Nokia Corporation - initial contribution.
1.14 +//
1.15 +// Contributors:
1.16 +//
1.17 +// Description:
1.18 +//
1.19 +
1.20 +#ifndef __TXTLAYDC_H__
1.21 +#define __TXTLAYDC_H__
1.22 +
1.23 +#include <e32std.h>
1.24 +
1.25 +class CParaFormat;
1.26 +class TCharFormat;
1.27 +class CPicture;
1.28 +
1.29 +
1.30 +class MLayDoc
1.31 +/**
1.32 +Specifies the interface for providing the information needed by the text
1.33 +layout engine to lay out a text object.
1.34 +
1.35 +Examples of derived classes are CRichText and CGlobalText.
1.36 +
1.37 +At the heart of the interface are two interrogation functions; one gives the
1.38 +paragraph formatting for a document position, and the other gives a pointer
1.39 +descriptor to a series of contiguous characters with identical character
1.40 +formatting, and their character formatting. This information is sufficient
1.41 +for the layout engine to find the formatting and content of an entire document.
1.42 +
1.43 +The constructor for the layout engine (CTextLayout) is prototyped as:
1.44 +static CTextLayout *NewL(MLayDoc *aDoc,TInt aWrapWidth);
1.45 +By viewing the text object purely in terms of the MLayDoc interface, the layout
1.46 +engine is insulated from any editable text implementation issues.
1.47 +@see static CTextLayout *NewL(MLayDoc *aDoc,TInt aWrapWidth)
1.48 +@publishedAll
1.49 +@released
1.50 +*/
1.51 + {
1.52 + // Defines interface for extracting content & format information from text source.
1.53 + // Designed to be 'mixed-in' with other classes.
1.54 + //
1.55 +public:
1.56 +
1.57 + /** Used as a parameter to the PictureHandleL() function to control whether
1.58 + picture data should be loaded into memory or not. */
1.59 + enum TForcePictureLoad
1.60 + {
1.61 + /** Do not load the picture data into memory. */
1.62 + EForceLoadFalse,
1.63 + /** Load the picture data into memory. */
1.64 + EForceLoadTrue
1.65 + };
1.66 +public:
1.67 +
1.68 + /** Gets the the number of characters in the document.
1.69 +
1.70 + @return The number of characters contained in the document. */
1.71 + virtual TInt LdDocumentLength()const=0; // Does not include final document terminator
1.72 +
1.73 + /** Gets the document position of the start of the paragraph containing a
1.74 + specified position.
1.75 +
1.76 + @param aCurrentPos A valid document position. On return contains the
1.77 + document position of the first character in the paragraph.
1.78 + @return The number of characters skipped in scanning to the start of the
1.79 + paragraph. */
1.80 + virtual TInt LdToParagraphStart(TInt& aCurrentPos)const=0;
1.81 +
1.82 + /** Gets the effective paragraph formatting which applies to the paragraph
1.83 + which contains a specified document position. On return, aFormat is filled
1.84 + with values for all paragraph format attributes.
1.85 +
1.86 + @param aFormat On return, filled with the paragraph's effective paragraph
1.87 + formatting.
1.88 + @param aPos Any document position within the paragraph of interest. */
1.89 + virtual void GetParagraphFormatL(CParaFormat* aFormat,TInt aPos)const=0;
1.90 +
1.91 + /** Gets a constant pointer descriptor to a portion of the text object with
1.92 + constant character formatting. The view starts at the document position
1.93 + specified, and ends at:
1.94 +
1.95 + the last character which shares the same character formatting (rich text
1.96 + only), or
1.97 +
1.98 + the end of the document, or
1.99 +
1.100 + the end of the segment, if segmented storage is being used
1.101 +
1.102 + whichever occurs first.
1.103 +
1.104 + Also fills a character format object with the character formatting of the
1.105 + range of characters.
1.106 +
1.107 + @param aView On return, a constant pointer to a portion of the text.
1.108 + @param aFormat On return, contains the character formatting of the text.
1.109 + @param aStartPos The start position for the view. Must be a valid document
1.110 + position, or a panic occurs. */
1.111 + virtual void GetChars(TPtrC& aView,TCharFormat& aFormat,TInt aStartPos)const=0;
1.112 +
1.113 + /** Gets the size of a picture located at a specified document position.
1.114 +
1.115 + Note: The global text implementation of this function always returns
1.116 + KErrNotFound because global text does not support pictures.
1.117 +
1.118 + @param aSize On return, contains the size of the picture located at aPos.
1.119 + @param aPos Document position of the picture.
1.120 + @return KErrNotFound if there is no picture at the specified document
1.121 + position, KErrNone if there is. */
1.122 + virtual TInt GetPictureSizeInTwips(TSize& aSize, TInt aPos)const=0;
1.123 +
1.124 + /** Gets a pointer to the picture located at a specified document position,
1.125 + if one exists. If the picture is not in memory, the function loads it (if
1.126 + the second argument has a value of EForceLoadTrue).
1.127 +
1.128 + Note: The global text implementation of this function always returns NULL
1.129 + because global text does not support pictures.
1.130 +
1.131 + @param aPos Document position of the picture character.
1.132 + @param aForceLoad If the picture is not loaded into memory, EForceLoadTrue
1.133 + loads it using the picture factory; EForceLoadFalse does not, and in this
1.134 + case, the function returns NULL.
1.135 + @return A pointer to the picture located at aPos. NULL if aPos does not
1.136 + specify a picture character, or if there is a picture at aPos which is not
1.137 + in memory, and the second argument is EForceLoadFalse. */
1.138 + virtual CPicture* PictureHandleL(TInt aPos,TForcePictureLoad aForceLoad=EForceLoadTrue)const=0;
1.139 +
1.140 + /** Tests whether a page break occurs within a range of characters. A page
1.141 + table should have been set up first: see CPlainText::SetPageTable().
1.142 +
1.143 + @param aPos The document position from which to begin searching for a page
1.144 + break.
1.145 + @param aLength The number of characters to search for a page break,
1.146 + beginning at aPos. The default is zero.
1.147 + @return ETrue if a page break occurs within the specified range, otherwise
1.148 + EFalse. */
1.149 + virtual TBool EnquirePageBreak(TInt aPos,TInt aLength=0)const=0;
1.150 +
1.151 + /** This function should be implemented by text objects which support
1.152 + paragraph labels. Each paragraph may have at most one label. By default,
1.153 + the functions provided by MLayDoc apply to the main body of text. This
1.154 + function is provided to change this so that the MLayDoc object is an
1.155 + individual paragraph label, (each of which is treated as a separate
1.156 + document). Paragraph labelling has not been implemented by global or rich
1.157 + text.
1.158 +
1.159 + This function should select the paragraph label associated with the
1.160 + paragraph containing document position aPos (aPos is a document position
1.161 + in the main document).
1.162 +
1.163 + @param aPos A document position within a paragraph. This paragraph's label
1.164 + should be set as the main MLayDoc document.
1.165 + @return Should return EFalse if the paragraph has no label, in which case
1.166 + the function has no effect, ETrue otherwise. */
1.167 + virtual TBool SelectParagraphLabel(TInt aPos)=0;
1.168 +
1.169 + /** Cancels a paragraph label selection made by a call to
1.170 + SelectParagraphLabel() so that the main document reverts back to the main
1.171 + body of text. */
1.172 + virtual void CancelSelectLabel()=0;
1.173 +
1.174 + /**
1.175 + @internalAll
1.176 + @prototype
1.177 + */
1.178 + IMPORT_C virtual void MLayDoc_Reserved_1();
1.179 + };
1.180 +
1.181 +#endif