| 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. static CTextLayout *NewL(MLayDoc *aDoc,TInt aWrapWidth)
| Public Member Functions | |
|---|---|
| void | CancelSelectLabel() |
| TBool | EnquirePageBreak(TInt, TInt) |
| void | GetChars(TPtrC &, TCharFormat &, TInt) |
| void | GetParagraphFormatL(CParaFormat *, TInt) |
| TInt | GetPictureSizeInTwips(TSize &, TInt) |
| TInt | LdDocumentLength() |
| TInt | LdToParagraphStart(TInt &) |
| IMPORT_C void | MLayDoc_Reserved_1() |
| CPicture * | PictureHandleL(TInt, TForcePictureLoad) |
| TBool | SelectParagraphLabel(TInt) |
| Public Member Enumerations | |
|---|---|
| enum | TForcePictureLoad { EForceLoadFalse, EForceLoadTrue } |
| void | CancelSelectLabel | ( | ) | [pure virtual] |
Cancels a paragraph label selection made by a call to SelectParagraphLabel() so that the main document reverts back to the main body of text.
| TBool | EnquirePageBreak | ( | TInt | aPos, |
| TInt | aLength = 0 | |||
| ) | const [pure virtual] | |||
Tests whether a page break occurs within a range of characters. A page table should have been set up first: see CPlainText::SetPageTable().
ETrue if a page break occurs within the specified range, otherwise EFalse.
| void | GetChars | ( | TPtrC & | aView, |
| TCharFormat & | aFormat, | |||
| TInt | aStartPos | |||
| ) | const [pure virtual] | |||
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.
| TPtrC & aView | On return, a constant pointer to a portion of the text. |
| TCharFormat & aFormat | On return, contains the character formatting of the text. |
| TInt aStartPos | The start position for the view. Must be a valid document position, or a panic occurs. |
| void | GetParagraphFormatL | ( | CParaFormat * | aFormat, |
| TInt | aPos | |||
| ) | const [pure virtual] | |||
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.
| CParaFormat * aFormat | On return, filled with the paragraph's effective paragraph formatting. |
| TInt aPos | Any document position within the paragraph of interest. |
| TInt | GetPictureSizeInTwips | ( | TSize & | aSize, |
| TInt | aPos | |||
| ) | const [pure virtual] | |||
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.
KErrNotFound if there is no picture at the specified document position, KErrNone if there is.
| TInt | LdDocumentLength | ( | ) | const [pure virtual] |
Gets the the number of characters in the document.
The number of characters contained in the document.
| TInt | LdToParagraphStart | ( | TInt & | aCurrentPos | ) | const [pure virtual] |
Gets the document position of the start of the paragraph containing a specified position.
The number of characters skipped in scanning to the start of the paragraph.
| TInt & aCurrentPos | A valid document position. On return contains the document position of the first character in the paragraph. |
| IMPORT_C void | MLayDoc_Reserved_1 | ( | ) | [virtual] |
This function is reserved for future purpose. It should not be used externally for now.
| CPicture * | PictureHandleL | ( | TInt | aPos, |
| TForcePictureLoad | aForceLoad = EForceLoadTrue | |||
| ) | const [pure virtual] | |||
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.
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.
| TInt aPos | Document position of the picture character. |
| TForcePictureLoad aForceLoad = EForceLoadTrue | 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. |
| TBool | SelectParagraphLabel | ( | TInt | aPos | ) | [pure virtual] |
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).
Should return EFalse if the paragraph has no label, in which case the function has no effect, ETrue otherwise.
| TInt aPos | A document position within a paragraph. This paragraph's label should be set as the main MLayDoc document. |
Used as a parameter to the PictureHandleL() function to control whether picture data should be loaded into memory or not.
| EForceLoadFalse |
Do not load the picture data into memory. |
| EForceLoadTrue |
Load the picture data into memory. |