CopperSpice API  1.7.2
QTextBlock Class Reference

The QTextBlock class provides a container for text fragments in a QTextDocument. More...


class  iterator
 The QTextBlock::iterator class provides an iterator for reading the contents of a QTextBlock More...

Public Methods

 QTextBlock (const QTextBlock &other) = default
iterator begin () const
QTextBlockFormat blockFormat () const
int blockFormatIndex () const
int blockNumber () const
QTextCharFormat charFormat () const
int charFormatIndex () const
void clearLayout ()
bool contains (int position) const
const QTextDocumentdocument () const
iterator end () const
int firstLineNumber () const
bool isValid () const
bool isVisible () const
QTextLayoutlayout () const
int length () const
int lineCount () const
QTextBlock next () const
bool operator!= (const QTextBlock &other) const
bool operator< (const QTextBlock &other) const
QTextBlock & operator= (const QTextBlock &other) = default
bool operator== (const QTextBlock &other) const
int position () const
QTextBlock previous () const
int revision () const
void setLineCount (int count)
void setRevision (int rev)
void setUserData (QTextBlockUserData *data)
void setUserState (int state)
void setVisible (bool visible)
QString text () const
Qt::LayoutDirection textDirection () const
QVector< QTextLayout::FormatRangetextFormats () const
QTextListtextList () const
QTextBlockUserDatauserData () const
int userState () const


class QSyntaxHighlighter
class QTextLayout

Detailed Description

The QTextBlock class provides a container for text fragments in a QTextDocument. A text block encapsulates a block or paragraph of text in a QTextDocument. QTextBlock provides read-only access to the block/paragraph structure of QTextDocuments. It is mainly of use if you want to implement your own layouts for the visual representation of a QTextDocument, or if you want to iterate over a document and write out the contents in your own custom format.

Text blocks are created by their parent documents. If you need to create a new text block, or modify the contents of a document while examining its contents, use the cursor-based interface provided by QTextCursor instead.

Each text block is located at a specific position() in a document(). The contents of the block can be obtained by using the text() function. The length() function determines the block's size within the document (including formatting characters). The visual properties of the block are determined by its text layout(), its charFormat(), and its blockFormat().

The next() and previous() functions enable iteration over consecutive valid blocks in a document under the condition that the document is not modified by other means during the iteration process. Note that, although blocks are returned in sequence, adjacent blocks may come from different places in the document structure. The validity of a block can be determined by calling isValid().

QTextBlock provides comparison operators to make it easier to work with blocks: operator==() compares two block for equality, operator!=() compares two blocks for inequality, and operator<() determines whether a block precedes another in the same document.

See also
QTextBlockFormat, QTextCharFormat, QTextFragment

Constructor & Destructor Documentation

QTextBlock::QTextBlock ( const QTextBlock &  other)

Copies the other text block's attributes to this text block.

Method Documentation

iterator QTextBlock::begin ( ) const

Returns a text block iterator pointing to the beginning of the text block.

See also
QTextBlockFormat QTextBlock::blockFormat ( ) const

Returns the QTextBlockFormat that describes block-specific properties.

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int QTextBlock::blockFormatIndex ( ) const

Returns an index into the document's internal list of block formats for the text block's format.

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int QTextBlock::blockNumber ( ) const

Returns the number of this block, or -1 if the block is invalid.

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QTextCharFormat QTextBlock::charFormat ( ) const

Returns the QTextCharFormat that describes the block's character format. The block's character format is used when inserting text into an empty block.

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int QTextBlock::charFormatIndex ( ) const

Returns an index into the document's internal list of character formats for the text block's character format.

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void QTextBlock::clearLayout ( )

Clears the QTextLayout that is used to lay out and display the block's contents.

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bool QTextBlock::contains ( int  position) const

Returns true if the given position is located within the text block, otherwise returns false.

const QTextDocument * QTextBlock::document ( ) const

Returns the text document this text block belongs to, or 0 if the text block does not belong to any document.

iterator QTextBlock::end ( ) const

Returns a text block iterator pointing to the end of the text block.

See also
begin(), next(), previous()
int QTextBlock::firstLineNumber ( ) const

Returns the first line number of this block, or -1 if the block is invalid. Unless the layout supports it, the line number is identical to the block number.

See also
bool QTextBlock::isValid ( ) const

Returns true if this text block is valid, otherwise returns false.

bool QTextBlock::isVisible ( ) const

Returns true if the block is visible, otherwise returns false.

See also
QTextLayout * QTextBlock::layout ( ) const

Returns the QTextLayout that is used to lay out and display the block's contents. The returned QTextLayout object can only be modified from the documentChanged implementation of a QAbstractTextDocumentLayout subclass. Any changes applied from the outside cause undefined behavior.

See also
int QTextBlock::length ( ) const

Returns the length of the block in characters. The length returned includes all formatting characters, for example, newline.

See also
text(), charFormat(), blockFormat()
int QTextBlock::lineCount ( ) const

Returns the line count. Not all document layouts support this feature.

See also
QTextBlock QTextBlock::next ( ) const

Returns the text block in the document after this block, or an empty text block if this is the last one. The next block may be in a different frame or table to this block.

See also
previous(), begin(), end()
bool QTextBlock::operator!= ( const QTextBlock &  other) const

Returns true if this text block is different from the other text block.

bool QTextBlock::operator< ( const QTextBlock &  other) const

Returns true if this text block occurs before the other text block in the document.

QTextBlock & QTextBlock::operator= ( const QTextBlock &  other)

Assigns the other text block to this text block.

bool QTextBlock::operator== ( const QTextBlock &  other) const

Returns true if this text block is the same as the other text block.

int QTextBlock::position ( ) const

Returns the index of the block's first character within the document.

QTextBlock QTextBlock::previous ( ) const

Returns the text block in the document before this block, or an empty text block if this is the first one. The next block may be in a different frame or table to this block.

See also
next(), begin(), end()
int QTextBlock::revision ( ) const

Returns the blocks revision.

See also
setRevision(), QTextDocument::revision()
void QTextBlock::setLineCount ( int  count)

Sets the line count to count.

See also
void QTextBlock::setRevision ( int  rev)

Sets a blocks revision to rev.

See also
revision(), QTextDocument::revision()
void QTextBlock::setUserData ( QTextBlockUserData data)

Attaches the given data object to the text block.

QTextBlockUserData can be used to store custom settings. The ownership is passed to the underlying text document, i.e. the provided QTextBlockUserData object will be deleted if the corresponding text block gets deleted. The user data object is not stored in the undo history, so it will not be available after undoing the deletion of a text block.

For example, if you write a programming editor in an IDE, you may want to let your user set breakpoints visually in your code for an integrated debugger. In a programming editor a line of text usually corresponds to one QTextBlock. The QTextBlockUserData interface allows the developer to store data for each QTextBlock, like for example in which lines of the source code the user has a breakpoint set. Of course this could also be stored externally, but by storing it inside the QTextDocument, it will for example be automatically deleted when the user deletes the associated line. It's really just a way to store custom information in the QTextDocument without using custom properties in QTextFormat which would affect the undo/redo stack.

See also
void QTextBlock::setUserState ( int  state)

Stores the specified state integer value in the text block. This may be useful for example in a syntax highlighter to store a text parsing state.

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void QTextBlock::setVisible ( bool  visible)

Sets the block's visibility to visible.

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QString QTextBlock::text ( ) const

Returns the block's contents as plain text.

See also
length(), charFormat(), blockFormat()
Qt::LayoutDirection QTextBlock::textDirection ( ) const

Returns the resolved text direction. If the block has no explicit direction set, it will resolve the direction from the blocks content. Returns either Qt::LeftToRight or Qt::RightToLeft.

See also
QTextFormat::layoutDirection(), Qt::LayoutDirection
QVector< QTextLayout::FormatRange > QTextBlock::textFormats ( ) const

Returns the block's text format options as a list of continuous ranges of QTextCharFormat. The range's character format is used when inserting text within the range boundaries.

See also
charFormat(), blockFormat()
QTextList * QTextBlock::textList ( ) const

If the block represents a list item, returns the list that the item belongs to, otherwise returns a nullptr.

QTextBlockUserData * QTextBlock::userData ( ) const

Returns a pointer to a QTextBlockUserData object if previously set with setUserData() or a null pointer.

See also
int QTextBlock::userState ( ) const

Returns the integer value previously set with setUserState() or -1.

See also