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QTextDocument Class Reference

The QTextDocument class holds formatted text that can be viewed and edited using a QTextEdit. More...

#include <QTextDocument>

Inherits QObject.

Public Types

Writable Properties

Public Functions

Public Slots

Signals

Static Public Members

Protected Functions


Detailed Description

The QTextDocument class holds formatted text that can be viewed and edited using a QTextEdit.

QTextDocument is a container for structured rich text documents, providing support for styled text and various types of document elements, such as lists, tables, frames, and images. They can be created for use in a QTextEdit, or used independently.

Each document element is described by an associated format object. Each format object is treated as a unique object by QTextDocuments, and can be passed to objectForFormat() to obtain the document element that it is applied to.

A QTextDocument can be edited programmatically using a QTextCursor, and its contents can be examined by traversing the document structure. The entire document structure is stored as a hierarchy of document elements beneath the root frame, found with the rootFrame() function. Alternatively, if you just want to iterate over the textual contents of the document you can use begin(), end(), and findBlock() to retrieve text blocks that you can examine and iterate over.

The layout of a document is determined by the documentLayout(); you can create your own QAbstractTextDocumentLayout subclass and set it using setDocumentLayout() if you want to use your own layout logic. The document's title can be obtained by calling the documentTitle() function.

The toPlainText() and toHtml() convenience functions allow you to retrieve the contents of the document as plain text and HTML. The document's text can be searched using the find() functions.

Undo/redo of operations performed on the document can be controlled using the setUndoRedoEnabled() function. The undo/redo system can be controlled by an editor widget through the undo() and redo() slots; the document also provides contentsChanged(), undoAvailable(), and redoAvailable() signals that inform connected editor widgets about the state of the undo/redo system.

See also QTextCursor, QTextEdit, and Rich Text Processing.


Member Type Documentation

enum QTextDocument::FindDirection

This enum is used to specify the search direction when searching for text with the find() function.

QTextDocument::FindForward 
QTextDocument::FindBackward 

enum QTextDocument::FindFlag
typedef QTextDocument::FindFlags

This enum describes the options available to QTextDocument's find function. The options can be OR-red together from the following list:

QTextDocument::FindCaseSensitivelyBy default find works case insensitive. Specifying this option changes the behaviour to a case sensitive find operation.
QTextDocument::FindWholeWordsMakes find match only complete words.

The FindFlags typedef can store a combination of FindFlag values.


Property Documentation

modified : bool

This property holds whether the document has been modified by the user.

Access functions:

See also modificationChanged().

undoRedoEnabled : bool

This property holds whether undo/redo are enabled for this document.

This defaults to true. If disabled, the undo stack is cleared and no items will be added to it.

Access functions:


Member Function Documentation

QTextDocument::QTextDocument ( QObject * parent = 0 )

Constructs an empty QTextDocument with the given parent.

QTextDocument::QTextDocument ( const QString & text, QObject * parent = 0 )

Constructs a QTextDocument containing the plain (unformatted) text specified, and with the given parent.

QTextDocument::~QTextDocument ()

Destroys the document.

QTextBlock QTextDocument::begin () const

Returns the document's first text block.

void QTextDocument::contentsChanged ()   [signal]

This signal is emitted whenever the documents content changes, for example, text is inserted or deleted, or formatting is applied.

QTextObject * QTextDocument::createObject ( const QTextFormat & format )   [virtual protected]

Creates and returns a new document object (a QTextObject), based on the given format.

QTextObjects will always get created through this method, so you must reimplement it if you use custom text objects inside your document.

void QTextDocument::cursorPositionChanged ( const QTextCursor & cursor )   [signal]

This signal is emitted whenever the position of a cursor changed due to an edition operation.

QAbstractTextDocumentLayout * QTextDocument::documentLayout () const

Returns the document layout for this document.

QString QTextDocument::documentTitle () const

Returns the document's title.

QTextBlock QTextDocument::end () const

Returns the document's last text block.

QTextCursor QTextDocument::find ( const QString & expr, const QTextCursor & cursor, FindFlags options = 0, FindDirection direction = FindForward ) const

Finds the next occurrence of the string, expr, in the document. The search starts at the position of the given cursor, and proceeds in the direction specified. The options control the type of search performed.

Returns a cursor with the match selected if expr was found; otherwise returns a null cursor.

If the given cursor has a selection, the search begins after the selection; otherwise it begins at the cursor's position.

By default the search is case-sensitive, and can match text anywhere in the document.

QTextCursor QTextDocument::find ( const QString & expr, int position = 0, FindFlags options = 0, FindDirection direction = FindForward ) const

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Finds the next occurrence of the string, expr, in the document. The search starts at the given position, and proceeds in the direction specified. The options control the type of search performed.

Returns a cursor with the match selected if expr was found; otherwise returns a null cursor.

If the position is 0 (the default) the search begins from the beginning of the document; otherwise it begins at the specified position.

QTextBlock QTextDocument::findBlock ( int pos ) const

Returns the text block that contains the pos-th character.

bool QTextDocument::isEmpty () const

Returns true if the document is empty; otherwise returns false.

bool QTextDocument::isRedoAvailable () const

Returns true is redo is available; otherwise returns false.

bool QTextDocument::isUndoAvailable () const

Returns true is undo is available; otherwise returns false.

void QTextDocument::modificationChanged ( bool changed )   [signal]

This signal is emitted whenever the content of the document changes in a way that affects the modification state. If changed is true if the document has been modified; otherwise it is false.

For example calling setModified(false) on a document and then inserting text causes the signal to get emitted. If you undo that operation, causing the document to return to its original unmodified state, the signal will get emitted again.

QTextObject * QTextDocument::object ( int objectIndex ) const

Returns the text object associated with the given objectIndex.

QTextObject * QTextDocument::objectForFormat ( const QTextFormat & f ) const

Returns the text object associated with the format f.

void QTextDocument::print ( QPrinter * printer ) const

void QTextDocument::redo ()   [slot]

Redoes the last editing operation on the document if redo is available.

void QTextDocument::redoAvailable ( bool available )   [signal]

This signal is emitted whenever redo operations become available (available is true) or unavailable (available is false).

QTextFrame * QTextDocument::rootFrame () const

Returns the document's root frame.

void QTextDocument::setDocumentLayout ( QAbstractTextDocumentLayout * layout )

Sets the document to use the given layout. The previous layout is deleted.

void QTextDocument::setHtml ( const QString & html )

Replaces the entire contents of the document with the given HTML-formatted text in the html string.

The HTML formatting is respected as much as possible; for example, "<b>bold</b> text" will produce text where the first word has a font weight that gives it a bold appearance: "bold text".

See also setPlainText().

void QTextDocument::setPlainText ( const QString & text )

Replaces the entire contents of the document with the given plain text.

See also setHtml().

QString QTextDocument::toHtml () const

Returns a string containing an HTML representation of the document.

QString QTextDocument::toPlainText () const

Returns the plain text contained in the document. If you want formatting information use a QTextCursor instead.

See also html().

void QTextDocument::undo ()   [slot]

Undoes the last editing operation on the document if undo is available.

void QTextDocument::undoAvailable ( bool available )   [signal]

This signal is emitted whenever undo operations become available (available is true) or unavailable (available is false).


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Qt 4.0.0-b1