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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>

Part of the QtGui module.

Inherits QObject.

- List of all members, including inherited members

### Public Types

- enum FindFlag { FindCaseSensitively, FindWholeWords }
- flags FindFlags
- enum MetaInformation { DocumentTitle }
- enum ResourceType { HtmlResource, ImageResource }

### Properties

- defaultFont : QFont
- modified : bool
- pageSize : QSizeF
- undoRedoEnabled : bool

- 1 property inherited from QObject

### Public Functions

- QTextDocument ( QObject * parent = 0 )
- QTextDocument ( const QString & text, QObject * parent = 0 )
- ~QTextDocument ()
- QVector<QTextFormat> allFormats () const
- QTextBlock begin () const
- QTextDocument * clone ( QObject * parent = 0 ) const
- QFont defaultFont () const
- QAbstractTextDocumentLayout * documentLayout () const
- QTextBlock end () const
- QTextCursor find ( const QString & expr, int from = 0, FindFlags options = 0 ) const
- QTextCursor find ( const QString & expr, const QTextCursor & from, FindFlags options = 0 ) const
- QTextBlock findBlock ( int pos ) const
- bool isEmpty () const
- bool isModified () const
- bool isRedoAvailable () const
- bool isUndoAvailable () const
- bool isUndoRedoEnabled () const
- virtual QVariant loadResource ( int type, const QUrl & name )
- void markContentsDirty ( int from, int length )
- QString metaInformation ( MetaInformation info ) const
- QTextObject * object ( int objectIndex ) const
- QTextObject * objectForFormat ( const QTextFormat & f ) const
- int pageCount () const
- QSizeF pageSize () const
- void print ( QPrinter * printer ) const
- QTextFrame * rootFrame () const
- void setDefaultFont ( const QFont & font )
- void setDocumentLayout ( QAbstractTextDocumentLayout * layout )
- void setHtml ( const QString & html )
- void setMetaInformation ( MetaInformation info, const QString & )
- void setPageSize ( const QSizeF & size )
- void setPlainText ( const QString & text )
- void setUndoRedoEnabled ( bool enable )
- QString toHtml ( const QByteArray & encoding = QByteArray() ) const
- QString toPlainText () const

- 28 public functions inherited from QObject

### Public Slots

- void redo ()
- void setModified ( bool m = true )
- void undo ()

- 1 public slot inherited from QObject

### Signals

- void contentsChange ( int from, int charsRemoved, int charsAdded )
- void contentsChanged ()
- void cursorPositionChanged ( const QTextCursor & cursor )
- void modificationChanged ( bool changed )
- void redoAvailable ( bool available )
- void undoAvailable ( bool available )

- 1 signal inherited from QObject

### Protected Functions

- virtual QTextObject * createObject ( const QTextFormat & format )

- 7 protected functions inherited from QObject

### Additional Inherited Members

- 4 static public members inherited from QObject

## 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::FindFlag
flags QTextDocument::FindFlags

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

Constant | Value | Description
--- | --- | ---
`QTextDocument::FindCaseSensitively` | `0x00002` | By default find works case insensitive. Specifying this option changes the behaviour to a case sensitive find operation.
`QTextDocument::FindWholeWords` | `0x00004` | Makes find match only complete words.

The `FindFlags` type stores an OR combination of `FindFlag` values.

### enum QTextDocument::MetaInformation

### enum QTextDocument::ResourceType

This enum describes the types of resources that can be loaded by QTextDocument's loadResource() function.

Constant | Value | Description
--- | --- | ---
`QTextDocument::HtmlResource` | `1` | The resource contains HTML.
`QTextDocument::ImageResource` | `2` | The resource contains image data.

See also loadResource().

## Property Documentation

### defaultFont : QFont

Access functions:

- QFont defaultFont () const
- void setDefaultFont ( const QFont & font )

### modified : bool

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

Access functions:

- bool isModified () const
- void setModified ( bool m = true )

See also modificationChanged().

### pageSize : QSizeF

This property holds the page size that should be used for layouting the document.

Access functions:

- QSizeF pageSize () const
- void setPageSize ( const QSizeF & size )

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:

- bool isUndoRedoEnabled () const
- void setUndoRedoEnabled ( bool enable )

## 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.

### QVector<QTextFormat> QTextDocument::allFormats () const

### QTextBlock QTextDocument::begin () const

Returns the document's first text block.

### QTextDocument * QTextDocument::clone ( QObject * parent = 0 ) const

Creates a new QTextDocument that is a copy of this text document. parent is the parent of the returned text document.

### void QTextDocument::contentsChange ( int from, int charsRemoved, int charsAdded ) `[signal]`

This signal is emitted whenever the documents content changes, for example, text is inserted or deleted, or formatting is applied. The signal is emitted before the documents layout gets notified about the change. This hook allows it to implement a syntax highlighter for the document.

See also QAbstractTextDocumentLayout::documentModified().

### void QTextDocument::contentsChanged () `[signal]`

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

This signal is emitted

### 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 editing operation. The cursor that changed is passed in cursor.

### QAbstractTextDocumentLayout * QTextDocument::documentLayout () const

Returns the document layout for this document.

### QTextBlock QTextDocument::end () const

Returns the document's last text block.

### QTextCursor QTextDocument::find ( const QString & expr, int from = 0, FindFlags options = 0 ) const

### QTextCursor QTextDocument::find ( const QString & expr, const QTextCursor & from, FindFlags options = 0 ) const

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

### 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.

### QVariant QTextDocument::loadResource ( int type, const QUrl & name ) `[virtual]`

This function is called by the rich text engine to request data that isn't directly stored by QTextDocument, but still associated with it. For example, images are referenced indirectly by the name attribute of a QTextImageFormat object.

When called by Qt, type is one of the values of QTextDocument::ResourceType.

If the QTextDocument is a child object of a QTextEdit, QTextBrowser, or a QTextDocument itself then the default implementation tries to retrieve the data from the parent.

### void QTextDocument::markContentsDirty ( int from, int length )

### QString QTextDocument::metaInformation ( MetaInformation info ) const

Returns meta information about the document.

### 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.

### int QTextDocument::pageCount () const

returns the number of pages in this document.

### void QTextDocument::print ( QPrinter * printer ) const

Prints the document to the given printer. The QPrinter must be set up before being used with this function.

This is only a convenience method to print the whole document to the printer.

### 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::setMetaInformation ( MetaInformation info, const QString & )

### 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 QByteArray & encoding = QByteArray() ) const

Returns a string containing an HTML representation of the document.

The encoding parameter specifies the value for the charset attribute in the html header. For example if 'utf-8' is specified then the beginning of the generated html will look like this:

        <html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body>...

If no encoding is specified then no such meta information is generated.

If you later on convert the returned html string into a byte array for transmission over a network or when saving to disk you should specify the encoding you're going to use for the conversion to a byte array here.

### 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).