QTextBrowser Class

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# QTextBrowser Class Reference

The QTextBrowser class provides a rich text browser with hypertext navigation. More...

`#include <qtextbrowser.h>`

Inherits QTextEdit.

List of all member functions.

## Public Members

- QTextBrowser ( QWidget * parent = 0, const char * name = 0 )
- QString source () const

## Public Slots

- virtual void setSource ( const QString & name )
- virtual void backward ()
- virtual void forward ()
- virtual void home ()
- virtual void reload ()

## Signals

- void backwardAvailable ( bool available )
- void forwardAvailable ( bool available )
- void sourceChanged ( const QString & src )
- void highlighted ( const QString & link )
- void linkClicked ( const QString & link )
- void anchorClicked ( const QString & name, const QString & link )

## Properties

- bool modified - whether the contents have been modified (read only)
- bool overwriteMode - this text browser's overwrite mode (read only)
- bool readOnly - whether the contents are read only (read only)
- QString source - the name of the displayed document
- int undoDepth - this text browser's undo depth (read only)
- bool undoRedoEnabled - whether undo and redo are enabled (read only)

## Protected Members

- virtual void keyPressEvent ( QKeyEvent * e )

## Detailed Description

The QTextBrowser class provides a rich text browser with hypertext navigation.

This class extends QTextEdit (in read-only mode), adding some navigation functionality so that users can follow links in hypertext documents. The contents of QTextEdit is set with setText(), but QTextBrowser has an additional function, setSource(), which makes it possible to set the text to a named document. The name is looked up in the text view's mime source factory. If a document name ends with an anchor (for example, "`#anchor"`), the text browser automatically scrolls to that position (using scrollToAnchor()). When the user clicks on a hyperlink, the browser will call setSource() itself, with the link's `href` value as argument. You can track the current source by connetion to the sourceChanged() signal.

QTextBrowser provides backward() and forward() slots which you can use to implement Back and Forward buttons. The home() slot sets the text to the very first document displayed. The linkClicked() signal is emitted when the user clicks a link.

By using QTextEdit::setMimeSourceFactory() you can provide your own subclass of QMimeSourceFactory. This makes it possible to access data from anywhere, for example from a network or from a database. See QMimeSourceFactory::data() for details.

If you intend using the mime factory to read the data directly from the file system, you may have to specify the encoding for the file extension you are using. For example:

        mimeSourceFactory()->setExtensionType("qml", "text/utf8");

This is to ensure that the factory is able to resolve the document names.

QTextBrowser interprets the tags it processes in accordance with the default style sheet. Change the style sheet with setStyleSheet(); see QStyleSheet for details.

If you want to provide your users with editable rich text use QTextEdit. If you want a text browser without hypertext navigation use QTextEdit, and use QTextEdit::setReadOnly() to disable editing. If you just need to display a small piece of rich text use QSimpleRichText or QLabel.

See also Advanced Widgets, Help System, and Text Related Classes.

## Member Function Documentation

### QTextBrowser::QTextBrowser ( QWidget * parent = 0, const char * name = 0 )

Constructs an empty QTextBrowser called name, with parent parent.

### void QTextBrowser::anchorClicked ( const QString & name, const QString & link )`[signal]`

This signal is emitted when the user clicks an anchor. The link is the value of the `href` i.e. the name of the target document. The name is the name of the anchor.

See also linkClicked().

### void QTextBrowser::backward ()`[virtual slot]`

Changes the document displayed to the previous document in the list of documents built by navigating links. Does nothing if there is no previous document.

See also forward() and backwardAvailable().

Example: helpviewer/helpwindow.cpp.

### void QTextBrowser::backwardAvailable ( bool available )`[signal]`

This signal is emitted when the availability of backward() changes. available is FALSE when the user is at home(); otherwise it is TRUE.

Example: helpviewer/helpwindow.cpp.

### void QTextBrowser::forward ()`[virtual slot]`

Changes the document displayed to the next document in the list of documents built by navigating links. Does nothing if there is no next document.

See also backward() and forwardAvailable().

Example: helpviewer/helpwindow.cpp.

### void QTextBrowser::forwardAvailable ( bool available )`[signal]`

This signal is emitted when the availability of forward() changes. available is TRUE after the user navigates backward() and FALSE when the user navigates or goes forward().

Example: helpviewer/helpwindow.cpp.

### void QTextBrowser::highlighted ( const QString & link )`[signal]`

This signal is emitted when the user has selected but not activated a link in the document. link is the value of the `href` i.e. the name of the target document.

Example: helpviewer/helpwindow.cpp.

### void QTextBrowser::home ()`[virtual slot]`

Changes the document displayed to be the first document the browser displayed.

Example: helpviewer/helpwindow.cpp.

### void QTextBrowser::keyPressEvent ( QKeyEvent * e )`[virtual protected]`

The event e is used to provide the following keyboard shortcuts:

Keypress | Action
--- | ---
Alt+Left Arrow | backward()
Alt+Right Arrow | forward()
Alt+Up Arrow | home()

Reimplemented from QTextEdit.

### void QTextBrowser::linkClicked ( const QString & link )`[signal]`

This signal is emitted when the user clicks a link. The link is the value of the `href` i.e. the name of the target document.

The link will be the absolute location of the document, based on the value of the anchor's href tag and the current context of the document.

See also anchorClicked() and context().

### void QTextBrowser::reload ()`[virtual slot]`

Reloads the current set source.

### void QTextBrowser::setSource ( const QString & name )`[virtual slot]`

Sets the name of the displayed document to name. See the "source" property for details.

### QString QTextBrowser::source () const

Returns the name of the displayed document. See the "source" property for details.

### void QTextBrowser::sourceChanged ( const QString & src )`[signal]`

This signal is emitted when the mime source has changed, src being the new source.

Source changes happen both programmatically when calling setSource(), forward(), backword() or home() or when the user clicks on links or presses the equivalent key sequences.

Example: helpviewer/helpwindow.cpp.

## Property Documentation

### bool modified

This property holds whether the contents have been modified.

### bool overwriteMode

This property holds this text browser's overwrite mode.

### bool readOnly

This property holds whether the contents are read only.

### QString source

This property holds the name of the displayed document.

This is a QString::null if no document is displayed or if the source is unknown.

Setting this property uses the mimeSourceFactory() to lookup the named document. It also checks for optional anchors and scrolls the document accordingly.

If the first tag in the document is `<qt type=detail>`, the document is displayed as a popup rather than as new document in the browser window itself. Otherwise, the document is displayed normally in the text browser with the text set to the contents of the named document with setText().

If you are using the filesystem access capabilities of the mime source factory, you must ensure that the factory knows about the encoding of specified files; otherwise no data will be available. The default factory handles a couple of common file extensions such as `*.html` and `*.txt` with reasonable defaults. See QMimeSourceFactory::data() for details.

Set this property's value with setSource() and get this property's value with source().

### int undoDepth

This property holds this text browser's undo depth.

### bool undoRedoEnabled

This property holds whether undo and redo are enabled.

This file is part of the Qt toolkit. Copyright © 1995-2005 Trolltech. All Rights Reserved.