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QTextEdit Class Reference
[QtGui module]

The QTextEdit class provides a widget that is used to edit and display both plain and rich text. More...

#include <QTextEdit>

Inherits QAbstractScrollArea.

Inherited by QTextBrowser.

Public Types

Properties

Public Functions

Public Slots

Signals

Protected Functions

Additional Inherited Members


Detailed Description

The QTextEdit class provides a widget that is used to edit and display both plain and rich text.

Introduction and Concepts

QTextEdit is an advanced WYSIWYG viewer/editor supporting rich text formatting using HTML-style tags. It is optimized to handle large documents and to respond quickly to user input.

QTextEdit works on paragraphs and characters. A paragraph is a formatted string which is word-wrapped to fit into the width of the widget. By default when reading plain text, one newline signifies a paragraph. A document consists of zero or more paragraphs. The words in the paragraph are aligned in accordance with the paragraph's alignment. Paragraphs are separated by hard line breaks. Each character within a paragraph has its own attributes, for example, font and color.

QTextEdit can display images, lists and tables. If the text is too large to view within the text edit's viewport, scrollbars will appear. The text edit can load both plain text and HTML files (a subset of HTML 3.2 and 4).

If you just need to display a small piece of rich text use QLabel.

Note that we do not intend to add a full-featured web browser widget to Qt (because that would easily double Qt's size and only a few applications would benefit from it). The rich text support in Qt is designed to provide a fast, portable and efficient way to add reasonable online help facilities to applications, and to provide a basis for rich text editors.

Using QTextEdit as a Display Widget

QTextEdit can display a large HTML subset, including tables and images.

The text is set or replaced using setHtml() which deletes any existing text and replaces it with the text passed in the setHtml() call. If you call setHtml() with legacy HTML, and then call text(), the text that is returned may have different markup, but will render the same. The entire text can be deleted with clear().

Text itself can be inserted using the QTextCursor class or using the convenience functions insertHtml(), insertPlainText(), append() or paste(). QTextCursor is also able to insert complex objects like tables or lists into the document, and it deals with creating selections and applying changes to selected text.

By default the text edit wraps words at whitespace to fit within the text edit widget. The setLineWrapMode() function is used to specify the kind of line wrap you want, or NoWrap if you don't want any wrapping. Call setLineWrapMode() to set a fixed pixel width FixedPixelWidth, or character column (e.g. 80 column) FixedColumnWidth with the pixels or columns specified with setLineWrapColumnOrWidth(). If you use word wrap to the widget's width WidgetWidth, you can specify whether to break on whitespace or anywhere with setWordWrapMode().

The find() function can be used to find and select a given string within the text.

Read-only Key Bindings

When QTextEdit is used read-only the key bindings are limited to navigation, and text may only be selected with the mouse:

KeypressesAction
Qt::UpArrowMoves one line up.
Qt::DownArrowMoves one line down.
Qt::LeftArrowMoves one character to the left.
Qt::RightArrowMoves one character to the right.
PageUpMoves one (viewport) page up.
PageDownMoves one (viewport) page down.
HomeMoves to the beginning of the text.
EndMoves to the end of the text.
Alt+WheelScrolls the page horizontally (the Wheel is the mouse wheel).
Ctrl+WheelZooms the text.
Ctrl+ASelects all text.

The text edit may be able to provide some meta-information. For example, the documentTitle() function will return the text from within HTML <title> tags.

Using QTextEdit as an Editor

All the information about using QTextEdit as a display widget also applies here.

The current char format's attributes are set with setFontItalic(), setFontWeight(), setFontUnderline(), setFontFamily(), setFontPointSize(), setTextColor() and setCurrentFont(). The current paragraph's alignment is set with setAlignment().

Selection of text is handled by the QTextCursor class, which provides functionality for creating selections, retrieving the text contents or deleting selections. You can retrieve the object that corresponds with the user-visible cursor using the textCursor() method. If you want to set a selection in QTextEdit just create one on a QTextCursor object and then make that cursor the visible cursor using setCursor(). The selection can be copied to the clipboard with copy(), or cut to the clipboard with cut(). The entire text can be selected using selectAll().

When the cursor is moved and the underlying formatting attributes change, the currentCharFormatChanged() signal is emitted to reflect the new attributes at the new cursor position.

QTextEdit holds a QTextDocument object which can be retrieved using the document() method. You can also set your own document object using setDocument(). QTextDocument emits a textChanged() signal if the text changes and it also provides a isModified() function which will return true if the text has been modified since it was either loaded or since the last call to setModified with false as argument. In addition it provides methods for undo and redo.

Editing Key Bindings

The list of key bindings which are implemented for editing:

KeypressesAction
BackspaceDeletes the character to the left of the cursor.
DeleteDeletes the character to the right of the cursor.
Ctrl+CCopy the selected text to the clipboard.
Ctrl+InsertCopy the selected text to the clipboard.
Ctrl+KDeletes to the end of the line.
Ctrl+VPastes the clipboard text into text edit.
Shift+InsertPastes the clipboard text into text edit.
Ctrl+XDeletes the selected text and copies it to the clipboard.
Shift+DeleteDeletes the selected text and copies it to the clipboard.
Ctrl+ZUndoes the last operation.
Ctrl+YRedoes the last operation.
LeftArrowMoves the cursor one character to the left.
Ctrl+LeftArrowMoves the cursor one word to the left.
RightArrowMoves the cursor one character to the right.
Ctrl+RightArrowMoves the cursor one word to the right.
UpArrowMoves the cursor one line up.
Ctrl+UpArrowMoves the cursor one word up.
DownArrowMoves the cursor one line down.
Ctrl+Down ArrowMoves the cursor one word down.
PageUpMoves the cursor one page up.
PageDownMoves the cursor one page down.
HomeMoves the cursor to the beginning of the line.
Ctrl+HomeMoves the cursor to the beginning of the text.
EndMoves the cursor to the end of the line.
Ctrl+EndMoves the cursor to the end of the text.
Alt+WheelScrolls the page horizontally (the Wheel is the mouse wheel).
Ctrl+WheelZooms the text.

To select (mark) text hold down the Shift key whilst pressing one of the movement keystrokes, for example, Shift+Right Arrow will select the character to the right, and Shift+Ctrl+Right Arrow will select the word to the right, etc.

See also QTextDocument, QTextCursor, document(), textCursor(), setDocument(), and setTextCursor().


Member Type Documentation

enum QTextEdit::AutoFormattingFlag
flags QTextEdit::AutoFormatting

ConstantValueDescription
QTextEdit::AutoNone0Don't do any automatic formatting.
QTextEdit::AutoBulletList0x00000001Automatically create bullet lists (e.g. when the user enters an asterisk ('*') in the left most column, or presses Enter in an existing list item.
QTextEdit::AutoAll0xffffffffApply all automatic formatting. Currently only automatic bullet lists are supported.

The AutoFormatting type is a typedef for QFlags<AutoFormattingFlag>. It stores an OR combination of AutoFormattingFlag values.

enum QTextEdit::CursorAction

ConstantValue
QTextEdit::MoveBackward0
QTextEdit::MoveForward1
QTextEdit::MoveWordBackward2
QTextEdit::MoveWordForward3
QTextEdit::MoveUp4
QTextEdit::MoveDown5
QTextEdit::MoveLineStart6
QTextEdit::MoveLineEnd7
QTextEdit::MoveHome8
QTextEdit::MoveEnd9
QTextEdit::MovePageUp10
QTextEdit::MovePageDown11

enum QTextEdit::LineWrapMode

ConstantValue
QTextEdit::NoWrap0
QTextEdit::WidgetWidth1
QTextEdit::FixedPixelWidth2
QTextEdit::FixedColumnWidth3


Property Documentation

acceptRichText : bool

This property holds whether the text edit accepts rich text insertions by the user.

When this propery is set to false text edit will accept only plain text input from the user. For example through clipboard or drag and drop.

This property's default is true.

This property was introduced in Qt 4.1.

Access functions:

autoFormatting : AutoFormatting

This property holds the enabled set of auto formatting features.

The value can be any combination of the values in the AutoFormattingFlag enum. The default is AutoNone. Choose AutoAll to enable all automatic formatting.

Currently, the only automatic formatting feature provided is AutoBulletList; future versions of Qt may offer more.

Access functions:

documentTitle : QString

This property holds the title of the document parsed from the text.

Access functions:

html : QString

This property provides an HTML interface to the text of the text edit.

toHtml() returns the text of the text edit as html.

setHtml() changes the text of the text edit. Any previous text is removed. The input text is interpreted as rich text in html format.

Note that the undo/redo history is cleared by calling setHtml().

Access functions:

See also Supported HTML Subset.

lineWrapColumnOrWidth : int

This property holds the position (in pixels or columns depending on the wrap mode) where text will be wrapped.

If the wrap mode is FixedPixelWidth, the value is the number of pixels from the left edge of the text edit at which text should be wrapped. If the wrap mode is FixedColumnWidth, the value is the column number (in character columns) from the left edge of the text edit at which text should be wrapped.

Access functions:

See also lineWrapMode.

lineWrapMode : LineWrapMode

This property holds the line wrap mode.

The default mode is WidgetWidth which causes words to be wrapped at the right edge of the text edit. Wrapping occurs at whitespace, keeping whole words intact. If you want wrapping to occur within words use setWrapPolicy(). If you set a wrap mode of FixedPixelWidth or FixedColumnWidth you should also call setWrapColumnOrWidth() with the width you want.

Access functions:

See also lineWrapColumnOrWidth.

overwriteMode : bool

This property was introduced in Qt 4.1.

Access functions:

readOnly : bool

This property holds whether the text edit is read-only.

In a read-only text edit the user can only navigate through the text and select text; modifying the text is not possible.

This property's default is false.

Access functions:

tabChangesFocus : bool

This property holds whether Tab changes focus or is accepted as input.

In some occasions text edits should not allow the user to input tabulators or change indentation using the Tab key, as this breaks the focus chain. The default is false.

Access functions:

tabStopWidth : int

This property holds the tab stop width in pixels.

This property was introduced in Qt 4.1.

Access functions:

undoRedoEnabled : bool

This property holds whether undo and redo are enabled.

Users are only able to undo or redo actions if this property is true, and if there is an action that can be undone (or redone).

Access functions:

wordWrapMode : QTextOption::WrapMode

This property holds the mode QTextEdit will use when wrapping text by words.

Access functions:

See also QTextOption::WrapMode.


Member Function Documentation

QTextEdit::QTextEdit ( QWidget * parent = 0 )

Constructs an empty QTextEdit with parent parent.

QTextEdit::QTextEdit ( const QString & text, QWidget * parent = 0 )

Constructs a QTextEdit with parent parent. The text edit will display the text text. The text is interpreted as html.

QTextEdit::~QTextEdit ()   [virtual]

Destructor.

Qt::Alignment QTextEdit::alignment () const

Returns the alignment of the current paragraph.

See also setAlignment().

QString QTextEdit::anchorAt ( const QPoint & pos ) const

Returns the reference of the anchor at position pos, or an empty string if no anchor exists at that point.

void QTextEdit::append ( const QString & text )   [slot]

Appends a new paragraph with text to the end of the text edit.

bool QTextEdit::canInsertFromMimeData ( const QMimeData * source ) const   [virtual protected]

This function returns true if the contents of the MIME data object, specified by source, can be decoded and inserted into the document. It is called for example when during a drag operation the mouse enters this widget and it is necessary to determine whether it is possible to accept the drag.

void QTextEdit::clear ()   [slot]

Deletes all the text in the text edit.

Note that the undo/redo history is cleared by this function.

See also cut(), setPlainText(), and setHtml().

void QTextEdit::contextMenuEvent ( QContextMenuEvent * e )   [virtual protected]

Shows the standard context menu created with createStandardContextMenu().

If you do not want the text edit to have a context menu, you can set its contextMenuPolicy to Qt::NoContextMenu. If you want to customize the context menu, reimplement this function. If you want to extend the standard context menu, reimplement this function, call createStandardContextMenu() and extend the menu returned.

Information about the event is passed in e.

    void TextEdit::contextMenuEvent(QContextMenuEvent * e) {
            QMenu *menu = createStandardContextMenu();
            menu->addAction(My Menu Item");
            //...
            menu->exec(e->globalPos());
            delete menu;
    }

Reimplemented from QWidget.

void QTextEdit::copy ()   [slot]

Copies any selected text to the clipboard.

See also copyAvailable().

void QTextEdit::copyAvailable ( bool yes )   [signal]

This signal is emitted when text is selected or de-selected in the text edit.

When text is selected this signal will be emitted with yes set to true. If no text has been selected or if the selected text is de-selected this signal is emitted with yes set to false.

If yes is true then copy() can be used to copy the selection to the clipboard. If yes is false then copy() does nothing.

See also selectionChanged().

QMimeData * QTextEdit::createMimeDataFromSelection () const   [virtual protected]

This function returns a new MIME data object to represent the contents of the text edit's current selection. It is called when the selection needs to be encapsulated into a new QMimeData object; for example, when a drag and drop operation is started, or when data is copyied to the clipboard.

If you reimplement this function, note that the ownership of the returned QMimeData object is passed to the caller. The selection can be retrieved by using the textCursor() function.

QMenu * QTextEdit::createStandardContextMenu ()

This function creates the standard context menu which is shown when the user clicks on the line edit with the right mouse button. It is called from the default contextMenuEvent() handler. The popup menu's ownership is transferred to the caller.

QTextCharFormat QTextEdit::currentCharFormat () const

Returns the char format that is used when inserting new text.

See also setCurrentCharFormat().

void QTextEdit::currentCharFormatChanged ( const QTextCharFormat & f )   [signal]

This signal is emitted if the current character format has changed, for example caused by a change of the cursor position.

The new format is f.

See also setCurrentCharFormat().

QFont QTextEdit::currentFont () const

Returns the font of the current format.

See also setCurrentFont(), setFontFamily(), and setFontPointSize().

QTextCursor QTextEdit::cursorForPosition ( const QPoint & pos ) const

returns a QTextCursor at position pos (in viewport coordinates).

void QTextEdit::cursorPositionChanged ()   [signal]

This signal is emitted whenever the position of the cursor changed.

QRect QTextEdit::cursorRect ( const QTextCursor & cursor ) const

returns a rectangle (in viewport coordinates) that includes the cursor.

QRect QTextEdit::cursorRect () const

This is an overloaded member function, provided for convenience.

returns a rectangle (in viewport coordinates) that includes the cursor of the text edit.

void QTextEdit::cut ()   [slot]

Copies the selected text to the clipboard and deletes it from the text edit.

If there is no selected text nothing happens.

See also copy() and paste().

QTextDocument * QTextEdit::document () const

Returns a pointer to the underlying document.

See also setDocument().

void QTextEdit::ensureCursorVisible ()

Ensures that the cursor is visible by scrolling the text edit if necessary.

bool QTextEdit::find ( const QString & exp, QTextDocument::FindFlags options = 0 )

Finds the next occurrence of the string, exp, using the given options. Returns true if exp was found and changes the cursor to select the match; otherwise returns false.

QString QTextEdit::fontFamily () const

Returns the font family of the current format.

See also setFontFamily(), setCurrentFont(), and setFontPointSize().

bool QTextEdit::fontItalic () const

Returns true if the font of the current format is italic; otherwise returns false.

See also setFontItalic().

qreal QTextEdit::fontPointSize () const

Returns the point size of the font of the current format.

See also setFontFamily(), setCurrentFont(), and setFontPointSize().

bool QTextEdit::fontUnderline () const

Returns true if the font of the current format is underlined; otherwise returns false.

See also setFontUnderline().

int QTextEdit::fontWeight () const

Returns the font weight of the current format.

See also setFontWeight(), setCurrentFont(), setFontPointSize(), and QFont::Weight.

void QTextEdit::insertFromMimeData ( const QMimeData * source )   [virtual protected]

This function inserts the contents of the MIME data object, specified by source, into the text edit at the current cursor position. It is called whenever text is inserted as the result of a clipboard paste operation, or when the text edit accepts data from a drag and drop operation.

void QTextEdit::insertHtml ( const QString & text )   [slot]

Convenience slot that inserts text which is assumed to be of html formatting at the current cursor position.

It is equivalent to:

    QTextDocumentFragment fragment = QTextDocumentFragment::fromHtml(text);
    edit->textCursor().insertFragment(fragment);

void QTextEdit::insertPlainText ( const QString & text )   [slot]

Convenience slot that inserts text at the current cursor position.

It is equivalent to

    edit->textCursor().insertText(text);

QVariant QTextEdit::loadResource ( int type, const QUrl & name )   [virtual]

Loads the resource specified by the given type and name.

This function is an extension of QTextDocument::loadResource().

See also QTextDocument::loadResource().

void QTextEdit::mergeCurrentCharFormat ( const QTextCharFormat & modifier )

If the editor has a selection then the properties of modifier are applied to the selection. Without a selection the properties are applied to the word under the cursor. In addition they are always merged into the current char format.

See also QTextCursor::mergeCharFormat().

void QTextEdit::paste ()   [slot]

Pastes the text from the clipboard into the text edit at the current cursor position.

If there is no text in the clipboard nothing happens.

To change the behavior of this function, i.e. to modify what QTextEdit can paste and how it is being pasted, reimplement the virtual canInsertFromMimeData() and insertFromMimeData() functions.

See also cut() and copy().

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

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

void QTextEdit::scrollToAnchor ( const QString & name )   [slot]

Scrolls the text edit so that the anchor with the given name is visible; does nothing if the name is empty, or is already visible, or isn't found.

void QTextEdit::selectAll ()   [slot]

Selects all text.

See also copy(), cut(), and textCursor().

void QTextEdit::selectionChanged ()   [signal]

This signal is emitted whenever the selection changes.

See also copyAvailable().

void QTextEdit::setAlignment ( Qt::Alignment a )   [slot]

Sets the alignment of the current paragraph to a. Valid alignments are Qt::AlignLeft, Qt::AlignRight, Qt::AlignJustify and Qt::AlignCenter (which centers horizontally).

See also alignment().

void QTextEdit::setCurrentCharFormat ( const QTextCharFormat & format )

Sets the char format that is be used when inserting new text to format .

See also currentCharFormat().

void QTextEdit::setCurrentFont ( const QFont & f )   [slot]

Sets the font of the current format to f.

See also currentFont(), setFontPointSize(), and setFontFamily().

void QTextEdit::setDocument ( QTextDocument * document )

Makes document the new document of the text editor.

The parent QObject of the provided document remains the owner of the object. If the current document is a child of the text editor, then it is deleted.

See also document().

void QTextEdit::setFontFamily ( const QString & fontFamily )   [slot]

Sets the font family of the current format to fontFamily.

See also fontFamily() and setCurrentFont().

void QTextEdit::setFontItalic ( bool italic )   [slot]

If italic is true, sets the current format to italic; otherwise sets the current format to non-italic.

See also fontItalic().

void QTextEdit::setFontPointSize ( qreal s )   [slot]

Sets the point size of the current format to s.

Note that if s is zero or negative, the behavior of this function is not defined.

See also fontPointSize(), setCurrentFont(), and setFontFamily().

void QTextEdit::setFontUnderline ( bool underline )   [slot]

If underline is true, sets the current format to underline; otherwise sets the current format to non-underline.

See also fontUnderline().

void QTextEdit::setFontWeight ( int w )   [slot]

Sets the font weight of the current format to w.

See also fontWeight(), setCurrentFont(), setFontFamily(), and QFont::Weight.

void QTextEdit::setPlainText ( const QString & text )   [slot]

Changes the text of the text edit to the string text. Any previous text is removed.

text is interpreted as plain text.

Note that the undo/redo history is cleared by this function.

See also toPlainText().

void QTextEdit::setTextColor ( const QColor & c )   [slot]

Sets the text color of the current format to c.

See also textColor().

void QTextEdit::setTextCursor ( const QTextCursor & cursor )

Sets the visible cursor.

See also textCursor().

void QTextEdit::textChanged ()   [signal]

This signal is emitted whenever the document's content changes; for example, when text is inserted or deleted, or when formatting is applied.

QColor QTextEdit::textColor () const

Returns the text color of the current format.

See also setTextColor().

QTextCursor QTextEdit::textCursor () const

Returns a copy of the QTextCursor that represents the currently visible cursor. Note that changes on the returned cursor do not affect QTextEdit's cursor; use setTextCursor() to update the visible cursor.

See also setTextCursor().

QString QTextEdit::toPlainText () const

Returns the text of the text edit as plain text.

See also QTextEdit::setPlainText().

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

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

void QTextEdit::zoomIn ( int range = 1 )   [slot]

Zooms in on the text by by making the base font size range points larger and recalculating all font sizes to be the new size. This does not change the size of any images.

See also zoomOut().

void QTextEdit::zoomOut ( int range = 1 )   [slot]

Zooms out on the text by making the base font size range points smaller and recalculating all font sizes to be the new size. This does not change the size of any images.

See also zoomIn().


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Qt 4.1.3