QLineEdit Class Reference
[QtGui module]

Detailed Description

The QLineEdit widget is a one-line text editor.

A line edit allows the user to enter and edit a single line of plain text with a useful collection of editing functions, including undo and redo, cut and paste, and drag and drop.

By changing the echoMode() of a line edit, it can also be used as a "write-only" field, for inputs such as passwords.

The length of the text can be constrained to maxLength(). The text can be arbitrarily constrained using a validator() or an inputMask(), or both.

A related class is QTextEdit which allows multi-line, rich text editing.

You can change the text with setText() or insert(). The text is retrieved with text(); the displayed text (which may be different, see EchoMode) is retrieved with displayText(). Text can be selected with setSelection() or selectAll(), and the selection can be cut(), copy()ied and paste()d. The text can be aligned with setAlignment().

When the text changes the textChanged() signal is emitted; when the text changes other than by calling setText() the textEdited() signal is emitted; when the cursor is moved the cursorPositionChanged() signal is emitted; and when the Return or Enter key is pressed the returnPressed() signal is emitted.

When editing is finished, either because the line edit lost focus or Return/Enter is pressed the editingFinished() signal is emitted.

Note that if there is a validator set on the line edit, the returnPressed()/editingFinished() signals will only be emitted if the validator returns QValidator::Acceptable.

By default, QLineEdits have a frame as specified by the Windows and Motif style guides; you can turn it off by calling setFrame(false).

The default key bindings are described below. The line edit also provides a context menu (usually invoked by a right mouse click) that presents some of these editing options.

Any other key sequence that represents a valid character, will cause the character to be inserted into the line edit.

	A line edit shown in the Macintosh widget style.
	A line edit shown in the Windows XP widget style.
	A line edit shown in the Plastique widget style.

See also QTextEdit, QLabel, QComboBox, GUI Design Handbook: Field, Entry, and Line Edits Example.

Member Type Documentation

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