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QKeySequence Class Reference
[QtGui module]

The QKeySequence class encapsulates a key sequence as used by shortcuts. More...

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Detailed Description

This class can be pickled.

StandardKey, QString or a Python int object may be used whenever QKeySequence is expected.

The QKeySequence class encapsulates a key sequence as used by shortcuts.

In its most common form, a key sequence describes a combination of keys that must be used together to perform some action. Key sequences are used with QAction objects to specify which keyboard shortcuts can be used to trigger actions.

Key sequences can be constructed for use as keyboard shortcuts in three different ways:

For example, Ctrl P might be a sequence used as a shortcut for printing a document, and can be specified in any of the following ways:

 QKeySequence(QKeySequence.Print);
 QKeySequence(tr("Ctrl+P"));
 QKeySequence(tr("Ctrl+p"));
 QKeySequence(Qt.CTRL + Qt.Key_P);

Note that, for letters, the case used in the specification string does not matter. In the above examples, the user does not need to hold down the Shift key to activate a shortcut specified with "Ctrl+P". However, for other keys, the use of Shift as an unspecified extra modifier key can lead to confusion for users of an application whose keyboards have different layouts to those used by the developers. See the Keyboard Layout Issues section below for more details.

It is preferable to use standard shortcuts where possible. When creating key sequences for non-standard shortcuts, you should use human-readable strings in preference to hard-coded integer values.

QKeySequence objects can be cast to a QString to obtain a human-readable translated version of the sequence. Similarly, the toString() function produces human-readable strings for use in menus. On Mac OS X, the appropriate symbols are used to describe keyboard shortcuts using special keys on the Macintosh keyboard.

An alternative way to specify hard-coded key codes is to use the Unicode code point of the character; for example, 'A' gives the same key sequence as Qt.Key_A.

Note: On Mac OS X, references to "Ctrl", Qt.CTRL, Qt.Control and Qt.ControlModifier correspond to the Command keys on the Macintosh keyboard, and references to "Meta", Qt.META, Qt.Meta and Qt.MetaModifier correspond to the Control keys. Developers on Mac OS X can use the same shortcut descriptions across all platforms, and their applications will automatically work as expected on Mac OS X.

Standard Shortcuts

QKeySequence defines many standard keyboard shortcuts to reduce the amount of effort required when setting up actions in a typical application. The table below shows some common key sequences that are often used for these standard shortcuts by applications on four widely-used platforms. Note that on Mac OS X, the Ctrl value corresponds to the Command keys on the Macintosh keyboard, and the Meta value corresponds to the Control keys.

StandardKey Windows Mac OS X KDE GNOME S60
HelpContents F1 Ctrl+? F1 F1 F2
WhatsThis Shift+F1 Shift+F1 Shift+F1 Shift+F1 Shift+F1
Open Ctrl+O Ctrl+O Ctrl+O Ctrl+O (none)
Close Ctrl+F4, Ctrl+W Ctrl+W, Ctrl+F4 Ctrl+W Ctrl+W (none)
Save Ctrl+S Ctrl+S Ctrl+S Ctrl+S (none)
Quit Ctrl+Q Qtrl+Q Qtrl+Q (none)
SaveAs Ctrl+Shift+S Ctrl+Shift+S (none)
New Ctrl+N Ctrl+N Ctrl+N Ctrl+N (none)
Delete Del Del, Meta+D Del, Ctrl+D Del, Ctrl+D Del
Cut Ctrl+X, Shift+Del Ctrl+X Ctrl+X, F20, Shift+Del Ctrl+X, F20, Shift+Del Ctrl+X
Copy Ctrl+C, Ctrl+Ins Ctrl+C Ctrl+C, F16, Ctrl+Ins Ctrl+C, F16, Ctrl+Ins Ctrl+C
Paste Ctrl+V, Shift+Ins Ctrl+V Ctrl+V, F18, Shift+Ins Ctrl+V, F18, Shift+Ins Ctrl+V
Preferences Ctrl+, (none)
Undo Ctrl+Z, Alt+Backspace Ctrl+Z Ctrl+Z, F14 Ctrl+Z, F14 Ctrl+Z
Redo Ctrl+Y, Shift+Ctrl+Z, Alt+Shift+Backspace Ctrl+Shift+Z Ctrl+Shift+Z Ctrl+Shift+Z (none)
Back Alt+Left, Backspace Ctrl+[ Alt+Left Alt+Left (none)
Forward Alt+Right, Shift+Backspace Ctrl+] Alt+Right Alt+Right (none)
Refresh F5 F5 F5 Ctrl+R, F5 (none)
ZoomIn Ctrl+Plus Ctrl+Plus Ctrl+Plus Ctrl+Plus (none)
ZoomOut Ctrl+Minus Ctrl+Minus Ctrl+Minus Ctrl+Minus (none)
Print Ctrl+P Ctrl+P Ctrl+P Ctrl+P (none)
AddTab Ctrl+T Ctrl+T Ctrl+Shift+N, Ctrl+T Ctrl+T (none)
NextChild Ctrl+Tab, Forward, Ctrl+F6 Ctrl+}, Forward, Ctrl+Tab Ctrl+Tab, Forward, Ctrl+Comma Ctrl+Tab, Forward (none)
PreviousChild Ctrl+Shift+Tab, Back, Ctrl+Shift+F6 Ctrl+{, Back, Ctrl+Shift+Tab Ctrl+Shift+Tab, Back, Ctrl+Period Ctrl+Shift+Tab, Back (none)
Find Ctrl+F Ctrl+F Ctrl+F Ctrl+F (none)
FindNext F3, Ctrl+G Ctrl+G F3 Ctrl+G, F3 (none)
FindPrevious Shift+F3, Ctrl+Shift+G Ctrl+Shift+G Shift+F3 Ctrl+Shift+G, Shift+F3 (none)
Replace Ctrl+H (none) Ctrl+R Ctrl+H (none)
SelectAll Ctrl+A Ctrl+A Ctrl+A Ctrl+A (none)
Bold Ctrl+B Ctrl+B Ctrl+B Ctrl+B (none)
Italic Ctrl+I Ctrl+I Ctrl+I Ctrl+I (none)
Underline Ctrl+U Ctrl+U Ctrl+U Ctrl+U (none)
MoveToNextChar Right Right Right Right Right
MoveToPreviousChar Left Left Left Left Left
MoveToNextWord Ctrl+Right Alt+Right Ctrl+Right Ctrl+Right Ctrl+Right
MoveToPreviousWord Ctrl+Left Alt+Left Ctrl+Left Ctrl+Left Ctrl+Left
MoveToNextLine Down Down Down Down Down
MoveToPreviousLine Up Up Up Up Up
MoveToNextPage PgDown PgDown, Alt+PgDown, Meta+Down, Meta+PgDown PgDown PgDown PgDown
MoveToPreviousPage PgUp PgUp, Alt+PgUp, Meta+Up, Meta+PgUp PgUp PgUp PgUp
MoveToStartOfLine Home Ctrl+Left, Meta+Left Home Home Home
MoveToEndOfLine End Ctrl+Right, Meta+Right End End End
MoveToStartOfBlock (none) Alt+Up, Meta+A (none) (none) (none)
MoveToEndOfBlock (none) Alt+Down, Meta+E (none) (none) (none)
MoveToStartOfDocument Ctrl+Home Ctrl+Up, Home Ctrl+Home Ctrl+Home Ctrl+Home
MoveToEndOfDocument Ctrl+End Ctrl+Down, End Ctrl+End Ctrl+End Ctrl+End
SelectNextChar Shift+Right Shift+Right Shift+Right Shift+Right Shift+Right
SelectPreviousChar Shift+Left Shift+Left Shift+Left Shift+Left Shift+Left
SelectNextWord Ctrl+Shift+Right Alt+Shift+Right Ctrl+Shift+Right Ctrl+Shift+Right Ctrl+Shift+Right
SelectPreviousWord Ctrl+Shift+Left Alt+Shift+Left Ctrl+Shift+Left Ctrl+Shift+Left Ctrl+Shift+Left
SelectNextLine Shift+Down Shift+Down Shift+Down Shift+Down Shift+Down
SelectPreviousLine Shift+Up Shift+Up Shift+Up Shift+Up Shift+Up
SelectNextPage Shift+PgDown Shift+PgDown Shift+PgDown Shift+PgDown Shift+PgDown
SelectPreviousPage Shift+PgUp Shift+PgUp Shift+PgUp Shift+PgUp Shift+PgUp
SelectStartOfLine Shift+Home Ctrl+Shift+Left Shift+Home Shift+Home Shift+Home
SelectEndOfLine Shift+End Ctrl+Shift+Right Shift+End Shift+End Shift+End
SelectStartOfBlock (none) Alt+Shift+Up, Meta+Shift+A (none) (none) (none)
SelectEndOfBlock (none) Alt+Shift+Down, Meta+Shift+E (none) (none) (none)
SelectStartOfDocument Ctrl+Shift+Home Ctrl+Shift+Up, Shift+Home Ctrl+Shift+Home Ctrl+Shift+Home Ctrl+Shift+Home
SelectEndOfDocument Ctrl+Shift+End Ctrl+Shift+Down, Shift+End Ctrl+Shift+End Ctrl+Shift+End Ctrl+Shift+End
DeleteStartOfWord Ctrl+Backspace Alt+Backspace Ctrl+Backspace Ctrl+Backspace (none)
DeleteEndOfWord Ctrl+Del (none) Ctrl+Del Ctrl+Del (none)
DeleteEndOfLine (none) (none) Ctrl+K Ctrl+K (none)
InsertParagraphSeparator Enter Enter Enter Enter (none)
InsertLineSeparator Shift+Enter Meta+Enter Shift+Enter Shift+Enter (none)

Note that, since the key sequences used for the standard shortcuts differ between platforms, you still need to test your shortcuts on each platform to ensure that you do not unintentionally assign the same key sequence to many actions.

Keyboard Layout Issues

Many key sequence specifications are chosen by developers based on the layout of certain types of keyboard, rather than choosing keys that represent the first letter of an action's name, such as Ctrl S ("Ctrl+S") or Ctrl C ("Ctrl+C"). Additionally, because certain symbols can only be entered with the help of modifier keys on certain keyboard layouts, key sequences intended for use with one keyboard layout may map to a different key, map to no keys at all, or require an additional modifier key to be used on different keyboard layouts.

For example, the shortcuts, Ctrl plus and Ctrl minus, are often used as shortcuts for zoom operations in graphics applications, and these may be specified as "Ctrl++" and "Ctrl+-" respectively. However, the way these shortcuts are specified and interpreted depends on the keyboard layout. Users of Norwegian keyboards will note that the + and - keys are not adjacent on the keyboard, but will still be able to activate both shortcuts without needing to press the Shift key. However, users with British keyboards will need to hold down the Shift key to enter the + symbol, making the shortcut effectively the same as "Ctrl+Shift+=".

Although some developers might resort to fully specifying all the modifiers they use on their keyboards to activate a shortcut, this will also result in unexpected behavior for users of different keyboard layouts.

For example, a developer using a British keyboard may decide to specify "Ctrl+Shift+=" as the key sequence in order to create a shortcut that coincidentally behaves in the same way as Ctrl plus. However, the = key needs to be accessed using the Shift key on Norwegian keyboard, making the required shortcut effectively Ctrl Shift Shift = (an impossible key combination).

As a result, both human-readable strings and hard-coded key codes can both be problematic to use when specifying a key sequence that can be used on a variety of different keyboard layouts. Only the use of standard shortcuts guarantees that the user will be able to use the shortcuts that the developer intended.

Despite this, we can address this issue by ensuring that human-readable strings are used, making it possible for translations of key sequences to be made for users of different languages. This approach will be successful for users whose keyboards have the most typical layout for the language they are using.

GNU Emacs Style Key Sequences

Key sequences similar to those used in GNU Emacs, allowing up to four key codes, can be created by using the multiple argument constructor, or by passing a human-readable string of comma-separated key sequences.

For example, the key sequence, Ctrl X followed by Ctrl C, can be specified using either of the following ways:

 QKeySequence(tr("Ctrl+X, Ctrl+C"));
 QKeySequence(Qt.CTRL + Qt.Key_X, Qt.CTRL + Qt.Key_C);

Warning: A QApplication instance must have been constructed before a QKeySequence is created; otherwise, your application may crash.


Type Documentation

QKeySequence.SequenceFormat

Constant Value Description
QKeySequence.NativeText 0 The key sequence as a platform specific string. This means that it will be shown translated and on the Mac it will resemble a key sequence from the menu bar. This enum is best used when you want to display the string to the user.
QKeySequence.PortableText 1 The key sequence is given in a "portable" format, suitable for reading and writing to a file. In many cases, it will look similar to the native text on Windows and X11.

QKeySequence.SequenceMatch

Constant Value Description
QKeySequence.NoMatch 0 The key sequences are different; not even partially matching.
QKeySequence.PartialMatch 1 The key sequences match partially, but are not the same.
QKeySequence.ExactMatch 2 The key sequences are the same.

QKeySequence.StandardKey

This enum represent standard key bindings. They can be used to assign platform dependent keyboard shortcuts to a QAction.

Note that the key bindings are platform dependent. The currently bound shortcuts can be queried using keyBindings().

Constant Value Description
QKeySequence.AddTab 19 Add new tab.
QKeySequence.Back 13 Navigate back.
QKeySequence.Bold 27 Bold text.
QKeySequence.Close 4 Close document/tab.
QKeySequence.Copy 9 Copy.
QKeySequence.Cut 8 Cut.
QKeySequence.Delete 7 Delete.
QKeySequence.DeleteEndOfLine 60 Delete end of line.
QKeySequence.DeleteEndOfWord 59 Delete word from the end of the cursor.
QKeySequence.DeleteStartOfWord 58 Delete the beginning of a word up to the cursor.
QKeySequence.Find 22 Find in document.
QKeySequence.FindNext 23 Find next result.
QKeySequence.FindPrevious 24 Find previous result.
QKeySequence.Forward 14 Navigate forward.
QKeySequence.HelpContents 1 Open help contents.
QKeySequence.InsertLineSeparator 62 Insert a new line.
QKeySequence.InsertParagraphSeparator 61 Insert a new paragraph.
QKeySequence.Italic 28 Italic text.
QKeySequence.MoveToEndOfBlock 41 Move cursor to end of block. This shortcut is only used on the OS X.
QKeySequence.MoveToEndOfDocument 43 Move cursor to end of document.
QKeySequence.MoveToEndOfLine 39 Move cursor to end of line.
QKeySequence.MoveToNextChar 30 Move cursor to next character.
QKeySequence.MoveToNextLine 34 Move cursor to next line.
QKeySequence.MoveToNextPage 36 Move cursor to next page.
QKeySequence.MoveToNextWord 32 Move cursor to next word.
QKeySequence.MoveToPreviousChar 31 Move cursor to previous character.
QKeySequence.MoveToPreviousLine 35 Move cursor to previous line.
QKeySequence.MoveToPreviousPage 37 Move cursor to previous page.
QKeySequence.MoveToPreviousWord 33 Move cursor to previous word.
QKeySequence.MoveToStartOfBlock 40 Move cursor to start of a block. This shortcut is only used on OS X.
QKeySequence.MoveToStartOfDocument 42 Move cursor to start of document.
QKeySequence.MoveToStartOfLine 38 Move cursor to start of line.
QKeySequence.New 6 Create new document.
QKeySequence.NextChild 20 Navigate to next tab or child window.
QKeySequence.Open 3 Open document.
QKeySequence.Paste 10 Paste.
QKeySequence.Preferences 64 Open the preferences dialog.
QKeySequence.PreviousChild 21 Navigate to previous tab or child window.
QKeySequence.Print 18 Print document.
QKeySequence.Quit 65 Quit the application.
QKeySequence.Redo 12 Redo.
QKeySequence.Refresh 15 Refresh or reload current document.
QKeySequence.Replace 25 Find and replace.
QKeySequence.SaveAs 63 Save document after prompting the user for a file name.
QKeySequence.Save 5 Save document.
QKeySequence.SelectAll 26 Select all text.
QKeySequence.SelectEndOfBlock 55 Extend selection to the end of a text block. This shortcut is only used on OS X.
QKeySequence.SelectEndOfDocument 57 Extend selection to end of document.
QKeySequence.SelectEndOfLine 53 Extend selection to end of line.
QKeySequence.SelectNextChar 44 Extend selection to next character.
QKeySequence.SelectNextLine 48 Extend selection to next line.
QKeySequence.SelectNextPage 50 Extend selection to next page.
QKeySequence.SelectNextWord 46 Extend selection to next word.
QKeySequence.SelectPreviousChar 45 Extend selection to previous character.
QKeySequence.SelectPreviousLine 49 Extend selection to previous line.
QKeySequence.SelectPreviousPage 51 Extend selection to previous page.
QKeySequence.SelectPreviousWord 47 Extend selection to previous word.
QKeySequence.SelectStartOfBlock 54 Extend selection to the start of a text block. This shortcut is only used on OS X.
QKeySequence.SelectStartOfDocument 56 Extend selection to start of document.
QKeySequence.SelectStartOfLine 52 Extend selection to start of line.
QKeySequence.Underline 29 Underline text.
QKeySequence.Undo 11 Undo.
QKeySequence.UnknownKey 0 Unbound key.
QKeySequence.WhatsThis 2 Activate whats this.
QKeySequence.ZoomIn 16 Zoom in.
QKeySequence.ZoomOut 17 Zoom out.

This enum was introduced or modified in Qt 4.2.


Method Documentation

QKeySequence.__init__ (self)

Constructs an empty key sequence.

QKeySequence.__init__ (self, QKeySequence ks)

Creates a key sequence from the key string. For example "Ctrl+O" gives CTRL+'O'. The strings "Ctrl", "Shift", "Alt" and "Meta" are recognized, as well as their translated equivalents in the "QShortcut" context (using QObject.tr()).

Up to four key codes may be entered by separating them with commas, e.g. "Alt+X,Ctrl+S,Q".

key should be in NativeText format.

This constructor is typically used with tr(), so that shortcut keys can be replaced in translations:

 QMenu *file = new QMenu(this);
 file->addAction(tr("&Open..."), this, SLOT(open()),
                   QKeySequence(tr("Ctrl+O", "File|Open")));

Note the "File|Open" translator comment. It is by no means necessary, but it provides some context for the human translator.

QKeySequence.__init__ (self, QString key, SequenceFormat format)

Creates a key sequence from the key string based on format.

This function was introduced in Qt 4.7.

QKeySequence.__init__ (self, int k1, int key2 = 0, int key3 = 0, int key4 = 0)

Constructs a key sequence with up to 4 keys k1, k2, k3 and k4.

The key codes are listed in Qt.Key and can be combined with modifiers (see Qt.Modifier) such as Qt.SHIFT, Qt.CTRL, Qt.ALT, or Qt.META.

QKeySequence.__init__ (self, QVariant variant)

Copy constructor. Makes a copy of keysequence.

int QKeySequence.count (self)

Returns the number of keys in the key sequence. The maximum is 4.

QKeySequence QKeySequence.fromString (QString str, SequenceFormat format = QKeySequence.PortableText)

Return a QKeySequence from the string str based on format.

This function was introduced in Qt 4.1.

See also toString().

bool QKeySequence.isDetached (self)

bool QKeySequence.isEmpty (self)

Returns true if the key sequence is empty; otherwise returns false.

unknown-type QKeySequence.keyBindings (StandardKey key)

Returns a list of key bindings for the given key. The result of calling this function will vary based on the target platform. The first element of the list indicates the primary shortcut for the given platform. If the result contains more than one result, these can be considered alternative shortcuts on the same platform for the given key.

This function was introduced in Qt 4.2.

SequenceMatch QKeySequence.matches (self, QKeySequence seq)

Matches the sequence with seq. Returns ExactMatch if successful, PartialMatch if seq matches incompletely, and NoMatch if the sequences have nothing in common. Returns NoMatch if seq is shorter.

QKeySequence QKeySequence.mnemonic (QString text)

Returns the shortcut key sequence for the mnemonic in text, or an empty key sequence if no mnemonics are found.

For example, mnemonic("E&xit") returns Qt.ALT+Qt.Key_X, mnemonic("&Quit") returns ALT+Key_Q, and mnemonic("Quit") returns an empty QKeySequence.

We provide a list of common mnemonics in English. At the time of writing, Microsoft and Open Group do not appear to have issued equivalent recommendations for other languages.

See also qt_set_sequence_auto_mnemonic().

QKeySequence.swap (self, QKeySequence other)

Swaps key sequence other with this key sequence. This operation is very fast and never fails.

This function was introduced in Qt 4.8.

QString QKeySequence.toString (self, SequenceFormat format = QKeySequence.PortableText)

Return a string representation of the key sequence, based on format.

For example, the value Qt.CTRL+Qt.Key_O results in "Ctrl+O". If the key sequence has multiple key codes, each is separated by commas in the string returned, such as "Alt+X, Ctrl+Y, Z". The strings, "Ctrl", "Shift", etc. are translated using QObject.tr() in the "QShortcut" context.

If the key sequence has no keys, an empty string is returned.

On Mac OS X, the string returned resembles the sequence that is shown in the menu bar.

This function was introduced in Qt 4.1.

See also fromString().

bool QKeySequence.__eq__ (self, QKeySequence other)

bool QKeySequence.__ge__ (self, QKeySequence other)

int QKeySequence.__getitem__ (self, int i)

bool QKeySequence.__gt__ (self, QKeySequence other)

int QKeySequence.__int__ (self)

bool QKeySequence.__le__ (self, QKeySequence other)

int QKeySequence.__len__ (self)

bool QKeySequence.__lt__ (self, QKeySequence ks)

bool QKeySequence.__ne__ (self, QKeySequence other)


PyQt 4.12.1 for X11Copyright © Riverbank Computing Ltd and The Qt Company 2015Qt 4.8.7