Struct qt_gui::QInputMethodEvent

#[repr(C)]pub struct QInputMethodEvent { /* fields omitted */ }

The QInputMethodEvent class provides parameters for input method events.

C++ class: QInputMethodEvent.

C++ documentation:

The QInputMethodEvent class provides parameters for input method events.

Input method events are sent to widgets when an input method is used to enter text into a widget. Input methods are widely used to enter text for languages with non-Latin alphabets.

Note that when creating custom text editing widgets, the Qt::WA_InputMethodEnabled window attribute must be set explicitly (using the QWidget::setAttribute() function) in order to receive input method events.

The events are of interest to authors of keyboard entry widgets who want to be able to correctly handle languages with complex character input. Text input in such languages is usually a three step process:

1. Starting to Compose

   When the user presses the first key on a keyboard, an input context is created. This input context will contain a string of the typed characters.

2. Composing

   With every new key pressed, the input method will try to create a matching string for the text typed so far called preedit string. While the input context is active, the user can only move the cursor inside the string belonging to this input context.

3. Completing

   At some point, the user will activate a user interface component (perhaps using a particular key) where they can choose from a number of strings matching the text they have typed so far. The user can either confirm their choice cancel the input; in either case the input context will be closed.

QInputMethodEvent models these three stages, and transfers the information needed to correctly render the intermediate result. A QInputMethodEvent has two main parameters: preeditString() and commitString(). The preeditString() parameter gives the currently active preedit string. The commitString() parameter gives a text that should get added to (or replace parts of) the text of the editor widget. It usually is a result of the input operations and has to be inserted to the widgets text directly before the preedit string.

If the commitString() should replace parts of the of the text in the editor, replacementLength() will contain the number of characters to be replaced. replacementStart() contains the position at which characters are to be replaced relative from the start of the preedit string.

A number of attributes control the visual appearance of the preedit string (the visual appearance of text outside the preedit string is controlled by the widget only). The AttributeType enum describes the different attributes that can be set.

A class implementing QWidget::inputMethodEvent() or QGraphicsItem::inputMethodEvent() should at least understand and honor the TextFormat and Cursor attributes.

Since input methods need to be able to query certain properties from the widget or graphics item, subclasses must also implement QWidget::inputMethodQuery() and QGraphicsItem::inputMethodQuery(), respectively.

When receiving an input method event, the text widget has to performs the following steps:

1. If the widget has selected text, the selected text should get removed.
2. Remove the text starting at replacementStart() with length replacementLength() and replace it by the commitString(). If replacementLength() is 0, replacementStart() gives the insertion position for the commitString().

   When doing replacement the area of the preedit string is ignored, thus a replacement starting at -1 with a length of 2 will remove the last character before the preedit string and the first character afterwards, and insert the commit string directly before the preedit string.

   If the widget implements undo/redo, this operation gets added to the undo stack.

3. If there is no current preedit string, insert the preeditString() at the current cursor position; otherwise replace the previous preeditString with the one received from this event.

   If the widget implements undo/redo, the preeditString() should not influence the undo/redo stack in any way.

   The widget should examine the list of attributes to apply to the preedit string. It has to understand at least the TextFormat and Cursor attributes and render them as specified.

Methods

impl QInputMethodEvent

pub unsafe fn attributes(&self) -> Ref<QListOfAttribute>

Returns the list of attributes passed to the QInputMethodEvent constructor. The attributes control the visual appearance of the preedit string (the visual appearance of text outside the preedit string is controlled by the widget only).

Calls C++ function: const QList<QInputMethodEvent::Attribute>& QInputMethodEvent::attributes() const.

C++ documentation:

Returns the list of attributes passed to the QInputMethodEvent constructor. The attributes control the visual appearance of the preedit string (the visual appearance of text outside the preedit string is controlled by the widget only).

See also preeditString() and Attribute.

pub unsafe fn commit_string(&self) -> Ref<QString>

Returns the text that should get added to (or replace parts of) the text of the editor widget. It usually is a result of the input operations and has to be inserted to the widgets text directly before the preedit string.

Calls C++ function: const QString& QInputMethodEvent::commitString() const.

C++ documentation:

Returns the text that should get added to (or replace parts of) the text of the editor widget. It usually is a result of the input operations and has to be inserted to the widgets text directly before the preedit string.

See also setCommitString(), preeditString(), replacementStart(), and replacementLength().

pub unsafe fn copy_from(
    &self,
    other: impl CastInto<Ref<QInputMethodEvent>>
) -> Ref<QInputMethodEvent>

The QInputMethodEvent class provides parameters for input method events.

Calls C++ function: QInputMethodEvent& QInputMethodEvent::operator=(const QInputMethodEvent& other).

C++ documentation:

The QInputMethodEvent class provides parameters for input method events.

Input method events are sent to widgets when an input method is used to enter text into a widget. Input methods are widely used to enter text for languages with non-Latin alphabets.

Note that when creating custom text editing widgets, the Qt::WA_InputMethodEnabled window attribute must be set explicitly (using the QWidget::setAttribute() function) in order to receive input method events.

The events are of interest to authors of keyboard entry widgets who want to be able to correctly handle languages with complex character input. Text input in such languages is usually a three step process:

1. Starting to Compose

   When the user presses the first key on a keyboard, an input context is created. This input context will contain a string of the typed characters.

2. Composing

   With every new key pressed, the input method will try to create a matching string for the text typed so far called preedit string. While the input context is active, the user can only move the cursor inside the string belonging to this input context.

3. Completing

   At some point, the user will activate a user interface component (perhaps using a particular key) where they can choose from a number of strings matching the text they have typed so far. The user can either confirm their choice cancel the input; in either case the input context will be closed.

QInputMethodEvent models these three stages, and transfers the information needed to correctly render the intermediate result. A QInputMethodEvent has two main parameters: preeditString() and commitString(). The preeditString() parameter gives the currently active preedit string. The commitString() parameter gives a text that should get added to (or replace parts of) the text of the editor widget. It usually is a result of the input operations and has to be inserted to the widgets text directly before the preedit string.

If the commitString() should replace parts of the of the text in the editor, replacementLength() will contain the number of characters to be replaced. replacementStart() contains the position at which characters are to be replaced relative from the start of the preedit string.

A number of attributes control the visual appearance of the preedit string (the visual appearance of text outside the preedit string is controlled by the widget only). The AttributeType enum describes the different attributes that can be set.

A class implementing QWidget::inputMethodEvent() or QGraphicsItem::inputMethodEvent() should at least understand and honor the TextFormat and Cursor attributes.

Since input methods need to be able to query certain properties from the widget or graphics item, subclasses must also implement QWidget::inputMethodQuery() and QGraphicsItem::inputMethodQuery(), respectively.

When receiving an input method event, the text widget has to performs the following steps:

1. If the widget has selected text, the selected text should get removed.
2. Remove the text starting at replacementStart() with length replacementLength() and replace it by the commitString(). If replacementLength() is 0, replacementStart() gives the insertion position for the commitString().

   When doing replacement the area of the preedit string is ignored, thus a replacement starting at -1 with a length of 2 will remove the last character before the preedit string and the first character afterwards, and insert the commit string directly before the preedit string.

   If the widget implements undo/redo, this operation gets added to the undo stack.

3. If there is no current preedit string, insert the preeditString() at the current cursor position; otherwise replace the previous preeditString with the one received from this event.

   If the widget implements undo/redo, the preeditString() should not influence the undo/redo stack in any way.

   The widget should examine the list of attributes to apply to the preedit string. It has to understand at least the TextFormat and Cursor attributes and render them as specified.

pub unsafe fn new_0a() -> CppBox<QInputMethodEvent>

Constructs an event of type QEvent::InputMethod. The attributes(), preeditString(), commitString(), replacementStart(), and replacementLength() are initialized to default values.

Calls C++ function: [constructor] void QInputMethodEvent::QInputMethodEvent().

C++ documentation:

Constructs an event of type QEvent::InputMethod. The attributes(), preeditString(), commitString(), replacementStart(), and replacementLength() are initialized to default values.

See also setCommitString().

pub unsafe fn new_2a(
    preedit_text: impl CastInto<Ref<QString>>,
    attributes: impl CastInto<Ref<QListOfAttribute>>
) -> CppBox<QInputMethodEvent>

Constructs an event of type QEvent::InputMethod. The preedit text is set to preeditText, the attributes to attributes.

Calls C++ function: [constructor] void QInputMethodEvent::QInputMethodEvent(const QString& preeditText, const QList<QInputMethodEvent::Attribute>& attributes).

C++ documentation:

Constructs an event of type QEvent::InputMethod. The preedit text is set to preeditText, the attributes to attributes.

The commitString(), replacementStart(), and replacementLength() values can be set using setCommitString().

See also preeditString() and attributes().

pub unsafe fn new_copy(
    other: impl CastInto<Ref<QInputMethodEvent>>
) -> CppBox<QInputMethodEvent>

Constructs a copy of other.

Calls C++ function: [constructor] void QInputMethodEvent::QInputMethodEvent(const QInputMethodEvent& other).

C++ documentation:

Constructs a copy of other.

pub unsafe fn preedit_string(&self) -> Ref<QString>

Returns the preedit text, i.e. the text before the user started editing it.

Calls C++ function: const QString& QInputMethodEvent::preeditString() const.

C++ documentation:

Returns the preedit text, i.e. the text before the user started editing it.

See also commitString() and attributes().

pub unsafe fn replacement_length(&self) -> c_int

Returns the number of characters to be replaced in the preedit string.

Calls C++ function: int QInputMethodEvent::replacementLength() const.

C++ documentation:

Returns the number of characters to be replaced in the preedit string.

See also replacementStart() and setCommitString().

pub unsafe fn replacement_start(&self) -> c_int

Returns the position at which characters are to be replaced relative from the start of the preedit string.

Calls C++ function: int QInputMethodEvent::replacementStart() const.

C++ documentation:

Returns the position at which characters are to be replaced relative from the start of the preedit string.

See also replacementLength() and setCommitString().

pub unsafe fn set_commit_string_3a(
    &self,
    commit_string: impl CastInto<Ref<QString>>,
    replace_from: c_int,
    replace_length: c_int
)

Sets the commit string to commitString.

Calls C++ function: void QInputMethodEvent::setCommitString(const QString& commitString, int replaceFrom = …, int replaceLength = …).

C++ documentation:

Sets the commit string to commitString.

The commit string is the text that should get added to (or replace parts of) the text of the editor widget. It usually is a result of the input operations and has to be inserted to the widgets text directly before the preedit string.

If the commit string should replace parts of the of the text in the editor, replaceLength specifies the number of characters to be replaced. replaceFrom specifies the position at which characters are to be replaced relative from the start of the preedit string.

See also commitString(), replacementStart(), and replacementLength().

pub unsafe fn set_commit_string_2a(
    &self,
    commit_string: impl CastInto<Ref<QString>>,
    replace_from: c_int
)

Sets the commit string to commitString.

Calls C++ function: void QInputMethodEvent::setCommitString(const QString& commitString, int replaceFrom = …).

C++ documentation:

Sets the commit string to commitString.

The commit string is the text that should get added to (or replace parts of) the text of the editor widget. It usually is a result of the input operations and has to be inserted to the widgets text directly before the preedit string.

If the commit string should replace parts of the of the text in the editor, replaceLength specifies the number of characters to be replaced. replaceFrom specifies the position at which characters are to be replaced relative from the start of the preedit string.

See also commitString(), replacementStart(), and replacementLength().

pub unsafe fn set_commit_string_1a(
    &self,
    commit_string: impl CastInto<Ref<QString>>
)

Sets the commit string to commitString.

Calls C++ function: void QInputMethodEvent::setCommitString(const QString& commitString).

C++ documentation:

Sets the commit string to commitString.

The commit string is the text that should get added to (or replace parts of) the text of the editor widget. It usually is a result of the input operations and has to be inserted to the widgets text directly before the preedit string.

If the commit string should replace parts of the of the text in the editor, replaceLength specifies the number of characters to be replaced. replaceFrom specifies the position at which characters are to be replaced relative from the start of the preedit string.

See also commitString(), replacementStart(), and replacementLength().

Trait Implementations

impl CppDeletable for QInputMethodEvent

unsafe fn delete(&self)

Destroys the instance of QInputMethodEvent.

Calls C++ function: virtual [destructor] void QInputMethodEvent::~QInputMethodEvent().

C++ documentation:

Destroys the instance of QInputMethodEvent.

impl Deref for QInputMethodEvent

type Target = QEvent

The resulting type after dereferencing.

fn deref(&self) -> &QEvent

Calls C++ function: QEvent* static_cast<QEvent*>(QInputMethodEvent* ptr).

impl DynamicCast<QInputMethodEvent> for QEvent

unsafe fn dynamic_cast(ptr: Ptr<QEvent>) -> Ptr<QInputMethodEvent>

Calls C++ function: QInputMethodEvent* dynamic_cast<QInputMethodEvent*>(QEvent* ptr).

impl StaticDowncast<QInputMethodEvent> for QEvent

unsafe fn static_downcast(ptr: Ptr<QEvent>) -> Ptr<QInputMethodEvent>

Calls C++ function: QInputMethodEvent* static_cast<QInputMethodEvent*>(QEvent* ptr).

impl StaticUpcast<QEvent> for QInputMethodEvent

unsafe fn static_upcast(ptr: Ptr<QInputMethodEvent>) -> Ptr<QEvent>

Calls C++ function: QEvent* static_cast<QEvent*>(QInputMethodEvent* ptr).