Class: MKeyEventHandler

Declaration: KeyboardInput.h

Taxonomy Categories:

Member Functions:

Interface Category:

API.

Inherits From:

None.

Inherited By:

TTypingInteractor TInputMethodKeyboardBehavior TCursorKeyFilter TDialogView TMenu TTextView

Purpose:

MKeyEventHandler is a mixin class that implements the protocol for handling keyboard events.

Instantiation:

Abstract base class; do not allocate.

Deriving Classes:

Classes deriving from MKeyEventHandler override the member functions responsible for handling keyboard events (KeyDown, KeyUp, ModifierKeyDown, and ModifierKeyUp.) You would normally mix this class into a derived class of MEventTarget.

Concurrency:

Not multithread safe.

Resource Use:

No special requirements.

Member Function: MKeyEventHandler::MKeyEventHandler

MKeyEventHandler ()
MKeyEventHandler (const MKeyEventHandler & copy)

Interface Category:

API.

Purpose:

Default constructor.
Copy constructor.

Calling Context:

Called by the stream-in operators. This can also be called directly by the deriving classes during construction.
Called to copy an object.

Parameters:

Takes no parameters.
const MKeyEventHandler & copy -The object to be copied.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: MKeyEventHandler::~MKeyEventHandler

virtual ~ MKeyEventHandler ()

Interface Category:

API.

Purpose:

Destructor.

Calling Context:

Called to destroy an object.

Parameters:

Takes no parameters.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: MKeyEventHandler::operator=

MKeyEventHandler & operator =(const MKeyEventHandler & assign)

Interface Category:

API.

Purpose:

Assignment operator.

Calling Context:

Called when an object is assigned to another compatible object.

Parameters:

const MKeyEventHandler & assign -The object to be copied.

Return Value:

Returns a const reference to the left-hand side object.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: MKeyEventHandler::KeyDown

virtual bool KeyDown (TKeyDownEvent & event)

Interface Category:

API.

Purpose:

Handles a key-down event.

Calling Context:

Called when a key is pressed on the keyboard.

Parameters:

TKeyDownEvent & event -The event generated on key down.

Return Value:

Returns false but will be overridden by the deriving classes to return the appropriate value.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

Classes deriving from MKeyEventHandler should override this function to implement specific key-down handling behavior.

Member Function: MKeyEventHandler::KeyUp

virtual bool KeyUp (TKeyUpEvent & event)

Interface Category:

API.

Purpose:

Handles a key-up event.

Calling Context:

Called when a key is pressed on the keyboard.

Parameters:

TKeyUpEvent & event -The event generated on key up.

Return Value:

Returns false but will be overridden by the deriving classes to return the appropriate value.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

Classes deriving from MKeyEventHandler should override this function to implement specific key-up handling behavior.

Member Function: MKeyEventHandler::ModifierKeyDown

virtual bool ModifierKeyDown (TModifierKeyDownEvent & event)

Interface Category:

API.

Purpose:

Handles a modifier key-down event.

Calling Context:

Called when a modifier key is pressed on the keyboard.

Parameters:

TModifierKeyDownEvent & event -The event generated when a modifier key is down.

Return Value:

Returns false but will be overridden by the deriving classes to return the appropriate value.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

Classes deriving from MKeyEventHandler should override this function to implement specific modifier key-down handling behavior.

Member Function: MKeyEventHandler::ModifierKeyUp

virtual bool ModifierKeyUp (TModifierKeyUpEvent & event)

Interface Category:

API.

Purpose:

Handles a key-up event.

Calling Context:

Called when a modifier key is up on the keyboard.

Parameters:

TModifierKeyUpEvent & event -The event generated when a modifier key is up.

Return Value:

Returns false but will be overridden by the deriving classes to return the appropriate value.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

Classes deriving from MKeyEventHandler should override this function to implement specific modifier key-up handling behavior.

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