VRS::InteractionTechnique Class Reference

Abstract base class for Interaction Techniques. More...

#include <vrs/sg/interactiontechnique.h>

Inheritance diagram for VRS::InteractionTechnique:

List of all members.

Public Types
typedef InteractionConcept::ViewParameterSet	ViewParameterSet
typedef int	KeyFunctionID
typedef int	MouseButtonFunctionID
Public Member Functions
SO< ViewParameterSet >	getViewParameters () const
	Provides access to the current view parameters.
SO< ViewParameterSet >	getPreviousViewParameters () const
	Provides access to the last applied view parameters.
virtual void	onTimer (SO< TimeEvent > event, double secondsSinceLastTimeEvent)
	If the InteractionTechnique is active (i.e.
SO< ConstraintHint >	getConstraintHint ()
	Some InteractionTechniques provide additional information that is used by certain constraints to find appropriate coorections if necessary.
void	assignKey (KeyFunctionID id, unsigned int key, InputEvent::Modifier mustModifier=InputEvent::NoModifier, InputEvent::Modifier mustNotModifier=InputEvent::AllKeys)
	Each InteractionTechnique defines functions that can be accessed via control keys or specific mouse buttons.
void	assignMouseButton (MouseButtonFunctionID id, InputEvent::Button button, InputEvent::Modifier mustModifier=InputEvent::NoModifier, InputEvent::Modifier mustNotModifier=InputEvent::AllKeys, InputEvent::Change mustChange=InputEvent::NoChange, InputEvent::Change mustNotChange=InputEvent::DoubleClick)
void	disableKeyFunction (KeyFunctionID id)
	These methods disable KeyFunctions or MouseButtonFunctions until they are newly assigned.
void	disableMouseButtonFunction (MouseButtonFunctionID id)
bool	getAssignedKey (KeyFunctionID id, unsigned int &key, InputEvent::Modifier &mustModifier, InputEvent::Modifier &mustNotModifier) const
	Puts the currently assigned key for 'id' in the three call-by-ref parameters 'key', 'mustModifier' and 'mustNotModifier' and returns true.
bool	getAssignedMouseButton (MouseButtonFunctionID id, InputEvent::Button &button, InputEvent::Modifier &mustModifier, InputEvent::Modifier &mustNotModifier, InputEvent::Change &mustChange, InputEvent::Change &mustNotChange) const
	Puts the currently assigned mouse button for 'id' in the five call-by-ref parameters 'button', 'mustModifier', 'mustNotModifier', 'mustChange' and 'mustNotChange' and returns true.
void	setWheelEnable (bool onOff)
	Disables or enable the mouse wheel for a certain InteractionTechnique.
virtual void	onKey (SO< KeyEvent > event, KeyFunctionID id)
	Called once for each key event.
virtual void	onDragStart (int x, int y, SO< ButtonEvent >, MouseButtonFunctionID id)
	Called for each mouse interaction (more exactly when a MouseButton is pressed).
virtual void	onDragMotion (int x, int y, SO< MotionEvent >, MouseButtonFunctionID id, int startX, int startY)
	During a mouse interaction (i.e.
virtual void	onDragEnd (int x, int y, SO< ButtonEvent >, MouseButtonFunctionID id, int startX, int startY)
	Called at the end of each mouse interaction, i.e. when a mouse button is released.
virtual void	onWheelEvent (SO< WheelEvent > we)
	For each incoming event the base class checks the event type and passes the event to the corresponding virtual method.
virtual void	onEvent (SO< Event > e)
	For each incoming event the base class checks the event type and passes the event to the corresponding virtual method.
virtual void	onEventPassive (SO< Event > e, bool modeActive)
	The aforementioned event handling methods are only called if the technique is active.
virtual void	onActivation ()
	Called each time a InteractionTechnique is activated, i.e.
virtual void	onDeactivation ()
	Called each time a InteractionTechnique is deactivated, i.e.
virtual bool	checkEventRelevance (SO< Event > event) const
	A Interaction is chosen as active Interaction (i.e.
bool	canWork () const
	Used by an orientation constraint to check whether a interaction technique can work based on the current view parameters.
virtual bool	preservingViewDirectionRequired () const
	Used to determine whether the view direction must be preserved after a constraintchecker has refused or corrected a movement of this technique.
virtual void	setEnabled (bool yesNo=true)
	Disables/Enables the technique within an InteractionMode.
virtual bool	enabled () const
	VRS_TYPEINFO (InteractionTechnique, SharedObj)
	VRS_SERIALIZABLE (InteractionTechnique)
Protected Member Functions
	InteractionTechnique ()
void	brake ()
	Should be used by InteractionTechniques if the user obviously wants to stop movement as fast as possible.
void	registerMouseButtonFunction (MouseButtonFunctionID id)
	Most interaction techniques define functions that can be called by assignable keys or mouse buttons.
void	registerKeyFunction (KeyFunctionID id)
bool	dragging (MouseButtonFunctionID id)
	Returns true if a dragging interaction is in progress (i.e.
bool	pressed (KeyFunctionID id)
	Returns true if a function key is currently pressed.
SO< InteractionConcept >	getParent () const
	Provides access to the parent interaction concept.
Friends
class	InteractionMode
Classes
struct	ButtonAssignment
struct	KeyAssignment

---

Detailed Description

Abstract base class for Interaction Techniques.

A InteractionTechnique converts user events (e.g. from mouse, keyboard or other devices) into changes on the current view parameters.

To use a InteractionTechnique:

• Create a InteractionMode nm
• Add the InteractionTechnique to nm
• Create a InteractionConcept nc
• Add nm to nc
• If you want to combine multiple InteractionTechniques (i.e. use it without explicit mode switches) add additional InteractionTechniques to nm
• If you want to allow mode switches between different interaction techniques via explicit mode switches, add additional InteractionModes to nc.

Only one InteractionTechnique of a InteractionMode, the active InteractionTechnique, has control over the view parameters. onTimer() is only called for the active Interaction.

Note: A InteractionTechnique must not used in multiple InteractionModes simulataneously.

Once per time event the current view parameters are applied. it is left to a derived techniqe whether to change the view parameters directly with each event or later in each onTimer() call.

---

Member Typedef Documentation

typedef InteractionConcept::ViewParameterSet VRS::InteractionTechnique::ViewParameterSet

typedef int VRS::InteractionTechnique::KeyFunctionID

typedef int VRS::InteractionTechnique::MouseButtonFunctionID

---

Constructor & Destructor Documentation

VRS::InteractionTechnique::InteractionTechnique

(

)

[protected]

---

Member Function Documentation

SO<ViewParameterSet> VRS::InteractionTechnique::getViewParameters

(

)

const

Provides access to the current view parameters.

The current ViewParameterSet is either the last one that have been applied, or it may be changed by the InteractionTechnique by user events since the last time event.

SO<ViewParameterSet> VRS::InteractionTechnique::getPreviousViewParameters

(

)

const

Provides access to the last applied view parameters.

It is used by Constraints to check what have been changed in the current cycle.

virtual void VRS::InteractionTechnique::onTimer	(	SO< TimeEvent >	event,
		double	secondsSinceLastTimeEvent
	)			[virtual]

If the InteractionTechnique is active (i.e.

has control of the view parameters) it receives user events and time events. The time event has a special meaning, because after the onTimer() call the current view parameters are finally applied. I.e. all view parameter states between two onTimer()-calls are not relevant. For convenience the time since the last time event is added, which could be alternatively calculated from the time event.

Reimplemented in VRS::CameraPathEditor, VRS::MoveFocusGroundPlateNavigation, VRS::SpaceMouseNavigation, and VRS::UndoNavigation.

SO<ConstraintHint> VRS::InteractionTechnique::getConstraintHint

(

)

Some InteractionTechniques provide additional information that is used by certain constraints to find appropriate coorections if necessary.

The InteractionHint refers to the change between the last and the last but one call of onTimer().

void VRS::InteractionTechnique::assignKey	(	KeyFunctionID	id,
		unsigned int	key,
		InputEvent::Modifier	mustModifier = InputEvent::NoModifier,
		InputEvent::Modifier	mustNotModifier = InputEvent::AllKeys
	)

Each InteractionTechnique defines functions that can be accessed via control keys or specific mouse buttons.

The assignment of keys and mouse buttons is managed by the InteractionTechnique base class. Each derived InteractionTechnique can register functions for control keys or mouse buttons. For this it must define an integer identifier for each such function. Only functionIDs that have been registered in the constructor of a derived class are accepted for assignment. If a modifier flag appears in both mustModifier and mustNotModifier, it is ignored as mustNotModifier.

void VRS::InteractionTechnique::assignMouseButton	(	MouseButtonFunctionID	id,
		InputEvent::Button	button,
		InputEvent::Modifier	mustModifier = InputEvent::NoModifier,
		InputEvent::Modifier	mustNotModifier = InputEvent::AllKeys,
		InputEvent::Change	mustChange = InputEvent::NoChange,
		InputEvent::Change	mustNotChange = InputEvent::DoubleClick
	)

void VRS::InteractionTechnique::disableKeyFunction

(

KeyFunctionID

id

)

These methods disable KeyFunctions or MouseButtonFunctions until they are newly assigned.

void VRS::InteractionTechnique::disableMouseButtonFunction

(

MouseButtonFunctionID

id

)

bool VRS::InteractionTechnique::getAssignedKey	(	KeyFunctionID	id,
		unsigned int &	key,
		InputEvent::Modifier &	mustModifier,
		InputEvent::Modifier &	mustNotModifier
	)			const

Puts the currently assigned key for 'id' in the three call-by-ref parameters 'key', 'mustModifier' and 'mustNotModifier' and returns true.

If the key is disabled, this method returns false.

bool VRS::InteractionTechnique::getAssignedMouseButton	(	MouseButtonFunctionID	id,
		InputEvent::Button &	button,
		InputEvent::Modifier &	mustModifier,
		InputEvent::Modifier &	mustNotModifier,
		InputEvent::Change &	mustChange,
		InputEvent::Change &	mustNotChange
	)			const

Puts the currently assigned mouse button for 'id' in the five call-by-ref parameters 'button', 'mustModifier', 'mustNotModifier', 'mustChange' and 'mustNotChange' and returns true.

If the button is disabled, this method returns false.

void VRS::InteractionTechnique::setWheelEnable

(

bool

onOff

)

Disables or enable the mouse wheel for a certain InteractionTechnique.

virtual void VRS::InteractionTechnique::onKey	(	SO< KeyEvent >	event,
		KeyFunctionID	id
	)			[virtual]

Called once for each key event.

virtual void VRS::InteractionTechnique::onDragStart	(	int	x,
		int	y,
		SO< ButtonEvent >	,
		MouseButtonFunctionID	id
	)			[virtual]

Called for each mouse interaction (more exactly when a MouseButton is pressed).

The MouseButtonFunctionID can be used to decide which function to activate.

virtual void VRS::InteractionTechnique::onDragMotion	(	int	x,
		int	y,
		SO< MotionEvent >	,
		MouseButtonFunctionID	id,
		int	startX,
		int	startY
	)			[virtual]

During a mouse interaction (i.e.

while a mouse button is hold)) dragMotion() is called. For convenience, the mouse coordinates of the previous dragMotion() call and the coordinates during the last dragStart() are passed as additional parameters.

virtual void VRS::InteractionTechnique::onDragEnd	(	int	x,
		int	y,
		SO< ButtonEvent >	,
		MouseButtonFunctionID	id,
		int	startX,
		int	startY
	)			[virtual]

Called at the end of each mouse interaction, i.e. when a mouse button is released.

virtual void VRS::InteractionTechnique::onWheelEvent

(

SO< WheelEvent >

we

)

[virtual]

For each incoming event the base class checks the event type and passes the event to the corresponding virtual method.

In addition each event() method is called for each event.

Reimplemented in VRS::ZoomGroundPlateNavigation.

virtual void VRS::InteractionTechnique::onEvent

(

SO< Event >

e

)

[virtual]

For each incoming event the base class checks the event type and passes the event to the corresponding virtual method.

In addition each event() method is called for each event.

Reimplemented in VRS::ScenePicker, and VRS::SpaceMouseNavigation.

virtual void VRS::InteractionTechnique::onEventPassive	(	SO< Event >	e,
		bool	modeActive
	)			[virtual]

The aforementioned event handling methods are only called if the technique is active.

onEventPassive() is called for all techniques of the current InteractionConcept. The parameter modeActive says if the mode of the technique is currently selected. Note: For a controlled access of the view, onEventPassive must not change the view parameters. It can be used to update internal states, e.g., to observe the current viewing position.

Reimplemented in VRS::AreaSelector, VRS::CameraPathEditor, and VRS::UndoNavigation.

virtual void VRS::InteractionTechnique::onActivation

(

)

[virtual]

Called each time a InteractionTechnique is activated, i.e.

selected as active Interaction of a InteractionMode. It can be implemented by derivatives to initialize internal parameters.

Reimplemented in VRS::ScenePicker.

virtual void VRS::InteractionTechnique::onDeactivation

(

)

[virtual]

Called each time a InteractionTechnique is deactivated, i.e.

deselected as active Interaction of a InteractionMode. It can be implemented by derivatives to reset internal parameters.

Reimplemented in VRS::BookmarkNavigation, and VRS::ScenePicker.

virtual bool VRS::InteractionTechnique::checkEventRelevance

(

SO< Event >

event

)

const [virtual]

A Interaction is chosen as active Interaction (i.e.

the one which has currently control) automatically when an event occurs that is relevant for the interaction. Registered keys or mouse buttons activate a technique automatically. In addition, a derived InteractionTechnique can be woken up at certain events, when checkEventRelevance() returns true. The default implementation returns always false.

Reimplemented in VRS::SpaceMouseNavigation.

bool VRS::InteractionTechnique::canWork

(

)

const

Used by an orientation constraint to check whether a interaction technique can work based on the current view parameters.

By default, the method returns always 'true'. It must be overloaded, e.g., by focus-point based techniques and then return 'false' if no valid focus point is defined.

virtual bool VRS::InteractionTechnique::preservingViewDirectionRequired

(

)

const [virtual]

Used to determine whether the view direction must be preserved after a constraintchecker has refused or corrected a movement of this technique.

By default, the method returns always 'false'. It must be overloaded, and return 'true' to force preserving of the view direction.

Reimplemented in VRS::PanGroundPlateNavigation.

virtual void VRS::InteractionTechnique::setEnabled

(

bool

yesNo = true

)

[virtual]

Disables/Enables the technique within an InteractionMode.

Disabled Techniques are ignored by InteractionModes. The default state is 'enabled'.

virtual bool VRS::InteractionTechnique::enabled

(

)

const [virtual]

VRS::InteractionTechnique::VRS_TYPEINFO	(	InteractionTechnique	,
		SharedObj
	)

VRS::InteractionTechnique::VRS_SERIALIZABLE

(

InteractionTechnique

)

void VRS::InteractionTechnique::brake

(

)

[protected]

Should be used by InteractionTechniques if the user obviously wants to stop movement as fast as possible.

If a physical engine is used, this information is passed to it, so that the slow down is shortened.

void VRS::InteractionTechnique::registerMouseButtonFunction

(

MouseButtonFunctionID

id

)

[protected]

Most interaction techniques define functions that can be called by assignable keys or mouse buttons.

The InteractionTechnique base class controls the assignment of keys and mouse buttons for the derived classes. Each InteractionTechnique defines int-constants for all functions that can be assigned to keys or mouse buttons. The assign-methods are only valid for registered FuncionIDs. Note: FunctionIDs can be specified arbitrarily, but all functionIDs for a class and the same purpose (i.e. mouse button or key) must be different.

void VRS::InteractionTechnique::registerKeyFunction

(

KeyFunctionID

id

)

[protected]

bool VRS::InteractionTechnique::dragging

(

MouseButtonFunctionID

id

)

[protected]

Returns true if a dragging interaction is in progress (i.e.

the corresponding mouse button is currently hold down.

bool VRS::InteractionTechnique::pressed

(

KeyFunctionID

id

)

[protected]

Returns true if a function key is currently pressed.

SO<InteractionConcept> VRS::InteractionTechnique::getParent

(

)

const [protected]

Provides access to the parent interaction concept.

---

Friends And Related Function Documentation

friend class InteractionMode [friend]

---

The documentation for this class was generated from the following file:

• interactiontechnique.h