CBaseTransition Class

Represents a basic transition.

Syntax

class CBaseTransition : public CObject;

Members

Public Enumerations

Public Constructors

Public Methods

Protected Data Members

Remarks

This class encapsulates IUIAnimationTransition interface and serves as a base class for all transitions.

Inheritance Hierarchy

CObject

CBaseTransition

Requirements

Header: afxanimationcontroller.h

CBaseTransition::~CBaseTransition

The destructor. Called when a transition object is being destroyed.

virtual ~CBaseTransition();

CBaseTransition::AddToStoryboard

Adds a transition to a storyboard.

BOOL AddToStoryboard(IUIAnimationStoryboard* pStoryboard);

Parameters

pStoryboard
A pointer to storyboard, which will animate the related variable.

Return Value

TRUE, if transition was successfully added to a storyboard.

Remarks

Applies the transition to the related variable in the storyboard. If this is the first transition applied to this variable in this storyboard, the transition begins at the start of the storyboard. Otherwise, the transition is appended to the transition added most recently to the variable.

CBaseTransition::AddToStoryboardAtKeyframes

Adds a transition to a storyboard.

BOOL AddToStoryboardAtKeyframes(IUIAnimationStoryboard* pStoryboard);

Parameters

pStoryboard
A pointer to storyboard, which will animate the related variable.

Return Value

TRUE, if transition was successfully added to a storyboard.

Remarks

Applies the transition to the related variable in the storyboard. If the start keyframe was specified, the transition begins at that keyframe. If the end keyframe was specified, the transition begins at the start keyframe and stops at the end keyframe. If the transition was created with a duration parameter specified, that duration is overwritten with the duration of time between the start and end keyframes. If no keyframe was specified, the transition is appended to the transition added most recently to the variable.

CBaseTransition::CBaseTransition

Constructs a base transition object.

CBaseTransition();

CBaseTransition::Clear

Releases encapsulated IUIAnimationTransition COM object.

void Clear();

Remarks

This method should be called from a derived class's Create method in order to prevent IUITransition interface leak.

CBaseTransition::Create

Creates a COM transition.

virtual BOOL Create(
    IUIAnimationTransitionLibrary* pLibrary,
    IUIAnimationTransitionFactory* pFactory) = 0;

Parameters

pLibrary
A pointer to transition library, which creates standard transitions. It can be NULL for custom transitions.

pFactory
A pointer to transition factory, which creates custom transitions. It can be NULL for standard transitions.

Return Value

TRUE if a transition COM object was created successfully; otherwise FALSE.

Remarks

This is a pure virtual function that must be overridden in a derived class. It's called by the framework to instantiate the underlying COM transition object.

CBaseTransition::GetEndKeyframe

Returns start keyframe.

CBaseKeyFrame* GetEndKeyframe();

Return Value

A valid pointer to a keyframe, or NULL if a transition should not be inserted between keyframes.

Remarks

This method can be used to access a keyframe object that was previously set by SetKeyframes. It's called by top-level code when transitions are being added to storyboard.

CBaseTransition::GetRelatedVariable

Returns a pointer to related variable.

CAnimationVariable* GetRelatedVariable();

Return Value

A valid pointer to animation variable, or NULL if an animation variable has not been set by SetRelatedVariable.

Remarks

This is an accessor to related animation variable.

CBaseTransition::GetStartKeyframe

Returns start keyframe.

CBaseKeyFrame* GetStartKeyframe();

Return Value

A valid pointer to a keyframe, or NULL if a transition should not start after a keyframe.

Remarks

This method can be used to access a keyframe object that was previously set by SetKeyframes. It's called by top-level code when transitions are being added to storyboard.

CBaseTransition::GetTransition

Returns a pointer to underlying COM transition object.

IUIAnimationTransition* GetTransition(
    IUIAnimationTransitionLibrary* pLibrary,
    IUIAnimationTransitionFactory* pFactory);

IUIAnimationTransition* GetTransition();

Parameters

pLibrary
A pointer to transition library, which creates standard transitions. It can be NULL for custom transitions.

pFactory
A pointer to transition factory, which creates custom transitions. It can be NULL for standard transitions.

Return Value

A valid pointer to IUIAnimationTransition or NULL if underlying transition can't be created.

Remarks

This method returns a pointer to underlying COM transition object and creates it if necessary.

CBaseTransition::GetType

Returns transition type.

TRANSITION_TYPE GetType() const;

Return Value

One of TRANSITION_TYPE enumerated values.

Remarks

This method can be used to identify a transition object by its type. The type is set in a constructor in a derived class.

CBaseTransition::IsAdded

Tells whether a transition has been added to a storyboard.

BOOL IsAdded();

Return Value

Returns TRUE if a transition has been added to a storyboard, otherwise FALSE.

Remarks

This flag is set internally when the top-level code adds transitions to storyboard.

CBaseTransition::m_bAdded

Specifies whether a transition has been added to a storyboard.

BOOL m_bAdded;

CBaseTransition::m_pEndKeyframe

Stores a pointer to the keyframe that specifies the end of the transition.

CBaseKeyFrame* m_pEndKeyframe;

CBaseTransition::m_pRelatedVariable

A pointer to an animation variable, which is animated with the transition stored in m_transition.

CAnimationVariable* m_pRelatedVariable;

CBaseTransition::m_pStartKeyframe

Stores a pointer to the keyframe that specifies the beginning of the transition.

CBaseKeyFrame* m_pStartKeyframe;

CBaseTransition::m_transition

Stores a pointer to IUIAnimationTransition. NULL if a COM transition object has not been created.

ATL::CComPtr<IUIAnimationTransition> m_transition;

CBaseTransition::m_type

Stores the transition type.

TRANSITION_TYPE m_type;

CBaseTransition::SetKeyframes

Sets keyframes for a transition.

void SetKeyframes(
    CBaseKeyFrame* pStart = NULL,
    CBaseKeyFrame* pEnd = NULL);

Parameters

pStart
A keyframe that specifies the beginning of the transition.

pEnd
A keyframe that specifies the end of the transition.

Remarks

This method tells the transition to start after specified keyframe and, optionally, if pEnd is not NULL, end before the specified keyframe. If the transition was created with a duration parameter specified, that duration is overwritten with the duration of time between the start and end keyframes.

CBaseTransition::SetRelatedVariable

Establishes a relationship between animation variable and transition.

void SetRelatedVariable(CAnimationVariable* pVariable);

Parameters

pVariable
A pointer to related animation variable.

Remarks

Establishes a relationship between animation variable and transition. A transition can be applied only to one variable.

CBaseTransition::TRANSITION_TYPE Enumeration

Defines the transition types currently supported by the MFC implementation of Windows Animation API.

enum TRANSITION_TYPE;

Remarks

A transition type is set in the constructor of specific transition. For example, CSinusoidalTransitionFromRange sets its type to SINUSOIDAL_FROM_RANGE.

See also

Classes