Class: TSeekActionState

Declaration: PlayerControls.h

Taxonomy Categories:

Member Functions:

Interface Category:

API.

Inherits From:

TFloatActionState

Inherited By:

None.

Purpose:

TSeekActionState is provided by the framework for the seek slider. It is a special action control state that is used to process playback notifications. Playback notifications are used to update the slider thumb to reflect progress of the playback.

Instantiation:

Allocate on the heap or the stack.

Deriving Classes:

None.

Concurrency:

Not multithread safe.

Resource Use:

No special requirements.

Other Considerations:

None.

Member Function: TSeekActionState::TSeekActionState

TSeekActionState (const TPresenterReference & reference, TViewHandle floatControl, bool continuousActions =true, const TSemanticActionType & action =TMediaPresenter :: kSeek)
TSeekActionState (const TSeekActionState &)
TSeekActionState ()

Interface Category:

API.

Purpose:

Normal constructor for creating a seek action state.
Copy constructor.
Default constructor.

Calling Context:

Called to create a seek action state object.
Called to copy an object.
Called by the stream-in operators and derived classes only.

Parameters:

const TPresenterReference & reference -A reference to the presenter object.
TViewHandle floatControl -The float control protocol for the object.
bool continuousActions =true -A flag indicating whether actions are continuous.
const TSemanticActionType & action =TMediaPresenter :: kSeek -The semantic action associated with this object.
const TSeekActionState & -A reference to the object to be copied.
Takes no parameters.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TSeekActionState::~TSeekActionState

virtual ~ TSeekActionState ()

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: TSeekActionState::operator=

TSeekActionState & operator =(const TSeekActionState &)

Interface Category:

API.

Purpose:

Assignment operator.

Calling Context:

Called when an object is assigned to another compatible object.

Parameters:

const TSeekActionState & -The object being copied.

Return Value:

A non-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: TSeekActionState::Hash

virtual long Hash () const

Interface Category:

API.

Purpose:

Returns the hash value that uniquely identifies this object within its type. Hash values are used to build dictionaries of objects.

Calling Context:

Call this function directly.

Parameters:

Takes no parameters.

Return Value:

Returns the hash value that uniquely identifies this object.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TSeekActionState::operator==

bool operator ==(const TSeekActionState &) const

Interface Category:

API.

Purpose:

Tests for equality between the specified TSeekActionState object and this TSeekActionState object.

Calling Context:

Call this function directly.

Parameters:

const TSeekActionState & -A reference to the other TSeekActionState object for the comparison.

Return Value:

Returns true if the two objects are equal; otherwise, returns false.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TSeekActionState::operator!=

bool operator != (const TSeekActionState &) const

Interface Category:

API.

Purpose:

Tests for inequality between the specified TSeekActionState object and this TSeekActionState object.

Calling Context:

Call this function directly.

Parameters:

const TSeekActionState & -A reference to the other TSeekActionState object for the comparison.

Return Value:

Returns true if the two objects are different; otherwise, returns false.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TSeekActionState::operator>>=

virtual TStream & operator >>=(TStream &) const

Interface Category:

API.

Purpose:

Stream-out operator.

Calling Context:

Called to stream out data.

Parameters:

TStream & -The stream the object streams itself out to.

Return Value:

Returns a reference to the stream the object streams itself out to.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TSeekActionState::operator<<=

virtual TStream & operator <<= (TStream &)

Interface Category:

API.

Purpose:

Stream-in operator.

Calling Context:

Called to stream in data.

Parameters:

TStream & -The stream the object streams itself in from.

Return Value:

Returns a reference to the stream the object streams itself in from.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TSeekActionState::SetPresenter

virtual void SetPresenter (const TPresenterReference & reference)

Interface Category:

API.

Purpose:

Sets a reference to the media presenter object that defines the semantics for the volume control actions and presentation.

Calling Context:

Call this function directly.

Parameters:

const TPresenterReference & reference -A reference to the media presenter object.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TSeekActionState::AddInterests

virtual void AddInterests (TSetOf < TInterest > &)

Interface Category:

API.

Purpose:

Establishes a notification connection from this state object to the float control that owns it. The notification connection is used to notify the control that the state has changed, outside the user's control, or indirectly as a result of the user manipulating something else. When the control receives such a notification, it calls GetFloatValue and updates the presentation accordingly. This function is derived from the one in MFloatControlState. When you implement this function, you can provide one or more TInterest objects to establish a notification connection with the float control that owns this state object.

Calling Context:

AddInterests is called by the float control that owns this state object during initialization of the control and after this state object has been adopted into the control.

Parameters:

TSetOf < TInterest > & -The set of interests for which to establish a notification connection with the float control that owns this state object. If this set is empty, no connection is established.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TSeekActionState::GetFloatValue

virtual double GetFloatValue () const

Interface Category:

API.

Purpose:

Returns the floating-point value that is the primary state of this control state.

Calling Context:

Call this function directly.

Parameters:

Takes no parameters.

Return Value:

Returns this float control state's current floating-point value.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TSeekActionState::SetFloatValue

virtual void SetFloatValue (double)

Interface Category:

API.

Purpose:

Sets the floating-point value that is the primary state of this control state.

Calling Context:

Call this function directly.

Parameters:

double -The new value for the floating-point.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TSeekActionState::GetFloatConstraints

virtual void GetFloatConstraints (double & minimum, double & maximum, double & intervalSize) const

Interface Category:

API.

Purpose:

Gets the constraints currently applied to this float control state's value. The first two parameters indicate the range within which this float control state's value must fall. The third parameter indicates the discrete interval by which to constrain this float control state's value. For example, if the interval is 1.0, then the float control state's value is constrained to whole numbers. An interval of 0.0 indicates that there is no interval constraint.

Calling Context:

Call this function directly.

Parameters:

double & minimum -The minimum value of this float control state.
double & maximum -The maximum value of this float control state.
double & intervalSize -The interval by which to constrain the value of this float control state.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

This function is declared as a pure virtual function in MFloatControlState and must be overridden by TSeekActionState.

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