Taxonomy Categories:
Member Functions:
Interface Category:
API.
Inherits From:
TFloatActionState
Inherited By:
None.
Purpose:
TVolumeActionState is derived from TFloatActionState and is used to control the volume slider.
Instantiation:
Allocate on the heap or the stack.
Deriving Classes:
None.
Concurrency:
Not multithread safe.
Resource Use:
No special requirements.
Other Considerations:
Virtual functions defined in TFloatActionState are overridden in this class.
- TVolumeActionState (const TPresenterReference & reference, TViewHandle floatControl, bool continuousActions =true, const TSemanticActionType & action =TMediaPresenter :: kVolume)
- TVolumeActionState (const TVolumeActionState &)
- TVolumeActionState ()
Interface Category:
API.
Purpose:
- Normal constructor for setting up a volume action state.
- Copy constructor.
- Default constructor.
Calling Context:
- Called to create a volume slider.
- 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 -The semantic action associated with this object.
- const TVolumeActionState & =TMediaPresenter :: kVolume -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.
virtual ~ TVolumeActionState ()
Interface Category:
API.
Purpose:
Destructor.
Calling Context:
Called to destroy an object.
Parameters:
Return Value:
None.
Exceptions:
Throws no exceptions, passes all exceptions through.
Concurrency:
Not multithread safe.
Other Considerations:
None.
TVolumeActionState & operator =(const TVolumeActionState &)
Interface Category:
API.
Purpose:
Assignment operator.
Calling Context:
Called when an object is assigned to another compatible object.
Parameters:
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.
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:
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.
bool operator ==(const TVolumeActionState &) const
Interface Category:
API.
Purpose:
Tests for equality between the specified TVolumeActionState object and this TVolumeActionState object.
Calling Context:
Call this function directly.
Parameters:
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.
bool operator != (const TVolumeActionState &) const
Interface Category:
API.
Purpose:
Tests for inequality between the specified TVolumeActionState object and this TVolumeActionState object.
Calling Context:
Call this function directly.
Parameters:
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.
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.
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.
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:
Return Value:
None.
Exceptions:
Throws no exceptions, passes all exceptions through.
Concurrency:
Not multithread safe.
Other Considerations:
None.
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:
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.
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: TVolumeActionState::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 the base class and must be overridden by TVolumeActionState.
Click the icon to mail questions or corrections about this material to Taligent personnel.
Copyright©1995 Taligent,Inc. All rights reserved.