The QTPlgEffectPlay class allows you to playback whether free–standing special effects (that is effects that no require any source to work), or transitions between images; also, you can apply filters to images and display the result onto the screen as well.
Like any other class derived from , the QTPlgEffectPlay class allows you to combine the result of an effect or transition with the set of graphics transformations and effects built–in into the .
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The QTPlgEffectPlay class constructors are called when you create a new instance of the class, while the ˜QTPlgEffectPlay class destructor, is called automatically when the class is no more in use. Also, you can invoke the class destructor by setting the instance of the class to nil.
Once a new class instance is returned, it is good practice to check the class property to be sure that the new object can be used. See the QTPlgEffectPlay’s validity conditions for more details.
The class provides you with the following initializer methods:
(params as )
this constructor version initializes the class instance with the effect settings defined by the
params object; if this object is
,
the initialization fails and the presentation context is
as well.
You can use the facilities provided by the
class to create and configure
appropriately an .
The following settings are used to initialize the presentation context:
If the and values of theparams object are not set to some valid value they are initialized to the default value of
128
If the and values of the
controls the duration of the presentation, if applicable; the value of this property must be expressed in the
time scale of the presentation. Changing this property will vary the number of frames displayed per time unit. This
property is effective for transitions only
specifies the number of data source required for the effect used by the presentation context
a 0–based array of pictures that represent the source data to display; though the index
i can range from 0 to 1, the number of source images
that makes sense to assign depends on the value returned by the
class property that, in turn, depends on
the type of effect used into the current presentation context