The QTPlgCompressionDialog is an abstract class that defines base services for any class of the QTPlugin class hierarchy that use the services provided by the standard image–compression dialog.
Because the standard image–compression dialog is a component, the any subclass will use the Component Manager to open and close a connection to the component; QTPlugin developers do not worry about it, cause the QTPlgCompressionDialog classes take care about the details of opening and closing a connection to the standard image–compression dialog component.
You can use the QTPlgCompressionDialog class hierarchy to obtain compression parameters from the user (or set them by yourself) and to manage the process of compressing the images,video and audio. You can follow several ways to control the different steps involved into the compression process.
The simplest way is to use the standard image–compression dialog component dialog box. The dialog box presents a consistent interface to the user; the QTPlgCompressionDialog class hierarchy eliminates the need for you to worry about the details of managing this dialog box. Also, provided that the requirements are met, this class features the class method as well. Once you have collected the parameter information from the user, you can use the class to instruct the Image Compression Manager to perform the compression of data. Again, the class manages the details for you.
Alternatively, you can use the methods the class provides you with to examine or modify the parameters
to be used during the compression process. This way allows you to perform the compression without using any user interface.
Whatever way you follow, the class allows you to store the compression parameters you have set into
files and restore them later.
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The class has not constructor at all (you can always use the Realbasic common constructor syntax, of course, but you will obtain an usless object). Its destructor, will be implicitly invoked every time one of its derived classes will be destroyed. The class destructor will also close the connection to the component in use if any.