A buffer is a document that is edited in Rogue Wave® Views Studio. It uses an IlvManager to display, edit, save, and read its contents. If you need to subclass the manager to save more information concerning your objects, for example, you have to subclass a corresponding buffer. The IlvStBuffer class is defined to encapsulate the IlvManager, and the IlvStGadgetBuffer class is defined to encapsulate an IlvGadgetManager. These classes are declared in the file <ivstudio/stbuffer.h> and <ivstudio/gadgets/gadbuf.h>. If you need to define a specialized manager class to edit and save your graphic objects, you have to define a corresponding buffer class.

When loading a .ilv file, Rogue Wave Views Studio first reads the file creator class information to determine the type of the buffer that must be created for editing this file. For example, when reading a file saved by an IlvGadgetManager, Rogue Wave Views Studio sees that the creator class of that .ilv file is IlvGadgetManagerOutputFile and then creates an IlvStGadgetBuffer. This is made possible by the registerType function that allows you to associate a buffer constructor function with a file creator class. Use this function to register your own buffer types. Rogue Wave Views Studio uses an IlvStBuffers object to manage all the buffers. You can obtain a reference to this object by calling the buffers function:

An IlvStPanelClass object is a Rogue Wave Views Studio object that describes the C++ panel class you wish to generate for a buffer. It contains all the information that Rogue Wave Views Studio requires to generate a subclass of IlvContainer using the data edited in your buffer.

An IlvStPanelClass object contains the class name, the base class, the base name of the file, the directories where the files are generated, and so on. Some of its properties are related to the type of the corresponding buffer, for example, the base class: a Gadgets buffer (IlvStGadgetBuffer) is used to generate a subclass of IlvGadgetContainer, while a 2D buffer (IlvStBuffer) is used to generate a subclass of IlvContainer.

Let us suppose that you have defined the class MyContainer, a subclass of IlvGadgetContainer that can read additional information saved by your manager. You will then want the generated class to derive from MyContainer. You may specify the base class in the Panel Class inspector each time you create a panel class using your buffer, but the best way is to automatically set up the panel class so its base class defaults to MyContainer.

You can do this by defining the setUpPanelClass virtual member function for your buffer. This function is called when Rogue Wave Views Studio creates a panel class from your buffer.

In many situations, Rogue Wave Views Studio creates instances of containers. For example, when you test a panel or add it to the Application buffer window. To select the appropriate classes Rogue Wave Views Studio uses a set of container information objects. An IlvStContainerInfo object provides the information that Rogue Wave Views Studio needs about a container subclass, and creates instances of that subclass.

To integrate a class of containers, you have to define a subclass of IlvStContainerInfo and add an instance of this class to the Rogue Wave Views Studio container information set as follows: