Inside Macintosh: Programmer's Guide to MacApp / Part 1 - MacApp Theory and Architecture

Chapter 8 - Displaying, Manipulating, and Printing Data

Overview

A MacApp application uses view objects, or views, to display, manipulate, and print data. A view is any instance of a subclass of MacApp's TView class.

When a user creates a new document or opens an existing one, an application typically opens a window to display the document's data. The window consists of many parts, including a frame and a main content area, each of which is represented by one or more views. The window itself is based on the TWindow class, a subclass of TView.

Views cooperate with documents. A document stores data, while its views display the data and support interaction with the user.

Among other things, a view can draw itself, has a size and a location relative to its window, and can respond to events such as mouse clicks, keystrokes, and menu commands. View classes also supply important fields and methods for MacApp's drag-and-drop support, which is described in Chapter 9, "Drag and Drop."

MacApp applications use views to handle user operations such as drawing, entering text, and modifying controls. MacApp uses views for printing, too, by attaching print-handler objects.

MacApp also provides facilities for tracking the cursor, changing its image based on the current location, changing its image for drag-and-drop operations, and displaying the wristwatch busy cursor image.