Extensions

This section provides suggestions for extending the Stock Browser program to support additional features. These enhancements are simply recommendations, you'll probably have ideas of your own.

Providing additional stock information

To make stock browsing more interesting for the user, you can provide more information on individual stocks in the Stock Picker. To accomplish this, you'll need to begin by modifying TPickerView.

Graphing more than one stock

In the current design of Stock Browser, the Stock Viewer displays stock information for a single stock. Graphed stock information for multiple stocks would be a valuable feature to users when comparing stock information. You would need to modify TViewerContentView to adopt more than one TGraphView object. In addition, you would need to modify TViewerPresenterState to adopt more than one TStockGraphConstructor and then change TGraphView to obtain the appropriate graph constructor from the presenter state.

Adding and modifying graphs

You can supply users with additional types of graphs or allow them to annotate graphs. To supply a new graph, you could derive a new class from TStockGraphConstructor and then modify TViewerPresenter to add your new graph constructor to the View menu. To allow users to supplement a graph, you could derive a new drawer class from TGraphDrawer and then modify the graph constructor to add your new drawer to the graph.

Providing a "live" server

The current implementation of TGraphView produces a static view of the stock history data. This is because the Stock Viewer is a viewer for stock histories. However, it is possible for you to support a live server that provides new and updated stock information. The simplest way to accomplish this is to create a thread that recopies the model's stock data at certain intervals and then reconstructs and displays the graph.

Simplified stock data

To simplify the display of stock information for the user, you could provide a tabular view or standard table format of stock data. To provide a tabular view, you could create a class called TTabularStockView and modify TViewerPresenter. To support a table format, you would need to change TPickerSelection.


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