Application Modernization: What Is It and How to Get Started
Special note:Thanks goes to Keith Rule for the CMemDC class which is used in the code.
In some of the applications I have developed, there has been a need for user creatable options and for the integration of new object types into an application without changing the application code. This presents a problem when the new objects do not share all of the properties of the previous objects. Visual Basic, MS Access and many other applictions handle this problem through a property list type interface (as shown above.)
I looked for a control to do this, but did not find one that I thought was all that great. So, I wrote my own. This is the result.
I think it should be fairly easy to implement into other projects without too much work. I have put together the sample application to demonstrate how to use it.
How it works:
The CFPSPropertyList class contains a list of CFPSPropertyListItems. These items implement the actual item draw/selection functionality. Items are drawn Top Down and Scroll support is provided.
The CFPSPropertyListItem class implements functions for the properties listed below. A message (FPS_PROPLIST_ITEM_CHANGED) is sent to the parent window whenever a property item changes the wParam member contains the item ID.
Edit Boxes/Combo Boxes are only created when needed and are destroyed as soon as is reasonble. Text (and colors) are drawn using standard CDC functions (not throught CEdit, CComboBox classes)
When the user sizes the window, the contents are automatically resized in the same way that VB does.
Property item types supported:
- Text (Edit Box)
- Combo (Combo Box)
- Numbers - Long and Integer (Edit Box)
- Font (CFontDialog)
- Color (CColorDialog)
- File (CFileDialog)
- BOOLEAN (Toggle)
How to use the control:
- Allocate a CFPSPropertyList object
- Call one of the 2 ::Create functions for the class
- Add items to the list using the AddItem functions (3 Versions provided)
How to set item values:Several SetItemValue functions are provided for setting the values for individual property list items.
How to get item values:Several GetItemValue functions are provided for retrieving values from individual property list items.
Additional Control:Individual CFPSPropertyListItem entries can be accessed through MFC style list functions. These are
Things to Improve:If new property types are required, they can either be added to the CFPSPropertyListItem class or a class can be derived from CFPSPropertyListItem to implement new features.
Known Issues:The scroll bar THUMB positioning mechanism is not implemented.
Last updated: 26 July 1998