UI Data MTMs

Message client applications are likely to need access to certain MTM-specific functions often and rapidly. These functions could be held in User Interface MTMs, but the resulting requirement to hold many User Interface MTMs in memory simultaneously could impose a large memory overhead. For this reason, a separate component type, the UI Data MTM, is defined.

UI Data MTMs offer the following capabilities:

• Provide bitmap icons for messages, folders, and services for display in the various folder views. For each icon, an array of bitmaps should be available, giving the icon in a number of sizes.

• Provide command captions for MTM-specific functions that the message client application can dynamically add to menus and dialog controls. A function ID is associated with each caption to identify the MTM-specific function that should be invoked when the command is chosen. This data is encapsulated in a resource file MTUD_FUNCTION type.

• Validate that specified functions are available on a particular entry, so that a message client application can, for example, grey out menu items that do not apply to that entry.

The implementation of UI Data MTMs is relatively simple, as they contain little more than functions to return the required icons and extra menu items.