SDK additions

With some additions to the X-Plane SDK, I think a lot of code could be simplified. Here's what I'd love to have:

  1. An API to notify plugins (via callback) of new/existing commands and datarefs would mean I could avoid scanning files in DRT. This is a hack I'd love to get rid of.

    // Called every time a new command is created by a plugin
    typedef void (* XPLMCommandCreation_f)(
        const char *         inCommandName,
        const char *         inCommandDescription,
        XPLMPluginID         inCreatingPlugin,
        void *               inRefcon);
    // Register a callback
        XPLMCommandCreationCallback_f inCallback,
        void *                inRefcon);
        XPLMCommandCreationCallback_f inCallback,
        void *                inRefcon);
    // Called every time a new dataref is created
    typedef void (* XPLMDataCreationCallback_f)(
        const char *         inDataName,
        const char *         inDataDescription,
        XPLMPluginID         inCreatingPlugin,
        XPLMDataTypeID       inDataType,
        int                  inIsWritable,
        void *               inRefcon);
        XPLMDataCreationCallback_f inCallback,
        void *                inRefcon);
        XPLMDataCreationCallback_f inCallback,
        void *                inRefcon);
  2. Functions to get attributes of commands and datarefs:

    a. Description (as provided in the UI, and DataRefs.txt), etc. The description is often informative for people trying to understand what a dataref found in DRT does. It would also be useful to describe commands to users using this text in the same way that the Settings window does.

    // Get the description of a command/dataref
    int XPLMGetDataRefDescription(XPLMDataRef inDataRef, char *outName, char *outDescription);
    int XPLMGetCommandDescription(XPLMCommand inCommand, char *outName, char *outDescription);

    b. Which plugin created a command/dataref. This would simply be informative in DRT, or could be used as a filter in the search window.

    // Which plugin originally created a command/dataref?
    XPLMPluginID XPLMGetDataRefCreator(XPLMDataRef inDataRef);
    XPLMPluginID XPLMGetCommandCreator(XPLMDataRef inDataRef);

    c. Check if a dataref is deprecated. The current version of DRT scans DataRefs.txt for the word DEPRECATED for this purpose.

    // Determine if a dataref is deprecated.
    // By the time you have a XPLMDataRef, X-Plane will have already thrown a warning about a
    // deprecated dataref being used. If possible, maybe that warning should be moved to the first
    // time a dataref is read? I suppose this is undesirable for performance reasons.
    // Another way to accomplish this would be to add a new bit in the dataref type flags to indicate
    // if a dataref is deprecated, but that could possibly break existing plugins that can't handle the
    // new bit.
    int XPLMIsDataRefDeprecated(XPLMDataRef inDataRef);

    d. Check if a command has been mapped to a keyboard button or joystick. To me this seems like it might be broadly useful. As an example, PlaneCommand needs the user to push a PTT button; if the user hasn't configured it, I could show a helpful dialog explaining the process.

    // Determine if a command is bound to a key or joystick button. This would be useful for plugins
    // that present controls via a command; for example, PlaneCommand needs a PTT button to be bound,
    // and could use this function to determine if we need to present a message guiding the user to
    // bind a key or joystick button to the PTT command.
    int XPLMIsCommandMapped(XPLMCommandRef inCommand);