Present a Modal dialog

Application dialogs in Visionary Render appear modal, however their APIs are not guaranteed to exhibit blocking behaviour. When displaying a message box, it should not be assumed that the plugin will always wait for it to be dismissed before continuing.

In the case of question dialogs, which require a response from the user before continuing, a callback mechanism must be used.

Message Boxes

Simple fire-and-forget message boxes are used to display information to the user.

When a plugin is loaded, it is given a pointer to a message box function, which should be stored by the plugin and called when it wants to display a message.

static VRPUserMessageProc s_msgProc = 0;
PLUGIN_ENTRY_POINT void VRTREE_APIENTRY VRPRegisterUserMessage(VRPUserMessageProc proc)
{
  s_msgProc = proc;
}

void showMyMessageBox(const char* msg)
{
    if (s_msgProc)
      s_msgProc(msg);
}

Question Boxes

Question boxes are used to get a yes/no answer from the user.

When a plugin is loaded, it is given a pointer to a question box function and a pointer to a response callback registration function. The plugin is expected to store these, and to use the callback registration function prior to presenting the question in order to register a callback function which is called with the user's answer.

static VRPUserQuestionProc s_qProc = 0;

static void question_callback(int result, void* userData) 
{
  //result is the option the user chose
  //userData is the data provided to the callback registration function
}

PLUGIN_ENTRY_POINT void VRTREE_APIENTRY VRPRegisterUserQuestionCallback(VRPUserQuestionCallbackRegisterProc proc)
{
  //call proc to register our callback.
  //if the plugin asks multiple questions this should be stored and called before asking.
  proc(question_callback, NULL);
}

PLUGIN_ENTRY_POINT void VRTREE_APIENTRY VRPRegisterUserQuestion(VRPUserQuestionProc proc)
{
  s_qProc = proc;
}

void askMyQuestion(const char* msg)
{
    if(s_qProc)
      s_qProc("Is this a question?");
}