defined in ApDlgParams.pas
TApCtrlQueryEvent = procedure (Sender: TObject; var AllowProceed : boolean) of object;
This type is used for the new event handlers in many components (first of all, in ApOpen/Save): OnUpLevelNavigating, etc. AllowProceed variable determines whether you can do appropriate action (for example, modify edit box text). Setting this variable to False will disable standard response on this action.
defined in ApDlgParams.pas
TApMsgQueryEvent = procedure (Sender: TObject; var m : TMessage; var AllowDispatch : boolean) of object;
This type is used in message processing mechanism in APRD components in OnEventHooking event handler. You can evaluate m message to decide whether dialog box procedure should process it or not by setting AllowDispatch value. Note that some messages wich are specific to call-back procedures could not be dispatched in this handler. For example you can not process BFFM_SELCHANGED message in TApFolderDialog or WM_NOTIFY with CDN_FOLDERCHANGE notification code in TApOpenDialog component in OnEventHooking handler.