Inside Macintosh: Programming With JManager /

Chapter 2 - JManager Reference / JManager Constants and Data Types

The AWT Context

AWT Context Callbacks Structure

When you create an AWT context associated with a session, you must pass a data structure that supplies callback information. The AWT context callback data structure is defined by the JMAWTContextCallbacks data type.

struct JMAWTContextCallbacks {
   UInt32                       fVersion;         
   JMRequestFrameProcPtr        fRequestFrame;   
   JMReleaseFrameProcPtr        fReleaseFrame;   
   JMUniqueMenuIDProcPtr        fUniqueMenuID;   
   JMExceptionOccurredProcPtr   fExceptionOccurred;
};

Field Description

fVersion

The version of JManager. You should set this field to kJMVersion.

fRequestFrame

A pointer to a function that creates a new frame. The client application must set up the new frame and supply callbacks for the new frame. This callback function has the following type definition:

               typedef OSStatus (*JMRequestFrameProcPtr) (
                  JMAWTContextRef context, JMFrameRef newFrame,
                  JMFrameKind kind, UInt32 width, UInt32 height, 
                  Boolean resizeable, JMFrameCallbacks* callbacks);

For more information, see the description of the application-defined function MyRequestFrame (page 99).

fReleaseFrame

A pointer to a function that removes a frame. This callback function has the following type definition:

               typedef OSStatus (*JMReleaseFrameProcPtr) (
                  JMAWTContextRef context, JMFrameRef oldFrame);

For more information, see the application-defined function MyReleaseFrame (page 100).

fUniqueMenuID

A pointer to a function that allocates a unique menu ID for later use in creating a menu. This callback function has the following type definition:

               typedef SInt16 (*JMUniqueMenuIDProcPtr) (
                  JMAWTContextRef context, Boolean isSubmenu);

For more information, see the description of the application-defined function MyUniqueMenuID (page 101).

fExceptionOccurred

A pointer to an exception notification function. This function can indicate only that an error occurred; you cannot recover from the exception using this function. This callback function has the following type definition:

               typedef void (*JMExceptionOccurredProcPtr) (
                  JMAWTContextRef context, 
                  const char* exceptionName, 
                  const char* exceptionMsg, 
                  const char* stackTrace);

For more information, see the description of the application-defined function MyExceptionOccurred (page 101).