/*
  File:			  AGValues.c
  Contains:   Functions for installing and handling AG handlers
  						Also Adds the additional apple event handlers
  Written by:	Don Swatman
  Copyright:	© 1996 by Apple Computer, Inc., all rights reserved.
*/

#include <AppleGuide.h>
#include <AppleEvents.h>

#include "AGValues.h"

//===============================================================================
//        AGValues
//
// This unit adds context check handlers and apple events to allow apple guides
// to store values and then interogate them.
// There are two calls into the unit. 
//      OSErr InitAGStuff();  // This installs the handlers
//      void RemoveAGStuff(); // This removes them
//
// Currently it only sets or clears 3 values. This can be easily expanded.
//
//-------------------------------------------------------------------------------
//
//        Apple Guide - Context Checks
//
// The helper app has a context check call back for 'vals' context check. More
// details can be found below.
//
//-------------------------------------------------------------------------------
//
//        Apple Events
//
// The helper app understands the 'Vals' class. This is an unregistered class
// which I've invented purely for demonstration puposes. The 'Cler' event id is
// used to clear all the stored values. 'Clr1', 'Clr2' and 'Clr3' set the values
// 1-3 respectively to 0, and 'Set1', 'Set2' and 'Set3' set the values to 1
//
//===============================================================================


//==============================================
// Constants
//==============================================

// Maximum number of values that can be stored by app
#define kMaxAGEntries 100  


//==============================================
//  Globals
//==============================================

// Storage for coach mark and context check references

AGCoachRefNum   coachRefNum;
AGContextRefNum contextRefNum;

// Storage for values

long gAGValues[kMaxAGEntries];

//==============================================
// Prototypes
//==============================================

pascal OSErr MyObjectCoachCallBack ( Rect *pRect, Ptr name, long refCon );

OSErr MySetContextResult( Boolean result,
													Ptr     *outMessage,
													Size    *outSize );

pascal OSErr MyContextCallBack( Ptr   pInputData,
																Size  inputDataSize,
																Ptr   *ppOutputData,
																Size  *pOutputDataSize,
																AGAppInfoHdl hAppInfo );

void	ClearAllAGValues();

pascal OSErr SetAGValues1	( const AppleEvent *message, const AppleEvent *reply, long refcon);		
pascal OSErr ClearAGValues1	( const AppleEvent *message, const AppleEvent *reply, long refcon);			
pascal OSErr SetAGValues2	( const AppleEvent *message, const AppleEvent *reply, long refcon);		
pascal OSErr ClearAGValues2	( const AppleEvent *message, const AppleEvent *reply, long refcon);			
pascal OSErr SetAGValues3	( const AppleEvent *message, const AppleEvent *reply, long refcon);		
pascal OSErr ClearAGValues3	( const AppleEvent *message, const AppleEvent *reply, long refcon);			

pascal OSErr ClearAGValues	( const AppleEvent *message, const AppleEvent *reply, long refcon);			


//==============================================
//  Initalize and remove Apple Guide call backs
//==============================================

//----------------------------------------------
//  InitAGStuff
//
// Clears all the values stored by the application
// Install object coach handler
// Install context check handler
// Initialize the AppleEvent handlers table used
//   for helping the guide file
//----------------------------------------------

OSErr InitAGStuff()
{
	OSErr theErr = noErr;
	short count;
	
// Clear all the values stored by the application
	ClearAllAGValues();
		
// Install object coach handler
	theErr = AGInstallCoachHandler( NewCoachReplyProc(MyObjectCoachCallBack), 0, &coachRefNum );
	if (theErr)
		DebugStr("\pGot an Err - AGInstallCoachHandler ");
			
// Install context check handler. MyContextCallBack will get called when a 
// context check of 'Vals' is queried by the Guide

	theErr = AGInstallContextHandler( NewContextReplyProc(MyContextCallBack), 'Vals', 0, &contextRefNum );
	if (theErr)
		DebugStr("\pGot an Err - AGInstallContextHandler ");
	
// set up the dispatch table for the AppleEvents
	theErr = AEInstallEventHandler( 'Vals', 'Cler', NewAEEventHandlerProc(ClearAGValues), 0, false) ;

	theErr = AEInstallEventHandler( 'Vals', 'Clr1', NewAEEventHandlerProc(ClearAGValues1), 0, false) ;
	theErr = AEInstallEventHandler( 'Vals', 'Clr2', NewAEEventHandlerProc(ClearAGValues2), 0, false) ;
	theErr = AEInstallEventHandler( 'Vals', 'Clr3', NewAEEventHandlerProc(ClearAGValues3), 0, false) ;

	theErr = AEInstallEventHandler( 'Vals', 'Set1', NewAEEventHandlerProc(SetAGValues1), 0, false) ;
	theErr = AEInstallEventHandler( 'Vals', 'Set2', NewAEEventHandlerProc(SetAGValues2), 0, false) ;
	theErr = AEInstallEventHandler( 'Vals', 'Set3', NewAEEventHandlerProc(SetAGValues3), 0, false) ;
	
	return theErr;
}

//----------------------------------------------
//  RemoveAGStuff
//
// Removes object coach handler
// Removes context check handler
//----------------------------------------------


void RemoveAGStuff()
{
	OSErr theErr;
	
	theErr = AGRemoveContextHandler( &contextRefNum );
	theErr = AGRemoveCoachHandler( &coachRefNum );

}

//==============================================
//  MyObjectCoachCallBack
//
// This is called whenever a guide requests an object coach
// from this application.
//   "pRect"  pointer to a rectangle you should retun the coaches rect in
//   "name"   contains a null terminated string passed from the Guide 
//            file. This is the final parameter in Apple Guides 
//            <Define Object Coach> command.
//   "refCon" This is the reference constant passed in AGInstallCoachHandler.
//            In this case 0.
//
// As this is only for demo purposes, this call back just returns a 
// 100x100 square.
//==============================================

pascal OSErr MyObjectCoachCallBack ( Rect *pRect, Ptr name, long refCon )
{
	OSErr theErr = noErr;
	
	SetRect ( pRect, 100,100, 200,200);
	
	return theErr;
}

//==============================================
//  MyContextCallBack
//
// This is called whenever a 'vals' context check is made. The
// additional parameters in Apple Guides <Define Context Check>
// are passed in "pInputData". In this case it contains 2 longs
// which correspond to the PassedAGParamType structure.
//   "command" is either 1 or 0. If it is zero then it tests if 
//             the specified value is zero, if it is 1 then it 
//             tests if the specified value is non-zero.
//   "index"   is used to specify which of the "gAGValues" is to
//             be tested
//
// Once a result, true or false, has been determined, MySetContextResult()
// is used to put the result into ppOutputData and pOutputDataSize. This
// is part of a far wider mechanism so a pointer to a boolean must be
// created which contains 1 for true and 0 for false
//
//==============================================


struct PassedAGParamType
{
	long command;
	long index;
};

typedef struct PassedAGParamType PassedAGParamType,
	*PassedAGParamPtr, **PassedAGParamHdl;


pascal OSErr MyContextCallBack( Ptr   pInputData,
																Size  inputDataSize,
																Ptr   *ppOutputData,
																Size  *pOutputDataSize,
																AGAppInfoHdl hAppInfo )
{
	OSErr   theErr = noErr;
	Boolean checkResult = false;
	long    count;

// Check the index is within range

	if (((PassedAGParamPtr)pInputData)->index >= kMaxAGEntries)
		checkResult = false;
	else

// Work out whether we need to return true or false

		if (((PassedAGParamPtr)pInputData)->command == 1)
			checkResult = gAGValues[((PassedAGParamPtr)pInputData)->index - 1] != 0;
		else
			checkResult = gAGValues[((PassedAGParamPtr)pInputData)->index - 1] == 0;
	
// Set up the return values ppOutputData and pOutputDataSize

	theErr = MySetContextResult ( checkResult, ppOutputData, pOutputDataSize );
	
	return theErr;
}

//==============================================
//  MySetContextResult
//
// This is sets up the reply, ppOutputData and pOutputDataSize
// used by custom context checks. It creates a pointer and moves
// the value in result into it.
//
//==============================================

OSErr MySetContextResult( Boolean result,
													Ptr     *outMessage,
													Size    *outSize )
{
	Ptr   pOut;
	Size  theSize = sizeof ( Boolean );
	OSErr theErr = noErr;
	
	pOut = NewPtr (theSize);
	if ( pOut )
	{
		BlockMove( (void *)&result, pOut, theSize );
		*outSize = theSize;
		*outMessage = pOut;
	}
	else
		theErr = MemError();

	return theErr;	
}

//==============================================
//  ClearAllAGValues
//
// Sets all the guides stored values in gAGValues to 0.
//==============================================

void ClearAllAGValues()			
{
	long    count;

	for (count=0;count < kMaxAGEntries;count++)
		gAGValues[count] = 0;
}



//===============================================================================
//   Event Handlers
//===============================================================================


//-------------------------------------------------------------------------------
//       Clear all AG stored values
//
// 
//-------------------------------------------------------------------------------
pascal OSErr ClearAGValues(const AppleEvent *message, const AppleEvent *reply, long refcon)			
 {
	ClearAllAGValues();
	return( noErr );
}
//-------------------------------------------------------------------------------
//       Set AG stored values to 1
//-------------------------------------------------------------------------------

pascal OSErr SetAGValues1(const AppleEvent *message, const AppleEvent *reply, long refcon)			
{
	gAGValues[0] = 1;
	return( noErr );
}

pascal OSErr SetAGValues2(const AppleEvent *message, const AppleEvent *reply, long refcon)			
{
	gAGValues[1] = 1;
	return( noErr );
}

pascal OSErr SetAGValues3(const AppleEvent *message, const AppleEvent *reply, long refcon)			
{
	gAGValues[2] = 1;
	return( noErr );
}

//-------------------------------------------------------------------------------
//       Clear AG stored values to 0
//-------------------------------------------------------------------------------

pascal OSErr ClearAGValues1(const AppleEvent *message, const AppleEvent *reply, long refcon)			
{
	gAGValues[0] = 0;
	return( noErr );
}

pascal OSErr ClearAGValues2(const AppleEvent *message, const AppleEvent *reply, long refcon)			
{
	gAGValues[1] = 0;
	return( noErr );
}

pascal OSErr ClearAGValues3(const AppleEvent *message, const AppleEvent *reply, long refcon)			
{
	gAGValues[2] = 0;
	return( noErr );
}