/************************************************************************
* COPYRIGHT:   Copyright  ©  1998, 2000 Symbol Technologies, Inc. 
*
* FILE:        Sscan.c
*
* SYSTEM:      Symbol barcode scanner for Symbol Palm Terminals
* 
* MODULE:      A Simple Scan Demo Application for both 1D and 2D Barcodes
*              
* DESCRIPTION: Contains application support functions, including main form event handlers
*              and event loop for the sample application.
*					
* FUNCTIONS:   StartApplication
* 					StopApplication
*					PilotMain
*					MainFormHandleEvent
*					MainFormOnInit
*					MainFormHandleMenu
*					EventLoop
*					ApplicationHandleEvent
*					OnDecoderData
* 					OnAbout
*					AboutHandleEvent
* 					AboutOnInit
*
* HISTORY:     5/25/98    KEF   Created
*			   3/17/99	  CFS   Set bHandled to true so that the default error processing will 
*								not be used.  The app processing is used (line 175).
*			   3/29/00	  MW	Modified for 2D Barcodes.
*              ...
*************************************************************************/
#ifdef __cplusplus
   extern "C" {
#endif

#include "PalmOS.h"				// all the system toolbox headers
#include <Menu.h>

#include "ScanMgrDef.h"				// Scan Manager constant definitions
#include "ScanMgrStruct.h"			// Scan Manager structure definitions 
#include "ScanMgr.h"	 			// Scan Manager API function definitions

#include "SscandemoRsc.h"			// application resource defines
#include "Utils.h"					// miscellaneous utility functions for this app

#define  SCANDATA_WIDTH	145

Boolean extend;
Int16 extendedDataLength;

/***********************************************************************
 * Prototypes for internal functions
 **********************************************************************/
static void StartApplication(void);
static void StopApplication(void);
static Boolean MainFormHandleEvent(EventPtr event);
static void MainFormHandleMenu( UInt16 menuSel );
static void EventLoop(void);
static MenuBarPtr	CurrentMenu;
static Boolean OnDecoderData(); 
static void MainFormOnInit();
static Boolean ApplicationHandleEvent (EventPtr event);
static void OnAbout();
static Boolean AboutHandleEvent( EventPtr ev );
static void AboutOnInit( void );
static void UpdateScrollbar(void);
static void	ScrollLines(Int16 numLinesToScroll, Boolean redraw);
static void PageScroll(WinDirectionType direction);

#ifdef __cplusplus
    }
#endif
/***********************************************************************
 *
 * FUNCTION: 		StartApplication
 *
 * DESCRIPTION: 	This routine sets up the initial state of the application.
 * 					Set the Main Form as the initial form to display.
 * 					Checks to make sure we're running on Symbol hardware, then 
 * 					calls ScanOpenDecoder to initialize the Scan Manager.  
 * 					If successful, then we proceed with setting decoder 
 * 					parameters that we care about for this application.
 * 					ScanCmdSendParams is called to send our params to the decoder.
 *
 * PARAMETERS: 	None.
 *
 * RETURNED: 		Nothing.
 *
 ***********************************************************************/
static void StartApplication(void)
{
	Err error;			
				
	// Call up the main form.
	FrmGotoForm( MainForm );
	
	// Make sure we're running on Symbol hardware before attempting to 
	// open the decoder or call any other Scan Manager functions.
	if (ScanIsPalmSymbolUnit())
	{
		// Now, open the scan manager library	
		error = ScanOpenDecoder();

		if (!error)
		{
			// Set decoder parameters we care about...
			ScanCmdScanEnable(); 				// enable scanning
			ScanSetTriggeringModes( HOST ); 	// allow software-triggered scans (from our Scan button)
			ScanSetBarcodeEnabled( barUPCA, true ); 	// Enable any barcodes to be scanned
			ScanSetBarcodeEnabled( barUPCE, true );
			ScanSetBarcodeEnabled( barUPCE1, true );
			ScanSetBarcodeEnabled( barEAN13, true );
			ScanSetBarcodeEnabled( barEAN8, true );
			ScanSetBarcodeEnabled( barBOOKLAND_EAN, true);
			ScanSetBarcodeEnabled( barCOUPON, true);
			ScanSetBarcodeEnabled( barPDF417, true);

			// We've set our parameters...
			// Now call "ScanCmdSendParams" to send them to the decoder
			ScanCmdSendParams( No_Beep); 
		}
	}
}

/***********************************************************************
 *
 * FUNCTION:     StopApplication
 *
 * DESCRIPTION:  This routine does any cleanup required, including shutting down
 * 				  the decoder and Scan Manager shared library.
 *
 * PARAMETERS:   None.
 *
 * RETURNED:     Nothing.
 *
 ***********************************************************************/
static void StopApplication(void)
{
	if (ScanIsPalmSymbolUnit())
	{
		// Disable the scanner and Close Scan Manager shared library
		ScanCmdScanDisable(); 			
		ScanCloseDecoder(); 	
	}
}

/***********************************************************************
 *
 * FUNCTION:		MainFormHandleEvent
 *
 * DESCRIPTION:	Handles processing of events for the Main Form.
 * 					The following events are handled:
 * 						frmOpenEvent and menuEvent - standard handling
 * 						scanDecodeEvent - indicates that a scan was completed
 * 						scanBatteryErrorEvent - indicates batteries too low to scan
 * 						ctlSelectEvent - for Scan button on the main form
 *
 * PARAMETERS:		event	- the most recent event.
 *
 * RETURNED:		True if the event is handled, false otherwise.
 *
 ***********************************************************************/
static Boolean MainFormHandleEvent(EventPtr event)
{
	Boolean		bHandled = false;
	UInt16		extendedDataFlag;

	switch( event->eType )
	{
		case frmOpenEvent:
			MainFormOnInit();
			bHandled = true;
			break;
			
		case menuEvent:
			MainFormHandleMenu(event->data.menu.itemID);
			bHandled = true;
			break;

		case scanDecodeEvent:
			// A decode has been performed.  
			// Use the decoder API to get the decoder data into our memory

			// Get barcode parameters from the registers
			extendedDataFlag = ((ScanEventPtr)event)->scanData.scanGen.data1;
			extendedDataLength  = (Int16)(((ScanEventPtr)event)->scanData.scanGen.data2);

			extend = extendedDataFlag & EXTENDED_DATA_FLAG;

			OnDecoderData();
			
			bHandled = true;
			break;
								
		case scanBatteryErrorEvent:
		{
			Char szTemp[10];
			StrIToA( szTemp, ((ScanEventPtr)event)->scanData.batteryError.batteryLevel );
			FrmCustomAlert( BatteryErrorAlert, szTemp, NULL, NULL );

			bHandled = true;
			break;
		}
		
		case ctlSelectEvent:
		{
			if (ScanIsPalmSymbolUnit())
			{
				// Scan Button
				if (event->data.ctlEnter.controlID == MainSCANButton)
				{
					ScanCmdStartDecode();
					bHandled = true;
				}
			}
		   	break;
		}
		
		case fldChangedEvent:
			UpdateScrollbar();
			bHandled = true;
			break;
		
		case sclRepeatEvent:
			ScrollLines(event->data.sclRepeat.newValue - event->data.sclRepeat.value, false);
			break;
		
		case keyDownEvent:
		{
			if (event->data.keyDown.chr == pageUpChr) {
				PageScroll(winUp);
				bHandled = true;
			} else if (event->data.keyDown.chr == pageDownChr) {
				PageScroll(winDown);
				bHandled = true;
			}
		
			break;
		}
		
	} //end switch

	return(bHandled);
}



/***********************************************************************
 *
 * FUNCTION:     MainFormOnInit
 *
 * DESCRIPTION:  This routine sets up the initial state of the main form
 *
 * PARAMETERS:   None.
 *
 * RETURNED:     Nothing.
 *
 ***********************************************************************/
static void MainFormOnInit()
{
	FormPtr pForm = FrmGetActiveForm();
	if( pForm )
	{
		// initialize the barcode type and barcode data fields
		SetFieldText( MainBarTypeField, "No Data", 20, false );
		SetFieldText( MainScandataField, "No Data", 80, false );
		FrmDrawForm( pForm );
	}
}

/***********************************************************************
 *
 * FUNCTION:     MainFormHandleMenu
 *
 * DESCRIPTION:  This routine handles menu selections off of the main form
 *
 * PARAMETERS:   None.
 *
 * RETURNED:     Nothing.
 *
 ***********************************************************************/
void MainFormHandleMenu( UInt16 menuSel )
{
	switch( menuSel )
	{
		// Options menu
		case OptionsResetDefaults:
			if (ScanIsPalmSymbolUnit()) {
				ScanCmdScanDisable(); 			

				if(ScanCmdParamDefaults() == STATUS_OK)
					ScanCmdScanEnable(); 				// enable scanning
			}
			break;
			
		case OptionsAbout:
			OnAbout();
			break;
	}
}

/***********************************************************************
 *
 * FUNCTION:		EventLoop
 *
 * DESCRIPTION:	A simple loop that obtains events from the Event
 *						Manager and passes them on to various applications and
 *						system event handlers before passing them on to
 *						FrmHandleEvent for default processing.
 *
 * PARAMETERS:		None.
 *
 * RETURNED:		Nothing.
 *
 ***********************************************************************/
static void EventLoop(void)
{
	static EventType	event;
	UInt16 error;
		
	do
	{
		// Get the next available event.
		EvtGetEvent(&event, /*5*/ evtWaitForever);

		// Give the system a chance to handle the event.
	  	if( !SysHandleEvent (&event))
			if( !MenuHandleEvent (CurrentMenu, &event, &error))
				// Give the application a chance to handle the event.
				if( !ApplicationHandleEvent(&event) )
					// Let the form object provide default handling of the event.
					FrmDispatchEvent(&event);
	} 
	while (event.eType != appStopEvent);
}


/***********************************************************************
 *
 * FUNCTION:		ApplicationHandleEvent
 *
 * DESCRIPTION:	An event handler for this application.  Gives control 
 * 					to the appropriate form (Main or About) by setting the
 * 					newly-loaded form's event handler.
 *
 * PARAMETERS:		None.
 *
 * RETURNED:		Nothing.
 *
 ***********************************************************************/
static Boolean ApplicationHandleEvent (EventPtr event)
{
	UInt16 formID;
	FormPtr frm;

	if (event->eType == frmLoadEvent)
	{
		// Load the form resource.
		formID = event->data.frmLoad.formID;
		frm = FrmInitForm (formID);
		FrmSetActiveForm (frm);		
		
		// Set the event handler for the form.  The handler of the currently
		// active form is called by FrmDispatchEvent each time is receives an
		// event.
		switch (formID)
		{
			case MainForm:
				FrmSetEventHandler (frm, MainFormHandleEvent);
				break;
		
			case AboutForm:
				FrmSetEventHandler (frm, AboutHandleEvent );
				break;
		}
		return (true);
	}
	return (false);
}


/***********************************************************************
 *
 * FUNCTION:		PilotMain
 *
 * DESCRIPTION:	This function is the equivalent of a main() function
 *						in standard C.  It is called by the Emulator to begin
 *						execution of this application.
 *
 * PARAMETERS:		cmd - command specifying how to launch the application.
 *						cmdPBP - parameter block for the command.
 *						launchFlags - flags used to configure the launch.			
 *
 * RETURNED:		Any applicable error code.
 *
 ***********************************************************************/
UInt32 PilotMain(UInt16 cmd, MemPtr cmdPBP, UInt16 launchFlags)
{
	// Check for a normal launch.
	if (cmd == sysAppLaunchCmdNormalLaunch)
	{
		Err error = STATUS_OK;
		
		// Set up Scan Manager and the initial (Main) form.
		StartApplication();
		
		// Start up the event loop.
		EventLoop();

		// Close down Scan Manager, decoder
		StopApplication();
	}
	
	return(0);
}

/***********************************************************************
 *
 * FUNCTION: 		OnDecoderData
 *
 * DESCRIPTION:	Called when the app receives a scanDecodeEvent, which
 * 					signals that a decode operation has been completed.
 * 					Calls the Scan Manager function "ScanGetDecodedData" 
 * 					to get the scan data and barcode type from the last 
 * 					scan.  Fills in the controls on the main form that 
 * 					display this information.
 *
 * RETURNED:		True if the event is handled, false otherwise.
 *
 ***********************************************************************/
Boolean OnDecoderData()
{

	static Char 	BarTypeStr[80]=" ";
	MESSAGE 		decodeDataMsg;
	Int16			status;
	MemHandle		hExtendedData;
	UInt8			*pExtendedData;
	Int16			extendedDataType;
	UInt16			numlines;

	
	if (extend)	{
		hExtendedData = MemHandleNew( extendedDataLength );
		pExtendedData = (UInt8 *)MemHandleLock( hExtendedData );
		status = ScanGetExtendedDecodedData(extendedDataLength, &extendedDataType, pExtendedData);
	}
	else	{
		status = ScanGetDecodedData( &decodeDataMsg );
		extendedDataType = decodeDataMsg.type;
		extendedDataLength = decodeDataMsg.length;
		hExtendedData = MemHandleNew(extendedDataLength+1);
		pExtendedData = (UInt8 *)MemHandleLock( hExtendedData );
		pExtendedData[extendedDataLength] = '\0';
		MemMove( &pExtendedData[0], &decodeDataMsg.data[0], extendedDataLength+1 );		
	}
	
	if( status == STATUS_OK ) // if we successfully got the decode data from the API...
	{
		FieldPtr 		pField;

		// call a function to translate barcoce type into a string, and display it
		ScanGetBarTypeStr( extendedDataType, BarTypeStr, 30 );	// in Utils.c
		SetFieldText( MainBarTypeField, BarTypeStr, 30, true );


		// Check to see if this scan was a "No Data Read" (indicated by type of zero).
		if( extendedDataType == 0)
		{
			SetFieldText( MainScandataField, "No Scan", 30, true );
		}
		else
		{
			FieldAttrType attr;
			// Place the barcode data into the field and display

		  	/* Set up data display field to display the memory */
			pField = (FieldPtr)GetObjectPtr(MainScandataField);

			FldGetAttributes(pField, &attr);
			attr.editable = true;
			FldSetAttributes(pField, &attr);

			FldDelete(pField, 0, FldGetTextLength(pField));		// clear out old data
  						
			if (extendedDataLength > FldGetMaxChars(pField))	
				FldSetMaxChars (pField, extendedDataLength);

			FldEraseField(pField);								// hide field so we don't
																// see the data scroll in

			FldInsert(pField, (Char *)&pExtendedData[0], extendedDataLength);

			// move to top of scroll bar
			numlines = FldCalcFieldHeight((Char *)&pExtendedData[0], SCANDATA_WIDTH);
			ScrollLines(-numlines, false);				// scroll to top of data
	
			FldDrawField(pField);								// show field

			FldGetAttributes(pField, &attr);
			attr.editable = false;
			FldSetAttributes(pField, &attr);

		}
	}

	UpdateScrollbar();

	MemHandleUnlock( hExtendedData );
	MemHandleFree( hExtendedData );

	return(0);	    			
}

/***********************************************************************
 *
 * FUNCTION:	UpdateScrollbar
 *
 * DESCRIPTION:	Updates the scroll bar according to the current condition
 *				of MainScandataField. Code taken from Palm Programming.
 *
 * PARAMETERS:		none
 *
 * RETURNED:		none
 *
 ***********************************************************************/

static void UpdateScrollbar(void)
{
	FormPtr			frm = FrmGetActiveForm();
	ScrollBarPtr	scroll;
	FieldPtr		field;
	UInt16			currentPosition;
	UInt16			textHeight;
	UInt16			fieldHeight;
	UInt16			maxValue;
	
	field = (FieldPtr)FrmGetObjectPtr(frm, FrmGetObjectIndex(frm, MainScandataField));
	FldGetScrollValues(field, &currentPosition, &textHeight, &fieldHeight);
	
	if (textHeight > fieldHeight)
		maxValue = textHeight - fieldHeight;
	else if (currentPosition)
		maxValue = currentPosition;
	else
		maxValue = 0;
		
	scroll = (ScrollBarPtr)FrmGetObjectPtr(frm, FrmGetObjectIndex(frm, MainScanScrollBar));
	SclSetScrollBar(scroll, currentPosition, 0, maxValue, fieldHeight - 1);
	
}

/***********************************************************************
 *
 * FUNCTION:	ScrollLines
 *
 * DESCRIPTION:	Scrolls the field according to the Scroll bar
 *
 * PARAMETERS:		numLinesToScroll - number of lines to scroll
 *					redraw - call update scrollbar
 *
 * RETURNED:		none
 *
 ***********************************************************************/

static void ScrollLines (Int16 numLinesToScroll, Boolean redraw)
{
	FormPtr		frm = FrmGetActiveForm();
	FieldPtr	field;

	field = (FieldPtr)FrmGetObjectPtr(frm, FrmGetObjectIndex(frm, MainScandataField));

	if (numLinesToScroll < 0)
		FldScrollField(field, -numLinesToScroll, winUp);
	else
		FldScrollField(field, numLinesToScroll, winDown);
		
	if (FldGetNumberOfBlankLines(field) && numLinesToScroll < 0 || redraw)
		UpdateScrollbar();
}
	

/***********************************************************************
 *
 * FUNCTION:	PageScroll
 *
 * DESCRIPTION:	Scrolls the field up or down one field page length
 *
 * PARAMETERS:		direction - up or down
 *
 * RETURNED:		none
 *
 ***********************************************************************/

static void PageScroll (WinDirectionType direction)
{
	FormPtr		frm = FrmGetActiveForm();
	FieldPtr	field;
	
	field = (FieldPtr)FrmGetObjectPtr(frm, FrmGetObjectIndex(frm, MainScandataField));
	if (FldScrollable(field, direction)){
		Int16 linesToScroll = FldGetVisibleLines(field) -1;
		
		if(direction == winUp)
			linesToScroll = -linesToScroll;
			
		ScrollLines(linesToScroll, true);
	}
}

/***********************************************************************
   About Form
************************************************************************/

/***********************************************************************
 *
 * FUNCTION:		OnAbout
 *
 * DESCRIPTION:	Changes the active form to the About Form
 *
 * PARAMETERS:		None.
 *
 * RETURNED:		Nothing
 *
 ***********************************************************************/
void OnAbout()
{
	FrmGotoForm( AboutForm );
}

/***********************************************************************
 *
 * FUNCTION:		AboutOnInit
 *
 * DESCRIPTION:	Initialize controls on the about form, after getting 
 * 					the version strings from the Scan Manager API.
 *
 * PARAMETERS:		None.
 *
 * RETURNED:		Nothing
 *
 ***********************************************************************/
static void AboutOnInit( void )
{
	Char chrDecoderVersion[MAX_PACKET_LENGTH];
	Char chrPortDriverVersion[20];
	Char chrScanMgrVersion[20];
	FormPtr pForm = FrmGetActiveForm();

	if (ScanIsPalmSymbolUnit())
	{
		// initialize text in all the version string fields
		ScanGetDecoderVersion( chrDecoderVersion, MAX_PACKET_LENGTH);
		SetFieldText(AboutDecoderField, chrDecoderVersion, MAX_PACKET_LENGTH, false);

		ScanGetScanPortDriverVersion(chrPortDriverVersion, 20 );
		SetFieldText(AboutPortDriverField, chrPortDriverVersion, 20, false);
		
		ScanGetScanManagerVersion(chrScanMgrVersion, 20 );
		SetFieldText(AboutScanManagerField, chrScanMgrVersion, 20, false);
	}
	
	FrmDrawForm( pForm );	
}

/***********************************************************************
 *
 * FUNCTION:		AboutHandleEvent
 *
 * DESCRIPTION:	Event handler for the About form.
 * 					Handles the frmOpenEvent, frmCloseEvent, and the 
 * 					ctlSelectEvent (for the OK button).
 *
 * PARAMETERS:		ev - pointer to the event information structure.
 *
 * RETURNED:		true - the event was handled by us.  false otherwise
 *
 ***********************************************************************/
Boolean AboutHandleEvent( EventPtr ev )
{
	Boolean bHandled = false;
	
	switch( ev->eType )
	{
		case ctlSelectEvent:
			if( ev->data.ctlSelect.controlID == AboutOKButton )
			{
				FrmGotoForm(MainForm);
				bHandled = true;
			}
			break;

		case frmOpenEvent:
			AboutOnInit();
			bHandled = true;
			break;
			
		case frmCloseEvent:
			FreeFieldHandle(AboutDecoderField);
			break;
			
		default:
			break;
	}
	
	return bHandled;
}