ndbtest.c

CD_高级PALM编程

					MainFormError( err );
					SetTextFieldWithHandle( MainPropertyField, CreateEmptyHandle(), true );
				}
			} // error occurred
				
				
			handled = true;
			break;
			
		case MainBackButton:
			if ( mainDatabaseRecordH )
			{
				if ( NDBRecordIsValid( mainDatabaseRecordH, &err ) )
				{

// Get the next record.

					mainDatabaseRecordH = NDBRecordGetPrev( mainDatabaseRecordH, &err );
					MainFormDrawRecordView( );
					if ( err != noErr )
					{
						if ( err == ndbErrorNoPreviousRecord )
						{
							FrmAlert( FirstRecordAlert );
						}
						else
						{
							MainFormError( err );
							SetTextFieldWithHandle( MainPropertyField, CreateEmptyHandle(), true );
						}
					} // error occurred
				}

			}
			handled = true;
			break;
			
		case MainNextButton:
			if ( mainDatabaseRecordH )
			{
				if ( NDBRecordIsValid( mainDatabaseRecordH, &err ) )
				{

// Get the next record.

					mainDatabaseRecordH = NDBRecordGetNext( mainDatabaseRecordH, &err );
					MainFormDrawRecordView( );
					if ( err != noErr )
					{
						if ( err == ndbErrorSearchOver )
						{
							FrmAlert( LastRecordAlert );
						}
						else
						{
							MainFormError( err );
							SetTextFieldWithHandle( MainPropertyField, CreateEmptyHandle(), true );
						}
					} // error occurred
				}

			}
			handled = true;
			break;	
	}
	return handled;
}

/***********************************************************************
 * FUNCTION:    	MainFormHandleDatabasePopup
 *
 * DESCRIPTION: 	This routine handles database popup events for 
 *                  the MainForm.
 *
 * RETURNED:    	true if the event is handled.
 ***********************************************************************/
static Boolean MainFormHandleFieldPopup	// (out) returns true if event handled.
(
	UInt16		selection 		//	(in)	the selection
)
{
	Boolean	handledEvt = false;
	NDBPropertyEnum prop;
	MemHandle resultH;
	Err err;
	
// Find out what property we should fetch.

	prop = mainDatabasePickerFields[ selection ];

// Fetch a handle to that property.

	resultH  = NDBRecordGetProp( mainDatabaseRecordH, prop, &err );
	
// If there's no error, show the property.

	if ( err == noErr )
	{
		if ( resultH != NULL )
		{
// Show the property

			SetTextFieldWithHandle( MainPropertyField, resultH, true );
		} // property available
		else
		{

// That property was empty... tell the user.

			FrmAlert( PropertyEmptyAlert );
			SetTextFieldWithHandle( MainPropertyField, CreateEmptyHandle(), true );
		} // no property available
	} // no error
	else
	{
		MainFormError( err );
		SetTextFieldWithHandle( MainPropertyField, CreateEmptyHandle(), true );
	} // error occurred
	
	return handledEvt;
}

/***********************************************************************
 * FUNCTION:    	MainFormHandleDatabasePopup
 *
 * DESCRIPTION: 	This routine handles database popup events for 
 *                  the MainForm.
 *
 * RETURNED:    	true if the event is handled.
 ***********************************************************************/
static Boolean MainFormHandleDatabasePopup	// (out) returns true if event handled.
(
	UInt16		selection 		//	(in)	the selection
)
{
	Boolean	handledEvt = false;
	Err	err;
	
	if ( mainDatabaseRecordH )
	{
		NDBRecordFree ( mainDatabaseRecordH, &err );
		mainDatabaseRecordH = NULL;
	}
	
	mainDatabaseRecordH = NDBFindRecordWith ( 
		mainDatabasePickerDatabases[ selection ],
		NULL,
		&err
	);
	
	if ( err != noErr )
	{
		if ( mainDatabaseRecordH != NULL )
		{
			NDBRecordFree( mainDatabaseRecordH, &err );
			mainDatabaseRecordH = NULL;
		}
	}

// Redraw fields with new values.

	MainFormDrawRecordView( );
	return handledEvt;
}

/***********************************************************************
 * FUNCTION:    	MainFormHandleEvent
 *
 * DESCRIPTION: 	This routine is the event handler for MainForm.
 *
 * RETURNED:    	true if the event is handled.
 ***********************************************************************/
 
static Boolean MainFormHandleEvent // (out) true if handled
(
	EventPtr eventP		// (in) Pointer to an EventType that contains the event to handle
)
{
    Boolean 	handled = false;
    FormPtr		frmP = FrmGetActiveForm ();

	switch ( eventP->eType ) 
	{
	
// Menu event - call MainFormDoMenuCommand to handle it.

		case menuEvent:
		
			handled = MainFormDoMenuCommand ( eventP->data.menu.itemID );
			break;

		case frmOpenEvent:	
			MainFormInit ( frmP );	// ***** WARNING  - falls thru to next case *****
			
		case frmUpdateEvent:
			FrmDrawForm ( frmP );
			MainFormDraw( frmP );
			handled = true;
			break; 
						
		case frmCloseEvent:
		
			MainFormDone ( frmP );
			handled = true;
			break;
			
// Control activities

		case keyDownEvent: 
			if ( eventP->data.keyDown.chr == pageUpChr )
			{
				handled = MainFormHandleControl( MainBackButton );
			}
			else if ( eventP->data.keyDown.chr == pageDownChr )
			{

				handled = MainFormHandleControl( MainNextButton );
			}

			
		case ctlSelectEvent:
			handled = MainFormHandleControl( eventP->data.ctlSelect.controlID );
			break;
			
		case popSelectEvent: // A popup list item was selected
			if ( eventP->data.ctlSelect.controlID == MainFieldPopTrigger )
				handled = MainFormHandleFieldPopup( (unsigned short)eventP->data.popSelect.selection );			
			if ( eventP->data.ctlSelect.controlID == MainDatabasePopTrigger )
				handled = MainFormHandleDatabasePopup( (unsigned short)eventP->data.popSelect.selection );			
			break;
			
			
	}
	return handled;
}


/***********************************************************************
 * FUNCTION:    	AppHandleEvent
 *
 * DESCRIPTION: 	Loads a form's resources and set its event handler.
 *
 * RETURNED:    	true if the event is handled.
 ***********************************************************************/
 
static Boolean AppHandleEvent // (out) true if handled
(
	EventPtr eventP		// (in) Pointer to an EventType that contains the event to handle
)
{
	
    Boolean 	handled = false;

	if ( eventP->eType == frmLoadEvent )
	{
	
// Form load event--initialize the form and make it the active form.

		UInt16 	formId = eventP->data.frmLoad.formID;
		FormPtr	frmP = FrmInitForm ( formId );
		FrmSetActiveForm ( frmP );

// Set the event handler for the form.

		switch (formId)
		{
			case MainForm:
			
				FrmSetEventHandler(frmP, MainFormHandleEvent);
				handled = true;
				break;

//	Insert other cases as needed for other forms.

		}
		handled = true;
	}
	return handled;
}


/***********************************************************************
 * FUNCTION:    	AppEventLoop
 *
 * DESCRIPTION: 	The main event loop for the application.  
 *
 * RETURNED:    	nothing
 ***********************************************************************/
 
static void AppEventLoop
(
	void
)
{
	UInt16 		error;
	EventType 	event;

	do {
		EvtGetEvent ( &event, evtWaitForever );

		if (! SysHandleEvent ( &event))
			if (! MenuHandleEvent ( 0, &event, &error ))
				if (! AppHandleEvent ( &event ))
					FrmDispatchEvent ( &event );

	} while ( event.eType != appStopEvent );
}


/***********************************************************************
 * FUNCTION:     	AppStart
 *
 * DESCRIPTION:  	Do whatever is necessary to get started, like read the app preferences.
 *
 * RETURNED:     	Err value or 0 if nothing went wrong
 ***********************************************************************/
 
static UInt32 AppStart
(
	void
)
{

// Return an error code if necessary. 

	return 0;
}


/***********************************************************************
 * FUNCTION:    	AppStop
 *
 * DESCRIPTION: 	Do whatever you need to do, like save the preferences.
 *
 * RETURNED:    	nothing
 ***********************************************************************/
static void AppStop
(
	void
)
{
	FrmCloseAllForms ();
}


/***********************************************************************
 * FUNCTION:    PilotMain
 *
 * DESCRIPTION: The application main entry point.
 *
 * RETURNED:    0 if launch & execution are successful, non-zero otherwise.
 ***********************************************************************/
 
UInt32 PilotMain
(
	UInt16	cmd,				// (in) The launch code
	MemPtr	/* cmdPBP*/,		// (in) Pointer to the launch code structure
	UInt16	launchFlags			// (in) Extra launch info
)
{

	UInt32 error = 0;

// Check the ROM version for compatibility.

	error = RomVersionCompatible ( MIN_ROM_VERSION, launchFlags);
	if ( error == 0 ){

// ROM OK, check for the various launch codes as needed.
	
		switch (cmd)
		{
			case sysAppLaunchCmdNormalLaunch:
			
				error = AppStart ();
				if ( error == 0 )
				{
					FrmGotoForm ( MainForm );
					AppEventLoop ();
					AppStop ();
				}
				break;
		}
	}
	return error;
}