main.c

/*
    File:       main.c
    
    Description: Sample Button Plugin
 
    Author: Image Capture Engineering
 
    Copyright:  © Copyright 2003 Apple Computer, Inc. All rights reserved.
    
    Disclaimer: IMPORTANT:  This Apple software is supplied to you by Apple Computer, Inc.
                ("Apple") in consideration of your agreement to the following terms, and your
                use, installation, modification or redistribution of this Apple software
                constitutes acceptance of these terms.  If you do not agree with these terms,
                please do not use, install, modify or redistribute this Apple software.
 
                In consideration of your agreement to abide by the following terms, and subject
                to these terms, Apple grants you a personal, non-exclusive license, under AppleÕs
                copyrights in this original Apple software (the "Apple Software"), to use,
                reproduce, modify and redistribute the Apple Software, with or without
                modifications, in source and/or binary forms; provided that if you redistribute
                the Apple Software in its entirety and without modifications, you must retain
                this notice and the following text and disclaimers in all such redistributions of
                the Apple Software.  Neither the name, trademarks, service marks or logos of
                Apple Computer, Inc. may be used to endorse or promote products derived from the
                Apple Software without specific prior written permission from Apple.  Except as
                expressly stated in this notice, no other rights or licenses, express or implied,
                are granted by Apple herein, including but not limited to any patent rights that
                may be infringed by your derivative works or by other works in which the Apple
                Software may be incorporated.
 
                The Apple Software is provided by Apple on an "AS IS" basis.  APPLE MAKES NO
                WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED
                WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
                PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND OPERATION ALONE OR IN
                COMBINATION WITH YOUR PRODUCTS.
 
                IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR
                CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
                GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION, MODIFICATION AND/OR DISTRIBUTION
                OF THE APPLE SOFTWARE, HOWEVER CAUSED AND WHETHER UNDER THEORY OF CONTRACT, TORT
                (INCLUDING NEGLIGENCE), STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN
                ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
                
    Change History (most recent first):
    
           <1>      6/17/03 WN          first file
 
*/
#include <Carbon/Carbon.h>
#include <CoreFoundation/CoreFoundation.h>
 
#include <mach/mach.h>
#include <pthread.h>
#include <time.h>
 
#define THREAD 0
#define DEBUG 0
 
typedef CALLBACK_API_C( void , ButtonPressedCallback )(OSType   message,
                                                       UInt32*  locationID,
                                                       UInt64*  guid);
 
//-------------------------------------------------------------------------------------- MyDevice
typedef struct MyDevice
{
    UInt32              sLocationID;
#if THREAD
    pthread_t           sUnsolEventProcThread;
#else
    EventLoopTimerRef   sTimerRef;
#endif
    ButtonPressedCallback sButtonCallback;
} MyDevice;
 
// globals
MyDevice gMyDevice;
 
// prototypes
UInt8 PushButtonStatus();
void CancelThreads();
void *UnsolEventProcThreadEntryPoint(void *inParam);
void UnsolEventProcThreadCleanupHandler(void *inParam);
 
#pragma mark -
 
//-------------------------------------------------------------------------------------- PushButtonStatus
UInt8 PushButtonStatus()
{
    KeyMap theKeys;
    KeyMap f5Key = { 0x00000000, 0x0000000C, 0x00000000, 0x00000000 };
    
    GetKeys(theKeys);
    return (0 == memcmp(theKeys, f5Key, sizeof(KeyMap)));
}
 
//-------------------------------------------------------------------------------------- CancelThreads
void CancelThreads()
{
#if THREAD
    int     fStatus;
    void    *fResult;
 
    // unblock thread processing unsol.status notifications and cancel it
    fStatus = pthread_cancel( gMyDevice.sUnsolEventProcThread );
    fStatus = pthread_join( gMyDevice.sUnsolEventProcThread, &fResult );
#endif
}
 
//-------------------------------------------------------------------------------------- UnsolEventProcThreadEntryPoint
void *UnsolEventProcThreadEntryPoint(void *inParam)
{
//  printf( "UnsolEventProcThreadEntryPoint\n" );
 
#if THREAD
    pthread_cleanup_push( UnsolEventProcThreadCleanupHandler, NULL );
    while( 1 )
    {
        UInt32 button;
        struct timespec sleepTime;
 
        pthread_testcancel();   // check if the thread has been canceled
        sleepTime.tv_sec = 1;
        sleepTime.tv_nsec = 0;
        button = PushButtonStatus();
        if (button)
            gMyDevice.sButtonCallback('but1', &gMyDevice.sLocationID, nil);
        nanosleep(&sleepTime, 0);
    }
    pthread_cleanup_pop( 1 );
#else
#endif
    return NULL;
}
 
//-------------------------------------------------------------------------------------- UnsolEventProcThreadCleanupHandler
void UnsolEventProcThreadCleanupHandler(void *inParam)
{
//    printf( "UnsolEventProcThreadCleanupHandler\n" );
}
 
//-------------------------------------------------------------------------------------- TimerEvent
pascal void TimerEvent (EventLoopTimerRef inTimer,
                        void *inUserData)
{
    UInt32 button;
    button = PushButtonStatus();
    if (button)
        gMyDevice.sButtonCallback('but1', &gMyDevice.sLocationID, nil);
}
 
#pragma mark -
 
//-------------------------------------------------------------------------------------- TWAINButtonPluginStart
OSErr TWAINButtonPluginStart(UInt32*     locationID,
                             UInt64*     guid,
                             io_string_t twainPath,
                             ButtonPressedCallback callback)
{
    IOReturn err = noErr;
 
#if DEBUG
    printf("---------------------------------------\n");
    printf("        TWAINButtonPluginStart\n");
    printf("---------------------------------------\n");
#endif
    
    memset(&gMyDevice, 0, sizeof(gMyDevice));
    gMyDevice.sLocationID = *locationID;
 
    require(err == noErr, bail);
    
    gMyDevice.sButtonCallback = callback;
#if THREAD
    err = pthread_create(
                &gMyDevice.sUnsolEventProcThread,
                NULL,
                UnsolEventProcThreadEntryPoint,
                NULL
            );
#else
    err = InstallEventLoopTimer( GetCurrentEventLoop(),
                                 (kEventDurationSecond),
                                 (kEventDurationSecond),
                                 NewEventLoopTimerUPP(TimerEvent),
                                 NULL,
                                 &gMyDevice.sTimerRef);
#endif
    
bail:
#if DEBUG
    if (err)
        printf("exiting TWAINButtonPluginStart err = 0x%08x\n", err);
#endif 
    return err;
}
 
//-------------------------------------------------------------------------------------- TWAINButtonPluginStop
OSErr TWAINButtonPluginStop(UInt32*      locationID,
                            UInt64*      guid,
                            io_string_t twainPath)
{
#if DEBUG
    printf("---------------------------------------\n");
    printf("        TWAINButtonPluginStop\n");
    printf("---------------------------------------\n");
#endif 
 
#if THREAD
    CancelThreads();
#else
    RemoveEventLoopTimer(gMyDevice.sTimerRef);
#endif
    
    return noErr;
}