main.c

//==============================================================================
//
//  DO NO MODIFY THE CONTENT OF THIS FILE
//
//  This file contains the generic CFPlug-in code necessary for your generator
//  To complete your generator implement the function in GenerateThumbnailForURL/GeneratePreviewForURL.c
//
//==============================================================================

#include <CoreFoundation/CFPlugInCOM.h>
#include <CoreFoundation/CoreFoundation.h>
#include <CoreServices/CoreServices.h>
#include <QuickLook/QuickLook.h>


// -----------------------------------------------------------------------------
//  constants
// -----------------------------------------------------------------------------

// Don't modify this line
#define PLUGIN_ID "A7AB3C73-4556-4833-9518-1FB00D7472FF"

//
// Below is the generic glue code for all plug-ins.
//
// You should not have to modify this code aside from changing
// names if you decide to change the names defined in the Info.plist
//

// -----------------------------------------------------------------------------
//  typedefs
// -----------------------------------------------------------------------------

// The thumbnail generation function to be implemented in GenerateThumbnailForURL.c
OSStatus GenerateThumbnailForURL(void *thisInterface, QLThumbnailRequestRef thumbnail, CFURLRef url,
                                 CFStringRef contentTypeUTI, CFDictionaryRef options, CGSize maxSize);
void CancelThumbnailGeneration(void *thisInterface, QLThumbnailRequestRef thumbnail);

// The preview generation function to be implemented in GeneratePreviewForURL.c
OSStatus GeneratePreviewForURL(void *thisInterface, QLPreviewRequestRef preview, CFURLRef url,
                               CFStringRef contentTypeUTI, CFDictionaryRef options);
void CancelPreviewGeneration(void *thisInterface, QLPreviewRequestRef preview);

// The layout for an instance of QuickLookGeneratorPlugIn
typedef struct __QuickLookGeneratorPluginType {
  void *conduitInterface;
  CFUUIDRef factoryID;
  UInt32 refCount;
} QuickLookGeneratorPluginType;

// -----------------------------------------------------------------------------
//  prototypes
// -----------------------------------------------------------------------------
//  Forward declaration for the IUnknown implementation.
//

QuickLookGeneratorPluginType *AllocQuickLookGeneratorPluginType(CFUUIDRef inFactoryID);
void DeallocQuickLookGeneratorPluginType(QuickLookGeneratorPluginType *thisInstance);
HRESULT QuickLookGeneratorQueryInterface(void *thisInstance, REFIID iid, LPVOID *ppv);
void *QuickLookGeneratorPluginFactory(CFAllocatorRef allocator, CFUUIDRef typeID);
ULONG QuickLookGeneratorPluginAddRef(void *thisInstance);
ULONG QuickLookGeneratorPluginRelease(void *thisInstance);

// -----------------------------------------------------------------------------
//  myInterfaceFtbl  definition
// -----------------------------------------------------------------------------
//  The QLGeneratorInterfaceStruct function table.
//
static QLGeneratorInterfaceStruct myInterfaceFtbl = {NULL,
                                                     QuickLookGeneratorQueryInterface,
                                                     QuickLookGeneratorPluginAddRef,
                                                     QuickLookGeneratorPluginRelease,
                                                     NULL,
                                                     NULL,
                                                     NULL,
                                                     NULL};

// -----------------------------------------------------------------------------
//  AllocQuickLookGeneratorPluginType
// -----------------------------------------------------------------------------
//  Utility function that allocates a new instance.
//      You can do some initial setup for the generator here if you wish
//      like allocating globals etc...
//
QuickLookGeneratorPluginType *AllocQuickLookGeneratorPluginType(CFUUIDRef inFactoryID) {
  QuickLookGeneratorPluginType *theNewInstance;

  theNewInstance = (QuickLookGeneratorPluginType *)malloc(sizeof(QuickLookGeneratorPluginType));
  memset(theNewInstance, 0, sizeof(QuickLookGeneratorPluginType));

  /* Point to the function table Malloc enough to store the stuff and copy the filler from myInterfaceFtbl over */
  theNewInstance->conduitInterface = malloc(sizeof(QLGeneratorInterfaceStruct));
  memcpy(theNewInstance->conduitInterface, &myInterfaceFtbl, sizeof(QLGeneratorInterfaceStruct));

  /*  Retain and keep an open instance refcount for each factory. */
  theNewInstance->factoryID = CFRetain(inFactoryID);
  CFPlugInAddInstanceForFactory(inFactoryID);

  /* This function returns the IUnknown interface so set the refCount to one. */
  theNewInstance->refCount = 1;
  return theNewInstance;
}

// -----------------------------------------------------------------------------
//  DeallocQuickLookGeneratorPluginType
// -----------------------------------------------------------------------------
//  Utility function that deallocates the instance when
//  the refCount goes to zero.
//      In the current implementation generator interfaces are never deallocated
//      but implement this as this might change in the future
//
void DeallocQuickLookGeneratorPluginType(QuickLookGeneratorPluginType *thisInstance) {
  CFUUIDRef theFactoryID;

  theFactoryID = thisInstance->factoryID;
  /* Free the conduitInterface table up */
  free(thisInstance->conduitInterface);

  /* Free the instance structure */
  free(thisInstance);
  if (theFactoryID) {
    CFPlugInRemoveInstanceForFactory(theFactoryID);
    CFRelease(theFactoryID);
  }
}

// -----------------------------------------------------------------------------
//  QuickLookGeneratorQueryInterface
// -----------------------------------------------------------------------------
//  Implementation of the IUnknown QueryInterface function.
//
HRESULT QuickLookGeneratorQueryInterface(void *thisInstance, REFIID iid, LPVOID *ppv) {
  CFUUIDRef interfaceID;

  interfaceID = CFUUIDCreateFromUUIDBytes(kCFAllocatorDefault, iid);

  if (CFEqual(interfaceID, kQLGeneratorCallbacksInterfaceID)) {
    /* If the Right interface was requested, bump the ref count,
     * set the ppv parameter equal to the instance, and
     * return good status.
     */
    ((QLGeneratorInterfaceStruct *)((QuickLookGeneratorPluginType *)thisInstance)->conduitInterface)
        ->GenerateThumbnailForURL = GenerateThumbnailForURL;
    ((QLGeneratorInterfaceStruct *)((QuickLookGeneratorPluginType *)thisInstance)->conduitInterface)
        ->CancelThumbnailGeneration = CancelThumbnailGeneration;
    ((QLGeneratorInterfaceStruct *)((QuickLookGeneratorPluginType *)thisInstance)->conduitInterface)
        ->GeneratePreviewForURL = GeneratePreviewForURL;
    ((QLGeneratorInterfaceStruct *)((QuickLookGeneratorPluginType *)thisInstance)->conduitInterface)
        ->CancelPreviewGeneration = CancelPreviewGeneration;
    ((QLGeneratorInterfaceStruct *)((QuickLookGeneratorPluginType *)thisInstance)->conduitInterface)
        ->AddRef(thisInstance);
    *ppv = thisInstance;
    CFRelease(interfaceID);
    return S_OK;
  } else {
    /* Requested interface unknown, bail with error. */
    *ppv = NULL;
    CFRelease(interfaceID);
    return E_NOINTERFACE;
  }
}

// -----------------------------------------------------------------------------
// QuickLookGeneratorPluginAddRef
// -----------------------------------------------------------------------------
//  Implementation of reference counting for this type. Whenever an interface
//  is requested, bump the refCount for the instance. NOTE: returning the
//  refcount is a convention but is not required so don't rely on it.
//
ULONG QuickLookGeneratorPluginAddRef(void *thisInstance) {
  ((QuickLookGeneratorPluginType *)thisInstance)->refCount += 1;
  return ((QuickLookGeneratorPluginType *)thisInstance)->refCount;
}

// -----------------------------------------------------------------------------
// QuickLookGeneratorPluginRelease
// -----------------------------------------------------------------------------
//  When an interface is released, decrement the refCount.
//  If the refCount goes to zero, deallocate the instance.
//
ULONG QuickLookGeneratorPluginRelease(void *thisInstance) {
  ((QuickLookGeneratorPluginType *)thisInstance)->refCount -= 1;
  if (((QuickLookGeneratorPluginType *)thisInstance)->refCount == 0) {
    DeallocQuickLookGeneratorPluginType((QuickLookGeneratorPluginType *)thisInstance);
    return 0;
  } else {
    return ((QuickLookGeneratorPluginType *)thisInstance)->refCount;
  }
}

// -----------------------------------------------------------------------------
//  QuickLookGeneratorPluginFactory
// -----------------------------------------------------------------------------
void *QuickLookGeneratorPluginFactory(CFAllocatorRef allocator, CFUUIDRef typeID) {
  QuickLookGeneratorPluginType *result;
  CFUUIDRef uuid;

  /* If correct type is being requested, allocate an
   * instance of kQLGeneratorTypeID and return the IUnknown interface.
   */
  if (CFEqual(typeID, kQLGeneratorTypeID)) {
    uuid = CFUUIDCreateFromString(kCFAllocatorDefault, CFSTR(PLUGIN_ID));
    result = AllocQuickLookGeneratorPluginType(uuid);
    CFRelease(uuid);
    return result;
  }
  /* If the requested type is incorrect, return NULL. */
  return NULL;
}