RetroZilla/modules/plugin/tools/sdk/samples/simple/plugin.cpp

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#include "plugin.h"
#include "nsIServiceManager.h"
#include "nsIMemory.h"
#include "nsISupportsUtils.h" // this is where some useful macros defined

// service manager which will give the access to all public browser services
// we will use memory service as an illustration
nsIServiceManager * gServiceManager = NULL;

// Unix needs this
#ifdef XP_UNIX
#define MIME_TYPES_HANDLED  "application/simple-plugin"
#define PLUGIN_NAME         "Simple Plugin Example for Mozilla"
#define MIME_TYPES_DESCRIPTION  MIME_TYPES_HANDLED"::"PLUGIN_NAME
#define PLUGIN_DESCRIPTION  PLUGIN_NAME " (Plug-ins SDK sample)" 

char* NPP_GetMIMEDescription(void)
{
    return(MIME_TYPES_DESCRIPTION);
}

// get values per plugin
NPError NS_PluginGetValue(NPPVariable aVariable, void *aValue)
{
  NPError err = NPERR_NO_ERROR;
  switch (aVariable) {
    case NPPVpluginNameString:
      *((char **)aValue) = PLUGIN_NAME;
      break;
    case NPPVpluginDescriptionString:
      *((char **)aValue) = PLUGIN_DESCRIPTION;
      break;
    default:
      err = NPERR_INVALID_PARAM;
      break;
  }
  return err;
}
#endif //XP_UNIX

//////////////////////////////////////
//
// general initialization and shutdown
//
NPError NS_PluginInitialize()
{
  // this is probably a good place to get the service manager
  // note that Mozilla will add reference, so do not forget to release
  nsISupports * sm = NULL;
  
  NPN_GetValue(NULL, NPNVserviceManager, &sm);

  // Mozilla returns nsIServiceManager so we can use it directly; doing QI on
  // nsISupports here can still be more appropriate in case something is changed 
  // in the future so we don't need to do casting of any sort.
  if(sm) {
    sm->QueryInterface(NS_GET_IID(nsIServiceManager), (void**)&gServiceManager);
    NS_RELEASE(sm);
  }
  
  return NPERR_NO_ERROR;
}

void NS_PluginShutdown()
{
  // we should release the service manager
  NS_IF_RELEASE(gServiceManager);
  gServiceManager = NULL;
}

/////////////////////////////////////////////////////////////
//
// construction and destruction of our plugin instance object
//
nsPluginInstanceBase * NS_NewPluginInstance(nsPluginCreateData * aCreateDataStruct)
{
  if(!aCreateDataStruct)
    return NULL;

  nsPluginInstance * plugin = new nsPluginInstance(aCreateDataStruct->instance);
  return plugin;
}

void NS_DestroyPluginInstance(nsPluginInstanceBase * aPlugin)
{
  if(aPlugin)
    delete (nsPluginInstance *)aPlugin;
}

////////////////////////////////////////
//
// nsPluginInstance class implementation
//
nsPluginInstance::nsPluginInstance(NPP aInstance) : nsPluginInstanceBase(),
  mInstance(aInstance),
  mInitialized(FALSE),
  mScriptablePeer(NULL)
{
  mString[0] = '\0';
}

nsPluginInstance::~nsPluginInstance()
{
  // mScriptablePeer may be also held by the browser 
  // so releasing it here does not guarantee that it is over
  // we should take precaution in case it will be called later
  // and zero its mPlugin member
  mScriptablePeer->SetInstance(NULL);
  NS_IF_RELEASE(mScriptablePeer);
}

NPBool nsPluginInstance::init(NPWindow* aWindow)
{
  if(aWindow == NULL)
    return FALSE;

  mInitialized = TRUE;
  return TRUE;
}

void nsPluginInstance::shut()
{
  mInitialized = FALSE;
}

NPBool nsPluginInstance::isInitialized()
{
  return mInitialized;
}

void nsPluginInstance::getVersion(char* *aVersion)
{
  const char *ua = NPN_UserAgent(mInstance);
  char*& version = *aVersion;

  // although we can use NPAPI NPN_MemAlloc call to allocate memory:
  //    version = (char*)NPN_MemAlloc(strlen(ua) + 1);
  // for illustration purposed we use the service manager to access 
  // the memory service provided by Mozilla
  nsIMemory * nsMemoryService = NULL;
  
  if (gServiceManager) {
    // get service using its contract id and use it to allocate the memory
    gServiceManager->GetServiceByContractID("@mozilla.org/xpcom/memory-service;1", NS_GET_IID(nsIMemory), (void **)&nsMemoryService);
    if(nsMemoryService)
      version = (char *)nsMemoryService->Alloc(strlen(ua) + 1);
  }

  if (version)
    strcpy(version, ua);

  // release service
  NS_IF_RELEASE(nsMemoryService);
}

// ==============================
// ! Scriptability related code !
// ==============================
//
// here the plugin is asked by Mozilla to tell if it is scriptable
// we should return a valid interface id and a pointer to 
// nsScriptablePeer interface which we should have implemented
// and which should be defined in the corressponding *.xpt file
// in the bin/components folder
NPError	nsPluginInstance::GetValue(NPPVariable aVariable, void *aValue)
{
  NPError rv = NPERR_NO_ERROR;

  switch (aVariable) {
    case NPPVpluginScriptableInstance: {
      // addref happens in getter, so we don't addref here
      nsISimplePlugin * scriptablePeer = getScriptablePeer();
      if (scriptablePeer) {
        *(nsISupports **)aValue = scriptablePeer;
      } else
        rv = NPERR_OUT_OF_MEMORY_ERROR;
    }
    break;

    case NPPVpluginScriptableIID: {
      static nsIID scriptableIID = NS_ISIMPLEPLUGIN_IID;
      nsIID* ptr = (nsIID *)NPN_MemAlloc(sizeof(nsIID));
      if (ptr) {
          *ptr = scriptableIID;
          *(nsIID **)aValue = ptr;
      } else
        rv = NPERR_OUT_OF_MEMORY_ERROR;
    }
    break;

    default:
      break;
  }

  return rv;
}

// ==============================
// ! Scriptability related code !
// ==============================
//
// this method will return the scriptable object (and create it if necessary)
nsScriptablePeer* nsPluginInstance::getScriptablePeer()
{
  if (!mScriptablePeer) {
    mScriptablePeer = new nsScriptablePeer(this);
    if(!mScriptablePeer)
      return NULL;

    NS_ADDREF(mScriptablePeer);
  }

  // add reference for the caller requesting the object
  NS_ADDREF(mScriptablePeer);
  return mScriptablePeer;
}