new

modules/libimg/pngcom/nsPNGModule.cpp

@@ -0,0 +1,207 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ *
+ * The contents of this file are subject to the Netscape Public License
+ * Version 1.0 (the "NPL"); you may not use this file except in
+ * compliance with the NPL.  You may obtain a copy of the NPL at
+ * http:/www.mozilla.org/NPL/
+ *
+ * Software distributed under the NPL is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
+ * for the specific language governing rights and limitations under the
+ * NPL.
+ *
+ * The Initial Developer of this code under the NPL is Netscape
+ * Communications Corporation.  Portions created by Netscape are
+ * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
+ * Reserved.
+ */
+
+#include "nsPNGModule.h"
+#include "nsPNGDecoder.h"
+#include "nsIComponentManager.h"
+#include "nsIGenericFactory.h"
+#include "nsISupports.h"
+#include "nsCOMPtr.h"
+
+static NS_DEFINE_CID(kPNGDecoderCID, NS_PNGDECODER_CID);
+static NS_DEFINE_IID(kISupportsIID, NS_ISUPPORTS_IID);
+
+
+//////////////////////////////////////////////////////////////////////
+// Module Global
+//
+// This is used by the module to count object. Constructors and
+// destructors of objects created by this module need to
+// inc/dec the object count for the module. Unload decision will
+// be taken based on this.
+//
+// Constructor:
+//	gModule->IncrementObjCount();
+//
+// Descructor:
+//	gModule->DecrementObjCount();
+//
+// WARNING: This is weak reference. XPCOM guarantees that this module
+// 			object will be deleted just before the dll is unloaded. Hence,
+//			holding a weak reference is ok.
+
+static nsPNGModule *gModule = NULL;
+
+//////////////////////////////////////////////////////////////////////
+// Module entry point
+
+extern "C" NS_EXPORT nsresult NSGetModule(nsIComponentManager *servMgr,
+                                          nsIFileSpec* location,
+                                          nsIModule** return_cobj)
+{
+    nsPNGModule *module;
+    nsresult rv = NS_OK;
+
+    NS_ASSERTION(return_cobj, "Null argument");
+    NS_ASSERTION(gModule == NULL, "nsPNGModule: Module already created.");
+
+    module = new nsPNGModule;
+    if (module == NULL) return NS_ERROR_OUT_OF_MEMORY;
+
+    rv = module->QueryInterface(nsIModule::GetIID(), (void **)return_cobj);
+
+    if (NS_FAILED(rv))
+    {
+        delete module;
+        module = NULL;
+    }
+
+    // WARNING: Weak Reference
+    gModule = module;
+
+    return rv;
+}
+
+//////////////////////////////////////////////////////////////////////
+// PNG Decoder Factory using nsIGenericFactory
+
+static NS_IMETHODIMP
+nsPNGDecoderCreateInstance(nsISupports *aOuter, REFNSIID aIID, void **aResult)
+{
+    PNGDecoder *dec = NULL;
+    *aResult = NULL;
+    il_container* ic = NULL;
+
+    if (aOuter && !aIID.Equals(kISupportsIID))
+        return NS_NOINTERFACE;  
+
+    ic = new il_container();
+    if (!ic)
+    {
+        return NS_ERROR_OUT_OF_MEMORY;
+    }
+    dec = new PNGDecoder(ic);
+    if (!dec)
+    {
+        delete ic;
+        return NS_ERROR_OUT_OF_MEMORY;
+    }
+    nsresult res = dec->QueryInterface(aIID, aResult);
+    if (NS_FAILED(res))
+    {
+        *aResult = NULL;
+        delete dec;
+    }
+    delete ic; /* is a place holder */
+    return res;
+}
+
+
+//////////////////////////////////////////////////////////////////////
+// PNG Decoder Module Implementation
+
+NS_IMPL_ISUPPORTS(nsPNGModule, nsIModule::GetIID())
+
+nsPNGModule::nsPNGModule(void)
+  : mObjCount(-1), mClassObject(NULL)
+{
+    NS_INIT_ISUPPORTS();
+}
+
+nsPNGModule::~nsPNGModule(void)
+{
+    NS_ASSERTION(mObjCount <= 0, "Module released while having outstanding objects.");
+    if (mClassObject)
+    {
+        int refcnt;
+        NS_RELEASE2(mClassObject, refcnt);
+        NS_ASSERTION(refcnt == 0, "nsPNGModule::~nsPNGModule() ClassObject refcount nonzero");
+    }
+}
+
+//
+// The class object for us is just the factory and nothing more.
+//
+NS_IMETHODIMP
+nsPNGModule::GetClassObject(nsIComponentManager *aCompMgr, const nsCID & aClass,
+                            const nsIID &aIID, void **r_classObj)
+{
+    nsresult rv;
+
+    if( !aClass.Equals(kPNGDecoderCID))
+		return NS_ERROR_FACTORY_NOT_REGISTERED;
+
+    // If this aint the first time, return the cached class object
+    if (mClassObject == NULL)
+    {
+        nsCOMPtr<nsIGenericFactory> fact;
+        rv = NS_NewGenericFactory(getter_AddRefs(fact), nsPNGDecoderCreateInstance);
+        if (NS_FAILED(rv)) return rv;
+    
+        // Store the class object in our global
+        rv = fact->QueryInterface(NS_GET_IID(nsISupports), (void **)&mClassObject);
+        if (NS_FAILED(rv)) return rv;
+    }
+
+    rv = mClassObject->QueryInterface(aIID, r_classObj);
+    return rv;
+}
+
+NS_IMETHODIMP
+nsPNGModule::RegisterSelf(nsIComponentManager *aCompMgr,
+                          nsIFileSpec *location,
+                          const char *registryLocation,
+                          const char *componentType)
+{
+    nsresult rv;
+    rv = aCompMgr->RegisterComponentSpec(kPNGDecoderCID, 
+                                         "Netscape PNGDec", 
+                                         "component://netscape/image/decoder&type=image/png",
+                                         location, PR_TRUE, PR_TRUE);
+    return rv;
+}
+
+NS_IMETHODIMP
+nsPNGModule::UnregisterSelf(nsIComponentManager *aCompMgr,
+                            nsIFileSpec *location,
+                            const char *registryLocation)
+{
+    nsresult rv;
+    rv = aCompMgr->UnregisterComponentSpec(kPNGDecoderCID, location);
+    return rv;
+}
+
+NS_IMETHODIMP
+nsPNGModule::CanUnload(nsIComponentManager *aCompMgr, PRBool *okToUnload)
+{
+    if (mObjCount < 0)
+    {
+        // Dll doesn't count objects.
+        return NS_ERROR_FAILURE;
+    }
+
+    PRBool unloadable = PR_FALSE;
+    if (mObjCount == 0)
+    {
+        // This dll can be unloaded now
+        unloadable = PR_TRUE;
+    }
+
+    if (okToUnload) *okToUnload = unloadable;
+    return NS_OK;
+}

modules/libimg/pngcom/nsPNGModule.h

@@ -0,0 +1,45 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ *
+ * The contents of this file are subject to the Netscape Public License
+ * Version 1.0 (the "NPL"); you may not use this file except in
+ * compliance with the NPL.  You may obtain a copy of the NPL at
+ * http:/www.mozilla.org/NPL/
+ *
+ * Software distributed under the NPL is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
+ * for the specific language governing rights and limitations under the
+ * NPL.
+ *
+ * The Initial Developer of this code under the NPL is Netscape
+ * Communications Corporation.  Portions created by Netscape are
+ * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
+ * Reserved.
+ */
+#ifndef nsPNGModule_h___
+#define nsPNGModule_h___
+
+#include "nsIModule.h"
+
+class nsPNGModule : public nsIModule
+{
+public:
+    NS_DECL_ISUPPORTS
+
+    // Construction, Init and desstruction
+    nsPNGModule();
+    virtual ~nsPNGModule();
+
+    // nsIModule Interfaces
+    NS_DECL_NSIMODULE
+
+    // Facility for counting object instances
+    int IncrementObjCount() { if (mObjCount == -1) mObjCount = 0; return ++mObjCount; }
+    int DecrementObjCount() { if (mObjCount == -1) mObjCount = 0; return --mObjCount; }
+    int GetObjCount() { return mObjCount; }
+
+private:
+    int mObjCount;
+    nsISupports* mClassObject;
+};
+
+#endif /* nsPNGModule_h___ */