CLOUD: Add object-oriented Callbacks

These callbacks can call object's methods, not some global C functions.

DropboxStorage::info2() and DropboxStorage::infoMethodCallback()
demonstrate the idea.

backends/cloud/dropbox/dropboxstorage.cpp

@@ -92,6 +92,30 @@ void infoCallback(Networking::Request* request, void *jsonPointer) {
 	}
 }
 
+void info2Callback(Networking::Request* request, void *jsonPointer) {
+	if (!request) {
+		warning("infoCallback: got NULL instead of Request");
+
+		Common::JSONValue *json = (Common::JSONValue *)jsonPointer;
+		if (json) delete json; //yeah I know we can delete NULL safely
+		return;
+	}
+
+	Common::BaseCallback *callback = (Common::BaseCallback *)request->pointer();
+
+	Common::JSONValue *json = (Common::JSONValue *)jsonPointer;
+	if (json) {
+		//Common::JSONObject result = json->asObject();
+		if (callback) {
+			(*callback)(new StorageInfo(json->stringify()));
+			delete callback;
+		}
+		delete json;
+	} else {
+		warning("infoCallback: got NULL instead of JSON!");
+	}
+}
+
 DropboxStorage::DropboxStorage(Common::String accessToken, Common::String userId): _token(accessToken), _uid(userId) {
 	curl_global_init(CURL_GLOBAL_ALL);
 }
@@ -104,9 +128,14 @@ void syncSavesInfoCallback(StorageInfo info) {
 	debug("info: %s", info.info().c_str());
 }
 
+void DropboxStorage::infoMethodCallback(void *storageInfo) {
+	StorageInfo *info = (StorageInfo *)storageInfo;
+	debug("info: %s", info->info().c_str());
+}
+
 void DropboxStorage::syncSaves(OperationCallback callback) {
 	//this is not the real syncSaves() implementation	
-	info(syncSavesInfoCallback);
+	info2(new Common::Callback<DropboxStorage>(this, &DropboxStorage::infoMethodCallback));
 }
 
 void DropboxStorage::info(InfoCallback callback) {	
@@ -117,6 +146,14 @@ void DropboxStorage::info(InfoCallback callback) {
 	request->setPointer(callback);
 }
 
+void DropboxStorage::info2(Common::Callback<DropboxStorage> *callback) {
+	Networking::CurlJsonRequest *request = new Networking::CurlJsonRequest(info2Callback, "https://api.dropboxapi.com/1/account/info");
+	request->addHeader("Authorization: Bearer " + _token);
+	ConnMan.addRequest(request);
+
+	request->setPointer(callback);
+}
+
 DropboxStorage *DropboxStorage::loadFromConfig() {
 	KEY = ConfMan.get("DROPBOX_KEY", "cloud");
 	SECRET = ConfMan.get("DROPBOX_SECRET", "cloud");

backends/cloud/dropbox/dropboxstorage.h

@@ -25,6 +25,7 @@
 
 #include "backends/cloud/storage.h"
 #include "backends/cloud/manager.h"
+#include "common/callback.h"
 
 namespace Cloud {
 namespace Dropbox {
@@ -39,6 +40,8 @@ class DropboxStorage: public Cloud::Storage {
 
 	static void getAccessToken(Common::String code);
 
+	void infoMethodCallback(void *serviceInfoPtr);
+
 public:	
 	virtual ~DropboxStorage();
 
@@ -65,6 +68,7 @@ public:
 
 	/** Returns pointer to the ServiceInfo struct. */
 	virtual void info(InfoCallback callback);
+	void info2(Common::Callback<DropboxStorage> *callback);
 
 	/** Returns whether saves sync process is running. */
 	virtual bool isSyncing() { return false; } //TODO

backends/networking/curl/curljsonrequest.cpp

@@ -31,7 +31,7 @@
 
 namespace Networking {
 
-CurlJsonRequest::CurlJsonRequest(Callback cb, const char *url) : Request(cb), _stream(0), _headersList(0), _contentsStream(DisposeAfterUse::YES) {
+CurlJsonRequest::CurlJsonRequest(SimpleCallback cb, const char *url) : Request(cb), _stream(0), _headersList(0), _contentsStream(DisposeAfterUse::YES) {
 	_url = url;
 }
 

backends/networking/curl/curljsonrequest.h

@@ -43,7 +43,7 @@ class CurlJsonRequest : public Request {
 	char *getPreparedContents();
 
 public:
-	CurlJsonRequest(Callback cb, const char *url);
+	CurlJsonRequest(SimpleCallback cb, const char *url);
 	virtual ~CurlJsonRequest();
 
 	virtual bool handle();

backends/networking/curl/request.h

@@ -27,14 +27,14 @@ namespace Networking {
 
 class Request {
 protected:
-	typedef void(*Callback)(Request* request, void *result);
+	typedef void(*SimpleCallback)(Request* request, void *result);
 
 	/**
 	* Callback, which should be called before Request returns true in handle().
 	* That's the way Requests pass the result to the code which asked to create this request.
 	*/
 
-	Callback _callback;
+	SimpleCallback _callback;
 
 	/**
 	* Pointer, which could be set by Request creating code. It might be accessed
@@ -44,7 +44,7 @@ protected:
 	void *_pointer;
 
 public:
-	Request(Callback cb): _callback(cb) {};
+	Request(SimpleCallback cb): _callback(cb) {};
 	virtual ~Request() {};
 
 	/**

common/callback.h

@@ -0,0 +1,47 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+#ifndef COMMON_CALLBACK_H
+#define COMMON_CALLBACK_H
+
+namespace Common {
+
+class BaseCallback {
+public:
+	BaseCallback() {}
+	virtual ~BaseCallback() {}
+	virtual void operator()(void *ptr) = 0;
+};
+
+template<class T> class Callback: public BaseCallback {
+	typedef void(T::*TMethod)(void *);
+	T *_object;
+	TMethod _method;
+public:
+	Callback(T *object, TMethod method): _object(object), _method(method) {}
+	virtual ~Callback() {}
+	void operator()(void *ptr) { (_object->*_method)(ptr); }
+};
+
+} // End of namespace Common
+
+#endif