/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ /* This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ #ifndef nsSample_h #define nsSample_h /** * A sample of XPConnect. This file is the header of an implementation * nsSample of the nsISample interface. * */ #include "nsISample.h" #include "mozilla/Attributes.h" /** * SampleImpl is an implementation of the nsISample interface. In XPCOM, * there can be more than one implementation of an given interface. Class * IDs (CIDs) uniquely identify a particular implementation of an interface. * Interface IDs (IIDs) uniquely identify an interface. * * The CID is also a unique number that looks just like an IID * and uniquely identifies an implementation * {7CB5B7A0-07D7-11d3-BDE2-000064657374} */ #define NS_SAMPLE_CID \ { 0x7cb5b7a0, 0x7d7, 0x11d3, { 0xbd, 0xe2, 0x0, 0x0, 0x64, 0x65, 0x73, 0x74 } } #define NS_SAMPLE_CONTRACTID "@mozilla.org/sample;1" class nsSampleImpl final : public nsISample { public: nsSampleImpl(); /** * This macro expands into a declaration of the nsISupports interface. * Every XPCOM component needs to implement nsISupports, as it acts * as the gateway to other interfaces this component implements. You * could manually declare QueryInterface, AddRef, and Release instead * of using this macro, but why? */ // nsISupports interface NS_DECL_ISUPPORTS /** * This macro is defined in the nsISample.h file, and is generated * automatically by the xpidl compiler. It expands to * declarations of all of the methods required to implement the * interface. xpidl will generate a NS_DECL_[INTERFACENAME] macro * for each interface that it processes. * * The methods of nsISample are discussed individually below, but * commented out (because this macro already defines them.) */ NS_DECL_NSISAMPLE /** * The following is an explanation of how the interface header * file expands to for a c++ implementation. NS_DELC_NSISAMPLE * takes care of defining the right c++ implementation. * * The following if provided for more understanding. * * NS_IMETHOD expands to the standard XPCOM return type. XPCOM methods * should never return any other type. The return value is used * behind the scenes by the XPConnect runtime to figure out if the call * failed in any way. * These methods were generated by "attribute string Value" in * nsISample.idl. When reflected into JavaScript, XPCOM will use these * calls as Getter/Setter ops, so that they can be called transparently * as "sample.Value='foo';" and "var val = sample.Value" */ /* NS_IMETHOD GetValue(char** aValue); */ /* NS_IMETHOD SetValue(char* aValue); */ /** * The const came from the "in" specifier in nsISample.idl. "in" * specifies that the value of this parameter is used only for input, * this method is not allowed to modify the contents of the buffer. */ /* NS_IMETHOD WriteValue(const char* aPrefix); */ /** * nsISample.idl specifies all of its string types as string, instead * of wstring (wide string), the Unicode type. If the world were a * perfect place, all normal strings in XPCOM interfaces would be unicode. * If this type had been specified as wstring, it would appear as * char16_t * in C++, which is the NSPR type for unicode characters. */ /* NS_IMETHOD Poke(const char* aValue); */ private: ~nsSampleImpl(); char* mValue; }; #endif