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