gecko/xpcom/sample/nsSample.h

98 lines
3.6 KiB
C
Raw Normal View History

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2012-05-21 04:12:37 -07:00
/* 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/. */
/**
* A sample of XPConnect. This file is the header of an implementation
* nsSample of the nsISample interface.
*
*/
#include "nsISample.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 : 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
* PRUnichar * in C++, which is the NSPR type for unicode characters.
*/
/* NS_IMETHOD Poke(const char* aValue); */
private:
~nsSampleImpl();
char* mValue;
};