os/graphics/graphicsresourceservices/graphicsresourceinterface/inc/sgresource.h
changeset 0 bde4ae8d615e
     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/os/graphics/graphicsresourceservices/graphicsresourceinterface/inc/sgresource.h	Fri Jun 15 03:10:57 2012 +0200
     1.3 @@ -0,0 +1,503 @@
     1.4 +// Copyright (c) 2007-2009 Nokia Corporation and/or its subsidiary(-ies).
     1.5 +// All rights reserved.
     1.6 +// This component and the accompanying materials are made available
     1.7 +// under the terms of "Eclipse Public License v1.0"
     1.8 +// which accompanies this distribution, and is available
     1.9 +// at the URL "http://www.eclipse.org/legal/epl-v10.html".
    1.10 +//
    1.11 +// Initial Contributors:
    1.12 +// Nokia Corporation - initial contribution.
    1.13 +//
    1.14 +// Contributors:
    1.15 +//
    1.16 +// Description:
    1.17 +// Graphics Resource - general functionality
    1.18 +//
    1.19 +
    1.20 +#ifndef SGRESOURCE_H
    1.21 +#define SGRESOURCE_H
    1.22 +
    1.23 +#include <e32std.h>
    1.24 +#include <sgresource/sgconst.h>
    1.25 +
    1.26 +/**
    1.27 +Panic codes defined for use by the Graphics Resource API.
    1.28 +*/
    1.29 +enum TSgResourcePanicReason
    1.30 +	{
    1.31 +	ESgPanicNoDriver = 1,
    1.32 +	ESgPanicUnclosedResources = 2,
    1.33 +	ESgPanicBadDrawableHandle = 3,
    1.34 +	ESgPanicBadAttributeArrayIndex = 4
    1.35 +	};
    1.36 +
    1.37 +/**
    1.38 +Panics the calling thread with category “SGRES” and the given panic code.
    1.39 +@param aReason The panic code.
    1.40 +*/
    1.41 +inline void Panic(TSgResourcePanicReason aReason);
    1.42 +
    1.43 +/**
    1.44 +A handle to the implementation of the Graphics Resource API 
    1.45 +initialised in the context of a process. It groups miscellaneous functions that 
    1.46 +do not apply to individual drawable resources.
    1.47 +
    1.48 +At least one thread in the process must call RSgDriver::Open() before the 
    1.49 +Graphics Resource API can be used in the context of the process. 
    1.50 +When the Graphics Resource API is no longer needed RSgDriver::Close() should be 
    1.51 +called to release unused resources.  Note that it is possible to call RSgDriver::Open() 
    1.52 +and RSgDriver::Close() from different threads.
    1.53 +*/
    1.54 +NONSHARABLE_CLASS(RSgDriver)
    1.55 +	{
    1.56 +public:
    1.57 +	/**
    1.58 +	Default constructor.
    1.59 +	@post The instance of RSgDriver is a null handle.
    1.60 +	*/
    1.61 +	inline RSgDriver();
    1.62 +
    1.63 +	/**
    1.64 +	Initialises the implementation of the Graphics Resource API in the context 
    1.65 +	of a process if it is not initialised already, updates the implementation 
    1.66 +	opening count in the process and returns KErrNone if successful.
    1.67 +	Each successful call to RSgDriver::Open() in a process should be balanced 
    1.68 +	by a corresponding call to RSgDriver::Close() in the same process, but not 
    1.69 +	necessarily from the same thread.
    1.70 +
    1.71 +	Note that an RSgDriver handle should never be bitwise-copied into another 
    1.72 +	but this function should be used instead in all cases, since it is the only 
    1.73 +	way to ensure that the implementation opening count is kept up to date.
    1.74 +	Failure to keep the implementation opening count up to date may result in 
    1.75 +	the implementation of the Graphics Resource API becoming unexpectedly 
    1.76 +	unavailable and, as a consequence, in an abnormal termination of the process.
    1.77 +
    1.78 +	@pre The instance of RSgDriver is a null handle.
    1.79 +	@post The instance of RSgDriver references the implementation of the Graphics 
    1.80 +		Resource API initialised in the context of the process.
    1.81 +	@return KErrNone if successful;
    1.82 +		KErrInUse if the instance of RSgDriver is not a null handle;
    1.83 +		KErrNoMemory if there is not enough system memory to initialise the 
    1.84 +			implementation of the Graphics Resource API;
    1.85 +		KErrNoGraphicsMemory if there is not enough specialised graphics memory
    1.86 +			to initialise the implementation of the Graphics Resource API.
    1.87 +	*/
    1.88 +	IMPORT_C TInt Open();
    1.89 +
    1.90 +	/**
    1.91 +	Decrements the implementation opening count in the process.
    1.92 +	When the count reaches zero, checks whether there are still open handles to
    1.93 +	drawable resources in the process and carries out termination tasks to
    1.94 +	release the internal resources used by the implementation of the Graphics
    1.95 +	Resource API.
    1.96 +
    1.97 +	An attempt to carry out these termination tasks will panic with category
    1.98 +	“SGRES” and code 2 in debug builds if there still are any open handles to 
    1.99 +	drawable resources in the process. In release builds all the open handles 
   1.100 +	to drawable resources in the process are silently closed at this point.
   1.101 +	Calling this function on a null handle has no effect.
   1.102 +
   1.103 +	@post The instance of RSgDriver is a null handle.
   1.104 +	@panic SGRES 2 Debug builds only.  There are open handles to drawable resources 
   1.105 +		in the process during termination.
   1.106 +	*/
   1.107 +	IMPORT_C void Close();
   1.108 +
   1.109 +	/**
   1.110 +	Makes the extension interface specified by the type of the parameter 
   1.111 +	aInterfacePtr available in the context of the process.
   1.112 +	This function stores a pointer to the extension interface in the variable 
   1.113 +	referenced by the parameter aInterfacePtr and returns KErrNone if successful.
   1.114 +
   1.115 +	@pre An RSgDriver has been opened in the context of the process.
   1.116 +	@param[out] aInterfacePtr Reference to a pointer to the interface class that on return points 
   1.117 +		to the extension interface or, in case of error, is set to NULL.
   1.118 +	@return KErrNone if successful;
   1.119 +		KErrBadHandle if the instance of RSgDriver is a null handle;
   1.120 +		KErrExtensionNotSupported if the requested extension interface is not supported.
   1.121 +	*/
   1.122 +	template<class M> inline TInt GetInterface(M*& aInterfacePtr) const;
   1.123 +
   1.124 +	/**
   1.125 +	Returns the version of the implementation of the Graphics Resource API.
   1.126 +	The version comprises 3 numbers: major version number, minor version number 
   1.127 +	and build number.
   1.128 +
   1.129 +	Major revisions mean incompatible changes in the API. 
   1.130 +	Minor revisions mean forward-compatible changes in the API. 
   1.131 +	Build numbers are unrelated to API changes.
   1.132 +
   1.133 +	@return The version of the implementation of the Graphics Resource API.
   1.134 +	*/
   1.135 +	IMPORT_C static TVersion Version();
   1.136 +private:
   1.137 +	/**
   1.138 +	Copy constructor.
   1.139 +	Implementation not provided. Declared private to prevent bit-wise copying 
   1.140 +	of handles.
   1.141 +	*/
   1.142 +	RSgDriver(const RSgDriver&);
   1.143 +
   1.144 +	/**
   1.145 +	Assignment operator.
   1.146 +	Implementation not provided. Declared private to prevent bit-wise copying 
   1.147 +	of handles.
   1.148 +	*/
   1.149 +	const RSgDriver& operator =(const RSgDriver&);
   1.150 +
   1.151 +	/**
   1.152 +	Makes the extension interface with the given UID available in the context 
   1.153 +	of the process.
   1.154 +	This function stores a pointer to the extension interface in the variable 
   1.155 +	referenced by the parameter aInterfacePtr and returns KErrNone if successful.
   1.156 +
   1.157 +	@pre An RSgDriver has been opened in the context of the process.
   1.158 +	@param[in] aInterfaceUid The UID of the extension interface.
   1.159 +	@param[out] aInterfacePtr Reference to an untyped pointer that on return points 
   1.160 +		to the extension interface or, in case of error, is set to NULL.
   1.161 +	@return KErrNone if successful;
   1.162 +		KErrBadHandle if the instance of RSgDriver is a null handle;
   1.163 +		KErrArgument if aInterfaceUid is the null UID;
   1.164 +		KErrExtensionNotSupported if the requested extension interface is not supported.
   1.165 +	*/
   1.166 +	IMPORT_C TInt GetInterface(TUid aInterfaceUid, TAny*& aInterfacePtr) const;
   1.167 +private:
   1.168 +	/** A pointer to an implementation-defined object initially set to NULL by the constructor.*/
   1.169 +	TAny* iImpl;
   1.170 +	};
   1.171 +
   1.172 +/**
   1.173 +An extension attribute.
   1.174 +*/
   1.175 +NONSHARABLE_CLASS(TSgAttribute)
   1.176 +	{
   1.177 +public:
   1.178 +	/**
   1.179 +	Default constructor.
   1.180 +	Data members remain uninitialised.
   1.181 +	*/
   1.182 +	inline TSgAttribute();
   1.183 +
   1.184 +	/**
   1.185 +	Constructor which initialises data members to the given values.
   1.186 +	*/
   1.187 +	inline TSgAttribute(TUid aUid, TInt aValue);
   1.188 +public:
   1.189 +	/** A UID that identifies the type of extension attribute.*/
   1.190 +	TUid iUid;
   1.191 +	/** The value of the extension attribute.*/
   1.192 +	TInt iValue;
   1.193 +	};
   1.194 +
   1.195 +/**
   1.196 +Base class of all attribute array classes.
   1.197 +It defines functions for bounds-checked access to extension attributes.
   1.198 +*/
   1.199 +NONSHARABLE_CLASS(TSgAttributeArrayBase)
   1.200 +	{
   1.201 +public:
   1.202 +	/**
   1.203 +	Returns the number of extension attributes in the array.
   1.204 +	@return The number of extension attributes in the array.
   1.205 +	*/
   1.206 +	inline TInt Count() const;
   1.207 +
   1.208 +	/**
   1.209 +	Returns a reference to the extension attribute located in the array at the 
   1.210 +	given position.
   1.211 +
   1.212 +	@pre aIndex is equal to or greater than zero and less than the number of 
   1.213 +		extension attributes in the array.
   1.214 +	@param aIndex The position of the extension attribute in the array.
   1.215 +	@return A reference to the extension attribute located in the array at the 
   1.216 +		given position.
   1.217 +	@panic SGRES 4 Debug builds only. aIndex is out of bounds.
   1.218 +	*/
   1.219 +	inline TSgAttribute& operator [](TInt aIndex);
   1.220 +
   1.221 +	/**
   1.222 +	Returns a const-qualified reference to the extension attribute located in 
   1.223 +	the array at the given position.
   1.224 +
   1.225 +	@pre aIndex is equal to or greater than zero and less than the number of 
   1.226 +		extension attributes in the array.
   1.227 +	@param aIndex The position of the extension attribute in the array.
   1.228 +	@return A reference to the extension attribute located in the array at the 
   1.229 +		given position.
   1.230 +	@panic SGRES 4 Debug builds only. aIndex is out of bounds.
   1.231 +	*/
   1.232 +	inline const TSgAttribute& operator [](TInt aIndex) const;
   1.233 +protected:
   1.234 +	/**
   1.235 +	Constructor used by constructors of derived classes to initialise the 
   1.236 +	attribute count.
   1.237 +	@param aCount The number of extension attributes.
   1.238 +	*/
   1.239 +	inline TSgAttributeArrayBase(TInt aCount);
   1.240 +
   1.241 +	/**
   1.242 +	Assignment operator.
   1.243 +	No operation is performed. Allows the compiler to generate assignment 
   1.244 +	operators for derived classes automatically.
   1.245 +	*/
   1.246 +	inline void operator =(const TSgAttributeArrayBase&);
   1.247 +private:
   1.248 +	const TInt iCount;
   1.249 +	};
   1.250 +
   1.251 +/**
   1.252 +A fixed-size array of extension attributes.
   1.253 +It is a thin wrapper with bounds checking for arrays of TSgAttribute.
   1.254 +*/
   1.255 +template<TInt S>
   1.256 +NONSHARABLE_CLASS(TSgAttributeArray): public TSgAttributeArrayBase
   1.257 +	{
   1.258 +public:
   1.259 +	/**
   1.260 +	Default constructor.
   1.261 +	Data members remain uninitialised.
   1.262 +	*/
   1.263 +	inline TSgAttributeArray();
   1.264 +private:
   1.265 +	TSgAttribute iAttributes[S];
   1.266 +	};
   1.267 +
   1.268 +/**
   1.269 +A system-wide unique 64-bit identifier that can be used to share a drawable 
   1.270 +resource between processes.
   1.271 +
   1.272 +The actual value of a drawable resource identifier has no meaning to the user 
   1.273 +of the Graphics Resource API, except that 64 zero bits represent the null 
   1.274 +drawable resource identifier, which explicitly identifies no drawable resource.
   1.275 +As a convenience, the constant KSgNullDrawableId is defined as the null drawable 
   1.276 +resource identifier.
   1.277 +*/
   1.278 +NONSHARABLE_CLASS(TSgDrawableId)
   1.279 +	{
   1.280 +public:
   1.281 +	/**
   1.282 +	Equality operator.
   1.283 +	Tests whether the given drawable resource identifier is the same as this.
   1.284 +	
   1.285 +	@param aId The drawable resource identifier to compare with this.
   1.286 +	@return ETrue if the 64-bit identifiers are the same, EFalse if not.
   1.287 +	*/
   1.288 +	inline TBool operator ==(TSgDrawableId aId) const;
   1.289 +
   1.290 +	/**
   1.291 +	Inequality operator.
   1.292 +	Tests whether the given drawable resource identifier is different from this.
   1.293 +	
   1.294 +	@param aId The drawable resource identifier to compare with this.
   1.295 +	@return ETrue if the 64-bit identifiers are different, EFalse if they are the same.
   1.296 +	*/
   1.297 +	inline TBool operator !=(TSgDrawableId aId) const;
   1.298 +public:
   1.299 +	/** The 64-bit identifier.*/
   1.300 +	TUint64 iId;
   1.301 +	};
   1.302 +
   1.303 +/**
   1.304 +The null drawable resource identifier.
   1.305 +*/
   1.306 +const TSgDrawableId KSgNullDrawableId = {0};
   1.307 +
   1.308 +/**
   1.309 +The UID identifying a RSgDrawable handle.
   1.310 +This must never be changed.
   1.311 +*/
   1.312 +const TUid KSgDrawableTypeUid = {0x102858EB};
   1.313 +
   1.314 +/**
   1.315 +A drawable resource handle. 
   1.316 +A null handle is a handle that explicitly does not reference any drawable resource. 
   1.317 +An open handle is a handle that references an existing drawable resource. 
   1.318 +An invalid handle is a handle that is not null but does not reference any 
   1.319 +existing drawable resource. 
   1.320 +Drawable resources are reference-counted so that a drawable resource is not 
   1.321 +destroyed while there still are open handles to it in any process in the system.
   1.322 +
   1.323 +RSgDrawable is not an abstract class, that is, it can be instantiated, 
   1.324 +but it can also be derived from to define subclasses representing types of 
   1.325 +handles that refer only to concrete types of drawable resources, for example, 
   1.326 +image handles. RSgImage is the only subclass of RSgDrawable defined in version 
   1.327 +1.1 of the Graphics Resource API. 
   1.328 +Instances of RSgDrawable are useful when drawable resources created in a 
   1.329 +component have to be passed to another component through a third component that 
   1.330 +cannot depend on the concrete type of the drawable resources being passed.
   1.331 +@see RSgImage
   1.332 +*/
   1.333 +NONSHARABLE_CLASS(RSgDrawable)
   1.334 +	{
   1.335 +public:
   1.336 +	/**
   1.337 +	Default constructor.
   1.338 +	@post The instance of RSgDrawable is a null handle.
   1.339 +	*/
   1.340 +	inline RSgDrawable();
   1.341 +
   1.342 +	/**
   1.343 +	Opens a new handle to the drawable resource with the given drawable resource 
   1.344 +	identifier.
   1.345 +	The drawable resource may have been created in the same process or in a 
   1.346 +	different one. This function does not allocate any specialised graphics memory.
   1.347 +
   1.348 +	Note that an RSgDrawable handle should never be bitwise-copied into another 
   1.349 +	but this function should be used instead in all cases, since it is the only 
   1.350 +	way to ensure that the reference count of the drawable resource is kept up 
   1.351 +	to date. Failure to keep the reference count of the resource up to date may 
   1.352 +	result in invalid handles.
   1.353 +
   1.354 +	@pre An RSgDriver handle has been opened in the context of the process.
   1.355 +	@pre The instance of RSgDrawable is a null handle.
   1.356 +	@post The specified drawable resource has its reference count incremented by one.
   1.357 +	@param aId The identifier of the drawable resource.
   1.358 +	@param aAttributes A pointer to an array of extension attributes, 
   1.359 +		if allowed by any extension of the Graphics Resource API, or NULL otherwise.
   1.360 +	@return KErrNone if successful;
   1.361 +		KErrInUse if the instance of RSgDrawable is an open handle;
   1.362 +		KErrArgument if the parameter aId is the null drawable resource identifier;
   1.363 +		KErrNotSupported if the parameter aAttributes is not NULL and one or more 
   1.364 +			of the extension attributes in the array is not defined by any extension 
   1.365 +			of the Graphics Resource API;
   1.366 +		KErrNotFound if the parameter aId cannot be found to refer to an existing 
   1.367 +			drawable resource;
   1.368 +		KErrNoMemory if it fails due to lack of system memory.
   1.369 +	@panic SGRES 1 No RSgDriver handle has been opened in the context of the process.
   1.370 +	*/
   1.371 +	IMPORT_C TInt Open(TSgDrawableId aId, const TSgAttributeArrayBase* aAttributes = NULL);
   1.372 +
   1.373 +	/**
   1.374 +	Closes a handle to a drawable resource. 
   1.375 +	It decrements the reference count of the drawable resource and, if it reaches
   1.376 +	zero, destroys the drawable resource. 
   1.377 +	Calling this function on a null handle has no effect.
   1.378 +
   1.379 +	@pre If the instance of RSgDrawable is not a null handle then an RSgDriver 
   1.380 +		handle has been opened in the context of the process.
   1.381 +	@post The instance of RSgDrawable is a null handle.
   1.382 +	@panic SGRES 1 The instance of RSgDrawable is not a null handle and no 
   1.383 +		RSgDriver handle has been opened in the context of the process.
   1.384 +	@panic SGRES 3 The instance of RSgDrawable is an invalid handle.
   1.385 +	*/
   1.386 +	IMPORT_C void Close();
   1.387 +
   1.388 +	/**
   1.389 +	Returns the identifier of the drawable resource.
   1.390 +	This identifier can be used to open another handle to the drawable resource 
   1.391 +	in the same process or in a different process. 
   1.392 +	Calling this function on a null handle returns the null drawable resource 
   1.393 +	identifier.
   1.394 +
   1.395 +	@pre If the instance of RSgDrawable is not a null handle then an RSgDriver 
   1.396 +		handle has been opened in the context of the process.
   1.397 +	@return The identifier of the drawable resource.
   1.398 +	@panic SGRES 1 The instance of RSgDrawable is not a null handle and no 
   1.399 +		RSgDriver handle has been opened in the context of the process.
   1.400 +	@panic SGRES 3 The instance of RSgDrawable is an invalid handle.
   1.401 +	*/
   1.402 +	IMPORT_C TSgDrawableId Id() const;
   1.403 +
   1.404 +	/**
   1.405 +	Tests whether a handle is null.
   1.406 +	@return ETrue if the instance of RSgDrawable is a null handle; EFalse otherwise.
   1.407 +	*/
   1.408 +	inline TBool IsNull() const;
   1.409 +
   1.410 +	/**
   1.411 +	Returns the UID corresponding to the concrete type of the drawable resource 
   1.412 +	referenced by a handle at run-time. 
   1.413 +	Calling this function on a null handle returns the null UID. 
   1.414 +	In version 1.1 of the Graphics Resource API every drawable resource is an image, 
   1.415 +	so this function always returns KSgImageTypeUid when called on an open handle.
   1.416 +
   1.417 +	@pre If the instance of RSgDrawable is not a null handle then an RSgDriver 
   1.418 +		handle has been opened in the context of the process.
   1.419 +	@return The UID corresponding to the concrete type of the drawable resource.
   1.420 +	@panic SGRES 1 The instance of RSgDrawable is not a null handle and no 
   1.421 +		RSgDriver handle has been opened in the context of the process.
   1.422 +	@panic SGRES 3 The instance of RSgDrawable is an invalid handle.
   1.423 +	*/
   1.424 +	IMPORT_C TUid DrawableType() const;
   1.425 +
   1.426 +	/**
   1.427 +	Makes the extension interface specified by the type of the parameter 
   1.428 +	aInterfacePtr available on a drawable resource.
   1.429 +	This function stores a pointer to the extension interface in the variable 
   1.430 +	referenced by the parameter aInterfacePtr and returns KErrNone if successful.
   1.431 +	The returned extension interface is tied to the drawable resource, that is, 
   1.432 +	calls to functions in the returned extension interface operate on the 
   1.433 +	drawable resource.
   1.434 +
   1.435 +	@pre An RSgDriver handle has been opened in the context of the process.
   1.436 +	@pre The instance of RSgDrawable is an open handle.
   1.437 +	@param[out] aInterfacePtr Reference to a pointer to the interface class. that on return points 
   1.438 +		to the extension interface or, in case of error, is set to NULL.
   1.439 +	@return KErrNone if successful;
   1.440 +		KErrBadHandle if the instance of RSgDrawable is a null handle;
   1.441 +		KErrExtensionNotSupported if the requested extension interface is not supported.
   1.442 +	@panic SGRES 1 No RSgDriver handle has been opened in the context of the process.
   1.443 +	@panic SGRES 3 The instance of RSgDrawable is an invalid handle.
   1.444 +	*/
   1.445 +	template<class M> inline TInt GetInterface(M*& aInterfacePtr) const;
   1.446 +protected:
   1.447 +	/**
   1.448 +	Handle base constructor.
   1.449 +	Used by constructors of derived classes to initialise the handle type.
   1.450 +	@post The instance of RSgDrawable is a null handle.
   1.451 +	@param aHandleType The UID identifying the handle type.
   1.452 +	*/
   1.453 +	inline RSgDrawable(TUid aHandleType);
   1.454 +private:
   1.455 +	/**
   1.456 +	Copy constructor.
   1.457 +	Implementation not provided. Declared private to prevent bit-wise copying 
   1.458 +	of handles.
   1.459 +	*/
   1.460 +	RSgDrawable(const RSgDrawable&);
   1.461 +
   1.462 +	/**
   1.463 +	Assignment operator.
   1.464 +	Implementation not provided. Declared private to prevent bit-wise copying 
   1.465 +	of handles.
   1.466 +	*/
   1.467 +	const RSgDrawable& operator =(const RSgDrawable&);
   1.468 +
   1.469 +	/**
   1.470 +	Makes the extension interface with the given UID available on a drawable 
   1.471 +	resource.
   1.472 +	This function stores a pointer to the extension interface in the variable 
   1.473 +	referenced by the parameter aInterfacePtr and returns KErrNone if successful.
   1.474 +	The returned extension interface is tied to the drawable resource, that is, 
   1.475 +	calls to functions in the returned extension interface operate on the 
   1.476 +	drawable resource.
   1.477 +
   1.478 +	@pre An RSgDriver handle has been opened in the context of the process.
   1.479 +	@pre The instance of RSgDrawable is an open handle.
   1.480 +	@param[in] aInterfaceUid The UID of the extension interface.
   1.481 +	@param[out] aInterfacePtr Reference to an untyped pointer that on return points 
   1.482 +		to the extension interface or, in case of error, is set to NULL.
   1.483 +	@return KErrNone if successful;
   1.484 +		KErrBadHandle if the instance of RSgDrawable is a null handle;
   1.485 +		KErrArgument if aInterfaceUid is the null UID;
   1.486 +		KErrExtensionNotSupported if the requested extension interface is not supported.
   1.487 +	@panic SGRES 1 No RSgDriver handle has been opened in the context of the process.
   1.488 +	@panic SGRES 3 The instance of RSgDrawable is an invalid handle.
   1.489 +	*/
   1.490 +	IMPORT_C TInt GetInterface(TUid aInterfaceUid, TAny*& aInterfacePtr) const;
   1.491 +protected:
   1.492 +	/**
   1.493 +	A UID permanently set by the constructor to the constant 
   1.494 +	KSgDrawableTypeUid, except for subclasses of RSgDrawable, in which case it 
   1.495 +	is permanently set by the constructor to the UID corresponding to the 
   1.496 +	concrete type of drawable resource referenced by instances of the subclass.
   1.497 +	*/
   1.498 +	const TUid iHandleType;
   1.499 +
   1.500 +	/** A pointer to an implementation-defined object initially set to NULL by the constructor.*/
   1.501 +	TAny* iImpl;
   1.502 +	};
   1.503 +
   1.504 +#include <sgresource/sgresource.inl>
   1.505 +
   1.506 +#endif // SGRESOURCE_H