genericservices/s60compatibilityheaders/commonengine/inc/textresolver.h
changeset 31 ce057bb09d0b
parent 0 e4d67989cc36
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/genericservices/s60compatibilityheaders/commonengine/inc/textresolver.h	Fri Jun 04 16:20:51 2010 +0100
@@ -0,0 +1,199 @@
+/*
+* Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description:
+*
+*/
+
+
+
+
+#ifndef TEXT_RESOLVER_H
+#define TEXT_RESOLVER_H
+
+#include <coemain.h>    //  CCoeEnv
+#include <textresolver.hrh> // Resource flags 
+#include <eikenv.h>    //  CEikonEnv
+
+// DEFINES
+typedef CArrayFixFlat<TInt> CErrorResourceIdArray;
+typedef CArrayFixFlat<TInt> CErrorResourceFlagArray;
+
+/**
+* Class offers functionality for resolving corresponding error texts for 
+* error codes. Text Resolver API provides operations with which a specific 
+* error code can be resolved to a human readable text. Descriptions for the
+* different error codes must be defined in the resource files of this 
+* component. 
+*
+* Text Resolver uses the CCoeEnv environment class to access the resource
+* files if the CCoeEnv environment is available. If the CCoeEnv environment
+* is not available, the files are accessed through the RResourceFile API.
+*
+* The API consist of the CTextResolver class which is used together with 
+* Text Resolver flags defined in textresolver.hrh file. The flags are used
+* to tell the priority of the error to the client:
+*
+* - EErrorResBlankErrorFlag is used to tell that error has no proper explanation.
+* - EErrorResUnknownErrorFlag indicates that Text Resolver does not support the error. 
+* - EErrorResOOMFlag Flag is returned while processing KErrNoMemory error code. 
+*
+*
+* Usage:
+*
+* @code
+*  #include <textresolver.h>
+*
+*  // Typically used as an instance variable.
+*  
+*  // Call the factory method NewLC() to create a new instance of CTextResolver.
+*  // NewLC() method leaves the instance of the object on the cleanup stack.	
+*  // The passed CCoeEnv instance is needed to access the resource files.
+*  CTextResolver* iTextResolver = CTextResolver::NewLC(*iCoeEnv); 
+*
+*  // // Error Resolving, simple:
+*
+*  // Get error code to be resolved.
+*  // TInt err1 = MyMethod(KInvalidValue);
+*  TInt err1 = KErrNoMemory;
+*    
+*  TPtrC buf1;  // For returned error text
+*    
+*  if (err1 != KErrNone)
+*      {
+*      // Resolve the given error code. 
+*      // The operation returns the error text for the resolved error.
+*      // There's no limit how long the resolved string can be.
+*      // Add context to 2nd param if needed.
+*      buf1.Set(iTextResolver->ResolveErrorString(err)); 
+*      }
+*  else
+*      {
+*      // Do something.
+*      }
+*        
+*  // Note that buf1 will only be valid as long as CTextResolver 
+*  // instance is alive and no new error is resolved by the same instance.
+*  // If for some reason you need to store the resolved error
+*  // beyond immediate use, make a copy of it.
+*
+*  // Error Resolving, advanced:
+* 
+*  // Get error code to be resolved.
+*  // TInt err2 = MyMethod(KInvalidValue);
+*  TInt err2 = KErrNotSupported;
+*        
+*  TInt textId(0);    // ID of the returned text
+*  TUint flags(0);    // Priority of the returned error 
+*  TPtrC buf2;      // For returned error text
+*   
+*  if (err2 != KErrNone)
+*      {
+*      // Resolve the given error code.
+*      // The operation returns the error text for the resolved error.
+*      // There's no limit on how long the resolved string can be.
+*      // Add Context to 4th param if needed.
+*      buf2.Set(iTextResolver->ResolveErrorString(err, textId, flags)); 
+*
+*      if (flags & EErrorResUnknownErrorFlag)
+*          {
+*          // The flag indicates that Text Resolver does not support
+*          // the error code. 
+*          // Do something.
+*          }
+*      }
+*  else
+*      {
+*      // Do something.
+*      }
+*    
+*  // Note that buf2 will only be valid as long as CTextResolver 
+*  // instance is alive and no new error is resolved by the same instance.
+*  // If for some reason you need to store the resolved error
+*  // beyond immediate use, make a copy of it.
+*
+*  // iTextResolver, Free loaded resources
+*  CleanupStack::PopAndDestroy(); 
+* @endcode
+*
+* @lib commonengine.lib
+* @since S60 2.0
+*/
+class CTextResolver : public CBase
+    {
+public:
+    /**
+    * Defines used error contexts. 
+    * Optional error contexes for aiding the mapping of error codes to 
+    * texts in a unique way. If no context is given the assumption is 
+    * that error codes are unique.
+    */
+    enum TErrorContext
+        {
+        /** Context is defined automatically from error code value.
+        * Here it is assumed that each error code is unique and in
+        * own range. This is a default value when resolving errors. */
+        ECtxAutomatic = 0,
+        /** Context text is not added to the beginning of the resolved error text,
+        * just context separator ':' and newline are added. */
+        ECtxNoCtx = 1,
+        /** No context text, context separator ':' or newline added to the 
+        * beginning of the resolved error text. */
+        ECtxNoCtxNoSeparator = 2
+        };
+public:
+    IMPORT_C static CTextResolver* NewL(CCoeEnv& aEnv);
+    IMPORT_C static CTextResolver* NewLC(CCoeEnv& aEnv);
+    IMPORT_C static CTextResolver* NewL();
+	IMPORT_C static CTextResolver* NewLC();
+    IMPORT_C ~CTextResolver();
+	IMPORT_C const TDesC& ResolveErrorString(TInt aError, TInt& aTextId, TUint& aFlags,TErrorContext aContext = ECtxAutomatic);
+    IMPORT_C const TDesC& ResolveErrorString(TInt aError, TErrorContext aContext = ECtxAutomatic);
+private: // Construction
+    virtual TInt ResourceForError(TInt aError);
+    virtual void LoadResourceFilesL() { ASSERT(0); }	// deprecated
+    CTextResolver(CCoeEnv& aEnv);
+    CTextResolver();
+    void ConstructL();
+    
+    // Utility
+    void DoRawReadOfSystemErrorResourcesToArraysL(TInt& aError, TInt& aTextId);
+    void Reset();
+    void ReadLocalizedSeparatorCharacterFromResourceL(CCoeEnv& aCoeEnv);
+    void ReadLocalizedSeparatorCharacterFromResourceAndPrepareResourceReaderLC(TResourceReader& aResReader);
+
+    // returns NULL if fails
+    static HBufC* AllocReadUnicodeString(RResourceFile& aResFile, TInt aTextId);
+    /** Returns false if any memory allocation fails or initial values 
+	of necessary pointers are NULL, indicating alloc failure earlier.*/
+    TBool AddContextAndSeparator(TErrorContext aContext);
+    void AllocBuffersL();
+    void DoResolveErrorStringL(TInt aError, TInt& aTextId, TUint& aFlags);
+private:
+    CCoeEnv* iCoe;
+    RResourceFile iResFile;
+    TInt iRDSupport;
+    TInt iBaseResourceFileOffset;
+    CArrayFix<TInt>* iStartError;
+    CArrayFix<TInt>* iAppTexts;
+    CArrayPtr<CErrorResourceIdArray>*   iErrorTexts;	// Array of arrays of ints
+    CArrayPtr<CErrorResourceFlagArray>* iFlags;			// Array of arrays of ints
+    HBufC* iTextBuffer;
+    HBufC* iTitleText;
+    HBufC* iContextSeparator;
+    RFs iFs;
+    TPtrC  iTruncatedTextPointer;
+	};
+
+#endif
+