TB10.1 Example Applications: examples/Base/BufsAndStrings/Desc/Buffer/Buffer.cpp Source File

00001 // Copyright (c) 2000-2009 Nokia Corporation and/or its subsidiary(-ies).
-00002 // All rights reserved.
-00003 // This component and the accompanying materials are made available
-00004 // under the terms of "Eclipse Public License v1.0"
-00005 // which accompanies this distribution, and is available
-00006 // at the URL "http://www.eclipse.org/legal/epl-v10.html".
-00007 //
-00008 // Initial Contributors:
-00009 // Nokia Corporation - initial contribution.
-00010 //
-00011 // Contributors:
-00012 //
-00013 // Description:
-00014 // Examples to demonstrate the basic ideas of
-00015 // buffer descriptors.
-00016 //
-00017 
-00018 #include "CommonFramework.h"
-00019 
-00020 //
-00021 // Common literal text
-00022 //
-00023 _LIT(KTxtHelloWorld,"Hello World!");
-00024 _LIT(KTxtRepText,"Replacement text");
-00025 _LIT(KTxtTBufC,"TBufC: ");
-00026 _LIT(KTxtTPtr,"TPtr:  ");
-00027 
-00028 //
-00029 // Common Format strings
-00030 //
-00031 _LIT(KCommonFormat2,"\"%S\"; ");
-00032 _LIT(KCommonFormat3,"Descriptor at %x; Ptr()=%x; ");
-00033 _LIT(KCommonFormat6,"\"%S\"; Ptr()=%x; Length()=%d; Size()=%d\n");
-00034 _LIT(KCommonFormat7,"\"%S\"; Ptr()=%x; Length()=%d; Size()=%d; ");
-00035 _LIT(KCommonFormat8,"\nMaxLength()=%d\n");
-00036 _LIT(KCommonFormat9,"Length()=%d; Size()=%d;\n");
-00037 _LIT(KCommonFormat10,"MaxLength()=%d\n");
-00038 
-00039 
-00040 LOCAL_C void doExampleL()
-00041     {                              
-00042                                 // Set up an area and initialise to a 
-00043                                 // C style string (including the NULL).
-00044         TText cstr[13] =  {'H', 'e' ,'l' ,'l' ,'o', ' ',
-00045                                        'W', 'o','r', 'l', 'd', '!', '\0'};
-00046 
-00047                                 // Construct a TBufC using the NULL 
-00048                                 // terminated string in cstr to initialise
-00049                                 // it.
-00050         TBufC<16> bufc1(&cstr[0]);
-00051 
-00052                                 // Look at the address of the C string
-00053         _LIT(KFormat1,"C string at %x; \n");
-00054         console->Printf(KFormat1,&cstr[0]);
-00055                                                                                                         
-00056                                 // Look at: 
-00057                                 //   1. Descriptor content
-00058                                 //   2. Address of descriptor
-00059                                 //   3. Address of descriptor data area
-00060                                 //   4. Length of descriptor
-00061                                 //   5. Size of descriptor
-00062                                 //         
-00063                                 // Address of descriptor data area is 
-00064                                 // different from the address of cstr but
-00065                                 // is offset 4 from the start of the 
-00066                                 // descriptor itself.
-00067                                 //
-00068                                 // Descriptor length is 12.
-00069                                 //
-00070                                 // The template parameter value defines 
-00071                                 // the length of the descriptor data area 
-00072                                 // and, therefore, governs its size 
-00073                                 // (depending on the build variant).
-00074                                 // Size of data is 24
-00075         console->Printf(KCommonFormat2,&bufc1);
-00076         console->Printf(KCommonFormat3,&bufc1,bufc1.Ptr());
-00077         _LIT(KFormat4,"Length()=%d; Size()=%d\n");
-00078         console->Printf(KFormat4,bufc1.Length(),bufc1.Size());  
-00079                                                                                         
-00080                                 // If the TBufC is to hold string data on
-00081                                 // construction, use a _LIT macro.
-00082         TBufC<16> bufc2(KTxtHelloWorld);
-00083 
-00084                                 // Cannot modify existing data but can replace
-00085                                 // it entirely using assignment operator. 
-00086                                 // The replacement text must not have a length 
-00087                                 // greater than 16
-00088         bufc2 = KTxtRepText;
-00089         _LIT(KFormat5,"\"%S\"; Length()=%d; Size()=%d\n");
-00090         console->Printf(KFormat5,&bufc2,bufc2.Length(),bufc2.Size());
-00091 
-00092                                 // Replacing text which has a length > 16
-00093                                 // causes panic !!
-00094                                 // 
-00095                                 // Remove the "//" marks on the next two lines
-00096                                 // to see this happen
-00097         //_LIT(KTxtRepTextPanic,"Text replacement causes panic");
-00098         //bufc2 = KTxtRepTextPanic;
-00099     
-00100         
-00101                                 // The Des() function returns a TPtr to the
-00102                                 // TBufC.
-00103                                 // The TBufC data can be changed through 
-00104                                 // the TPtr.
-00105                                 // The maximum length of the TPtr is the 
-00106                                 // value of the TBufC template parameter,
-00107                                 // i.e. 16 
-00108 
-00109         bufc2 = KTxtHelloWorld;
-00110         TPtr ptr = bufc2.Des();
-00111         
-00112         console->Printf(KTxtTBufC);
-00113         console->Printf(KCommonFormat6,
-00114                                         &bufc2,
-00115                                         bufc2.Ptr(),
-00116                                         bufc2.Length(),
-00117                                         bufc2.Size()
-00118                                    );
-00119         
-00120         console->Printf(KTxtTPtr);
-00121         console->Printf(KCommonFormat7,
-00122                                         &ptr,
-00123                                         ptr.Ptr(),
-00124                                         ptr.Length(),
-00125                                         ptr.Size()
-00126                                    );
-00127 
-00128         console->Printf(KCommonFormat8,ptr.MaxLength());
-00129 
-00130                                 // Now change the TBufC data through
-00131                                 // the TPtr. This is OK provided the length
-00132                                 // of the changed data does not exceed 16.
-00133                                 //
-00134                                 // The following change deletes the last 
-00135                                 // character (the "!") and appends 
-00136                                 // the characters " & Hi".
-00137                                 //
-00138                                 // Note that the length of both the TBufC 
-00139                                 // and the TPtr reflect the changed data.
-00140         _LIT(KTxtAndHi," & Hi");
-00141         ptr.Delete((ptr.Length()-1),1);
-00142         ptr.Append(KTxtAndHi);
-00143 
-00144         console->Printf(KTxtTBufC);
-00145         console->Printf(KCommonFormat6,
-00146                                         &bufc2,
-00147                                         bufc2.Ptr(),
-00148                                         bufc2.Length(),
-00149                                         bufc2.Size()
-00150                                    );
-00151 
-00152         console->Printf(KTxtTPtr);
-00153         console->Printf(KCommonFormat7,
-00154                                         &ptr,
-00155                                         ptr.Ptr(),
-00156                                         ptr.Length(),
-00157                                         ptr.Size()
-00158                                    );
-00159         console->Printf(KCommonFormat8,ptr.MaxLength());
-00160 
-00161         // * * * * * * * * * * * * * * * * * * * * * * * * * * * *
-00162         // * * * * * * * * * * * * * * * * * * * * * * * * * * * *
-00163         
-00164         _LIT(KTxtBasicConcepts,"\n-->TBuf basic concepts");
-00165         console->Printf(KTxtBasicConcepts);
-00166         _LIT(KTxtPressToContinue," (press any key to continue)\n");
-00167         console->Printf(KTxtPressToContinue);
-00168         console->Getch();
-00169 
-00170                                 // Construct a TBuf using a Literal                        
-00171         TBuf<16> buf(KTxtHelloWorld);
-00172         
-00173                                 // Look at: 
-00174                                 //   1. Descriptor content
-00175                                 //   2. Address of descriptor
-00176                                 //   3. Address of descriptor data area
-00177                                 //   4. Length of descriptor
-00178                                 //   5. Size of descriptor
-00179                                 //   6. Maximum length of descriptor      
-00180                                 //
-00181                                 // Like a TBufC, the address of the descriptor
-00182                                 // data area is offset 4 from the start of the
-00183                                 // descriptor itself.
-00184                                 //
-00185                                 // Descriptor length is 12.
-00186                                 //
-00187                                 // The template parameter value defines 
-00188                                 // the maximum length of the descriptor. 
-00189                                 // and, therefore, governs its size 
-00190                                 // (depending on the build variant).
-00191                                 // Size of data is 24
-00192                                                                 
-00193         console->Printf(KCommonFormat2,&buf);
-00194         console->Printf(KCommonFormat3,&buf,buf.Ptr());
-00195         console->Printf(KCommonFormat9,buf.Length(),buf.Size());        
-00196         console->Printf(KCommonFormat10,buf.MaxLength());
-00197                                                 
-00198                                 // The data can be modified
-00199         buf.Append('@');
-00200         console->Printf(KCommonFormat2,&buf);
-00201         console->Printf(KCommonFormat9,buf.Length(),buf.Size());        
-00202         console->Printf(KCommonFormat10,buf.MaxLength());
-00203 
-00204                             // Length can be changed; data represented
-00205                             // by the descriptor is now "Hel"
-00206         buf.SetLength(3);
-00207         console->Printf(KCommonFormat2,&buf);
-00208         console->Printf(KCommonFormat9,buf.Length(),buf.Size());        
-00209         console->Printf(KCommonFormat10,buf.MaxLength());
-00210 
-00211                                 // Length can be zeroised; no data is now 
-00212                                 // represented by the descriptor but 
-00213                                 // the maximum length is still 16
-00214         buf.Zero();
-00215         console->Printf(KCommonFormat2,&buf);
-00216         console->Printf(KCommonFormat9,buf.Length(),buf.Size());        
-00217         console->Printf(KCommonFormat10,buf.MaxLength());
-00218                                                                                                           
-00219                                 // The data can be replaced entirely 
-00220                                 // using the assignment operator.
-00221                                 // The replacement text must not have a
-00222                                 // length greater than 16.
-00223         buf = KTxtRepText;
-00224         console->Printf(KCommonFormat2,&buf);
-00225         console->Printf(KCommonFormat9,buf.Length(),buf.Size());        
-00226         console->Printf(KCommonFormat10,buf.MaxLength());
-00227         
-00228                                 // Replacing text which has a length > 16
-00229                                 // causes panic !!
-00230                                 // 
-00231                                 // Remove the "//" marks on the next two lines
-00232                                 // to see this happen
-00233         //_LIT(KTxtRepTextPanic,"Text replacement causes panic");
-00234         //buf = _L("Text replacement causes panic!");
-00235     }
-00236 
-00237 
-00238 
-00239 
-00240 
-00241         
-00242         
-