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3 <title>TB10.1 Example Applications: examples/SysLibs/EUserHLExample/src/euserhlexample.cpp Source File</title> |
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8 <h1>examples/SysLibs/EUserHLExample/src/euserhlexample.cpp</h1><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">// Copyright (c) 2008-2009 Nokia Corporation and/or its subsidiary(-ies).</span> |
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9 <a name="l00002"></a>00002 <span class="comment">// All rights reserved.</span> |
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10 <a name="l00003"></a>00003 <span class="comment">// This component and the accompanying materials are made available</span> |
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11 <a name="l00004"></a>00004 <span class="comment">// under the terms of "Eclipse Public License v1.0"</span> |
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12 <a name="l00005"></a>00005 <span class="comment">// which accompanies this distribution, and is available</span> |
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13 <a name="l00006"></a>00006 <span class="comment">// at the URL "http://www.eclipse.org/legal/epl-v10.html".</span> |
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14 <a name="l00007"></a>00007 <span class="comment">//</span> |
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15 <a name="l00008"></a>00008 <span class="comment">// Initial Contributors:</span> |
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16 <a name="l00009"></a>00009 <span class="comment">// Nokia Corporation - initial contribution.</span> |
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17 <a name="l00010"></a>00010 <span class="comment">//</span> |
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18 <a name="l00011"></a>00011 <span class="comment">// Contributors:</span> |
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19 <a name="l00012"></a>00012 <span class="comment">//</span> |
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20 <a name="l00013"></a>00013 <span class="comment">// Description:</span> |
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21 <a name="l00014"></a>00014 <span class="comment">//</span> |
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22 <a name="l00015"></a>00015 |
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23 <a name="l00016"></a>00016 <span class="preprocessor">#include <f32file.h></span> |
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24 <a name="l00017"></a>00017 <span class="preprocessor">#include <e32cons.h></span> |
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25 <a name="l00018"></a>00018 <span class="preprocessor">#include <euserhl.h></span> |
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26 <a name="l00019"></a>00019 |
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27 <a name="l00020"></a>00020 |
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28 <a name="l00021"></a>00021 _LIT(KTxtExample,<span class="stringliteral">"EUsableExample\n"</span>); |
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29 <a name="l00022"></a>00022 _LIT(KTxtPressAnyKeyToContinue,<span class="stringliteral">"Press any key to continue\n"</span>); |
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30 <a name="l00023"></a>00023 |
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31 <a name="l00024"></a>00024 CConsoleBase* gConsole; |
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32 <a name="l00025"></a>00025 |
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33 <a name="l00032"></a>00032 _LIT(KPath, <span class="stringliteral">"c:\\a\\b\\c"</span>); |
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34 <a name="l00033"></a>00033 _LIT(KOne, <span class="stringliteral">"One "</span>); |
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35 <a name="l00034"></a>00034 _LIT(KTwo, <span class="stringliteral">"Two "</span>); |
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36 <a name="l00035"></a>00035 _LIT(KTesting, <span class="stringliteral">"Testing "</span>); |
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37 <a name="l00036"></a>00036 |
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38 <a name="l00037"></a>00037 <span class="keywordtype">void</span> MaybeLeave() |
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39 <a name="l00038"></a>00038 { |
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40 <a name="l00039"></a>00039 <span class="comment">// Some code that may leave</span> |
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41 <a name="l00040"></a>00040 } |
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42 <a name="l00041"></a>00041 |
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43 <a name="l00042"></a>00042 HBufC* AllocateNameL(<span class="keyword">const</span> TDesC& aDes) |
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44 <a name="l00043"></a>00043 { |
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45 <a name="l00044"></a>00044 <span class="keywordflow">return</span> aDes.AllocL(); |
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46 <a name="l00045"></a>00045 } |
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47 <a name="l00046"></a>00046 |
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48 <a name="l00047"></a>00047 <span class="keywordtype">void</span> GetCurrentPath(TDes& aDes) |
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49 <a name="l00048"></a>00048 { |
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50 <a name="l00049"></a>00049 aDes = KPath; |
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51 <a name="l00050"></a>00050 } |
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52 <a name="l00051"></a>00051 |
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53 <a name="l00052"></a>00052 <span class="keywordtype">void</span> GetCurrentPathString(LString& aString) |
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54 <a name="l00053"></a>00053 { |
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55 <a name="l00054"></a>00054 aString = KPath; <span class="comment">// Will auto-grow if necessary, may leave</span> |
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56 <a name="l00055"></a>00055 } |
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57 <a name="l00056"></a>00056 |
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58 <a name="l00057"></a>00057 LString AppendCurrentPathStringL(LString aString) |
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59 <a name="l00058"></a>00058 { |
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60 <a name="l00059"></a>00059 <span class="comment">/*</span> |
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61 <a name="l00060"></a>00060 <span class="comment"> This method accepts and returns LStrings by value. It works but</span> |
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62 <a name="l00061"></a>00061 <span class="comment"> is not recommended due to the inherent inefficiencies.</span> |
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63 <a name="l00062"></a>00062 <span class="comment"> */</span> |
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64 <a name="l00063"></a>00063 LString result(aString); |
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65 <a name="l00064"></a>00064 result += KPath; |
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66 <a name="l00065"></a>00065 <span class="keywordflow">return</span> result; |
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67 <a name="l00066"></a>00066 } |
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68 <a name="l00067"></a>00067 |
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69 <a name="l00068"></a>00068 <span class="keyword">class </span>CTicker : <span class="keyword">public</span> CBase |
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70 <a name="l00069"></a>00069 { |
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71 <a name="l00070"></a>00070 <span class="keyword">public</span>: |
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72 <a name="l00071"></a>00071 <span class="keywordtype">void</span> Tick() { ++iTicks; } |
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73 <a name="l00072"></a>00072 <span class="keywordtype">void</span> Tock() { ++iTocks; } |
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74 <a name="l00073"></a>00073 |
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75 <a name="l00074"></a>00074 <span class="keywordtype">void</span> Zap() { <span class="keyword">delete</span> <span class="keyword">this</span>; } |
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76 <a name="l00075"></a>00075 |
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77 <a name="l00076"></a>00076 <span class="keyword">public</span>: |
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78 <a name="l00077"></a>00077 TInt iTicks; |
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79 <a name="l00078"></a>00078 TInt iTocks; |
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80 <a name="l00079"></a>00079 }; |
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81 <a name="l00080"></a>00080 |
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82 <a name="l00081"></a>00081 <span class="comment">// Defines a custom pointer cleanup policy that calls the Zap member</span> |
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83 <a name="l00082"></a>00082 <span class="keyword">class </span>TTickerZapStrategy |
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84 <a name="l00083"></a>00083 { |
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85 <a name="l00084"></a>00084 <span class="keyword">public</span>: |
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86 <a name="l00085"></a>00085 <span class="keyword">static</span> <span class="keywordtype">void</span> Cleanup(CTicker* aPtr) |
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87 <a name="l00086"></a>00086 { |
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88 <a name="l00087"></a>00087 <span class="comment">/*</span> |
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89 <a name="l00088"></a>00088 <span class="comment"> The general template/class scaffolding remains the same</span> |
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90 <a name="l00089"></a>00089 <span class="comment"> for all custom cleanups, just this cleanup body varies</span> |
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91 <a name="l00090"></a>00090 <span class="comment"> */</span> |
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92 <a name="l00091"></a>00091 aPtr->Zap(); |
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93 <a name="l00092"></a>00092 _LIT(KTxtPrintZapp, <span class="stringliteral">"Zapped CTicker\n"</span>); |
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94 <a name="l00093"></a>00093 gConsole->Printf(KTxtPrintZapp); |
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95 <a name="l00094"></a>00094 } |
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96 <a name="l00095"></a>00095 }; |
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97 <a name="l00096"></a>00096 |
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98 <a name="l00097"></a>00097 <span class="keywordtype">void</span> RegisterTicker(CTicker& aTicker) |
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99 <a name="l00098"></a>00098 { |
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100 <a name="l00099"></a>00099 (void)aTicker; |
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101 <a name="l00100"></a>00100 } |
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102 <a name="l00101"></a>00101 |
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103 <a name="l00102"></a>00102 <span class="keywordtype">void</span> RegisterTickerPtr(CTicker* aTicker) |
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104 <a name="l00103"></a>00103 { |
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105 <a name="l00104"></a>00104 (void)aTicker; |
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106 <a name="l00105"></a>00105 } |
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107 <a name="l00106"></a>00106 |
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108 <a name="l00107"></a>00107 <span class="keywordtype">void</span> TakeTickerOwnership(CTicker* aTicker) |
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109 <a name="l00108"></a>00108 { |
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110 <a name="l00109"></a>00109 <span class="keyword">delete</span> aTicker; |
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111 <a name="l00110"></a>00110 } |
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112 <a name="l00111"></a>00111 |
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113 <a name="l00112"></a>00112 <span class="keywordtype">void</span> RegisterTimer(RTimer& aTimer) |
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114 <a name="l00113"></a>00113 { |
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115 <a name="l00114"></a>00114 (void)aTimer; |
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116 <a name="l00115"></a>00115 } |
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117 <a name="l00116"></a>00116 |
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118 <a name="l00117"></a>00117 <span class="comment">// Defines a custom handle cleanup policy that calls Cancel() then Close()</span> |
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119 <a name="l00118"></a>00118 <span class="keyword">class </span>TCancelClose |
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120 <a name="l00119"></a>00119 { |
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121 <a name="l00120"></a>00120 <span class="keyword">public</span>: |
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122 <a name="l00121"></a>00121 <span class="keyword">template</span> <<span class="keyword">class</span> T> |
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123 <a name="l00122"></a>00122 <span class="keyword">static</span> <span class="keywordtype">void</span> Cleanup(T* aHandle) |
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124 <a name="l00123"></a>00123 { |
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125 <a name="l00124"></a>00124 <span class="comment">/*</span> |
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126 <a name="l00125"></a>00125 <span class="comment"> The general template/class scaffolding remains the same</span> |
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127 <a name="l00126"></a>00126 <span class="comment"> for all custom cleanups, just this cleanup body varies</span> |
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128 <a name="l00127"></a>00127 <span class="comment"> */</span> |
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129 <a name="l00128"></a>00128 aHandle->Cancel(); |
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130 <a name="l00129"></a>00129 aHandle->Close(); |
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131 <a name="l00130"></a>00130 _LIT(KTxtCancel,<span class="stringliteral">"Cancel Closed RTimer\n"</span>); |
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132 <a name="l00131"></a>00131 gConsole->Printf(KTxtCancel); |
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133 <a name="l00132"></a>00132 } |
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134 <a name="l00133"></a>00133 }; |
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135 <a name="l00134"></a>00134 |
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136 <a name="l00135"></a>00135 <span class="keywordtype">void</span> BespokeCleanupFunction(TAny* <span class="comment">/*aData*/</span>) |
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137 <a name="l00136"></a>00136 { |
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138 <a name="l00137"></a>00137 _LIT(KTxtCleanup,<span class="stringliteral">"BespokeCleanupFunction\n"</span>); |
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139 <a name="l00138"></a>00138 gConsole->Printf(KTxtCleanup); |
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140 <a name="l00139"></a>00139 } |
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141 <a name="l00140"></a>00140 |
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142 <a name="l00141"></a>00141 <span class="comment">// The walkthroughs themselves</span> |
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143 <a name="l00142"></a>00142 |
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144 <a name="l00149"></a>00149 <span class="keyword">class </span>CStringUserTwoPhase : <span class="keyword">public</span> CBase |
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145 <a name="l00150"></a>00150 { |
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146 <a name="l00151"></a>00151 <span class="keyword">public</span>: |
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147 <a name="l00152"></a>00152 <span class="keyword">static</span> CStringUserTwoPhase* NewL(<span class="keyword">const</span> TDesC& aName) |
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148 <a name="l00153"></a>00153 { |
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149 <a name="l00154"></a>00154 <span class="comment">/*</span> |
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150 <a name="l00155"></a>00155 <span class="comment"> We can use the resource management utility classes in</span> |
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151 <a name="l00156"></a>00156 <span class="comment"> two-phase if we want.</span> |
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152 <a name="l00157"></a>00157 <span class="comment"> */</span> |
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153 <a name="l00158"></a>00158 LCleanedupPtr<CStringUserTwoPhase> <span class="keyword">self</span>(<span class="keyword">new</span>(ELeave) CStringUserTwoPhase); |
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154 <a name="l00159"></a>00159 <span class="keyword">self</span>->Construct(aName); |
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155 <a name="l00160"></a>00160 <span class="comment">/*</span> |
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156 <a name="l00161"></a>00161 <span class="comment"> Calling Unmanage() disables cleanup and yields the</span> |
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157 <a name="l00162"></a>00162 <span class="comment"> previously managed pointer so that it can be safely</span> |
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158 <a name="l00163"></a>00163 <span class="comment"> returned</span> |
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159 <a name="l00164"></a>00164 <span class="comment"> */</span> |
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160 <a name="l00165"></a>00165 <span class="keywordflow">return</span> <span class="keyword">self</span>.Unmanage(); |
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161 <a name="l00166"></a>00166 } |
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162 <a name="l00167"></a>00167 |
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163 <a name="l00168"></a>00168 <span class="keyword">virtual</span> <span class="keywordtype">void</span> Construct(<span class="keyword">const</span> TDesC& aName) |
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164 <a name="l00169"></a>00169 { |
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165 <a name="l00170"></a>00170 <span class="comment">/*</span> |
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166 <a name="l00171"></a>00171 <span class="comment"> This assignment may leave if LString fails to allocate a</span> |
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167 <a name="l00172"></a>00172 <span class="comment"> heap buffer large enough to hold the data in aName</span> |
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168 <a name="l00173"></a>00173 <span class="comment"> */</span> |
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169 <a name="l00174"></a>00174 iName = aName; |
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170 <a name="l00175"></a>00175 } |
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171 <a name="l00176"></a>00176 |
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172 <a name="l00177"></a>00177 ~CStringUserTwoPhase() |
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173 <a name="l00178"></a>00178 { |
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174 <a name="l00179"></a>00179 <span class="comment">// The iName LString cleans up after itself automatically </span> |
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175 <a name="l00180"></a>00180 } |
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176 <a name="l00181"></a>00181 |
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177 <a name="l00182"></a>00182 <span class="keyword">const</span> TDesC& Name() |
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178 <a name="l00183"></a>00183 { |
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179 <a name="l00184"></a>00184 <span class="comment">// We can just return an LString directly as a const TDesC</span> |
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180 <a name="l00185"></a>00185 <span class="keywordflow">return</span> iName; |
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181 <a name="l00186"></a>00186 } |
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182 <a name="l00187"></a>00187 |
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183 <a name="l00188"></a>00188 <span class="keyword">protected</span>: |
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184 <a name="l00189"></a>00189 CStringUserTwoPhase() |
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185 <a name="l00190"></a>00190 { |
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186 <a name="l00191"></a>00191 <span class="comment">/*</span> |
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187 <a name="l00192"></a>00192 <span class="comment"> Everything interesting happens in ConstructL in this</span> |
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188 <a name="l00193"></a>00193 <span class="comment"> version. </span> |
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189 <a name="l00194"></a>00194 <span class="comment"></span> |
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190 <a name="l00195"></a>00195 <span class="comment"> Default initialization of the iName LString does not</span> |
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191 <a name="l00196"></a>00196 <span class="comment"> allocate a heap buffer, and so cannot leave. As long as</span> |
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192 <a name="l00197"></a>00197 <span class="comment"> initialization is deferred to ConstructL, LStrings can be</span> |
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193 <a name="l00198"></a>00198 <span class="comment"> used safely with two-phase construction.</span> |
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194 <a name="l00199"></a>00199 <span class="comment"> */</span> |
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195 <a name="l00200"></a>00200 } |
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196 <a name="l00201"></a>00201 |
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197 <a name="l00202"></a>00202 <span class="keyword">protected</span>: |
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198 <a name="l00203"></a>00203 LString iName; |
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199 <a name="l00204"></a>00204 }; |
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200 <a name="l00205"></a>00205 |
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201 <a name="l00217"></a>00217 <span class="keyword">class </span>CStringUserSinglePhase : <span class="keyword">public</span> CBase |
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202 <a name="l00218"></a>00218 { |
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203 <a name="l00219"></a>00219 <span class="keyword">public</span>: |
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204 <a name="l00220"></a>00220 <span class="comment">/*</span> |
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205 <a name="l00221"></a>00221 <span class="comment"> This macro is necessary to ensure cleanup is correctly handled</span> |
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206 <a name="l00222"></a>00222 <span class="comment"> in the event that a constructor may leave beneath a call to</span> |
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207 <a name="l00223"></a>00223 <span class="comment"> new(ELeave)</span> |
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208 <a name="l00224"></a>00224 <span class="comment"> */</span> |
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209 <a name="l00225"></a>00225 CONSTRUCTORS_MAY_LEAVE |
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210 <a name="l00226"></a>00226 |
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211 <a name="l00227"></a>00227 <span class="keyword">static</span> CStringUserSinglePhase* NewL(<span class="keyword">const</span> TDesC& aName) |
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212 <a name="l00228"></a>00228 { |
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213 <a name="l00229"></a>00229 <span class="keywordflow">return</span> <span class="keyword">new</span>(ELeave) CStringUserSinglePhase(aName); |
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214 <a name="l00230"></a>00230 } |
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215 <a name="l00231"></a>00231 |
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216 <a name="l00232"></a>00232 ~CStringUserSinglePhase() |
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217 <a name="l00233"></a>00233 { |
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218 <a name="l00234"></a>00234 <span class="comment">// The iName LString cleans up after itself automatically</span> |
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219 <a name="l00235"></a>00235 } |
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220 <a name="l00236"></a>00236 |
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221 <a name="l00237"></a>00237 <span class="keyword">const</span> TDesC& Name() |
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222 <a name="l00238"></a>00238 { |
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223 <a name="l00239"></a>00239 <span class="comment">// We can just return an LString directly as a const TDesC</span> |
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224 <a name="l00240"></a>00240 <span class="keywordflow">return</span> iName; |
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225 <a name="l00241"></a>00241 } |
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226 <a name="l00242"></a>00242 |
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227 <a name="l00243"></a>00243 <span class="keyword">protected</span>: |
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228 <a name="l00244"></a>00244 CStringUserSinglePhase(<span class="keyword">const</span> TDesC& aName) |
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229 <a name="l00245"></a>00245 <span class="comment">/*</span> |
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230 <a name="l00246"></a>00246 <span class="comment"> This initialization of iName may leave because LString</span> |
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231 <a name="l00247"></a>00247 <span class="comment"> needs to allocate a heap buffer to copy the aName string</span> |
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232 <a name="l00248"></a>00248 <span class="comment"> data into</span> |
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233 <a name="l00249"></a>00249 <span class="comment"> */</span> |
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234 <a name="l00250"></a>00250 : iName(aName) |
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235 <a name="l00251"></a>00251 { |
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236 <a name="l00252"></a>00252 <span class="comment">/*</span> |
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237 <a name="l00253"></a>00253 <span class="comment"> If iName initialization is successful but the constructor</span> |
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238 <a name="l00254"></a>00254 <span class="comment"> then goes on to leave later, iName (like all fields fully</span> |
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239 <a name="l00255"></a>00255 <span class="comment"> constructed at the point of a leave in a constructor) will</span> |
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240 <a name="l00256"></a>00256 <span class="comment"> be destructed, and so clean up after itself</span> |
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241 <a name="l00257"></a>00257 <span class="comment"> */</span> |
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242 <a name="l00258"></a>00258 MaybeLeave(); |
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243 <a name="l00259"></a>00259 } |
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244 <a name="l00260"></a>00260 |
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245 <a name="l00261"></a>00261 <span class="keyword">protected</span>: |
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246 <a name="l00262"></a>00262 LString iName; |
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247 <a name="l00263"></a>00263 }; |
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248 <a name="l00264"></a>00264 |
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249 <a name="l00265"></a>00265 |
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250 <a name="l00266"></a>00266 <span class="keywordtype">void</span> WalkthroughStringsL() |
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251 <a name="l00267"></a>00267 { |
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252 <a name="l00268"></a>00268 _LIT(KTxtOption1,<span class="stringliteral">"Option1: String handling using EUser high level library\n"</span>); |
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253 <a name="l00269"></a>00269 gConsole->Printf(KTxtOption1); |
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254 <a name="l00270"></a>00270 _LIT(KTxtFormatString,<span class="stringliteral">"String %d"</span>); |
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255 <a name="l00271"></a>00271 _LIT(KTxtPrintString,<span class="stringliteral">"String %d = %S\n"</span>); |
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256 <a name="l00272"></a>00272 { |
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257 <a name="l00273"></a>00273 <span class="comment">// Trivially exercise the LString using classes defined above</span> |
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258 <a name="l00274"></a>00274 |
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259 <a name="l00275"></a>00275 LCleanedupPtr<CStringUserTwoPhase> one(CStringUserTwoPhase::NewL(KOne)); |
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260 <a name="l00276"></a>00276 _LIT(KTxtSinglePhaseConstructor,<span class="stringliteral">"Single phase name: %S\n"</span>); |
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261 <a name="l00277"></a>00277 gConsole->Printf(KTxtSinglePhaseConstructor, &one->Name()); |
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262 <a name="l00278"></a>00278 |
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263 <a name="l00279"></a>00279 LCleanedupPtr<CStringUserSinglePhase> two(CStringUserSinglePhase::NewL(KTwo)); |
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264 <a name="l00280"></a>00280 _LIT(KTxtTwoPhaseConstructor,<span class="stringliteral">"Single phase name: %S\n"</span>); |
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265 <a name="l00281"></a>00281 gConsole->Printf(KTxtTwoPhaseConstructor, &two->Name()); |
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266 <a name="l00282"></a>00282 |
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267 <a name="l00283"></a>00283 gConsole->Printf(KTxtPressAnyKeyToContinue); |
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268 <a name="l00284"></a>00284 gConsole->Getch(); |
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269 <a name="l00285"></a>00285 <span class="comment">// Both instances are automatically deleted as we go out of scope</span> |
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270 <a name="l00286"></a>00286 } |
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271 <a name="l00287"></a>00287 |
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272 <a name="l00288"></a>00288 { |
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273 <a name="l00289"></a>00289 <span class="comment">/*</span> |
|
274 <a name="l00290"></a>00290 <span class="comment"> A default constructed LString starts empty, doesn't</span> |
|
275 <a name="l00291"></a>00291 <span class="comment"> allocate any memory on the heap, and therefore the</span> |
|
276 <a name="l00292"></a>00292 <span class="comment"> following cannot leave</span> |
|
277 <a name="l00293"></a>00293 <span class="comment"> */</span> |
|
278 <a name="l00294"></a>00294 LString s; |
|
279 <a name="l00295"></a>00295 |
|
280 <a name="l00296"></a>00296 <span class="comment">/*</span> |
|
281 <a name="l00297"></a>00297 <span class="comment"> But it will grow on demand if you assign to it, so it has</span> |
|
282 <a name="l00298"></a>00298 <span class="comment"> enough space to hold the copied string data, and so</span> |
|
283 <a name="l00299"></a>00299 <span class="comment"> assignment may leave</span> |
|
284 <a name="l00300"></a>00300 <span class="comment"> */</span> |
|
285 <a name="l00301"></a>00301 s = KOne; |
|
286 <a name="l00302"></a>00302 |
|
287 <a name="l00303"></a>00303 <span class="comment">/*</span> |
|
288 <a name="l00304"></a>00304 <span class="comment"> Similarly if you append to it with the leaving variant of</span> |
|
289 <a name="l00305"></a>00305 <span class="comment"> Append(), AppendL(), if may grow on demand</span> |
|
290 <a name="l00306"></a>00306 <span class="comment"> */</span> |
|
291 <a name="l00307"></a>00307 s.AppendL(KTwo); |
|
292 <a name="l00308"></a>00308 |
|
293 <a name="l00309"></a>00309 <span class="comment">// The += operator for LString also maps to AppendL()</span> |
|
294 <a name="l00310"></a>00310 _LIT(KThree, <span class="stringliteral">"Three "</span>); |
|
295 <a name="l00311"></a>00311 s += KThree; |
|
296 <a name="l00312"></a>00312 |
|
297 <a name="l00313"></a>00313 <span class="comment">/*</span> |
|
298 <a name="l00314"></a>00314 <span class="comment"> You can also use new leaving format methods that also grow</span> |
|
299 <a name="l00315"></a>00315 <span class="comment"> on demand</span> |
|
300 <a name="l00316"></a>00316 <span class="comment"> */</span> |
|
301 <a name="l00317"></a>00317 s.AppendFormatL(KTesting); |
|
302 <a name="l00318"></a>00318 |
|
303 <a name="l00319"></a>00319 <span class="comment">/*</span> |
|
304 <a name="l00320"></a>00320 <span class="comment"> This general style of use of LString may be preferable to</span> |
|
305 <a name="l00321"></a>00321 <span class="comment"> typical descriptor use for a number of reasons e.g. it</span> |
|
306 <a name="l00322"></a>00322 <span class="comment"> avoids the common temptation to set an artificial maximum</span> |
|
307 <a name="l00323"></a>00323 <span class="comment"> buffer size; it avoids massive conservative over-allocation</span> |
|
308 <a name="l00324"></a>00324 <span class="comment"> when the average case length of a string is far less than</span> |
|
309 <a name="l00325"></a>00325 <span class="comment"> the worst-case maximum; it will not surprise you (compared</span> |
|
310 <a name="l00326"></a>00326 <span class="comment"> to the alternative of a large stack-allocated TBuf) by</span> |
|
311 <a name="l00327"></a>00327 <span class="comment"> triggering stack overflow.</span> |
|
312 <a name="l00328"></a>00328 <span class="comment"> */</span> |
|
313 <a name="l00329"></a>00329 |
|
314 <a name="l00330"></a>00330 <span class="comment">// An LString can be printed the same way as any descriptor</span> |
|
315 <a name="l00331"></a>00331 _LIT(KTxtValue,<span class="stringliteral">"Value: %S\n"</span>); |
|
316 <a name="l00332"></a>00332 gConsole->Printf(KTxtValue, &s); |
|
317 <a name="l00333"></a>00333 |
|
318 <a name="l00334"></a>00334 <span class="comment">// An LString can be compared the same way as any descriptor</span> |
|
319 <a name="l00335"></a>00335 _LIT(KTxtLStringCompare,<span class="stringliteral">" Comparing LString with a literal is successful\n"</span>); |
|
320 <a name="l00336"></a>00336 _LIT(KPhrase, <span class="stringliteral">"One Two Three Testing "</span>); |
|
321 <a name="l00337"></a>00337 <span class="keywordflow">if</span>(s == KPhrase) |
|
322 <a name="l00338"></a>00338 { |
|
323 <a name="l00339"></a>00339 gConsole->Printf(KTxtLStringCompare); |
|
324 <a name="l00340"></a>00340 } |
|
325 <a name="l00341"></a>00341 |
|
326 <a name="l00342"></a>00342 <span class="comment">// An LString supports all TDesC and TDes methods</span> |
|
327 <a name="l00343"></a>00343 _LIT(KTxtLStringSupportedAPI1,<span class="stringliteral">"LString supports TDesC and TDes methods\n"</span>); |
|
328 <a name="l00344"></a>00344 <span class="keywordflow">if</span>(s.Find(KTwo) == 4) |
|
329 <a name="l00345"></a>00345 { |
|
330 <a name="l00346"></a>00346 gConsole->Printf(KTxtLStringSupportedAPI1); |
|
331 <a name="l00347"></a>00347 } |
|
332 <a name="l00348"></a>00348 <span class="comment">// An LString supports all TDesC and TDes operators</span> |
|
333 <a name="l00349"></a>00349 _LIT(KTxtLStringSupportedAPI2,<span class="stringliteral">"LString supports TDesC and TDes operators\n"</span>); |
|
334 <a name="l00350"></a>00350 <span class="keywordflow">if</span>(s[4] == TChar(<span class="charliteral">'T'</span>)) |
|
335 <a name="l00351"></a>00351 { |
|
336 <a name="l00352"></a>00352 gConsole->Printf(KTxtLStringSupportedAPI2); |
|
337 <a name="l00353"></a>00353 } |
|
338 <a name="l00354"></a>00354 TInt untrimmed = s.Length(); |
|
339 <a name="l00355"></a>00355 s.Trim(); |
|
340 <a name="l00356"></a>00356 <span class="keywordflow">if</span>(s.Length() == untrimmed - 1) |
|
341 <a name="l00357"></a>00357 { |
|
342 <a name="l00358"></a>00358 <span class="comment">//LString supports Trim API</span> |
|
343 <a name="l00359"></a>00359 } |
|
344 <a name="l00360"></a>00360 |
|
345 <a name="l00361"></a>00361 s.UpperCase(); |
|
346 <a name="l00362"></a>00362 _LIT(KTxtPrintUpperCase,<span class="stringliteral">"UpperCase: %S\n"</span>); |
|
347 <a name="l00363"></a>00363 gConsole->Printf(KTxtPrintUpperCase, &s); |
|
348 <a name="l00364"></a>00364 s.LowerCase(); |
|
349 <a name="l00365"></a>00365 _LIT(KTxtPrintLowerCase,<span class="stringliteral">"UpperCase: %S\n"</span>); |
|
350 <a name="l00366"></a>00366 gConsole->Printf(KTxtPrintLowerCase, &s); |
|
351 <a name="l00367"></a>00367 gConsole->Printf(KTxtPressAnyKeyToContinue); |
|
352 <a name="l00368"></a>00368 gConsole->Getch(); |
|
353 <a name="l00369"></a>00369 <span class="comment">/*</span> |
|
354 <a name="l00370"></a>00370 <span class="comment"> The underlying heap allocated buffer is released</span> |
|
355 <a name="l00371"></a>00371 <span class="comment"> automatically when the LString goes out of scope, either</span> |
|
356 <a name="l00372"></a>00372 <span class="comment"> normally or through a leave</span> |
|
357 <a name="l00373"></a>00373 <span class="comment"> */</span> |
|
358 <a name="l00374"></a>00374 } |
|
359 <a name="l00375"></a>00375 |
|
360 <a name="l00376"></a>00376 { |
|
361 <a name="l00377"></a>00377 <span class="comment">// You can initialize with a MaxLength value</span> |
|
362 <a name="l00378"></a>00378 LString s(KMaxFileName); <span class="comment">// This operation may leave</span> |
|
363 <a name="l00379"></a>00379 <span class="keywordflow">if</span>(s.MaxLength() == KMaxFileName) |
|
364 <a name="l00380"></a>00380 { |
|
365 <a name="l00381"></a>00381 <span class="comment">//LString supports MaxLength API</span> |
|
366 <a name="l00382"></a>00382 } |
|
367 <a name="l00383"></a>00383 |
|
368 <a name="l00384"></a>00384 <span class="comment">/*</span> |
|
369 <a name="l00385"></a>00385 <span class="comment"> And you can dynamically adjust MaxLength later using </span> |
|
370 <a name="l00386"></a>00386 <span class="comment"> SetMaxLengthL() if you want an exact allocated size.</span> |
|
371 <a name="l00387"></a>00387 <span class="comment"> Setting MaxLength() on construction or via SetMaxLengthL() is</span> |
|
372 <a name="l00388"></a>00388 <span class="comment"> exact; calling MaxLength() immediately afterwards is</span> |
|
373 <a name="l00389"></a>00389 <span class="comment"> guaranteed to return exactly the value you specified.</span> |
|
374 <a name="l00390"></a>00390 <span class="comment"> */</span> |
|
375 <a name="l00391"></a>00391 s.SetMaxLengthL(2 * KMaxFileName); |
|
376 <a name="l00392"></a>00392 <span class="keywordflow">if</span>(s.MaxLength() == 2 * KMaxFileName) |
|
377 <a name="l00393"></a>00393 { |
|
378 <a name="l00394"></a>00394 <span class="comment">//MaxLength is successfully adjusted.</span> |
|
379 <a name="l00395"></a>00395 } |
|
380 <a name="l00396"></a>00396 |
|
381 <a name="l00397"></a>00397 <span class="comment">/*</span> |
|
382 <a name="l00398"></a>00398 <span class="comment"> Pre-setting MaxLength is important when passing an LString</span> |
|
383 <a name="l00399"></a>00399 <span class="comment"> as a TDes to a library function, because the LString can't</span> |
|
384 <a name="l00400"></a>00400 <span class="comment"> be auto-grown via the TDes API.</span> |
|
385 <a name="l00401"></a>00401 <span class="comment"> */</span> |
|
386 <a name="l00402"></a>00402 |
|
387 <a name="l00403"></a>00403 } |
|
388 <a name="l00404"></a>00404 |
|
389 <a name="l00405"></a>00405 { |
|
390 <a name="l00406"></a>00406 <span class="comment">/*</span> |
|
391 <a name="l00407"></a>00407 <span class="comment"> You can initialize from any descriptor (or literal) and the</span> |
|
392 <a name="l00408"></a>00408 <span class="comment"> string data is copied into the LString</span> |
|
393 <a name="l00409"></a>00409 <span class="comment"> */</span> |
|
394 <a name="l00410"></a>00410 LString s(KOne); <span class="comment">// From a literal</span> |
|
395 <a name="l00411"></a>00411 s += KTwo; |
|
396 <a name="l00412"></a>00412 LString half(s.Left(s.Length() / 2)); <span class="comment">// Left returns a TPtrC</span> |
|
397 <a name="l00413"></a>00413 _LIT(KTxtPrintAllandHalf,<span class="stringliteral">"All: %S, Half: %S\n"</span>); |
|
398 <a name="l00414"></a>00414 gConsole->Printf(KTxtPrintAllandHalf, &s, &half); |
|
399 <a name="l00415"></a>00415 |
|
400 <a name="l00416"></a>00416 <span class="comment">/*</span> |
|
401 <a name="l00417"></a>00417 <span class="comment"> On the other hand, you can initialize from a returned</span> |
|
402 <a name="l00418"></a>00418 <span class="comment"> HBufC* and the LString automatically takes ownership</span> |
|
403 <a name="l00419"></a>00419 <span class="comment"> */</span> |
|
404 <a name="l00420"></a>00420 LString own(AllocateNameL(KTesting)); |
|
405 <a name="l00421"></a>00421 _LIT(KTxtOwnedString,<span class="stringliteral">"What I own: %S\n"</span>); |
|
406 <a name="l00422"></a>00422 gConsole->Printf(KTxtOwnedString, &own); |
|
407 <a name="l00423"></a>00423 |
|
408 <a name="l00424"></a>00424 <span class="comment">/*</span> |
|
409 <a name="l00425"></a>00425 <span class="comment"> Following that you can re-assign an HBufC to an existing</span> |
|
410 <a name="l00426"></a>00426 <span class="comment"> string using the assignment operator </span> |
|
411 <a name="l00427"></a>00427 <span class="comment"> taking ownership of the new content. </span> |
|
412 <a name="l00428"></a>00428 <span class="comment"> */</span> |
|
413 <a name="l00429"></a>00429 own = AllocateNameL(KTesting); |
|
414 <a name="l00430"></a>00430 |
|
415 <a name="l00431"></a>00431 <span class="comment">/*</span> |
|
416 <a name="l00432"></a>00432 <span class="comment"> Following that you can re-assign an HBufC to an existing</span> |
|
417 <a name="l00433"></a>00433 <span class="comment"> string. The string destroys its original content before</span> |
|
418 <a name="l00434"></a>00434 <span class="comment"> taking ownership of the new content. </span> |
|
419 <a name="l00435"></a>00435 <span class="comment"> */</span> |
|
420 <a name="l00436"></a>00436 own.Assign(AllocateNameL(KTesting)); |
|
421 <a name="l00437"></a>00437 |
|
422 <a name="l00438"></a>00438 <span class="comment">/*</span> |
|
423 <a name="l00439"></a>00439 <span class="comment"> The content of one string can similarly be assigned</span> |
|
424 <a name="l00440"></a>00440 <span class="comment"> to another to avoid copying. In this example, the content </span> |
|
425 <a name="l00441"></a>00441 <span class="comment"> is detached from 's' and transfered to 'own'.</span> |
|
426 <a name="l00442"></a>00442 <span class="comment"> */</span> |
|
427 <a name="l00443"></a>00443 own.Assign(s); |
|
428 <a name="l00444"></a>00444 |
|
429 <a name="l00445"></a>00445 <span class="comment">/*</span> |
|
430 <a name="l00446"></a>00446 <span class="comment"> The same content transfer can be achieved from an RBuf to a</span> |
|
431 <a name="l00447"></a>00447 <span class="comment"> string. You may need to do this if a legacy method returns</span> |
|
432 <a name="l00448"></a>00448 <span class="comment"> you an RBuf. The RBuf is emptied of its content.</span> |
|
433 <a name="l00449"></a>00449 <span class="comment"> */</span> |
|
434 <a name="l00450"></a>00450 RBuf16 buf; |
|
435 <a name="l00451"></a>00451 buf.CreateL(KOne); |
|
436 <a name="l00452"></a>00452 own.Assign(buf); |
|
437 <a name="l00453"></a>00453 |
|
438 <a name="l00454"></a>00454 <span class="comment">/*</span> |
|
439 <a name="l00455"></a>00455 <span class="comment"> You can also assign a simple text array to a string as its</span> |
|
440 <a name="l00456"></a>00456 <span class="comment"> new buffer. This method initialises the length to zero.</span> |
|
441 <a name="l00457"></a>00457 <span class="comment"> */</span> |
|
442 <a name="l00458"></a>00458 own.Assign((TText*)User::Alloc(24*(TInt)<span class="keyword">sizeof</span>(TText)), 24); |
|
443 <a name="l00459"></a>00459 |
|
444 <a name="l00460"></a>00460 <span class="comment">/*</span> |
|
445 <a name="l00461"></a>00461 <span class="comment"> If the buffer has already been filled with some characters</span> |
|
446 <a name="l00462"></a>00462 <span class="comment"> then you supply the length in this alternative Assign() method.</span> |
|
447 <a name="l00463"></a>00463 <span class="comment"> */</span> |
|
448 <a name="l00464"></a>00464 own.Assign((TText*)User::Alloc(24*(TInt)<span class="keyword">sizeof</span>(TText)), 12,24); |
|
449 <a name="l00465"></a>00465 gConsole->Printf(KTxtPressAnyKeyToContinue); |
|
450 <a name="l00466"></a>00466 gConsole->Getch(); |
|
451 <a name="l00467"></a>00467 <span class="comment">/*</span> |
|
452 <a name="l00468"></a>00468 <span class="comment"> Each Assign() destroys the old content before assuming ownership</span> |
|
453 <a name="l00469"></a>00469 <span class="comment"> of the new.</span> |
|
454 <a name="l00470"></a>00470 <span class="comment"> As usual the last content of the string is destroyed when the </span> |
|
455 <a name="l00471"></a>00471 <span class="comment"> LString goes out of scope</span> |
|
456 <a name="l00472"></a>00472 <span class="comment"> */</span> |
|
457 <a name="l00473"></a>00473 } |
|
458 <a name="l00474"></a>00474 |
|
459 <a name="l00475"></a>00475 { |
|
460 <a name="l00476"></a>00476 <span class="comment">/*</span> |
|
461 <a name="l00477"></a>00477 <span class="comment"> You can reserve extra free space in preparation for an </span> |
|
462 <a name="l00478"></a>00478 <span class="comment"> operation that adds characters to the string. You may</span> |
|
463 <a name="l00479"></a>00479 <span class="comment"> need to do this when you cannot use any of the auto-buffer</span> |
|
464 <a name="l00480"></a>00480 <span class="comment"> extending LString methods to achieve your objective.</span> |
|
465 <a name="l00481"></a>00481 <span class="comment"> */</span> |
|
466 <a name="l00482"></a>00482 LString s(KOne); |
|
467 <a name="l00483"></a>00483 s.ReserveFreeCapacityL(4); |
|
468 <a name="l00484"></a>00484 <span class="keywordflow">if</span>(s.Length() == 4) |
|
469 <a name="l00485"></a>00485 { |
|
470 <a name="l00486"></a>00486 <span class="comment">//Length() API gives the current length of the string</span> |
|
471 <a name="l00487"></a>00487 } |
|
472 <a name="l00488"></a>00488 <span class="keywordflow">if</span>(s.MaxLength() >= 8) |
|
473 <a name="l00489"></a>00489 { |
|
474 <a name="l00490"></a>00490 <span class="comment">//MaxLength() gives the maximum length supported by the string</span> |
|
475 <a name="l00491"></a>00491 } |
|
476 <a name="l00492"></a>00492 |
|
477 <a name="l00493"></a>00493 <span class="comment">/*</span> |
|
478 <a name="l00494"></a>00494 <span class="comment"> Almost all the methods that may extend the string buffer,</span> |
|
479 <a name="l00495"></a>00495 <span class="comment"> including the explicit ReserveFreeCapacityL(), but excluding</span> |
|
480 <a name="l00496"></a>00496 <span class="comment"> SetMaxLengthL(), attempt to grow the size exponentially. </span> |
|
481 <a name="l00497"></a>00497 <span class="comment"> The exponential growth pattern is expected to give better </span> |
|
482 <a name="l00498"></a>00498 <span class="comment"> performance at an amortised complexity of O(n) when adding n characters.</span> |
|
483 <a name="l00499"></a>00499 <span class="comment"> If the exponential growth is less than the supplied extra size</span> |
|
484 <a name="l00500"></a>00500 <span class="comment"> then the supplied size is used instead to save time.</span> |
|
485 <a name="l00501"></a>00501 <span class="comment"> The exponential growth is used in anticipation of further additions</span> |
|
486 <a name="l00502"></a>00502 <span class="comment"> to a string. This trades-off speed efficiency for space efficiency.</span> |
|
487 <a name="l00503"></a>00503 <span class="comment"> If required you may be able to swap the oversized buffer for </span> |
|
488 <a name="l00504"></a>00504 <span class="comment"> a more compact one using:</span> |
|
489 <a name="l00505"></a>00505 <span class="comment"> */</span> |
|
490 <a name="l00506"></a>00506 s.Compress(); |
|
491 <a name="l00507"></a>00507 <span class="keywordflow">if</span>(s.MaxLength() >= 4) |
|
492 <a name="l00508"></a>00508 { |
|
493 <a name="l00509"></a>00509 <span class="comment">//Compress() API is used to compress the unused memory.</span> |
|
494 <a name="l00510"></a>00510 } |
|
495 <a name="l00511"></a>00511 |
|
496 <a name="l00512"></a>00512 <span class="comment">/*</span> |
|
497 <a name="l00513"></a>00513 <span class="comment"> Resize() attempts to re-allocate a smaller buffer to copy</span> |
|
498 <a name="l00514"></a>00514 <span class="comment"> the content into. If the new memory cannot be allocated then the</span> |
|
499 <a name="l00515"></a>00515 <span class="comment"> original string is left unaffected. </span> |
|
500 <a name="l00516"></a>00516 <span class="comment"> </span> |
|
501 <a name="l00517"></a>00517 <span class="comment"> When you have finished using the content of a string you can</span> |
|
502 <a name="l00518"></a>00518 <span class="comment"> get its buffer released without destroying the string itself. </span> |
|
503 <a name="l00519"></a>00519 <span class="comment"> You may want to do this when using member declared strings.</span> |
|
504 <a name="l00520"></a>00520 <span class="comment"> Automatic strings are destroyed when they go out of scope.</span> |
|
505 <a name="l00521"></a>00521 <span class="comment"> */</span> |
|
506 <a name="l00522"></a>00522 s.Reset(); |
|
507 <a name="l00523"></a>00523 <span class="keywordflow">if</span>(s.Length() == 0) |
|
508 <a name="l00524"></a>00524 { |
|
509 <a name="l00525"></a>00525 <span class="comment">//Buffer of the string is released, hence length is zero.</span> |
|
510 <a name="l00526"></a>00526 } |
|
511 <a name="l00527"></a>00527 <span class="keywordflow">if</span>(s.MaxLength() == 0) |
|
512 <a name="l00528"></a>00528 { |
|
513 <a name="l00529"></a>00529 <span class="comment">//Buffer of the string is released, hence maximum length is zero.</span> |
|
514 <a name="l00530"></a>00530 } |
|
515 <a name="l00531"></a>00531 |
|
516 <a name="l00532"></a>00532 } |
|
517 <a name="l00533"></a>00533 |
|
518 <a name="l00534"></a>00534 { |
|
519 <a name="l00535"></a>00535 <span class="comment">/*</span> |
|
520 <a name="l00536"></a>00536 <span class="comment"> An LString can be passed directly to any function requiring</span> |
|
521 <a name="l00537"></a>00537 <span class="comment"> a const TDesC&</span> |
|
522 <a name="l00538"></a>00538 <span class="comment"> */</span> |
|
523 <a name="l00539"></a>00539 TInt year = 2009; |
|
524 <a name="l00540"></a>00540 |
|
525 <a name="l00541"></a>00541 LString s; |
|
526 <a name="l00542"></a>00542 _LIT(KTxtFormatYear1,<span class="stringliteral">"Happy New Year %d"</span>); |
|
527 <a name="l00543"></a>00543 s.FormatL(KTxtFormatYear1, year); |
|
528 <a name="l00544"></a>00544 <span class="comment">// InfoPrint() takes a const TDesC&</span> |
|
529 <a name="l00545"></a>00545 User::InfoPrint(s); |
|
530 <a name="l00546"></a>00546 |
|
531 <a name="l00547"></a>00547 LString pattern; |
|
532 <a name="l00548"></a>00548 _LIT(KTxtFormatYear2,<span class="stringliteral">"*Year %d"</span>); |
|
533 <a name="l00549"></a>00549 pattern.FormatL(KTxtFormatYear2, year); |
|
534 <a name="l00550"></a>00550 <span class="comment">// Match() takes a const TDesC& as a pattern</span> |
|
535 <a name="l00551"></a>00551 TInt loc = s.Match(pattern); |
|
536 <a name="l00552"></a>00552 <span class="keywordflow">if</span>(loc == 10) |
|
537 <a name="l00553"></a>00553 { |
|
538 <a name="l00554"></a>00554 <span class="comment">//Match() API is demonstrated successfully.</span> |
|
539 <a name="l00555"></a>00555 } |
|
540 <a name="l00556"></a>00556 } |
|
541 <a name="l00557"></a>00557 |
|
542 <a name="l00558"></a>00558 { |
|
543 <a name="l00559"></a>00559 <span class="comment">/*</span> |
|
544 <a name="l00560"></a>00560 <span class="comment"> An LString can be passed directly to any function requiring</span> |
|
545 <a name="l00561"></a>00561 <span class="comment"> a TDes& but care must always be taken to pre-set MaxLength()</span> |
|
546 <a name="l00562"></a>00562 <span class="comment"> since LStrings can't be automatically grown via the TDes</span> |
|
547 <a name="l00563"></a>00563 <span class="comment"> interface</span> |
|
548 <a name="l00564"></a>00564 <span class="comment"> */</span> |
|
549 <a name="l00565"></a>00565 |
|
550 <a name="l00566"></a>00566 LString s; |
|
551 <a name="l00567"></a>00567 <span class="comment">/*</span> |
|
552 <a name="l00568"></a>00568 <span class="comment"> Calling GetCurrentPath(s) now would panic because LStrings</span> |
|
553 <a name="l00569"></a>00569 <span class="comment"> are initialized by default to MaxLength 0. Although s is</span> |
|
554 <a name="l00570"></a>00570 <span class="comment"> an LString GetCurrentPath() takes a TDes& and so inside the function</span> |
|
555 <a name="l00571"></a>00571 <span class="comment"> 's' behaves as a TDes and would panic with USER 11 if the resulting </span> |
|
556 <a name="l00572"></a>00572 <span class="comment"> new length of s is greater than its maximum length.</span> |
|
557 <a name="l00573"></a>00573 <span class="comment"> */</span> |
|
558 <a name="l00574"></a>00574 <span class="keywordflow">if</span>(s.MaxLength() == 0) |
|
559 <a name="l00575"></a>00575 { |
|
560 <a name="l00576"></a>00576 <span class="comment">//LStrings are initialized by default to MaxLength 0</span> |
|
561 <a name="l00577"></a>00577 } |
|
562 <a name="l00578"></a>00578 |
|
563 <a name="l00579"></a>00579 <span class="comment">/*</span> |
|
564 <a name="l00580"></a>00580 <span class="comment"> Calling SetMaxLengthL() will automatically realloc the</span> |
|
565 <a name="l00581"></a>00581 <span class="comment"> underlying buffer if required, and is guaranteed to leave</span> |
|
566 <a name="l00582"></a>00582 <span class="comment"> MaxLength() equal to the specified value</span> |
|
567 <a name="l00583"></a>00583 <span class="comment"> */</span> |
|
568 <a name="l00584"></a>00584 s.SetMaxLengthL(KMaxFileName); |
|
569 <a name="l00585"></a>00585 GetCurrentPath(s); |
|
570 <a name="l00586"></a>00586 _LIT(KTxtPrintPath,<span class="stringliteral">"Path: %S\n"</span>); |
|
571 <a name="l00587"></a>00587 gConsole->Printf(KTxtPrintPath, &s); |
|
572 <a name="l00588"></a>00588 <span class="keywordflow">if</span>(s == KPath) |
|
573 <a name="l00589"></a>00589 { |
|
574 <a name="l00590"></a>00590 <span class="comment">//String comparison is successful</span> |
|
575 <a name="l00591"></a>00591 } |
|
576 <a name="l00592"></a>00592 |
|
577 <a name="l00593"></a>00593 <span class="comment">/*</span> |
|
578 <a name="l00594"></a>00594 <span class="comment"> If SetMaxLengthL() adjusts MaxLength() to be lower than the current</span> |
|
579 <a name="l00595"></a>00595 <span class="comment"> Length(), the data is truncated to the new MaxLength() and</span> |
|
580 <a name="l00596"></a>00596 <span class="comment"> Length() set to the new MaxLength().</span> |
|
581 <a name="l00597"></a>00597 <span class="comment"> */</span> |
|
582 <a name="l00598"></a>00598 s.SetMaxLengthL(s.Length() / 2); |
|
583 <a name="l00599"></a>00599 _LIT(KTxtTruncatedPath,<span class="stringliteral">"Truncated path: %S\n"</span>); |
|
584 <a name="l00600"></a>00600 gConsole->Printf(KTxtTruncatedPath, &s); |
|
585 <a name="l00601"></a>00601 <span class="keywordflow">if</span>(s.Length() == s.MaxLength()) |
|
586 <a name="l00602"></a>00602 { |
|
587 <a name="l00603"></a>00603 <span class="comment">//String comparison is successful</span> |
|
588 <a name="l00604"></a>00604 } |
|
589 <a name="l00605"></a>00605 |
|
590 <a name="l00606"></a>00606 <span class="comment">/*</span> |
|
591 <a name="l00607"></a>00607 <span class="comment"> An initial MaxLength() can be specified when constructing an</span> |
|
592 <a name="l00608"></a>00608 <span class="comment"> LString. Note that unlike the default constructor, this</span> |
|
593 <a name="l00609"></a>00609 <span class="comment"> variant allocates and may leave.</span> |
|
594 <a name="l00610"></a>00610 <span class="comment"> */</span> |
|
595 <a name="l00611"></a>00611 LString s2(KMaxFileName); |
|
596 <a name="l00612"></a>00612 GetCurrentPath(s2); |
|
597 <a name="l00613"></a>00613 gConsole->Printf(KTxtPrintPath, &s2); |
|
598 <a name="l00614"></a>00614 <span class="keywordflow">if</span>(s2 == KPath) |
|
599 <a name="l00615"></a>00615 { |
|
600 <a name="l00616"></a>00616 <span class="comment">//String comparison is successful</span> |
|
601 <a name="l00617"></a>00617 } |
|
602 <a name="l00618"></a>00618 |
|
603 <a name="l00619"></a>00619 <span class="comment">/*</span> |
|
604 <a name="l00620"></a>00620 <span class="comment"> Your code and APIs can benefit from LString's auto-growth</span> |
|
605 <a name="l00621"></a>00621 <span class="comment"> behaviour by accepting an LString to fill in as an output</span> |
|
606 <a name="l00622"></a>00622 <span class="comment"> parameter. Using LString rather than TDes parameters means </span> |
|
607 <a name="l00623"></a>00623 <span class="comment"> that the function is able to safely increase the size of the </span> |
|
608 <a name="l00624"></a>00624 <span class="comment"> string as the LString will re-allocate as necessary</span> |
|
609 <a name="l00625"></a>00625 <span class="comment"> */</span> |
|
610 <a name="l00626"></a>00626 LString s3; |
|
611 <a name="l00627"></a>00627 <span class="comment">// GetCurrentPathString() takes an LString&</span> |
|
612 <a name="l00628"></a>00628 GetCurrentPathString(s3); |
|
613 <a name="l00629"></a>00629 gConsole->Printf(KTxtPrintPath, &s3); |
|
614 <a name="l00630"></a>00630 <span class="keywordflow">if</span>(s3 == KPath) |
|
615 <a name="l00631"></a>00631 { |
|
616 <a name="l00632"></a>00632 <span class="comment">//String comparison is successful</span> |
|
617 <a name="l00633"></a>00633 } |
|
618 <a name="l00634"></a>00634 |
|
619 <a name="l00635"></a>00635 <span class="comment">/*</span> |
|
620 <a name="l00636"></a>00636 <span class="comment"> As a well-defined value class, if you want to, LStrings can</span> |
|
621 <a name="l00637"></a>00637 <span class="comment"> be passed and returned by value. This is relatively</span> |
|
622 <a name="l00638"></a>00638 <span class="comment"> inefficient however due to the amount of copying and heap</span> |
|
623 <a name="l00639"></a>00639 <span class="comment"> reallocation involved. </span> |
|
624 <a name="l00640"></a>00640 <span class="comment"> */</span> |
|
625 <a name="l00641"></a>00641 LString s4(AppendCurrentPathStringL(s3)); |
|
626 <a name="l00642"></a>00642 _LIT(KTxtAppendedPath,<span class="stringliteral">"Appended path: %S\n"</span>); |
|
627 <a name="l00643"></a>00643 gConsole->Printf(KTxtAppendedPath, &s4); |
|
628 <a name="l00644"></a>00644 <span class="keywordflow">if</span>(s4.Length() == s3.Length() * 2) |
|
629 <a name="l00645"></a>00645 { |
|
630 <a name="l00646"></a>00646 <span class="comment">//String comparison is successful</span> |
|
631 <a name="l00647"></a>00647 } |
|
632 <a name="l00648"></a>00648 } |
|
633 <a name="l00649"></a>00649 |
|
634 <a name="l00650"></a>00650 { |
|
635 <a name="l00651"></a>00651 <span class="comment">/*</span> |
|
636 <a name="l00652"></a>00652 <span class="comment"> LStrings can be allocated on the heap if necessary. </span> |
|
637 <a name="l00653"></a>00653 <span class="comment"> Then it can managed as part of an array of string pointers.</span> |
|
638 <a name="l00654"></a>00654 <span class="comment"> */</span> |
|
639 <a name="l00655"></a>00655 TInt n = 5; |
|
640 <a name="l00656"></a>00656 LCleanedupHandle<RPointerArray<LString>, TResetAndDestroy> sarray; |
|
641 <a name="l00657"></a>00657 |
|
642 <a name="l00658"></a>00658 <span class="keywordflow">for</span> (TInt i = 0; i < n; ++i) |
|
643 <a name="l00659"></a>00659 { |
|
644 <a name="l00660"></a>00660 LString* s = <span class="keyword">new</span>(ELeave) LString; |
|
645 <a name="l00661"></a>00661 s->FormatL(KTxtFormatString, i); |
|
646 <a name="l00662"></a>00662 sarray->Append(s); |
|
647 <a name="l00663"></a>00663 } |
|
648 <a name="l00664"></a>00664 |
|
649 <a name="l00665"></a>00665 <span class="keywordflow">for</span> (TInt i = 0, n = sarray->Count(); i < n; ++i) |
|
650 <a name="l00666"></a>00666 { |
|
651 <a name="l00667"></a>00667 LString tmp; |
|
652 <a name="l00668"></a>00668 tmp.FormatL(KTxtFormatString, i); |
|
653 <a name="l00669"></a>00669 <span class="keywordflow">if</span>(tmp == *(*sarray)[i]) |
|
654 <a name="l00670"></a>00670 { |
|
655 <a name="l00671"></a>00671 |
|
656 <a name="l00672"></a>00672 } |
|
657 <a name="l00673"></a>00673 gConsole->Printf(KTxtPrintString, i, (*sarray)[i]); |
|
658 <a name="l00674"></a>00674 } |
|
659 <a name="l00675"></a>00675 |
|
660 <a name="l00676"></a>00676 } |
|
661 <a name="l00677"></a>00677 |
|
662 <a name="l00678"></a>00678 { |
|
663 <a name="l00679"></a>00679 <span class="comment">/*</span> |
|
664 <a name="l00680"></a>00680 <span class="comment"> Any allocation failure in new(ELeave)LString throws</span> |
|
665 <a name="l00681"></a>00681 <span class="comment"> KErrNoMemory and cleans up fully after itself.</span> |
|
666 <a name="l00682"></a>00682 <span class="comment"> */</span> |
|
667 <a name="l00683"></a>00683 |
|
668 <a name="l00684"></a>00684 __UHEAP_MARK; |
|
669 <a name="l00685"></a>00685 TRAPD(status, <span class="keyword">new</span>(ELeave) LString(100 * 1024 * 1024)); |
|
670 <a name="l00686"></a>00686 <span class="keywordflow">if</span>(status == KErrNoMemory) |
|
671 <a name="l00687"></a>00687 { |
|
672 <a name="l00688"></a>00688 <span class="comment">//cleans up after itself fully, there is no need to take any further action.</span> |
|
673 <a name="l00689"></a>00689 } |
|
674 <a name="l00690"></a>00690 __UHEAP_MARKEND; |
|
675 <a name="l00691"></a>00691 } |
|
676 <a name="l00692"></a>00692 |
|
677 <a name="l00693"></a>00693 { |
|
678 <a name="l00694"></a>00694 <span class="comment">/*</span> |
|
679 <a name="l00695"></a>00695 <span class="comment"> Native C arrays (both heap and stack allocated) of LStrings</span> |
|
680 <a name="l00696"></a>00696 <span class="comment"> also work, although their use is not recommended.</span> |
|
681 <a name="l00697"></a>00697 <span class="comment"> */</span> |
|
682 <a name="l00698"></a>00698 |
|
683 <a name="l00699"></a>00699 TInt n = 5; |
|
684 <a name="l00700"></a>00700 LCleanedupArray<LString> sarray(<span class="keyword">new</span>(ELeave) LString[n]); |
|
685 <a name="l00701"></a>00701 |
|
686 <a name="l00702"></a>00702 <span class="keywordflow">for</span> (TInt i = 0; i < n; ++i) |
|
687 <a name="l00703"></a>00703 { |
|
688 <a name="l00704"></a>00704 sarray[i].FormatL(KTxtFormatString, i); |
|
689 <a name="l00705"></a>00705 } |
|
690 <a name="l00706"></a>00706 |
|
691 <a name="l00707"></a>00707 <span class="keywordflow">for</span> (TInt i = 0; i < n; ++i) |
|
692 <a name="l00708"></a>00708 { |
|
693 <a name="l00709"></a>00709 LString tmp; |
|
694 <a name="l00710"></a>00710 tmp.FormatL(KTxtFormatString, i); |
|
695 <a name="l00711"></a>00711 <span class="keywordflow">if</span>(tmp == sarray[i]) |
|
696 <a name="l00712"></a>00712 { |
|
697 <a name="l00713"></a>00713 <span class="comment">//comparison of strings is successful</span> |
|
698 <a name="l00714"></a>00714 } |
|
699 <a name="l00715"></a>00715 gConsole->Printf(KTxtPrintString, i, &sarray[i]); |
|
700 <a name="l00716"></a>00716 } |
|
701 <a name="l00717"></a>00717 |
|
702 <a name="l00718"></a>00718 } |
|
703 <a name="l00719"></a>00719 |
|
704 <a name="l00720"></a>00720 } |
|
705 <a name="l00721"></a>00721 |
|
706 <a name="l00727"></a>00727 <span class="keyword">class </span>CManagedUserTwoPhase : <span class="keyword">public</span> CBase |
|
707 <a name="l00728"></a>00728 { |
|
708 <a name="l00729"></a>00729 <span class="keyword">public</span>: |
|
709 <a name="l00730"></a>00730 <span class="keyword">static</span> CManagedUserTwoPhase* NewL(CTicker* aTicker) |
|
710 <a name="l00731"></a>00731 { |
|
711 <a name="l00732"></a>00732 <span class="comment">/*</span> |
|
712 <a name="l00733"></a>00733 <span class="comment"> We can use the resource management utility classes in</span> |
|
713 <a name="l00734"></a>00734 <span class="comment"> two-phase if we want to.</span> |
|
714 <a name="l00735"></a>00735 <span class="comment"> */</span> |
|
715 <a name="l00736"></a>00736 LCleanedupPtr<CManagedUserTwoPhase> <span class="keyword">self</span>(<span class="keyword">new</span>(ELeave) CManagedUserTwoPhase); |
|
716 <a name="l00737"></a>00737 <span class="keyword">self</span>->ConstructL(aTicker); |
|
717 <a name="l00738"></a>00738 <span class="comment">/*</span> |
|
718 <a name="l00739"></a>00739 <span class="comment"> Calling Unmanage() disables cleanup and yields the</span> |
|
719 <a name="l00740"></a>00740 <span class="comment"> previously managed pointer so that it can be safely</span> |
|
720 <a name="l00741"></a>00741 <span class="comment"> returned.</span> |
|
721 <a name="l00742"></a>00742 <span class="comment"> */</span> |
|
722 <a name="l00743"></a>00743 <span class="keywordflow">return</span> <span class="keyword">self</span>.Unmanage(); |
|
723 <a name="l00744"></a>00744 } |
|
724 <a name="l00745"></a>00745 |
|
725 <a name="l00746"></a>00746 ~CManagedUserTwoPhase() |
|
726 <a name="l00747"></a>00747 { |
|
727 <a name="l00748"></a>00748 <span class="comment">/*</span> |
|
728 <a name="l00749"></a>00749 <span class="comment"> The iTicker manager will automatically delete the CTicker</span> |
|
729 <a name="l00750"></a>00750 <span class="comment"> The iTimer manager will automatically Close() the RTimer.</span> |
|
730 <a name="l00751"></a>00751 <span class="comment"> */</span> |
|
731 <a name="l00752"></a>00752 } |
|
732 <a name="l00753"></a>00753 |
|
733 <a name="l00754"></a>00754 CTicker& Ticker() |
|
734 <a name="l00755"></a>00755 { |
|
735 <a name="l00756"></a>00756 <span class="comment">// If we dereference the management object we get a CTicker&.</span> |
|
736 <a name="l00757"></a>00757 <span class="keywordflow">return</span> *iTicker; |
|
737 <a name="l00758"></a>00758 } |
|
738 <a name="l00759"></a>00759 |
|
739 <a name="l00760"></a>00760 RTimer& Timer() |
|
740 <a name="l00761"></a>00761 { |
|
741 <a name="l00762"></a>00762 <span class="comment">// If we dereference the management object we get an RTimer&.</span> |
|
742 <a name="l00763"></a>00763 <span class="keywordflow">return</span> *iTimer; |
|
743 <a name="l00764"></a>00764 } |
|
744 <a name="l00765"></a>00765 |
|
745 <a name="l00766"></a>00766 <span class="keyword">private</span>: |
|
746 <a name="l00767"></a>00767 |
|
747 <a name="l00768"></a>00768 <span class="keyword">virtual</span> <span class="keywordtype">void</span> ConstructL(CTicker* aTicker) |
|
748 <a name="l00769"></a>00769 { |
|
749 <a name="l00770"></a>00770 <span class="comment">// Take ownership and manage aTicker.</span> |
|
750 <a name="l00771"></a>00771 iTicker = aTicker; |
|
751 <a name="l00772"></a>00772 |
|
752 <a name="l00773"></a>00773 <span class="comment">// Note use of -> to indirect through the management wrapper.</span> |
|
753 <a name="l00774"></a>00774 iTimer->CreateLocal() OR_LEAVE; |
|
754 <a name="l00775"></a>00775 } |
|
755 <a name="l00776"></a>00776 |
|
756 <a name="l00777"></a>00777 CManagedUserTwoPhase() |
|
757 <a name="l00778"></a>00778 { |
|
758 <a name="l00779"></a>00779 <span class="comment">/*</span> |
|
759 <a name="l00780"></a>00780 <span class="comment"> Everything interesting happens in ConstructL() in this</span> |
|
760 <a name="l00781"></a>00781 <span class="comment"> version. </span> |
|
761 <a name="l00782"></a>00782 <span class="comment"></span> |
|
762 <a name="l00783"></a>00783 <span class="comment"> Default initialization of the iName LString does not</span> |
|
763 <a name="l00784"></a>00784 <span class="comment"> allocate a heap buffer, and so cannot leave. As long as</span> |
|
764 <a name="l00785"></a>00785 <span class="comment"> initialization is deferred to ConstructL(), LStrings can be</span> |
|
765 <a name="l00786"></a>00786 <span class="comment"> used safely with two-phase construction.</span> |
|
766 <a name="l00787"></a>00787 <span class="comment"> */</span> |
|
767 <a name="l00788"></a>00788 } |
|
768 <a name="l00789"></a>00789 |
|
769 <a name="l00790"></a>00790 <span class="keyword">private</span>: |
|
770 <a name="l00791"></a>00791 <span class="comment">// We have to use LManagedXxx for fields, not LCleanedupXxx</span> |
|
771 <a name="l00792"></a>00792 LManagedPtr<CTicker> iTicker; |
|
772 <a name="l00793"></a>00793 LManagedHandle<RTimer> iTimer; |
|
773 <a name="l00794"></a>00794 }; |
|
774 <a name="l00795"></a>00795 |
|
775 <a name="l00808"></a>00808 <span class="keyword">class </span>CManagedUserSinglePhase : <span class="keyword">public</span> CBase |
|
776 <a name="l00809"></a>00809 { |
|
777 <a name="l00810"></a>00810 <span class="keyword">public</span>: |
|
778 <a name="l00811"></a>00811 <span class="comment">/*</span> |
|
779 <a name="l00812"></a>00812 <span class="comment"> This macro is necessary to ensure cleanup is correctly handled</span> |
|
780 <a name="l00813"></a>00813 <span class="comment"> in the event that a constructor may leave beneath a call to</span> |
|
781 <a name="l00814"></a>00814 <span class="comment"> new(ELeave)</span> |
|
782 <a name="l00815"></a>00815 <span class="comment"> */</span> |
|
783 <a name="l00816"></a>00816 CONSTRUCTORS_MAY_LEAVE |
|
784 <a name="l00817"></a>00817 |
|
785 <a name="l00818"></a>00818 <span class="keyword">static</span> CManagedUserSinglePhase* NewL(CTicker* aTicker) |
|
786 <a name="l00819"></a>00819 { |
|
787 <a name="l00820"></a>00820 <span class="keywordflow">return</span> <span class="keyword">new</span>(ELeave) CManagedUserSinglePhase(aTicker); |
|
788 <a name="l00821"></a>00821 } |
|
789 <a name="l00822"></a>00822 |
|
790 <a name="l00823"></a>00823 ~CManagedUserSinglePhase() |
|
791 <a name="l00824"></a>00824 { |
|
792 <a name="l00825"></a>00825 <span class="comment">/*</span> |
|
793 <a name="l00826"></a>00826 <span class="comment"> The iTicker manager destructor will automatically Zap() the CTicker.</span> |
|
794 <a name="l00827"></a>00827 <span class="comment"> The iTimer manager destructor will automatically Close() the RTimer.</span> |
|
795 <a name="l00828"></a>00828 <span class="comment"> */</span> |
|
796 <a name="l00829"></a>00829 } |
|
797 <a name="l00830"></a>00830 |
|
798 <a name="l00831"></a>00831 CTicker& Ticker() |
|
799 <a name="l00832"></a>00832 { |
|
800 <a name="l00833"></a>00833 <span class="comment">// If we dereference the management object we get a CTicker&.</span> |
|
801 <a name="l00834"></a>00834 <span class="keywordflow">return</span> *iTicker; |
|
802 <a name="l00835"></a>00835 } |
|
803 <a name="l00836"></a>00836 |
|
804 <a name="l00837"></a>00837 RTimer& Timer() |
|
805 <a name="l00838"></a>00838 { |
|
806 <a name="l00839"></a>00839 <span class="comment">// If we dereference the management object we get an RTimer&.</span> |
|
807 <a name="l00840"></a>00840 <span class="keywordflow">return</span> *iTimer; |
|
808 <a name="l00841"></a>00841 } |
|
809 <a name="l00842"></a>00842 |
|
810 <a name="l00843"></a>00843 <span class="keyword">private</span>: |
|
811 <a name="l00844"></a>00844 CManagedUserSinglePhase(CTicker* aTicker) |
|
812 <a name="l00845"></a>00845 <span class="comment">/*</span> |
|
813 <a name="l00846"></a>00846 <span class="comment"> Take ownership and manage aTicker. Note that initialization</span> |
|
814 <a name="l00847"></a>00847 <span class="comment"> of the LManagedXxx classes does not actually leave, but</span> |
|
815 <a name="l00848"></a>00848 <span class="comment"> initialization of the LCleanedupXxx classes can.</span> |
|
816 <a name="l00849"></a>00849 <span class="comment"> */</span> |
|
817 <a name="l00850"></a>00850 : iTicker(aTicker) |
|
818 <a name="l00851"></a>00851 { |
|
819 <a name="l00852"></a>00852 <span class="comment">/*</span> |
|
820 <a name="l00853"></a>00853 <span class="comment"> If iTicker initialization is successful but the constructor</span> |
|
821 <a name="l00854"></a>00854 <span class="comment"> then goes on to leave later, iTicker (like all fields fully</span> |
|
822 <a name="l00855"></a>00855 <span class="comment"> constructed at the point of a leave in a constructor) will</span> |
|
823 <a name="l00856"></a>00856 <span class="comment"> be destructed, and the manager will cleanup the CTicker.</span> |
|
824 <a name="l00857"></a>00857 <span class="comment"></span> |
|
825 <a name="l00858"></a>00858 <span class="comment"> Note use of -> to indirect through the management wrapper.</span> |
|
826 <a name="l00859"></a>00859 <span class="comment"> */</span> |
|
827 <a name="l00860"></a>00860 iTimer->CreateLocal(); |
|
828 <a name="l00861"></a>00861 |
|
829 <a name="l00862"></a>00862 <span class="comment">// Likewise if we leave here, both iTicker and iTimer will</span> |
|
830 <a name="l00863"></a>00863 <span class="comment">// undergo managed cleanup.</span> |
|
831 <a name="l00864"></a>00864 MaybeLeave(); |
|
832 <a name="l00865"></a>00865 } |
|
833 <a name="l00866"></a>00866 |
|
834 <a name="l00867"></a>00867 <span class="keyword">private</span>: |
|
835 <a name="l00868"></a>00868 <span class="comment">// We have to use LManagedXxx for fields, not LCleanedupXxx.</span> |
|
836 <a name="l00869"></a>00869 LManagedPtr<CTicker, TTickerZapStrategy> iTicker; |
|
837 <a name="l00870"></a>00870 LManagedHandle<RTimer> iTimer; |
|
838 <a name="l00871"></a>00871 }; |
|
839 <a name="l00872"></a>00872 |
|
840 <a name="l00873"></a>00873 <span class="comment">//Class definition of trivial R-Class</span> |
|
841 <a name="l00874"></a>00874 <span class="keyword">class </span>RSimple |
|
842 <a name="l00875"></a>00875 { |
|
843 <a name="l00876"></a>00876 <span class="keyword">public</span>: |
|
844 <a name="l00877"></a>00877 |
|
845 <a name="l00878"></a>00878 RSimple(){iData = NULL;} |
|
846 <a name="l00879"></a>00879 |
|
847 <a name="l00880"></a>00880 <span class="comment">//Open function sets value</span> |
|
848 <a name="l00881"></a>00881 <span class="keywordtype">void</span> OpenL(TInt aValue) |
|
849 <a name="l00882"></a>00882 { |
|
850 <a name="l00883"></a>00883 iData = <span class="keyword">new</span>(ELeave) TInt(aValue); |
|
851 <a name="l00884"></a>00884 } |
|
852 <a name="l00885"></a>00885 |
|
853 <a name="l00886"></a>00886 <span class="comment">//Cleanup function – frees resource</span> |
|
854 <a name="l00887"></a>00887 <span class="keywordtype">void</span> Close() |
|
855 <a name="l00888"></a>00888 { |
|
856 <a name="l00889"></a>00889 <span class="keyword">delete</span> iData; |
|
857 <a name="l00890"></a>00890 iData = NULL; |
|
858 <a name="l00891"></a>00891 } |
|
859 <a name="l00892"></a>00892 |
|
860 <a name="l00893"></a>00893 <span class="comment">//Cleanup function – frees resource</span> |
|
861 <a name="l00894"></a>00894 <span class="keywordtype">void</span> Free() |
|
862 <a name="l00895"></a>00895 { |
|
863 <a name="l00896"></a>00896 <span class="keyword">delete</span> iData; |
|
864 <a name="l00897"></a>00897 iData = NULL; |
|
865 <a name="l00898"></a>00898 } |
|
866 <a name="l00899"></a>00899 |
|
867 <a name="l00900"></a>00900 <span class="comment">//Cleanup function – frees resource</span> |
|
868 <a name="l00901"></a>00901 <span class="keywordtype">void</span> ReleaseData() |
|
869 <a name="l00902"></a>00902 { |
|
870 <a name="l00903"></a>00903 <span class="keyword">delete</span> iData; |
|
871 <a name="l00904"></a>00904 iData = NULL; |
|
872 <a name="l00905"></a>00905 } |
|
873 <a name="l00906"></a>00906 |
|
874 <a name="l00907"></a>00907 <span class="comment">//static cleanup function – frees aRSimple resources</span> |
|
875 <a name="l00908"></a>00908 <span class="keyword">static</span> <span class="keywordtype">void</span> Cleanup(TAny* aRSimple) |
|
876 <a name="l00909"></a>00909 { |
|
877 <a name="l00910"></a>00910 <span class="keyword">static_cast<</span>RSimple*<span class="keyword">></span>(aRSimple)->Close(); |
|
878 <a name="l00911"></a>00911 } |
|
879 <a name="l00912"></a>00912 |
|
880 <a name="l00913"></a>00913 |
|
881 <a name="l00914"></a>00914 <span class="keyword">private</span>: |
|
882 <a name="l00915"></a>00915 TInt* iData; |
|
883 <a name="l00916"></a>00916 |
|
884 <a name="l00917"></a>00917 }; |
|
885 <a name="l00918"></a>00918 |
|
886 <a name="l00919"></a>00919 |
|
887 <a name="l00926"></a>00926 DEFINE_CLEANUP_FUNCTION(RSimple, ReleaseData); |
|
888 <a name="l00927"></a>00927 |
|
889 <a name="l00928"></a>00928 |
|
890 <a name="l00929"></a>00929 <span class="keywordtype">void</span> WalkthroughManagedL() |
|
891 <a name="l00930"></a>00930 { |
|
892 <a name="l00931"></a>00931 _LIT(KTxtOption2,<span class="stringliteral">"Option2: Object creation and resource management using EUser high level library\n"</span>); |
|
893 <a name="l00932"></a>00932 gConsole->Printf(KTxtOption2); |
|
894 <a name="l00933"></a>00933 { |
|
895 <a name="l00934"></a>00934 <span class="comment">// Trivially exercise the manager-using classes defined above.</span> |
|
896 <a name="l00935"></a>00935 CTicker* ticker1 = <span class="keyword">new</span>(ELeave) CTicker; |
|
897 <a name="l00936"></a>00936 LCleanedupPtr<CManagedUserTwoPhase> one(CManagedUserTwoPhase::NewL(ticker1)); |
|
898 <a name="l00937"></a>00937 <span class="keywordflow">if</span>(&one->Ticker() == ticker1) |
|
899 <a name="l00938"></a>00938 { |
|
900 <a name="l00939"></a>00939 _LIT(KTxtLCleanedupPtrDemo1,<span class="stringliteral">"Creating an instance of CTicker using LCleanedupPtr\n"</span>); |
|
901 <a name="l00940"></a>00940 gConsole->Printf(KTxtLCleanedupPtrDemo1); |
|
902 <a name="l00941"></a>00941 } |
|
903 <a name="l00942"></a>00942 one->Timer().Cancel(); <span class="comment">// Just to check we can get at it</span> |
|
904 <a name="l00943"></a>00943 |
|
905 <a name="l00944"></a>00944 CTicker* ticker2 = <span class="keyword">new</span>(ELeave) CTicker; |
|
906 <a name="l00945"></a>00945 LCleanedupPtr<CManagedUserSinglePhase> two(CManagedUserSinglePhase::NewL(ticker2)); |
|
907 <a name="l00946"></a>00946 <span class="keywordflow">if</span>(&two->Ticker() == ticker2) |
|
908 <a name="l00947"></a>00947 { |
|
909 <a name="l00948"></a>00948 _LIT(KTxtLCleanedupPtrDemo2,<span class="stringliteral">"Creating second instance of CTicker using LCleanedupPtr\n"</span>); |
|
910 <a name="l00949"></a>00949 gConsole->Printf(KTxtLCleanedupPtrDemo2); |
|
911 <a name="l00950"></a>00950 } |
|
912 <a name="l00951"></a>00951 two->Timer().Cancel(); <span class="comment">// Just to check we can get at it</span> |
|
913 <a name="l00952"></a>00952 _LIT(KTxtLCleanedupPtr,<span class="stringliteral">"Both instances are automatically deleted as we go out of scope\n"</span>); |
|
914 <a name="l00953"></a>00953 gConsole->Printf(KTxtLCleanedupPtr); |
|
915 <a name="l00954"></a>00954 gConsole->Printf(KTxtPressAnyKeyToContinue); |
|
916 <a name="l00955"></a>00955 gConsole->Getch(); |
|
917 <a name="l00956"></a>00956 } |
|
918 <a name="l00957"></a>00957 |
|
919 <a name="l00958"></a>00958 <span class="comment">// Always use LCleanedupXxx for locals, not LManagedXxx</span> |
|
920 <a name="l00959"></a>00959 |
|
921 <a name="l00960"></a>00960 { |
|
922 <a name="l00961"></a>00961 <span class="comment">/*</span> |
|
923 <a name="l00962"></a>00962 <span class="comment"> Behind the scenes the LCleanedupXxx constructors push a</span> |
|
924 <a name="l00963"></a>00963 <span class="comment"> cleanup item onto the cleanup stack and so may leave. If</span> |
|
925 <a name="l00964"></a>00964 <span class="comment"> there is a leave during construction, the supplied pointer</span> |
|
926 <a name="l00965"></a>00965 <span class="comment"> will still get cleaned up.</span> |
|
927 <a name="l00966"></a>00966 <span class="comment"> */</span> |
|
928 <a name="l00967"></a>00967 LCleanedupPtr<CTicker> t(<span class="keyword">new</span>(ELeave) CTicker); |
|
929 <a name="l00968"></a>00968 |
|
930 <a name="l00969"></a>00969 <span class="comment">/*</span> |
|
931 <a name="l00970"></a>00970 <span class="comment"> We can access CTicker's members via the management object</span> |
|
932 <a name="l00971"></a>00971 <span class="comment"> using -></span> |
|
933 <a name="l00972"></a>00972 <span class="comment"> */</span> |
|
934 <a name="l00973"></a>00973 t->Tick(); |
|
935 <a name="l00974"></a>00974 t->Tock(); |
|
936 <a name="l00975"></a>00975 <span class="keywordflow">if</span>(t->iTicks == t->iTocks) |
|
937 <a name="l00976"></a>00976 { |
|
938 <a name="l00977"></a>00977 _LIT(KTxtLCleanedupPtrDemo3,<span class="stringliteral">"CTicker members access using LCleanedupPtr is successful\n"</span>); |
|
939 <a name="l00978"></a>00978 gConsole->Printf(KTxtLCleanedupPtrDemo3); |
|
940 <a name="l00979"></a>00979 gConsole->Printf(KTxtPressAnyKeyToContinue); |
|
941 <a name="l00980"></a>00980 gConsole->Getch(); |
|
942 <a name="l00981"></a>00981 } |
|
943 <a name="l00982"></a>00982 |
|
944 <a name="l00983"></a>00983 <span class="comment">/*</span> |
|
945 <a name="l00984"></a>00984 <span class="comment"> We can get at a reference to the managed object using *</span> |
|
946 <a name="l00985"></a>00985 <span class="comment"> when we need to, e.g. if we need to pass it to a function.</span> |
|
947 <a name="l00986"></a>00986 <span class="comment"> */</span> |
|
948 <a name="l00987"></a>00987 RegisterTicker(*t); <span class="comment">// Takes a CTicker&</span> |
|
949 <a name="l00988"></a>00988 |
|
950 <a name="l00989"></a>00989 <span class="comment">/*</span> |
|
951 <a name="l00990"></a>00990 <span class="comment"> If some unfriendly interface needs a pointer rather than a</span> |
|
952 <a name="l00991"></a>00991 <span class="comment"> ref, we have a couple of options.</span> |
|
953 <a name="l00992"></a>00992 <span class="comment"> */</span> |
|
954 <a name="l00993"></a>00993 RegisterTickerPtr(&*t); <span class="comment">// Takes a CTicker*</span> |
|
955 <a name="l00994"></a>00994 RegisterTickerPtr(t.Get()); <span class="comment">// Takes a CTicker*</span> |
|
956 <a name="l00995"></a>00995 |
|
957 <a name="l00996"></a>00996 <span class="comment">/*</span> |
|
958 <a name="l00997"></a>00997 <span class="comment"> Note the use of . in t.Get() above; this distinguishes</span> |
|
959 <a name="l00998"></a>00998 <span class="comment"> operations on the managing type from operations on the</span> |
|
960 <a name="l00999"></a>00999 <span class="comment"> managed object.</span> |
|
961 <a name="l01000"></a>01000 <span class="comment"> </span> |
|
962 <a name="l01001"></a>01001 <span class="comment"> When the management object goes out of scope, either</span> |
|
963 <a name="l01002"></a>01002 <span class="comment"> normally or as the result of a leave, the managed object is</span> |
|
964 <a name="l01003"></a>01003 <span class="comment"> automatically deleted.</span> |
|
965 <a name="l01004"></a>01004 <span class="comment"> */</span> |
|
966 <a name="l01005"></a>01005 } |
|
967 <a name="l01006"></a>01006 |
|
968 <a name="l01007"></a>01007 { |
|
969 <a name="l01008"></a>01008 <span class="comment">/*</span> |
|
970 <a name="l01009"></a>01009 <span class="comment"> Sometimes you need to protect something temporarily before</span> |
|
971 <a name="l01010"></a>01010 <span class="comment"> transferring ownership e.g. by returning the pointer or</span> |
|
972 <a name="l01011"></a>01011 <span class="comment"> passing it to a function that takes ownership.</span> |
|
973 <a name="l01012"></a>01012 <span class="comment"> */</span> |
|
974 <a name="l01013"></a>01013 |
|
975 <a name="l01014"></a>01014 LCleanedupPtr<CTicker> t(<span class="keyword">new</span>(ELeave) CTicker); |
|
976 <a name="l01015"></a>01015 |
|
977 <a name="l01016"></a>01016 <span class="comment">// Protected while we do this</span> |
|
978 <a name="l01017"></a>01017 MaybeLeave(); |
|
979 <a name="l01018"></a>01018 |
|
980 <a name="l01019"></a>01019 <span class="comment">/*</span> |
|
981 <a name="l01020"></a>01020 <span class="comment"> But now we want to hand it off, so we use Unmanage() to</span> |
|
982 <a name="l01021"></a>01021 <span class="comment"> both return a pointer and break the management link</span> |
|
983 <a name="l01022"></a>01022 <span class="comment"> */</span> |
|
984 <a name="l01023"></a>01023 TakeTickerOwnership(t.Unmanage()); |
|
985 <a name="l01024"></a>01024 |
|
986 <a name="l01025"></a>01025 <span class="comment">/*</span> |
|
987 <a name="l01026"></a>01026 <span class="comment"> Now when it goes out of scope, no cleanup action is</span> |
|
988 <a name="l01027"></a>01027 <span class="comment"> performed.</span> |
|
989 <a name="l01028"></a>01028 <span class="comment"> */</span> |
|
990 <a name="l01029"></a>01029 } |
|
991 <a name="l01030"></a>01030 |
|
992 <a name="l01031"></a>01031 { |
|
993 <a name="l01032"></a>01032 <span class="comment">/*</span> |
|
994 <a name="l01033"></a>01033 <span class="comment"> If needed, it is possible to reuse a manager by using = to</span> |
|
995 <a name="l01034"></a>01034 <span class="comment"> assign it a new managed object.</span> |
|
996 <a name="l01035"></a>01035 <span class="comment"> */</span> |
|
997 <a name="l01036"></a>01036 |
|
998 <a name="l01037"></a>01037 <span class="comment">// Not managing anything to start with</span> |
|
999 <a name="l01038"></a>01038 LCleanedupPtr<CTicker> t; |
|
1000 <a name="l01039"></a>01039 <span class="keywordflow">if</span>(t.Get() == NULL) |
|
1001 <a name="l01040"></a>01040 { |
|
1002 <a name="l01041"></a>01041 <span class="comment">//Successfully initialised to NULL</span> |
|
1003 <a name="l01042"></a>01042 } |
|
1004 <a name="l01043"></a>01043 <span class="keywordflow">if</span>(&*t == NULL) |
|
1005 <a name="l01044"></a>01044 { |
|
1006 <a name="l01045"></a>01045 <span class="comment">//CTicker* value is also NULL</span> |
|
1007 <a name="l01046"></a>01046 } |
|
1008 <a name="l01047"></a>01047 |
|
1009 <a name="l01048"></a>01048 <span class="keywordflow">for</span> (TInt i = 0; i < 10; ++i) |
|
1010 <a name="l01049"></a>01049 { |
|
1011 <a name="l01050"></a>01050 <span class="comment">/*</span> |
|
1012 <a name="l01051"></a>01051 <span class="comment"> If an object is already being managed, it is cleaned up</span> |
|
1013 <a name="l01052"></a>01052 <span class="comment"> before taking ownership of the new object.</span> |
|
1014 <a name="l01053"></a>01053 <span class="comment"> */</span> |
|
1015 <a name="l01054"></a>01054 t = <span class="keyword">new</span>(ELeave) CTicker; |
|
1016 <a name="l01055"></a>01055 } |
|
1017 <a name="l01056"></a>01056 <span class="comment">/*</span> |
|
1018 <a name="l01057"></a>01057 <span class="comment"> We're left owning the final ticker instance, all prior</span> |
|
1019 <a name="l01058"></a>01058 <span class="comment"> instances having been automatically deleted.</span> |
|
1020 <a name="l01059"></a>01059 <span class="comment"> */</span> |
|
1021 <a name="l01060"></a>01060 } |
|
1022 <a name="l01061"></a>01061 |
|
1023 <a name="l01062"></a>01062 { |
|
1024 <a name="l01063"></a>01063 <span class="comment">// If you have stateful code where a pointer can sometimes be NULL.</span> |
|
1025 <a name="l01064"></a>01064 LCleanedupPtr<CTicker> t(<span class="keyword">new</span>(ELeave) CTicker); |
|
1026 <a name="l01065"></a>01065 |
|
1027 <a name="l01066"></a>01066 <span class="comment">// Does t refer to NULL?</span> |
|
1028 <a name="l01067"></a>01067 <span class="keywordflow">if</span> (!t) |
|
1029 <a name="l01068"></a>01068 { |
|
1030 <a name="l01069"></a>01069 _LIT(KTxtNull,<span class="stringliteral">"LCleanedupPtr object refers to Null\n"</span> ); |
|
1031 <a name="l01070"></a>01070 gConsole->Printf(KTxtNull); |
|
1032 <a name="l01071"></a>01071 } |
|
1033 <a name="l01072"></a>01072 |
|
1034 <a name="l01073"></a>01073 t = NULL; <span class="comment">// Also releases the currently managed CTicker </span> |
|
1035 <a name="l01074"></a>01074 |
|
1036 <a name="l01075"></a>01075 <span class="comment">// Does t refer to a non-NULL pointer?</span> |
|
1037 <a name="l01076"></a>01076 <span class="keywordflow">if</span> (t) |
|
1038 <a name="l01077"></a>01077 { |
|
1039 <a name="l01078"></a>01078 _LIT(KTxtNonNull,<span class="stringliteral">"LCleanedupPtr object refers to Non Null pointer\n"</span> ); |
|
1040 <a name="l01079"></a>01079 gConsole->Printf(KTxtNonNull); |
|
1041 <a name="l01080"></a>01080 } |
|
1042 <a name="l01081"></a>01081 } |
|
1043 <a name="l01082"></a>01082 |
|
1044 <a name="l01083"></a>01083 { |
|
1045 <a name="l01084"></a>01084 <span class="comment">// LCleanedupPtr uses delete to cleanup by default, but alternative cleanups can be specified</span> |
|
1046 <a name="l01085"></a>01085 |
|
1047 <a name="l01086"></a>01086 <span class="comment">// We just want to free this one and not invoke the destructor</span> |
|
1048 <a name="l01087"></a>01087 LCleanedupPtr<CTicker, TPointerFree> t(static_cast<CTicker*>(User::AllocL(<span class="keyword">sizeof</span>(CTicker)))); |
|
1049 <a name="l01088"></a>01088 |
|
1050 <a name="l01089"></a>01089 <span class="comment">// Now User::Free() is called when t goes out of scope</span> |
|
1051 <a name="l01090"></a>01090 } |
|
1052 <a name="l01091"></a>01091 |
|
1053 <a name="l01092"></a>01092 { |
|
1054 <a name="l01093"></a>01093 <span class="comment">/*</span> |
|
1055 <a name="l01094"></a>01094 <span class="comment"> As well as the stock options, custom cleanup policies can</span> |
|
1056 <a name="l01095"></a>01095 <span class="comment"> also be defined. See above for the definition of</span> |
|
1057 <a name="l01096"></a>01096 <span class="comment"> TTickerZap.</span> |
|
1058 <a name="l01097"></a>01097 <span class="comment"> */</span> |
|
1059 <a name="l01098"></a>01098 LCleanedupPtr<CTicker, TTickerZapStrategy> t(<span class="keyword">new</span>(ELeave) CTicker); |
|
1060 <a name="l01099"></a>01099 |
|
1061 <a name="l01100"></a>01100 <span class="comment">// Now Zap() is called on the CTicker instance when t goes out of scope</span> |
|
1062 <a name="l01101"></a>01101 } |
|
1063 <a name="l01102"></a>01102 |
|
1064 <a name="l01103"></a>01103 { |
|
1065 <a name="l01104"></a>01104 <span class="comment">/*</span> |
|
1066 <a name="l01105"></a>01105 <span class="comment"> LCleanedupHandle is very similar in behaviour to</span> |
|
1067 <a name="l01106"></a>01106 <span class="comment"> LCleanedupPtr, the main difference being that it can define</span> |
|
1068 <a name="l01107"></a>01107 <span class="comment"> and contain its own instance of a handle rather than</span> |
|
1069 <a name="l01108"></a>01108 <span class="comment"> being supplied one.</span> |
|
1070 <a name="l01109"></a>01109 <span class="comment"> */</span> |
|
1071 <a name="l01110"></a>01110 LCleanedupHandle<RTimer> t; |
|
1072 <a name="l01111"></a>01111 |
|
1073 <a name="l01112"></a>01112 <span class="comment">// Again, access to managed handle members is via -></span> |
|
1074 <a name="l01113"></a>01113 t->CreateLocal() OR_LEAVE; |
|
1075 <a name="l01114"></a>01114 t->Cancel(); |
|
1076 <a name="l01115"></a>01115 |
|
1077 <a name="l01116"></a>01116 <span class="comment">//We can get a reference to the handle for passing to functions using *</span> |
|
1078 <a name="l01117"></a>01117 RegisterTimer(*t); |
|
1079 <a name="l01118"></a>01118 |
|
1080 <a name="l01119"></a>01119 <span class="comment">/*</span> |
|
1081 <a name="l01120"></a>01120 <span class="comment"> When the management object goes out of scope, either</span> |
|
1082 <a name="l01121"></a>01121 <span class="comment"> normally or as the result of a leave, the managed object is</span> |
|
1083 <a name="l01122"></a>01122 <span class="comment"> automatically cleanup by calling Close() on it.</span> |
|
1084 <a name="l01123"></a>01123 <span class="comment"> */</span> |
|
1085 <a name="l01124"></a>01124 } |
|
1086 <a name="l01125"></a>01125 |
|
1087 <a name="l01126"></a>01126 { |
|
1088 <a name="l01127"></a>01127 <span class="comment">/*</span> |
|
1089 <a name="l01128"></a>01128 <span class="comment"> LCleanedupHandle calls Close() by default, but alternative</span> |
|
1090 <a name="l01129"></a>01129 <span class="comment"> cleanups can be specified.</span> |
|
1091 <a name="l01130"></a>01130 <span class="comment"> </span> |
|
1092 <a name="l01131"></a>01131 <span class="comment"> We want this RPointerArray cleanup with with</span> |
|
1093 <a name="l01132"></a>01132 <span class="comment"> ResetAndDestroy instead of Close().</span> |
|
1094 <a name="l01133"></a>01133 <span class="comment"> */</span> |
|
1095 <a name="l01134"></a>01134 LCleanedupHandle<RPointerArray<HBufC>, TResetAndDestroy> array; |
|
1096 <a name="l01135"></a>01135 <span class="keywordflow">for</span> (TInt i = 0; i < 10; ++i) |
|
1097 <a name="l01136"></a>01136 { |
|
1098 <a name="l01137"></a>01137 array->AppendL(HBufC::NewL(5)); |
|
1099 <a name="l01138"></a>01138 } |
|
1100 <a name="l01139"></a>01139 |
|
1101 <a name="l01140"></a>01140 <span class="comment">//Now when array goes out of scope, ResetAndDestroy is called to clean it up.</span> |
|
1102 <a name="l01141"></a>01141 } |
|
1103 <a name="l01142"></a>01142 |
|
1104 <a name="l01143"></a>01143 { |
|
1105 <a name="l01144"></a>01144 <span class="comment">/*</span> |
|
1106 <a name="l01145"></a>01145 <span class="comment"> As well as the stock options, custom cleanup policies can</span> |
|
1107 <a name="l01146"></a>01146 <span class="comment"> also be defined. See above for the definition of TCancelClose.</span> |
|
1108 <a name="l01147"></a>01147 <span class="comment"> */</span> |
|
1109 <a name="l01148"></a>01148 LCleanedupHandle<RTimer, TCancelClose> t; |
|
1110 <a name="l01149"></a>01149 t->CreateLocal(); |
|
1111 <a name="l01150"></a>01150 |
|
1112 <a name="l01151"></a>01151 <span class="comment">// Now Cancel() followed by Close() are called when t goes out of scope</span> |
|
1113 <a name="l01152"></a>01152 } |
|
1114 <a name="l01153"></a>01153 |
|
1115 <a name="l01154"></a>01154 |
|
1116 <a name="l01155"></a>01155 { |
|
1117 <a name="l01156"></a>01156 <span class="comment">/*</span> |
|
1118 <a name="l01157"></a>01157 <span class="comment"> LCleanedupHandleRef calls Close() by default, but alternative</span> |
|
1119 <a name="l01158"></a>01158 <span class="comment"> cleanups can be specified.</span> |
|
1120 <a name="l01159"></a>01159 <span class="comment"> </span> |
|
1121 <a name="l01160"></a>01160 <span class="comment"> We want this RPointerArray cleanup with</span> |
|
1122 <a name="l01161"></a>01161 <span class="comment"> ResetAndDestroy instead of Close().</span> |
|
1123 <a name="l01162"></a>01162 <span class="comment"> */</span> |
|
1124 <a name="l01163"></a>01163 RPointerArray<HBufC> rar; |
|
1125 <a name="l01164"></a>01164 <span class="comment">// calls to functions that cannot leave here</span> |
|
1126 <a name="l01165"></a>01165 rar.Append(HBufC::NewL(5)); |
|
1127 <a name="l01166"></a>01166 rar.Append(HBufC::NewL(5)); |
|
1128 <a name="l01167"></a>01167 |
|
1129 <a name="l01168"></a>01168 |
|
1130 <a name="l01169"></a>01169 LCleanedupRef<RPointerArray<HBufC>, TResetAndDestroy> array(rar); |
|
1131 <a name="l01170"></a>01170 <span class="comment">// calls to functions that could leave here</span> |
|
1132 <a name="l01171"></a>01171 <span class="keywordflow">for</span> (TInt i = 0; i < 10; ++i) |
|
1133 <a name="l01172"></a>01172 { |
|
1134 <a name="l01173"></a>01173 array->AppendL(HBufC::NewL(5)); |
|
1135 <a name="l01174"></a>01174 } |
|
1136 <a name="l01175"></a>01175 |
|
1137 <a name="l01176"></a>01176 <span class="comment">// Now when array goes out of scope, ResetAndDestroy is called to clean it up</span> |
|
1138 <a name="l01177"></a>01177 } |
|
1139 <a name="l01178"></a>01178 |
|
1140 <a name="l01179"></a>01179 { |
|
1141 <a name="l01180"></a>01180 <span class="comment">/*</span> |
|
1142 <a name="l01181"></a>01181 <span class="comment"> Never mix direct cleanup stack API calls with management</span> |
|
1143 <a name="l01182"></a>01182 <span class="comment"> class use within the same function, because their</span> |
|
1144 <a name="l01183"></a>01183 <span class="comment"> interaction can be confusing and counter-intuitive. Avoid</span> |
|
1145 <a name="l01184"></a>01184 <span class="comment"> the use of LC methods that leave objects on the cleanup</span> |
|
1146 <a name="l01185"></a>01185 <span class="comment"> stack, and use L methods instead.</span> |
|
1147 <a name="l01186"></a>01186 <span class="comment"></span> |
|
1148 <a name="l01187"></a>01187 <span class="comment"> If a badly-behaved API were to offer only an LC variant,</span> |
|
1149 <a name="l01188"></a>01188 <span class="comment"> you would have to use it as follows</span> |
|
1150 <a name="l01189"></a>01189 <span class="comment"> */</span> |
|
1151 <a name="l01190"></a>01190 HBufC* raw = HBufC::NewLC(5); |
|
1152 <a name="l01191"></a>01191 <span class="comment">// Must pop immediately to balance the cleanup stack, before instantiating the manager</span> |
|
1153 <a name="l01192"></a>01192 CleanupStack::Pop(); |
|
1154 <a name="l01193"></a>01193 LCleanedupPtr<HBufC> wrapped(raw); |
|
1155 <a name="l01194"></a>01194 |
|
1156 <a name="l01195"></a>01195 <span class="comment">/*</span> |
|
1157 <a name="l01196"></a>01196 <span class="comment"> Never do this:</span> |
|
1158 <a name="l01197"></a>01197 <span class="comment"> LCleanedupPtr<HBufC> buf(HBufC::NewLC(5));</span> |
|
1159 <a name="l01198"></a>01198 <span class="comment"> CleanupStack::Pop();</span> |
|
1160 <a name="l01199"></a>01199 <span class="comment"> because the manager will be popped (having been pushed</span> |
|
1161 <a name="l01200"></a>01200 <span class="comment"> last), not the raw buf pointer as you might have hoped</span> |
|
1162 <a name="l01201"></a>01201 <span class="comment"></span> |
|
1163 <a name="l01202"></a>01202 <span class="comment"> A cleaner alternative may be to write your own L function</span> |
|
1164 <a name="l01203"></a>01203 <span class="comment"> wrapper around the LC function supplied.</span> |
|
1165 <a name="l01204"></a>01204 <span class="comment"></span> |
|
1166 <a name="l01205"></a>01205 <span class="comment"> Luckily this situation (an LC method without a</span> |
|
1167 <a name="l01206"></a>01206 <span class="comment"> corresponding L method) is rare in practice.</span> |
|
1168 <a name="l01207"></a>01207 <span class="comment"> */</span> |
|
1169 <a name="l01208"></a>01208 } |
|
1170 <a name="l01209"></a>01209 |
|
1171 <a name="l01210"></a>01210 { |
|
1172 <a name="l01211"></a>01211 <span class="comment">// Although rarely used on Symbian platform, C++ arrays are supported with a custom management class</span> |
|
1173 <a name="l01212"></a>01212 LCleanedupArray<CTicker> array(<span class="keyword">new</span> CTicker[5]); |
|
1174 <a name="l01213"></a>01213 |
|
1175 <a name="l01214"></a>01214 <span class="comment">// The array is cleaned up with delete[] on scope exit</span> |
|
1176 <a name="l01215"></a>01215 } |
|
1177 <a name="l01216"></a>01216 |
|
1178 <a name="l01217"></a>01217 { |
|
1179 <a name="l01218"></a>01218 <span class="comment">/*</span> |
|
1180 <a name="l01219"></a>01219 <span class="comment"> Although most cases are best covered by applying custom</span> |
|
1181 <a name="l01220"></a>01220 <span class="comment"> cleanup policies to the management classes already</span> |
|
1182 <a name="l01221"></a>01221 <span class="comment"> described, there is also a general TCleanupItem style</span> |
|
1183 <a name="l01222"></a>01222 <span class="comment"> cleanup option.</span> |
|
1184 <a name="l01223"></a>01223 <span class="comment"> */</span> |
|
1185 <a name="l01224"></a>01224 TAny* data = NULL; <span class="comment">// But could be anything</span> |
|
1186 <a name="l01225"></a>01225 LCleanedupGuard guard1(BespokeCleanupFunction, data); |
|
1187 <a name="l01226"></a>01226 <span class="comment">// On scope exit BespokeCleanupFunction() is called on data.</span> |
|
1188 <a name="l01227"></a>01227 |
|
1189 <a name="l01228"></a>01228 LCleanedupGuard guard2(BespokeCleanupFunction, data); |
|
1190 <a name="l01229"></a>01229 <span class="comment">// But cleanup can also be disabled in this case, as follows:</span> |
|
1191 <a name="l01230"></a>01230 guard2.Dismiss(); |
|
1192 <a name="l01231"></a>01231 } |
|
1193 <a name="l01232"></a>01232 |
|
1194 <a name="l01233"></a>01233 { |
|
1195 <a name="l01234"></a>01234 LCleanedupHandle<RFs> managedFs; |
|
1196 <a name="l01235"></a>01235 managedFs->Connect(); |
|
1197 <a name="l01236"></a>01236 <span class="comment">//default cleanup strategy is to call RFs::Close() on scope exit;</span> |
|
1198 <a name="l01237"></a>01237 } |
|
1199 <a name="l01238"></a>01238 |
|
1200 <a name="l01239"></a>01239 { |
|
1201 <a name="l01240"></a>01240 LCleanedupHandle<RSimple, TFree> simple; |
|
1202 <a name="l01241"></a>01241 simple->OpenL(23); |
|
1203 <a name="l01242"></a>01242 <span class="comment">//Specified cleanup strategy is to call RSimple::Free() on scope exit;</span> |
|
1204 <a name="l01243"></a>01243 } |
|
1205 <a name="l01244"></a>01244 |
|
1206 <a name="l01245"></a>01245 <span class="comment">/*</span> |
|
1207 <a name="l01246"></a>01246 <span class="comment"> Because the DEFINE_CLEANUP_FUNCTION is defined above, the default</span> |
|
1208 <a name="l01247"></a>01247 <span class="comment"> cleanup function for RSimple is RSimple::ReleaseData() rather than</span> |
|
1209 <a name="l01248"></a>01248 <span class="comment"> RSimple::Close()</span> |
|
1210 <a name="l01249"></a>01249 <span class="comment"> */</span> |
|
1211 <a name="l01250"></a>01250 { |
|
1212 <a name="l01251"></a>01251 LCleanedupHandle<RSimple> simple; |
|
1213 <a name="l01252"></a>01252 simple->OpenL(23); |
|
1214 <a name="l01253"></a>01253 <span class="comment">//Custom cleanup strategy is to call RSimple::ReleaseData() on scope exit</span> |
|
1215 <a name="l01254"></a>01254 } |
|
1216 <a name="l01255"></a>01255 |
|
1217 <a name="l01256"></a>01256 { |
|
1218 <a name="l01257"></a>01257 RSimple simple; |
|
1219 <a name="l01258"></a>01258 |
|
1220 <a name="l01259"></a>01259 <span class="comment">//The RSimple class above defines a static cleanup function</span> |
|
1221 <a name="l01260"></a>01260 <span class="comment">//RSimple::Cleanup().</span> |
|
1222 <a name="l01261"></a>01261 LCleanedupGuard guard(RSimple::Cleanup, &simple); |
|
1223 <a name="l01262"></a>01262 |
|
1224 <a name="l01263"></a>01263 simple.OpenL(10); |
|
1225 <a name="l01264"></a>01264 |
|
1226 <a name="l01265"></a>01265 <span class="comment">//On scope exit RSimple::Cleanup() is called passing &simple.</span> |
|
1227 <a name="l01266"></a>01266 } |
|
1228 <a name="l01267"></a>01267 } |
|
1229 <a name="l01268"></a>01268 |
|
1230 <a name="l01269"></a>01269 <span class="keywordtype">void</span> WalkthroughUsageL() |
|
1231 <a name="l01270"></a>01270 { |
|
1232 <a name="l01271"></a>01271 _LIT(KTxtOption3,<span class="stringliteral">"Option3: Memory used by EUser high level classes\n"</span>); |
|
1233 <a name="l01272"></a>01272 gConsole->Printf(KTxtOption3); |
|
1234 <a name="l01273"></a>01273 RFile file; |
|
1235 <a name="l01274"></a>01274 |
|
1236 <a name="l01275"></a>01275 _LIT(KTxtSizeofRFile,<span class="stringliteral">"Size of RFile = %d\n"</span>); |
|
1237 <a name="l01276"></a>01276 gConsole->Printf(KTxtSizeofRFile, <span class="keyword">sizeof</span>(file)); |
|
1238 <a name="l01277"></a>01277 |
|
1239 <a name="l01278"></a>01278 LCleanedupHandle<RFile> cFile; |
|
1240 <a name="l01279"></a>01279 |
|
1241 <a name="l01280"></a>01280 _LIT(KTxtSizeofLCleanedupHandleRFile,<span class="stringliteral">"Size of LCleanedupHandle<RFile> = %d\n"</span>); |
|
1242 <a name="l01281"></a>01281 gConsole->Printf(KTxtSizeofLCleanedupHandleRFile, <span class="keyword">sizeof</span>(cFile)); |
|
1243 <a name="l01282"></a>01282 gConsole->Printf(KTxtPressAnyKeyToContinue); |
|
1244 <a name="l01283"></a>01283 gConsole->Getch(); |
|
1245 <a name="l01284"></a>01284 |
|
1246 <a name="l01285"></a>01285 LCleanedupRef<RFile> crFile(file); |
|
1247 <a name="l01286"></a>01286 _LIT(KTxtSizeofLCleanedupRefRFile,<span class="stringliteral">"Size of LCleanedupRef<RFile> = %d\n"</span>); |
|
1248 <a name="l01287"></a>01287 gConsole->Printf(KTxtSizeofLCleanedupRefRFile, <span class="keyword">sizeof</span>(crFile)); |
|
1249 <a name="l01288"></a>01288 gConsole->Printf(KTxtPressAnyKeyToContinue); |
|
1250 <a name="l01289"></a>01289 gConsole->Getch(); |
|
1251 <a name="l01290"></a>01290 |
|
1252 <a name="l01291"></a>01291 CTicker* tracker = <span class="keyword">new</span>(ELeave) CTicker; |
|
1253 <a name="l01292"></a>01292 _LIT(KTxtSizeofCTracker,<span class="stringliteral">"Size of CTracker* = %d\n"</span>); |
|
1254 <a name="l01293"></a>01293 gConsole->Printf(KTxtSizeofCTracker, <span class="keyword">sizeof</span>(tracker)); |
|
1255 <a name="l01294"></a>01294 gConsole->Printf(KTxtPressAnyKeyToContinue); |
|
1256 <a name="l01295"></a>01295 gConsole->Getch(); |
|
1257 <a name="l01296"></a>01296 |
|
1258 <a name="l01297"></a>01297 LCleanedupPtr<CTicker> cTracker(tracker); |
|
1259 <a name="l01298"></a>01298 _LIT(KTxtSizeofLCleanedupHandleCTicker,<span class="stringliteral">"Size of LCleanedupPtr<CTicker> = %d\n"</span>); |
|
1260 <a name="l01299"></a>01299 gConsole->Printf(KTxtSizeofLCleanedupHandleCTicker, <span class="keyword">sizeof</span>(LCleanedupPtr<CTicker>)); |
|
1261 <a name="l01300"></a>01300 gConsole->Printf(KTxtPressAnyKeyToContinue); |
|
1262 <a name="l01301"></a>01301 gConsole->Getch(); |
|
1263 <a name="l01302"></a>01302 } |
|
1264 <a name="l01303"></a>01303 |
|
1265 <a name="l01304"></a>01304 TInt TestL() |
|
1266 <a name="l01305"></a>01305 { |
|
1267 <a name="l01306"></a>01306 gConsole=Console::NewL(KTxtExample,TSize(KConsFullScreen,KConsFullScreen)); |
|
1268 <a name="l01307"></a>01307 CleanupStack::PushL(gConsole); |
|
1269 <a name="l01308"></a>01308 gConsole->Printf(KTxtExample); |
|
1270 <a name="l01309"></a>01309 gConsole->Printf(KTxtPressAnyKeyToContinue); |
|
1271 <a name="l01310"></a>01310 gConsole->Getch(); |
|
1272 <a name="l01311"></a>01311 WalkthroughStringsL(); |
|
1273 <a name="l01312"></a>01312 gConsole->Printf(KTxtPressAnyKeyToContinue); |
|
1274 <a name="l01313"></a>01313 gConsole->Getch(); |
|
1275 <a name="l01314"></a>01314 WalkthroughManagedL(); |
|
1276 <a name="l01315"></a>01315 gConsole->Printf(KTxtPressAnyKeyToContinue); |
|
1277 <a name="l01316"></a>01316 gConsole->Getch(); |
|
1278 <a name="l01317"></a>01317 WalkthroughUsageL(); |
|
1279 <a name="l01318"></a>01318 _LIT(KTxtPressAnyKeyToExit,<span class="stringliteral">"\nPress any key to exit"</span>); |
|
1280 <a name="l01319"></a>01319 gConsole->Printf(KTxtPressAnyKeyToExit); |
|
1281 <a name="l01320"></a>01320 gConsole->Getch(); |
|
1282 <a name="l01321"></a>01321 CleanupStack::PopAndDestroy(gConsole); <span class="comment">// delete the gConsole</span> |
|
1283 <a name="l01322"></a>01322 <span class="keywordflow">return</span> KErrNone; |
|
1284 <a name="l01323"></a>01323 } |
|
1285 <a name="l01324"></a>01324 |
|
1286 <a name="l01325"></a>01325 TInt <a class="code" href="dbllist_8cpp.html#0f358e9c4355138f629b8c4f37310295">E32Main</a>() |
|
1287 <a name="l01326"></a>01326 { |
|
1288 <a name="l01327"></a>01327 __UHEAP_MARK; |
|
1289 <a name="l01328"></a>01328 CTrapCleanup* cleanup=CTrapCleanup::New(); <span class="comment">// Create clean-up stack.</span> |
|
1290 <a name="l01329"></a>01329 TInt status; |
|
1291 <a name="l01330"></a>01330 <span class="keywordflow">if</span>(cleanup!=NULL) |
|
1292 <a name="l01331"></a>01331 { |
|
1293 <a name="l01332"></a>01332 TRAP(status, TestL()); |
|
1294 <a name="l01333"></a>01333 __ASSERT_ALWAYS(!status,User::Panic(KTxtExample,status)); |
|
1295 <a name="l01334"></a>01334 } |
|
1296 <a name="l01335"></a>01335 <span class="keyword">delete</span> cleanup; <span class="comment">// Delete clean-up stack. </span> |
|
1297 <a name="l01336"></a>01336 __UHEAP_MARKEND; |
|
1298 <a name="l01337"></a>01337 |
|
1299 <a name="l01338"></a>01338 <span class="keywordflow">return</span> status; |
|
1300 <a name="l01339"></a>01339 } |
|
1301 <a name="l01340"></a>01340 |
|
1302 <a name="l01341"></a>01341 |
|
1303 <a name="l01342"></a>01342 <span class="comment">// eof</span> |
|
1304 </pre></div><hr size="1"><address style="text-align: right;"><small>Generated on Thu Jan 21 10:33:00 2010 for TB10.1 Example Applications by |
|
1305 <a href="http://www.doxygen.org/index.html"> |
|
1306 <img src="doxygen.png" alt="doxygen" align="middle" border="0"></a> 1.5.3 </small></address> |
|
1307 </body> |
|
1308 </html> |