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  16         <h1>eVaf Tutorial</h1>
  17
  18         <h2>04 - Generator Module</h2>
  19
  20         <p>Now we are going to implement all the classes declared in the <tt>module.h</tt>. Create the <tt>module.cpp</tt> file
  21         in the <tt>src/apps/PswGen/Generator</tt> directory. We obviously include the <tt>module.h</tt> header file, but also
  22         the <tt>QtCore</tt> header file for any non-GUI Qt classes.</p>
  23
  24 <pre class="hl"><span class="hl com">/**</span>
  25 <span class="hl com"> * &#64;file src/apps/PswGen/Generator/module.cpp</span>
  26 <span class="hl com"> */</span>
  27
  28 <span class="hl ppc">#include</span> <span class="hl pps">&quot;module.h&quot;</span><span class="hl ppc"></span>
  29
  30 <span class="hl ppc">#include &lt;QtCore&gt;</span></pre>
  31
  32         <p>All the eVaf modules need to include version information. This is common for all the modules and we can simply
  33         copy existing version info files from another eVaf module:</p>
  34
  35         <pre>evaf/src/apps/PswGen/Generator $ <code>cp ../../../plugins/SdiWindow/version.{h,rc} .</code></pre>
  36
  37         <p>The <tt>version.h</tt> file contains version information for the module. The <tt>version.rc</tt> is for Windows
  38         builds only and embeds the same version information into the dll or exe file. Modify the copied <tt>version.h</tt>
  39         file for our new module. The <tt>version.rc</tt> file uses the values from the <tt>version.h</tt> and does not
  40         need to be touched.</p>
  41
  42 <pre class="hl"><span class="hl com">/**</span>
  43 <span class="hl com"> * &#64;file src/apps/PswGen/Generator/version.h</span>
  44 <span class="hl com"> */</span>
  45 <span class="hl ppc">#ifndef __PSWGEN_GENERATOR_VERSION_H</span>
  46 <span class="hl ppc">#define __PSWGEN_GENERATOR_VERSION_H</span>
  47
  48 <span class="hl ppc">#include &lt;version_rc.h&gt;</span>
  49
  50 <span class="hl com">/**</span>
  51 <span class="hl com"> * Module/library version number in the form major,minor,release,build</span>
  52 <span class="hl com"> */</span>
  53 <span class="hl ppc">#define VER_FILE_VERSION                0,1,1,1</span>
  54
  55 <span class="hl com">/**</span>
  56 <span class="hl com"> * Module/library version number in the string format (shall end with \0)</span>
  57 <span class="hl com"> */</span>
  58 <span class="hl ppc">#define VER_FILE_VERSION_STR</span>            <span class="hl pps">&quot;0.1.1.1\0&quot;</span><span class="hl ppc"></span>
  59
  60 <span class="hl com">/**</span>
  61 <span class="hl com"> * Module/library name (shall end with \0)</span>
  62 <span class="hl com"> */</span>
  63 <span class="hl ppc">#define VER_MODULE_NAME_STR</span>             <span class="hl pps">&quot;PswGen\0&quot;</span><span class="hl ppc"></span>
  64
  65 <span class="hl com">/**</span>
  66 <span class="hl com"> * Module type (see version_rc.h for all the types)</span>
  67 <span class="hl com"> */</span>
  68 <span class="hl ppc">#define VER_MODULE_TYPE                 MT_GENERIC</span>
  69
  70 <span class="hl com">/**</span>
  71 <span class="hl com"> * Module type in the string format (see version_rc for all the types)</span>
  72 <span class="hl com"> */</span>
  73 <span class="hl ppc">#define VER_MODULE_TYPE_STR             MT_GENERIC</span>
  74
  75 <span class="hl com">/**</span>
  76 <span class="hl com"> * Original file name for windows (shall end with \0)</span>
  77 <span class="hl com"> */</span>
  78 <span class="hl ppc">#define VER_ORIGINAL_FILE_NAME_STR</span>      <span class="hl pps">&quot;PswGen.dll\0&quot;</span><span class="hl ppc"></span>
  79
  80 <span class="hl com">/**</span>
  81 <span class="hl com"> * Description of the module/library (shall end with \0)</span>
  82 <span class="hl com"> */</span>
  83 <span class="hl ppc">#define VER_FILE_DESCRIPTION_STR</span>         <span class="hl pps">&quot;Module that generates strong passwords using MD5 hashes.\0&quot;</span><span class="hl ppc"></span>
  84
  85 <span class="hl ppc">#endif</span> <span class="hl slc">// version.h</span><span class="hl ppc"></span></pre>
  86
  87         <p>Then include the version info file in the <tt>module.cpp</tt> file and use the <tt>VER_EXPORT_VERSION_INFO()</tt> macro
  88         to export version information from the module. This macro defines a public function that all the eVaf modules export and
  89         is used to collect version information from them. In your modules you only need to modify the <tt>version.h</tt> file and then
  90         use the <tt>VER_EXPORT_VERSION_INFO()</tt> macro once somewhere in your code.</p>
  91
  92 <pre class="hl"><span class="hl ppc">#include</span> <span class="hl pps">&quot;version.h&quot;</span><span class="hl ppc"></span>
  93
  94 <span class="hl kwd">VER_EXPORT_VERSION_INFO</span><span class="hl opt">()</span></pre>
  95
  96         <p>To make the <tt>Module</tt> class a proper Qt plugin, we use the <tt>Q_EXPORT_PLUGIN2</tt> macro. The name of the module is already
  97         defined in the <tt>version.h</tt> header file as <tt>VER_MODULE_NAME_STR</tt>.
  98
  99         <pre class="hl"><span class="hl kwd">Q_EXPORT_PLUGIN2</span><span class="hl opt">(</span>VER_MODULE_NAME_STR<span class="hl opt">,</span> eVaf<span class="hl opt">::</span>PswGen<span class="hl opt">::</span>Generator<span class="hl opt">::</span>Module<span class="hl opt">)</span></pre>
 100
 101         <p>We make our life easier with several <tt>using namespace</tt> keywords:</p>
 102
 103 <pre class="hl"><span class="hl kwa">using namespace</span> eVaf<span class="hl opt">;</span>
 104 <span class="hl kwa">using namespace</span> eVaf<span class="hl opt">::</span>PswGen<span class="hl opt">;</span>
 105 <span class="hl kwa">using namespace</span> eVaf<span class="hl opt">::</span>PswGen<span class="hl opt">::</span>Generator<span class="hl opt">;</span></pre>
 106
 107         <p>The Module class needs to instantiate the <tt>iGenerator</tt> interface in the constructor. We also need to set
 108         the QObject's name property to the name of the plugin by combining the name of the module with the name of the class.
 109         While the application would work without the name property, it makes our life much easier if the name property is set.</p>
 110
 111         <p>Finally, we output an info message telling that the object was created. Every eVaf module and class is expected to
 112         output info messages when they are created, destroyed, initialized or destroyed.</p>
 113
 114 <pre class="hl">Module<span class="hl opt">::</span><span class="hl kwd">Module</span><span class="hl opt">()</span>
 115     <span class="hl opt">:</span> Plugins<span class="hl opt">::</span><span class="hl kwd">iPlugin</span><span class="hl opt">()</span>
 116 <span class="hl opt">{</span>
 117     <span class="hl kwd">setObjectName</span><span class="hl opt">(</span><span class="hl kwd">QString</span><span class="hl opt">(</span><span class="hl str">&quot;%1.%2&quot;</span><span class="hl opt">).</span><span class="hl kwd">arg</span><span class="hl opt">(</span>VER_MODULE_NAME_STR<span class="hl opt">).</span><span class="hl kwd">arg</span><span class="hl opt">(</span>__FUNCTION__<span class="hl opt">));</span>
 118
 119     mGenerator <span class="hl opt">=</span> <span class="hl kwa">new</span> Internal<span class="hl opt">::</span>GeneratorImpl<span class="hl opt">;</span>
 120
 121     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s created&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 122 <span class="hl opt">}</span></pre>
 123
 124         <p>The <tt>EVAF_INFO</tt> macro comes from the <tt>Common/iLogger</tt> header file ane we need to include it:</p>
 125
 126 <pre class="hl"><span class="hl ppc">#include &lt;Common/iLogger&gt;</span></pre>
 127
 128         <p>The destructor should delete the <tt>iGenerator</tt> interface object, which we created in the constructor. The common
 129         rule is that any resources allocated in the constructor shall be released in the destructor, preferrably in the opposite
 130         order, ie. the first resource allocated in the constructor is released last in the destructor.</tt>
 131
 132 <pre class="hl">Module<span class="hl opt">::~</span><span class="hl kwd">Module</span><span class="hl opt">()</span>
 133 <span class="hl opt">{</span>
 134     <span class="hl kwa">delete</span> mGenerator<span class="hl opt">;</span>
 135
 136     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s destroyed&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 137 <span class="hl opt">}</span></pre>
 138
 139         <p>We also need to implement <tt>init()</tt> and <tt>done()</tt> functions, which are used to initialize and finalize modules.
 140         They are similar to the constructor and destructor with two major differences:</p>
 141         <ol>
 142             <li>The <tt>init()</tt> function can fail and return <tt>false</tt> to indicate a failure. eVaf does not use exceptions and
 143             this is the only way for a module to fail without terminating the whole application. A failed module will be disabled
 144             and the rest of the application can still run if it can.</li>
 145             <li>eVaf modules are loaded in two steps. At first, all the modules are created, which means that all the objects
 146             are constructed. Only then will eVaf call <tt>init()</tt> functions meaning that when the <tt>init()</tt> function is
 147             called, all the modules are already loaded and instantiated. Interfaces and resources from other modules that might be not
 148             available when the object is created, are available when the <tt>init()</tt> function is called.</li>
 149         </ol>
 150
 151         <p>The rule for <tt>init()</tt> and <tt>done()</tt> functions is the same than for constructors and destructors -- any resource
 152         allocated in the <tt>init()</tt> function shall be released in the <tt>done()</tt> function and preferrably in the opposite
 153         order.</p>
 154
 155         <p>This simple module needs no extra resources to be allocated and our <tt>init()</tt> and <tt>done()</tt> functions can be
 156         the following:</p>
 157
 158 <pre class="hl"><span class="hl kwb">bool</span> Module<span class="hl opt">::</span><span class="hl kwd">init</span><span class="hl opt">(</span>QString <span class="hl kwb">const</span> <span class="hl opt">&amp;</span> args<span class="hl opt">)</span>
 159 <span class="hl opt">{</span>
 160     <span class="hl kwd">Q_UNUSED</span><span class="hl opt">(</span>args<span class="hl opt">);</span>
 161
 162     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s initialized&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 163
 164     <span class="hl kwa">return true</span><span class="hl opt">;</span>
 165 <span class="hl opt">}</span>
 166
 167 <span class="hl kwb">void</span> Module<span class="hl opt">::</span><span class="hl kwd">done</span><span class="hl opt">()</span>
 168 <span class="hl opt">{</span>
 169     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s finalized&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 170 <span class="hl opt">}</span></pre>
 171
 172         <p>We continue by implementing the <tt>iGenerator</tt> interface. There are no resources to be allocated in the constructor
 173         and we just set the QObject's name property and output the info message.</p>
 174
 175         <p>We also register the <tt>iGenerator</tt> interface in the global registry so that other modules can query for it and
 176         use our interface. This is done by using the <tt>Common::iRegistry</tt> interface, which we need to include:</p>
 177
 178 <pre class="hl"><span class="hl ppc">#include &lt;Common/iRegistry&gt;</span></pre>
 179
 180         <p>The <tt>GeneratorImpl</tt> class was declared in the <tt>eVaf::PswGen::Generator::Internal</tt> namespace, so we need
 181         another <tt>using namespace</tt> keyword before the implementation of the class:</p>
 182
 183 <pre class="hl"><span class="hl kwa">using namespace</span> eVaf<span class="hl opt">::</span>PswGen<span class="hl opt">::</span>Generator<span class="hl opt">::</span>Internal<span class="hl opt">;</span>
 184
 185 GeneratorImpl<span class="hl opt">::</span><span class="hl kwd">GeneratorImpl</span><span class="hl opt">()</span>
 186     <span class="hl opt">:</span> <span class="hl kwd">iGenerator</span><span class="hl opt">()</span>
 187 <span class="hl opt">{</span>
 188     <span class="hl kwd">setObjectName</span><span class="hl opt">(</span><span class="hl kwd">QString</span><span class="hl opt">(</span><span class="hl str">&quot;%1.iGenerator&quot;</span><span class="hl opt">).</span><span class="hl kwd">arg</span><span class="hl opt">(</span>VER_MODULE_NAME_STR<span class="hl opt">));</span>
 189
 190     Common<span class="hl opt">::</span>iRegistry<span class="hl opt">::</span><span class="hl kwd">instance</span><span class="hl opt">()-&gt;</span><span class="hl kwd">registerInterface</span><span class="hl opt">(</span><span class="hl str">&quot;iGenerator&quot;</span><span class="hl opt">,</span> <span class="hl kwa">this</span><span class="hl opt">);</span>
 191
 192     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s created&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 193 <span class="hl opt">}</span>
 194
 195 GeneratorImpl<span class="hl opt">::~</span><span class="hl kwd">GeneratorImpl</span><span class="hl opt">()</span>
 196 <span class="hl opt">{</span>
 197     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s destroyed&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 198 <span class="hl opt">}</span></pre>
 199
 200     <p>Finally, we write the <tt>generatePassword</tt> function that does the actual job of the module.</p>
 201
 202     <p>We use the MD5 cryptographic hash function to calculate a hash value over the <tt>name</tt> and <tt>masterPassword</tt> values.
 203     The result, which is a binary blob, needs to be convert into something that can be used as a password and we use base 64 encoding
 204     for this and cut the result to the requested length:</p>
 205
 206 <pre class="hl">QString GeneratorImpl<span class="hl opt">::</span><span class="hl kwd">generatePassword</span><span class="hl opt">(</span>QString <span class="hl kwb">const</span> <span class="hl opt">&amp;</span> name<span class="hl opt">,</span> QString <span class="hl kwb">const</span> <span class="hl opt">&amp;</span> masterPassword<span class="hl opt">,</span> <span class="hl kwb">int</span> length<span class="hl opt">,</span> uint flags<span class="hl opt">)</span> <span class="hl kwb">const</span>
 207 <span class="hl opt">{</span>
 208     <span class="hl kwd">Q_UNUSED</span><span class="hl opt">(</span>flags<span class="hl opt">);</span>
 209
 210     QByteArray inputString <span class="hl opt">=</span> <span class="hl kwd">QString</span><span class="hl opt">(</span><span class="hl str">&quot;%1%2&quot;</span><span class="hl opt">).</span><span class="hl kwd">arg</span><span class="hl opt">(</span>name<span class="hl opt">).</span><span class="hl kwd">arg</span><span class="hl opt">(</span>masterPassword<span class="hl opt">).</span><span class="hl kwd">toLatin1</span><span class="hl opt">();</span>
 211     QCryptographicHash <span class="hl kwd">hash</span><span class="hl opt">(</span>QCryptographicHash<span class="hl opt">::</span>Md5<span class="hl opt">);</span>
 212     hash<span class="hl opt">.</span><span class="hl kwd">addData</span><span class="hl opt">(</span>inputString<span class="hl opt">);</span>
 213     QByteArray result <span class="hl opt">=</span> hash<span class="hl opt">.</span><span class="hl kwd">result</span><span class="hl opt">().</span><span class="hl kwd">toBase64</span><span class="hl opt">();</span>
 214     <span class="hl kwa">if</span> <span class="hl opt">(</span>length <span class="hl opt">&gt;</span> <span class="hl num">0</span><span class="hl opt">)</span>
 215         <span class="hl kwa">return</span> result<span class="hl opt">.</span><span class="hl kwd">left</span><span class="hl opt">(</span>length<span class="hl opt">);</span>
 216     <span class="hl kwa">else</span>
 217         <span class="hl kwa">return</span> result<span class="hl opt">;</span>
 218 <span class="hl opt">}</span></pre>
 219
 220     <p>We also know now the maximum length of the generated password, which is 24. Go back to the <tt>module.h</tt> header file and
 221     modify the <tt>GeneratorImpl::maxLength()</tt> function:</p>
 222
 223 <pre class="hl"><span class="hl kwc">virtual</span> <span class="hl kwb">int</span> <span class="hl kwd">maxLength</span><span class="hl opt">()</span> <span class="hl kwb">const</span> <span class="hl opt">{</span> <span class="hl kwa">return</span> <span class="hl num">24</span><span class="hl opt">; }</span></pre>
 224
 225     <p>Here is the final <tt>module.cpp</tt> file:</p>
 226
 227 <pre class="hl"><span class="hl com">/**</span>
 228 <span class="hl com"> * &#64;file src/apps/PswGen/Generator/module.cpp</span>
 229 <span class="hl com"> */</span>
 230
 231 <span class="hl ppc">#include</span> <span class="hl pps">&quot;module.h&quot;</span><span class="hl ppc"></span>
 232 <span class="hl ppc">#include</span> <span class="hl pps">&quot;version.h&quot;</span><span class="hl ppc"></span>
 233
 234 <span class="hl ppc">#include &lt;Common/iLogger&gt;</span>
 235 <span class="hl ppc">#include &lt;Common/iRegistry&gt;</span>
 236
 237 <span class="hl ppc">#include &lt;QtCore&gt;</span>
 238
 239 <span class="hl kwd">VER_EXPORT_VERSION_INFO</span><span class="hl opt">()</span>
 240 <span class="hl kwd">Q_EXPORT_PLUGIN2</span><span class="hl opt">(</span>VER_MODULE_NAME_STR<span class="hl opt">,</span> eVaf<span class="hl opt">::</span>PswGen<span class="hl opt">::</span>Generator<span class="hl opt">::</span>Module<span class="hl opt">)</span>
 241
 242 <span class="hl kwa">using namespace</span> eVaf<span class="hl opt">;</span>
 243 <span class="hl kwa">using namespace</span> eVaf<span class="hl opt">::</span>PswGen<span class="hl opt">;</span>
 244 <span class="hl kwa">using namespace</span> eVaf<span class="hl opt">::</span>PswGen<span class="hl opt">::</span>Generator<span class="hl opt">;</span>
 245
 246 Module<span class="hl opt">::</span><span class="hl kwd">Module</span><span class="hl opt">()</span>
 247     <span class="hl opt">:</span> Plugins<span class="hl opt">::</span><span class="hl kwd">iPlugin</span><span class="hl opt">()</span>
 248 <span class="hl opt">{</span>
 249     <span class="hl kwd">setObjectName</span><span class="hl opt">(</span><span class="hl kwd">QString</span><span class="hl opt">(</span><span class="hl str">&quot;%1.%2&quot;</span><span class="hl opt">).</span><span class="hl kwd">arg</span><span class="hl opt">(</span>VER_MODULE_NAME_STR<span class="hl opt">).</span><span class="hl kwd">arg</span><span class="hl opt">(</span>__FUNCTION__<span class="hl opt">));</span>
 250
 251     mGenerator <span class="hl opt">=</span> <span class="hl kwa">new</span> Internal<span class="hl opt">::</span>GeneratorImpl<span class="hl opt">;</span>
 252
 253     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s created&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 254 <span class="hl opt">}</span>
 255
 256 Module<span class="hl opt">::~</span><span class="hl kwd">Module</span><span class="hl opt">()</span>
 257 <span class="hl opt">{</span>
 258     <span class="hl kwa">delete</span> mGenerator<span class="hl opt">;</span>
 259
 260     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s destroyed&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 261 <span class="hl opt">}</span>
 262
 263 <span class="hl kwb">bool</span> Module<span class="hl opt">::</span><span class="hl kwd">init</span><span class="hl opt">(</span>QString <span class="hl kwb">const</span> <span class="hl opt">&amp;</span> args<span class="hl opt">)</span>
 264 <span class="hl opt">{</span>
 265     <span class="hl kwd">Q_UNUSED</span><span class="hl opt">(</span>args<span class="hl opt">);</span>
 266
 267     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s initialized&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 268
 269     <span class="hl kwa">return true</span><span class="hl opt">;</span>
 270 <span class="hl opt">}</span>
 271
 272 <span class="hl kwb">void</span> Module<span class="hl opt">::</span><span class="hl kwd">done</span><span class="hl opt">()</span>
 273 <span class="hl opt">{</span>
 274     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s finalized&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 275 <span class="hl opt">}</span>
 276
 277 <span class="hl kwa">using namespace</span> eVaf<span class="hl opt">::</span>PswGen<span class="hl opt">::</span>Generator<span class="hl opt">::</span>Internal<span class="hl opt">;</span>
 278
 279 GeneratorImpl<span class="hl opt">::</span><span class="hl kwd">GeneratorImpl</span><span class="hl opt">()</span>
 280     <span class="hl opt">:</span> <span class="hl kwd">iGenerator</span><span class="hl opt">()</span>
 281 <span class="hl opt">{</span>
 282     <span class="hl kwd">setObjectName</span><span class="hl opt">(</span><span class="hl kwd">QString</span><span class="hl opt">(</span><span class="hl str">&quot;%1.iGenerator&quot;</span><span class="hl opt">).</span><span class="hl kwd">arg</span><span class="hl opt">(</span>VER_MODULE_NAME_STR<span class="hl opt">));</span>
 283
 284     Common<span class="hl opt">::</span>iRegistry<span class="hl opt">::</span><span class="hl kwd">instance</span><span class="hl opt">()-&gt;</span><span class="hl kwd">registerInterface</span><span class="hl opt">(</span><span class="hl str">&quot;iGenerator&quot;</span><span class="hl opt">,</span> <span class="hl kwa">this</span><span class="hl opt">);</span>
 285
 286     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s created&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 287 <span class="hl opt">}</span>
 288
 289 GeneratorImpl<span class="hl opt">::~</span><span class="hl kwd">GeneratorImpl</span><span class="hl opt">()</span>
 290 <span class="hl opt">{</span>
 291     <span class="hl kwd">EVAF_INFO</span><span class="hl opt">(</span><span class="hl str">&quot;%s destroyed&quot;</span><span class="hl opt">,</span> <span class="hl kwd">qPrintable</span><span class="hl opt">(</span><span class="hl kwd">objectName</span><span class="hl opt">()));</span>
 292 <span class="hl opt">}</span>
 293
 294 QString GeneratorImpl<span class="hl opt">::</span><span class="hl kwd">generatePassword</span><span class="hl opt">(</span>QString <span class="hl kwb">const</span> <span class="hl opt">&amp;</span> name<span class="hl opt">,</span> QString <span class="hl kwb">const</span> <span class="hl opt">&amp;</span> masterPassword<span class="hl opt">,</span> <span class="hl kwb">int</span> length<span class="hl opt">,</span> uint flags<span class="hl opt">)</span> <span class="hl kwb">const</span>
 295 <span class="hl opt">{</span>
 296     <span class="hl kwd">Q_UNUSED</span><span class="hl opt">(</span>flags<span class="hl opt">);</span>
 297
 298     QByteArray inputString <span class="hl opt">=</span> <span class="hl kwd">QString</span><span class="hl opt">(</span><span class="hl str">&quot;%1%2&quot;</span><span class="hl opt">).</span><span class="hl kwd">arg</span><span class="hl opt">(</span>name<span class="hl opt">).</span><span class="hl kwd">arg</span><span class="hl opt">(</span>masterPassword<span class="hl opt">).</span><span class="hl kwd">toLatin1</span><span class="hl opt">();</span>
 299     QCryptographicHash <span class="hl kwd">hash</span><span class="hl opt">(</span>QCryptographicHash<span class="hl opt">::</span>Md5<span class="hl opt">);</span>
 300     hash<span class="hl opt">.</span><span class="hl kwd">addData</span><span class="hl opt">(</span>inputString<span class="hl opt">);</span>
 301     QByteArray result <span class="hl opt">=</span> hash<span class="hl opt">.</span><span class="hl kwd">result</span><span class="hl opt">().</span><span class="hl kwd">toBase64</span><span class="hl opt">();</span>
 302     <span class="hl kwa">if</span> <span class="hl opt">(</span>length <span class="hl opt">&gt;</span> <span class="hl num">0</span><span class="hl opt">)</span>
 303         <span class="hl kwa">return</span> result<span class="hl opt">.</span><span class="hl kwd">left</span><span class="hl opt">(</span>length<span class="hl opt">);</span>
 304     <span class="hl kwa">else</span>
 305         <span class="hl kwa">return</span> result<span class="hl opt">;</span>
 306 <span class="hl opt">}</span></pre>
 307
 308         <p>Next -- <a href="pswgen05.html">05 - Building Generator Module</a>.</p>
 309
 310     </body>
 311 </html>