| 1 | <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
|
|---|
| 2 | <!-- /home/espenr/tmp/qt-3.3.8-espenr-2499/qt-x11-free-3.3.8/extensions/motif/doc/walkthrough.doc:334 -->
|
|---|
| 3 | <html>
|
|---|
| 4 | <head>
|
|---|
| 5 | <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
|
|---|
| 6 | <title>Using Qt Standard Dialogs</title>
|
|---|
| 7 | <style type="text/css"><!--
|
|---|
| 8 | fn { margin-left: 1cm; text-indent: -1cm; }
|
|---|
| 9 | a:link { color: #004faf; text-decoration: none }
|
|---|
| 10 | a:visited { color: #672967; text-decoration: none }
|
|---|
| 11 | body { background: #ffffff; color: black; }
|
|---|
| 12 | --></style>
|
|---|
| 13 | </head>
|
|---|
| 14 | <body>
|
|---|
| 15 |
|
|---|
| 16 | <table border="0" cellpadding="0" cellspacing="0" width="100%">
|
|---|
| 17 | <tr bgcolor="#E5E5E5">
|
|---|
| 18 | <td valign=center>
|
|---|
| 19 | <a href="index.html">
|
|---|
| 20 | <font color="#004faf">Home</font></a>
|
|---|
| 21 | | <a href="classes.html">
|
|---|
| 22 | <font color="#004faf">All Classes</font></a>
|
|---|
| 23 | | <a href="mainclasses.html">
|
|---|
| 24 | <font color="#004faf">Main Classes</font></a>
|
|---|
| 25 | | <a href="annotated.html">
|
|---|
| 26 | <font color="#004faf">Annotated</font></a>
|
|---|
| 27 | | <a href="groups.html">
|
|---|
| 28 | <font color="#004faf">Grouped Classes</font></a>
|
|---|
| 29 | | <a href="functions.html">
|
|---|
| 30 | <font color="#004faf">Functions</font></a>
|
|---|
| 31 | </td>
|
|---|
| 32 | <td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>Using Qt Standard Dialogs</h1>
|
|---|
| 33 |
|
|---|
| 34 |
|
|---|
| 35 |
|
|---|
| 36 | [ <a href="motif-walkthrough-2.html">Previous: Preparing to Migrate the User Interface</a> ]
|
|---|
| 37 | [ <a href="motif-walkthrough.html">Home</a> ]
|
|---|
| 38 | [ <a href="motif-walkthrough-4.html">Next: Using Custom QDialogs</a> ]
|
|---|
| 39 | <p> We start by using two of the <a href="dialogs.html">Qt Standard
|
|---|
| 40 | Dialogs</a>: <a href="qfiledialog.html">QFileDialog</a> and <a href="qmessagebox.html">QMessageBox</a>. Both of these classes
|
|---|
| 41 | provide useful static convenience functions.
|
|---|
| 42 | <p> <center><table cellpadding="4" cellspacing="2" border="0">
|
|---|
| 43 | <tr bgcolor="#f0f0f0"> <td valign="top">QFileDialog::getOpenFileName() <td valign="top">replacement for the <em>Open</em> dialog
|
|---|
| 44 | <tr bgcolor="#d0d0d0"> <td valign="top">QFileDialog::getSaveFileName() <td valign="top">replacement for the <em>Save As</em> dialog
|
|---|
| 45 | <tr bgcolor="#f0f0f0"> <td valign="top">QMessageBox::information() <td valign="top">replacement for <em>Page Delete</em> dialog
|
|---|
| 46 | <tr bgcolor="#d0d0d0"> <td valign="top">QMessageBox::warning() <td valign="top">replacement for <em>IO Error</em> dialog.
|
|---|
| 47 | </table></center>
|
|---|
| 48 | <p> Each of these functions takes a <em>QWidget *parent</em> argument. If we
|
|---|
| 49 | pass zero as the <em>parent</em> argument, then we will have dialogs that
|
|---|
| 50 | are centered on the screen, instead of being centered over our main
|
|---|
| 51 | window. We can have <a href="qmotifwidget.html">QMotifWidget</a> create our <tt>XmMainWindow</tt>, and we
|
|---|
| 52 | can then use this class as the parent for both <a href="motif-extension.html#Motif">Motif</a> dialogs and Qt
|
|---|
| 53 | dialogs.
|
|---|
| 54 | <p> We need to include the appropriate headers for QMotifWidget and
|
|---|
| 55 | <a href="qfiledialog.html">QFileDialog</a> in <tt>todo.cpp</tt>.
|
|---|
| 56 | <p>
|
|---|
| 57 |
|
|---|
| 58 | <pre></pre>
|
|---|
| 59 | <p> Next, we make a few modifications to how the application is
|
|---|
| 60 | initialized. We could initialize Xt/Motif and create the <tt>XtAppContext</tt> ourselves, but <a href="qmotif.html">QMotif</a> can do this for us.
|
|---|
| 61 | We also let <a href="qapplication.html">QApplication</a> open the connection to the X server. Next,
|
|---|
| 62 | we create a QMotifWidget, passing <tt>xmMainWindowWidgetClass</tt> as the <em>widgetclass</em> argument. We can now use the <a href="qmotifwidget.html#motifWidget">QMotifWidget::motifWidget</a>()
|
|---|
| 63 | function to access the Motif widget. The shell widget is created
|
|---|
| 64 | automatically by QMotifWidget. We use <tt>XtParent()</tt> to access it.
|
|---|
| 65 | The top-level window is now a QMotifWidget, which means we can use it
|
|---|
| 66 | as the parent for the Qt Standard Dialogs.
|
|---|
| 67 | <p> <pre></pre>
|
|---|
| 68 | <p> <h2> Replacing the <em>Open</em> and <em>Save As</em> Dialogs
|
|---|
| 69 | </h2>
|
|---|
| 70 | <a name="1"></a><p> First, we completely remove all use of the existing Motif file
|
|---|
| 71 | selection dialog. We remove the <tt>Xm/FileSB.h</tt> include, the global <tt>file_dialog</tt> variable, and the code to create the dialog. We also
|
|---|
| 72 | remove the <tt>PresentFDialog()</tt> callback function. None of this code
|
|---|
| 73 | is needed to use <a href="qfiledialog.html">QFileDialog</a>.
|
|---|
| 74 | <p> After removing the <tt>PresentFDialog()</tt> callback function, we need to
|
|---|
| 75 | make <em>Open</em> and <em>Save As</em> popup-menu callbacks call the <tt>Open()</tt>
|
|---|
| 76 | and <tt>Save()</tt> functions.
|
|---|
| 77 | <p> First we must change the declaration of these two functions.
|
|---|
| 78 | <p>
|
|---|
| 79 |
|
|---|
| 80 | <p> <pre></pre>
|
|---|
| 81 | <p> We also change the arguments to the callbacks. We pass the top-level
|
|---|
| 82 | <a href="qmotifwidget.html">QMotifWidget</a> as the <tt>client_data</tt> to these functions, since we will
|
|---|
| 83 | be using it as the parent for the QFileDialog.
|
|---|
| 84 | <p> <pre></pre>
|
|---|
| 85 | <p> <pre>
|
|---|
| 86 | ...
|
|---|
| 87 | </pre>
|
|---|
| 88 |
|
|---|
| 89 | <p> <pre></pre>
|
|---|
| 90 | <p> Next, we modify the <tt>Save()</tt> function to use
|
|---|
| 91 | <a href="qfiledialog.html#getSaveFileName">QFileDialog::getSaveFileName</a>().
|
|---|
| 92 | <p> <pre></pre>
|
|---|
| 93 | <p> ... and the <tt>Open()</tt> function to use <a href="qfiledialog.html#getOpenFileName">QFileDialog::getOpenFileName</a>().
|
|---|
| 94 | <p> <pre></pre>
|
|---|
| 95 | <p> After we build the project, the application runs and operates as
|
|---|
| 96 | expected. The difference is that the <em>Open</em> and <em>Save As</em> dialogs
|
|---|
| 97 | now use <a href="qfiledialog.html">QFileDialog</a>.
|
|---|
| 98 | <p> <h2> Replacing the <em>Page Delete</em> and <em>IO Error</em> Dialogs
|
|---|
| 99 | </h2>
|
|---|
| 100 | <a name="2"></a><p> The <em>Page Delete</em> dialog is created and used in <tt>actions.c</tt>. We
|
|---|
| 101 | need to migrate this file to C++. We rename it to <tt>actions.cpp</tt>,
|
|---|
| 102 | modify the project file and regenerate the <tt>Makefile</tt>.
|
|---|
| 103 | <p> The changes required to make <tt>actions.cpp</tt> compile are minimal. We
|
|---|
| 104 | need to wrap more C header files and global variables in an <tt>extern "C"</tt> block.
|
|---|
| 105 | <p>
|
|---|
| 106 |
|
|---|
| 107 | <p> <pre></pre>
|
|---|
| 108 | <p> We need to forward declare the <tt>NewPage()</tt>, <tt>DeletePage()</tt>, <tt>EditPage()</tt> and <tt>SaveIt()</tt> functions so that the compiler generates
|
|---|
| 109 | the correct symbols for these functions.
|
|---|
| 110 | <p> <pre></pre>
|
|---|
| 111 | <p> We need to fix a single invalid pointer cast.
|
|---|
| 112 | <p> <pre></pre>
|
|---|
| 113 | <p> And we need to change the variable named <em>new</em> to <em>newstr</em> in the <tt>Trim()</tt> function.
|
|---|
| 114 | <p> We can now change the <tt>DeletePage()</tt> function to use
|
|---|
| 115 | <a href="qmessagebox.html#information">QMessageBox::information</a>().
|
|---|
| 116 | <p> First, we need to make sure we include the proper header for
|
|---|
| 117 | <a href="qmessagebox.html">QMessageBox</a>.
|
|---|
| 118 | <p>
|
|---|
| 119 |
|
|---|
| 120 | <pre></pre>
|
|---|
| 121 | <p> The code for <tt>DeletePage()</tt> looks like this:
|
|---|
| 122 | <p> <pre></pre>
|
|---|
| 123 | <p> At this point in the code, the page should be deleted. The code to do
|
|---|
| 124 | this is in the <tt>DoDeletePage()</tt> function. We move the contents of <tt>DoDeletePage()</tt> to this point and remove the <tt>DoDeletePage()</tt> function
|
|---|
| 125 | completely.
|
|---|
| 126 | <p> Next, we change <tt>todo.cpp</tt> to pass the top-level <a href="qmotifwidget.html">QMotifWidget</a> as the
|
|---|
| 127 | <tt>client_data</tt> tot he <tt>DeletePage()</tt> function.
|
|---|
| 128 | <p>
|
|---|
| 129 |
|
|---|
| 130 | <p> <pre></pre>
|
|---|
| 131 | <p> The <em>IO Error</em> dialog is created and used in <tt>io.c</tt>. We need to
|
|---|
| 132 | migrate this file to C++. We rename it to <tt>io.cpp</tt>, modify the
|
|---|
| 133 | project file and regenerate the <tt>Makefile</tt>.
|
|---|
| 134 | <p> The changes required to make <tt>io.cpp</tt> compile are minimal. We need
|
|---|
| 135 | to wrap more C header files and global variables in an <tt>extern "C"</tt>
|
|---|
| 136 | block.
|
|---|
| 137 | <p>
|
|---|
| 138 |
|
|---|
| 139 | <p> <pre></pre>
|
|---|
| 140 | <p> We need to forward declare the <tt>ReadDB()</tt> and <tt>SaveDB()</tt> functions
|
|---|
| 141 | so that the compiler generates the correct symbols for these
|
|---|
| 142 | functions.
|
|---|
| 143 | <p> <pre></pre>
|
|---|
| 144 | <p> The <tt>ParseNewLines()</tt> function needs to be converted to proper C++.
|
|---|
| 145 | <p> <pre></pre>
|
|---|
| 146 | <p> The <tt>PrintWithNewLines()</tt> function also needs to be converted to proper
|
|---|
| 147 | C++.
|
|---|
| 148 | <p> <pre></pre>
|
|---|
| 149 | <p> We can now change the <tt>ReadDB()</tt> and <tt>SaveDB()</tt> functions to use
|
|---|
| 150 | <a href="qmessagebox.html#warning">QMessageBox::warning</a>().
|
|---|
| 151 | <p> First, we need to make sure we include the proper header for <a href="qmessagebox.html">QMessageBox</a>.
|
|---|
| 152 | <p>
|
|---|
| 153 |
|
|---|
| 154 | <pre></pre>
|
|---|
| 155 | <p> The code for <tt>ReadDB()</tt> looks like this:
|
|---|
| 156 | <p> <pre></pre><pre>
|
|---|
| 157 | ...
|
|---|
| 158 | </pre>
|
|---|
| 159 |
|
|---|
| 160 | <p> The code for <tt>SaveDB()</tt> looks like this:
|
|---|
| 161 | <p> <pre></pre><pre>
|
|---|
| 162 | ...
|
|---|
| 163 | </pre>
|
|---|
| 164 |
|
|---|
| 165 | <p> After we build the project, the application runs and operates as
|
|---|
| 166 | expected. The difference is that the <em>Page Delete</em> and <em>IO Error</em> dialogs now use QMessageBox.
|
|---|
| 167 | <p> [ <a href="motif-walkthrough-2.html">Previous: Preparing to Migrate the User Interface</a> ]
|
|---|
| 168 | [ <a href="motif-walkthrough.html">Home</a> ]
|
|---|
| 169 | [ <a href="motif-walkthrough-4.html">Next: Using Custom QDialogs</a> ]
|
|---|
| 170 | <p>
|
|---|
| 171 | <!-- eof -->
|
|---|
| 172 | <p><address><hr><div align=center>
|
|---|
| 173 | <table width=100% cellspacing=0 border=0><tr>
|
|---|
| 174 | <td>Copyright © 2007
|
|---|
| 175 | <a href="troll.html">Trolltech</a><td align=center><a href="trademarks.html">Trademarks</a>
|
|---|
| 176 | <td align=right><div align=right>Qt 3.3.8</div>
|
|---|
| 177 | </table></div></address></body>
|
|---|
| 178 | </html>
|
|---|
