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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"><!-- /home/edba/dist/qtopia/main-Sunday/qtopia/doc/qpepim.doc:49 --><html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Qtopia PIM Library Overview</title><style type="text/css"><!--h3.fn,span.fn { margin-left: 1cm; text-indent: -1cm; }a:link { color: #004faf; text-decoration: none }a:visited { color: #672967; text-decoration: none }body { background: #ffffff; color: black; }--></style></head><body><table border="0" cellpadding="0" cellspacing="0" width="100%"><tr><td width="200" align="left" valign="top"><a href="index.html"><img height="27" width="472" src="dochead.png" border="0"></a><br><font face="Arial,Helvetica,Geneva,Swiss,SunSans-Regular" align="center" size=32>Qtopia</font> <a href="index.html">Home</a> - <a href="qtopiaclasses.html">Classes</a> - <a href="qtopiaannotated.html">Annotated</a> - <a href="qtopiafunctions.html">Functions</a> - <a href="qtindex.html">Qt Embedded</a></td><td align="right" valign="top"> <table border="0" cellpadding="0" cellspacing="0" width="137"> <tr> <td><a href="http://www.trolltech.com/company/about/trolls.html"><img height="100" width="100" src="face.png" border="0"></a></td> <td><img height="100" width="100" src="qtlogo.png" align="top" border="0"></td> </tr> </table></td></tr></table><h1 align=center>Qtopia PIM Library Overview</h1><!-- toc --><ul><li><a href="#1"> Introduction</a><li><a href="#2"> Overview of Classes</a><ul><li><a href="#2-1"> Value classes</a><li><a href="#2-2"> Access classes</a><li><a href="#2-3"> Iterator classes</a></ul><li><a href="#3"> Using the Qtopia PIM Library</a><li><a href="#4"> PIM Change signals</a><li><a href="#5"> Data Refresh</a></ul><!-- endtoc --><p> <h2> Introduction</h2><a name="1"></a><p> The Qtopia PIM library provides a set of safe APIs for accessingQtopia PIM data and provides a smooth transition to the next majorrevision of Qtopia. Specifically, classes are provided to retrieve,edit, and save Contacts, Tasks, and Events. The access classesattempt to keep themselves in sync with Qtopia's AddressBook, Todo, and Datebook applications, and any other applications.<p> <h2> Overview of Classes</h2><a name="2"></a><p> There are three types of data represented in the PIM library, contacts,events and tasks. For each data type there is three different types ofclasses to access that data. A Value class, an Access class and anIterator class.<p> <center><table cellpadding="4" cellspacing="2" border="0"><tr bgcolor="#a2c511"> <th valign="top">Value class <th valign="top">Access class <th valign="top">Iterator class<tr bgcolor="#f0f0f0"> <td valign="top"><a href="pimcontact.html">PimContact</a> <td valign="top"><a href="addressbookaccess.html">AddressBookAccess</a> <td valign="top"><a href="addressbookiterator.html">AddressBookIterator</a><tr bgcolor="#d0d0d0"> <td valign="top"><a href="pimevent.html">PimEvent</a> <td valign="top"><a href="datebookaccess.html">DateBookAccess</a> <td valign="top"><a href="datebookiterator.html">DateBookIterator</a><tr bgcolor="#f0f0f0"> <td valign="top"><a href="pimtask.html">PimTask</a> <td valign="top"><a href="todoaccess.html">TodoAccess</a> <td valign="top"><a href="todoiterator.html">TodoIterator</a></table></center><p> <h3> Value classes</h3><a name="2-1"></a><p> The Value class is the class used to pass around data for the particularkind of PIM data. For example the <a href="pimevent.html">PimEvent</a> class is used to get thedescription of an event, and determine when the event will next occur. It is also this class that you would use to pass the data betweenapplications.<p> <h3> Access classes</h3><a name="2-2"></a><p> The Access class is used to access the database or table for a particularkind of PIM data. To get the list of contacts first you need to createan instance of <a href="addressbookaccess.html">AddressBookAccess</a>. This is also the class used to addor update records.<p> <h3> Iterator classes</h3><a name="2-3"></a><p> The Iterator class is for traversing the stored list of data for aparticular kind of PIM data. To determine what <a href="pimtask.html">PimTask</a>s remain openan application would create a <a href="todoiterator.html">TodoIterator</a> using a <a href="todoaccess.html">TodoAccess</a>instance, and then use the <a href="todoiterator.html">TodoIterator</a> to traverse over each<a href="pimtask.html">PimTask</a>. It is recommend that an instance of an Iterator class iskept only as long as needed. The PIM library hides the type of storageused for the PIM data, and due to performance reasons keeping an Iteratorclass while not needed may affect notifications of updates to the PIM data.<p> <h2> Using the Qtopia PIM Library</h2><a name="3"></a><p> This example reads a list of open tasks and then displays a label detailingthe tasks. First a <a href="todoaccess.html">TodoAccess</a> instance is created to load the datafor Tasks. Then a <a href="todoiterator.html">TodoIterator</a> is initialized from the <a href="todoaccess.html">TodoAccess</a> to traverse the data. For each item a <a href="pimtask.html">PimTask</a> is created to get thecompletion status of the task and the description of the task.<p> <pre>#include <qtextbrowser.h>#include <qtopia/qpeapplication.h>#include <qtopia/todoaccess.h>class TaskList : public QTextBrowser{public: TaskList(QWidget *parent) : QTextBrowser(parent) { QString text; <a href="todoaccess.html">TodoAccess</a> a; <a href="todoiterator.html">TodoIterator</a> it(a); for(;it.<a href="todoiterator.html#current">current</a>(); ++it) { <a href="pimtask.html">PimTask</a> t(*it); if (!t.<a href="pimtask.html#isCompleted">isCompleted</a>()) { text += "ITEM: " + t.<a href="pimtask.html#description">description</a>() + "<BR>"; } } setText(text); }};int main(int argc, char **argv){ <a href="qpeapplication.html">QPEApplication</a> qpe(argc, argv); TaskList *tl = new TaskList(0); qpe.showMainWindow(tl); return qpe.exec();}</pre> <p> <h2> PIM Change signals</h2><a name="4"></a><p> The access class listen for various QCop calls to keep in sync with the main pim applications. When an access class detects an update it will emit a signal indicating it has been udpated.<p> <h2> Data Refresh</h2><a name="5"></a><p> The Qtopia PIM Library will always try to return the most current data to the user.This is done by monitoring the time stamp on the actual data file aswell as listening for QPE/PIM messages that are relavent to the datafiles used by the specific accessor. If a QPE/PIM message isreceived that indicates the data has been updated the accessor willemit a signal indicating the event and during the next data query theQtopia PIM Library will refresh its internal caches. Note that since Qtopia PIM Librarydoes not employ a polling mechanism simply touching the data filewill not trigger the event to be emitted, however it will bedetected the next time data is requested. <!-- eof --><p><address><hr><div align="center"><table width="100%" cellspacing="0" border="0"><tr><td>Copyright © 2001-2004 Trolltech<td><a href="http://www.trolltech.com/trademarks.html">Trademarks</a><td align="right"><div align="right">Qtopia version 2.0.0</div></table></div></address></body></html>⌨️ 快捷键说明
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