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This example presents a small outliner program to show the basic usage of the DOM classes. The format of the outlines is the OPML format as described in http://www.opml.org/spec.
This example shows how to load a DOM tree from an XML file and how to traverse it.
Sample XML file (todos.opml):
<?xml version="1.0" encoding="ISO-8859-1"?>
<opml version="1.0">
<head>
<title>Todo List</title>
<dateCreated>Tue, 31 Oct 2000 17:00:17 CET</dateCreated>
<dateModified>Tue, 31 Oct 2000 17:00:17 CET</dateModified>
<ownerName>Arthur Dent</ownerName>
<ownerEmail>info@trolltech.com</ownerEmail>
</head>
<body>
<outline text="Background">
<outline text="This is an example todo list."/>
</outline>
<outline text="Books to read">
<outline text="Science Fiction">
<outline text="Philip K. Dick">
<outline text="Do Androids Dream of Electical Sheep?"/>
<outline text="The Three Stigmata of Palmer Eldritch"/>
</outline>
<outline text="Robert A. Heinlein">
<outline text="Stranger in a Strange Land"/>
</outline>
<outline text="Isaac Asimov">
<outline text="Foundation and Empire"/>
</outline>
</outline>
<outline text="Qt Books (in English)">
<outline text="Blanchette & Summerfield: C++ GUI Programming with Qt 3"/>
<outline text="Dalheimer: Programming with Qt"/>
<outline text="Griffith: KDE 2/Qt Programming Bible"/>
<outline text="Hughes: Linux Rapid Application Development"/>
<outline text="Solin: Qt Programming in 24 hours"/>
<outline text="Ward: Qt 2 Programming for Linux and Windows 2000"/>
</outline>
</outline>
<outline text="Shopping list">
<outline text="General">
<outline text="Towel"/>
<outline text="Hair dryer"/>
<outline text="Underpants"/>
</outline>
<outline text="For Sunday">
<outline text="Beef"/>
<outline text="Rice"/>
<outline text="Carrots"/>
<outline text="Beans"/>
<outline text="Beer"/>
<outline text="Wine"/>
<outline text="Orange juice"/>
</outline>
</outline>
<outline text="Write a letter to Ford">
</outline>
</body>
</opml>
Header file (outlinetree.h):
/****************************************************************************
** $Id: qt/outlinetree.h 3.3.0 edited May 27 2003 $
**
** Copyright (C) 1992-2000 Trolltech AS. All rights reserved.
**
** This file is part of an example program for Qt. This example
** program may be used, distributed and modified without limitation.
**
*****************************************************************************/
#ifndef OUTLINETREE_H
#define OUTLINETREE_H
#include <qlistview.h>
#include <qdom.h>
class OutlineTree : public QListView
{
Q_OBJECT
public:
OutlineTree( const QString fileName, QWidget *parent = 0, const char *name = 0 );
~OutlineTree();
private:
QDomDocument domTree;
void getHeaderInformation( const QDomElement &header );
void buildTree( QListViewItem *parentItem, const QDomElement &parentElement );
};
#endif // OUTLINETREE_H
Implementation (outlinetree.cpp):
/****************************************************************************
** $Id: qt/outlinetree.cpp 3.3.0 edited May 27 2003 $
**
** Copyright (C) 1992-2000 Trolltech AS. All rights reserved.
**
** This file is part of an example program for Qt. This example
** program may be used, distributed and modified without limitation.
**
*****************************************************************************/
#include "outlinetree.h"
#include <qfile.h>
#include <qmessagebox.h>
OutlineTree::OutlineTree( const QString fileName, QWidget *parent, const char *name )
: QListView( parent, name )
{
// div. configuration of the list view
addColumn( "Outlines" );
setSorting( -1 );
setRootIsDecorated( TRUE );
// read the XML file and create DOM tree
QFile opmlFile( fileName );
if ( !opmlFile.open( IO_ReadOnly ) ) {
QMessageBox::critical( 0,
tr( "Critical Error" ),
tr( "Cannot open file %1" ).arg( fileName ) );
return;
}
if ( !domTree.setContent( &opmlFile ) ) {
QMessageBox::critical( 0,
tr( "Critical Error" ),
tr( "Parsing error for file %1" ).arg( fileName ) );
opmlFile.close();
return;
}
opmlFile.close();
// get the header information from the DOM
QDomElement root = domTree.documentElement();
QDomNode node;
node = root.firstChild();
while ( !node.isNull() ) {
if ( node.isElement() && node.nodeName() == "head" ) {
QDomElement header = node.toElement();
getHeaderInformation( header );
break;
}
node = node.nextSibling();
}
// create the tree view out of the DOM
node = root.firstChild();
while ( !node.isNull() ) {
if ( node.isElement() && node.nodeName() == "body" ) {
QDomElement body = node.toElement();
buildTree( 0, body );
break;
}
node = node.nextSibling();
}
}
OutlineTree::~OutlineTree()
{
}
void OutlineTree::getHeaderInformation( const QDomElement &header )
{
// visit all children of the header element and look if you can make
// something with it
QDomNode node = header.firstChild();
while ( !node.isNull() ) {
if ( node.isElement() ) {
// case for the different header entries
if ( node.nodeName() == "title" ) {
QDomText textChild = node.firstChild().toText();
if ( !textChild.isNull() ) {
setColumnText( 0, textChild.nodeValue() );
}
}
}
node = node.nextSibling();
}
}
void OutlineTree::buildTree( QListViewItem *parentItem, const QDomElement &parentElement )
{
QListViewItem *thisItem = 0;
QDomNode node = parentElement.firstChild();
while ( !node.isNull() ) {
if ( node.isElement() && node.nodeName() == "outline" ) {
// add a new list view item for the outline
if ( parentItem == 0 )
thisItem = new QListViewItem( this, thisItem );
else
thisItem = new QListViewItem( parentItem, thisItem );
thisItem->setText( 0, node.toElement().attribute( "text" ) );
// recursive build of the tree
buildTree( thisItem, node.toElement() );
}
node = node.nextSibling();
}
}
Main (main.cpp):
/****************************************************************************
** $Id: qt/main.cpp 3.3.0 edited May 27 2003 $
**
** Copyright (C) 1992-2000 Trolltech AS. All rights reserved.
**
** This file is part of an example program for Qt. This example
** program may be used, distributed and modified without limitation.
**
*****************************************************************************/
#include <qapplication.h>
#include "outlinetree.h"
int main( int argc, char **argv )
{
QApplication a( argc, argv );
OutlineTree outline( "todos.opml" );
a.setMainWidget( &outline );
outline.show();
return a.exec();
}
See also Qt XML Examples.
| Copyright © 2004 Trolltech | Trademarks | Qt 3.3.0
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