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Simple HTML Browser


The QBrowser exampple implements a simple HTML browser using Qt's Richtext widget.
Header file:
/****************************************************************************
** $Id: helpwindow.h,v 1.3.2.1 1999/07/13 19:17:56 reggie Exp $
**
** Copyright (C) 1992-1999 Troll Tech 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 HELPWINDOW_H
#define HELPWINDOW_H

#include <qtextbrowser.h>
#include <qmainwindow.h>
#include <qstringlist.h>
#include <qmap.h>
#include <qdir.h>

class QComboBox;
class QPopupMenu;

class HelpWindow : public QMainWindow
{
    Q_OBJECT
public:
    HelpWindow( const QString& home_,  const QString& path, QWidget* parent = 0, const char *name=0 );
    ~HelpWindow();

private slots:
    void setBackwardAvailable( bool );
    void setForwardAvailable( bool );

    void textChanged();
    void about();
    void aboutQt();
    void openFile();
    void newWindow();

    void pathSelected( const QString & );
    void histChosen( int );
    void bookmChosen( int );
    void addBookmark();

private:
    bool eventFilter( QObject * o, QEvent * e );
    void readHistory();
    void readBookmarks();

    QTextBrowser* browser;
    QComboBox *pathCombo;
    int backwardId, forwardId;
    QString selectedURL;
    QDir path;
    QStringList fileList, history, bookmarks;
    QMap<int, QString> mHistory, mBookmarks;
    QPopupMenu *hist, *bookm;

};

#endif

Implementation:
/****************************************************************************
** $Id: helpwindow.cpp,v 1.9.2.1 1999/07/13 19:17:55 reggie Exp $
**
** Copyright (C) 1992-1999 Troll Tech 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 "helpwindow.h"
#include <qstatusbar.h>
#include <qpixmap.h>
#include <qpopupmenu.h>
#include <qmenubar.h>
#include <qtoolbar.h>
#include <qtoolbutton.h>
#include <qiconset.h>
#include <qfile.h>
#include <qtextstream.h>
#include <qstylesheet.h>
#include <qmessagebox.h>
#include <qfiledialog.h>
#include <qapplication.h>
#include <qcombobox.h>
#include <qevent.h>
#include <qlineedit.h>
#include <qobjectlist.h>
#include <qfileinfo.h>
#include <qfile.h>
#include <qdatastream.h>

#include <ctype.h>

HelpWindow::HelpWindow( const QString& home_, const QString& _path, QWidget* parent, const char *name )
    : QMainWindow( parent, name, WDestructiveClose ), pathCombo( 0 ), selectedURL(),
      path( QFileInfo( home_ ).dirPath( TRUE ), "*.htm*" )
{
    readHistory();
    readBookmarks();

    fileList = path.entryList();

    browser = new QTextBrowser( this );
    browser->mimeSourceFactory()->setFilePath( _path );
    browser->setFrameStyle( QFrame::Panel | QFrame::Sunken );
    connect( browser, SIGNAL( textChanged() ),
             this, SLOT( textChanged() ) );

    setCentralWidget( browser );

    if ( !home_.isEmpty() )
        browser->setSource( home_ );

    connect( browser, SIGNAL( highlighted( const QString&) ),
             statusBar(), SLOT( message( const QString&)) );

    resize( 640,700 );

    QPopupMenu* file = new QPopupMenu( this );
    file->insertItem( tr("&New Window"), this, SLOT( newWindow() ), ALT | Key_N );
    file->insertItem( tr("&Open File"), this, SLOT( openFile() ), ALT | Key_O );
    file->insertSeparator();
    file->insertItem( tr("&Close"), this, SLOT( close() ), ALT | Key_Q );
    file->insertItem( tr("E&xit"), qApp, SLOT( closeAllWindows() ), ALT | Key_X );

    QPopupMenu* go = new QPopupMenu( this );
    backwardId = go->insertItem( QPixmap("back.xpm"),
                                 tr("&Backward"), browser, SLOT( backward() ),
                                 ALT | Key_Left );
    forwardId = go->insertItem( QPixmap("forward.xpm"),
                                tr("&Forward"), browser, SLOT( forward() ),
                                ALT | Key_Right );
    go->insertItem( QPixmap("home.xpm"), tr("&Home"), browser, SLOT( home() ) );

    QPopupMenu* help = new QPopupMenu( this );
    help->insertItem( tr("&About ..."), this, SLOT( about() ) );
    help->insertItem( tr("About &Qt ..."), this, SLOT( aboutQt() ) );

    hist = new QPopupMenu( this );
    QStringList::Iterator it = history.begin();
    for ( ; it != history.end(); ++it )
        mHistory[ hist->insertItem( *it ) ] = *it;
    connect( hist, SIGNAL( activated( int ) ),
             this, SLOT( histChosen( int ) ) );

    bookm = new QPopupMenu( this );
    bookm->insertItem( tr( "Add Bookmark" ), this, SLOT( addBookmark() ) );
    bookm->insertSeparator();

    QStringList::Iterator it2 = bookmarks.begin();
    for ( ; it2 != bookmarks.end(); ++it2 )
        mBookmarks[ bookm->insertItem( *it2 ) ] = *it2;
    connect( bookm, SIGNAL( activated( int ) ),
             this, SLOT( bookmChosen( int ) ) );

    menuBar()->insertItem( tr("&File"), file );
    menuBar()->insertItem( tr("&Go"), go );
    menuBar()->insertItem( tr( "History" ), hist );
    menuBar()->insertItem( tr( "Bookmarks" ), bookm );
    menuBar()->insertSeparator();
    menuBar()->insertItem( tr("&Help"), help );

    menuBar()->setItemEnabled( forwardId, FALSE);
    menuBar()->setItemEnabled( backwardId, FALSE);
    connect( browser, SIGNAL( backwardAvailable( bool ) ),
             this, SLOT( setBackwardAvailable( bool ) ) );
    connect( browser, SIGNAL( forwardAvailable( bool ) ),
             this, SLOT( setForwardAvailable( bool ) ) );

    QToolBar* toolbar = new QToolBar( this );
    addToolBar( toolbar, "Toolbar");
    QToolButton* button;

    button = new QToolButton( QPixmap("back.xpm"), tr("Backward"), "", browser, SLOT(backward()), toolbar );
    connect( browser, SIGNAL( backwardAvailable(bool) ), button, SLOT( setEnabled(bool) ) );
    button->setEnabled( FALSE );
    button = new QToolButton( QPixmap("forward.xpm"), tr("Forward"), "", browser, SLOT(forward()), toolbar );
    connect( browser, SIGNAL( forwardAvailable(bool) ), button, SLOT( setEnabled(bool) ) );
    button->setEnabled( FALSE );
    button = new QToolButton( QPixmap("home.xpm"), tr("Home"), "", browser, SLOT(home()), toolbar );

    toolbar->addSeparator();

    pathCombo = new QComboBox( TRUE, toolbar );
    connect( pathCombo, SIGNAL( activated( const QString & ) ),
             this, SLOT( pathSelected( const QString & ) ) );
    toolbar->setStretchableWidget( pathCombo );
    setRightJustification( TRUE );

    pathCombo->insertItem( home_ );
    pathCombo->installEventFilter( this );
    QObjectList *l = queryList( "QLineEdit" );
    if ( l && l->first() )
        ( (QLineEdit*)l->first() )->installEventFilter( this );

    browser->setFocus();
}

void HelpWindow::setBackwardAvailable( bool b)
{
    menuBar()->setItemEnabled( backwardId, b);
}

void HelpWindow::setForwardAvailable( bool b)
{
    menuBar()->setItemEnabled( forwardId, b);
}

void HelpWindow::textChanged()
{
    if ( browser->documentTitle().isNull() )
        setCaption( browser->context() );
    else
        setCaption( browser->documentTitle() ) ;

    selectedURL = caption();
    if ( !selectedURL.isEmpty() && pathCombo ) {
        path = QDir( QFileInfo( selectedURL ).dirPath( TRUE ), "*.htm*" );
        fileList = path.entryList();
        bool exists = FALSE;
        int i;
        for ( i = 0; i < pathCombo->count(); ++i ) {
            if ( pathCombo->text( i ) == selectedURL ) {
                exists = TRUE;
                break;
            }
        }
        if ( !exists ) {
            pathCombo->insertItem( selectedURL, 0 );
            pathCombo->setCurrentItem( 0 );
            mHistory[ hist->insertItem( selectedURL ) ] = selectedURL;
        } else
            pathCombo->setCurrentItem( i );
        selectedURL = QString::null;
    }
}

HelpWindow::~HelpWindow()
{
    history.clear();
    QMap<int, QString>::Iterator it = mHistory.begin();
    for ( ; it != mHistory.end(); ++it )
        history.append( *it );

    QFile f( QDir::currentDirPath() + "/.history" );
    f.open( IO_WriteOnly );
    QDataStream s( &f );
    s << history;
    f.close();

    bookmarks.clear();
    QMap<int, QString>::Iterator it2 = mBookmarks.begin();
    for ( ; it2 != mBookmarks.end(); ++it2 )
        bookmarks.append( *it2 );

    QFile f2( QDir::currentDirPath() + "/.bookmarks" );
    f2.open( IO_WriteOnly );
    QDataStream s2( &f2 );
    s2 << bookmarks;
    f2.close();
}

void HelpWindow::about()
{
    QMessageBox::about( this, "QBrowser Example",
                        "<p>This example implements a simple HTML browser "
                        "using Qt's rich text capabilities</p>"
                        "<p>It's just about 100 lines of C++ code, so don't expect too much :-)</p>"
        );
}

void HelpWindow::aboutQt()
{
    QMessageBox::aboutQt( this, "QBrowser" );
}

void HelpWindow::openFile()
{
    QString fn = QFileDialog::getOpenFileName( QString::null, QString::null, this );
    if ( !fn.isEmpty() )
        browser->setSource( fn );
}

void HelpWindow::newWindow()
{
    ( new HelpWindow(browser->source(), "qbrowser") )->show();
}

void HelpWindow::pathSelected( const QString &_path )
{
    browser->setSource( _path );
    path = QDir( QFileInfo( _path ).dirPath( TRUE ), "*.htm*" );
    fileList = path.entryList();
    QMap<int, QString>::Iterator it = mHistory.begin();
    bool exists = FALSE;
    for ( ; it != mHistory.end(); ++it ) {
        if ( *it == _path ) {
            exists = TRUE;
            break;
        }
    }
    if ( !exists )
        mHistory[ hist->insertItem( _path ) ] = _path;
}

bool HelpWindow::eventFilter( QObject * o, QEvent * e )
{
    QObjectList *l = queryList( "QLineEdit" );
    if ( !l || !l->first() )
        return FALSE;

    QLineEdit *lined = (QLineEdit*)l->first();

    if ( ( o == pathCombo || o == lined ) &&
         e->type() == QEvent::KeyPress ) {

        if ( isprint(((QKeyEvent *)e)->ascii()) ) {
            if ( lined->hasMarkedText() )
                lined->del();
            QString nt( lined->text() );
            nt.remove( 0, nt.findRev( '/' ) + 1 );
            nt.truncate( lined->cursorPosition() );
            nt += (char)(((QKeyEvent *)e)->ascii());

            QStringList::Iterator it = fileList.begin();
            while ( it != fileList.end() && (*it).left( nt.length() ) != nt )
                ++it;

            if ( !(*it).isEmpty() ) {
                nt = *it;
                int cp = lined->cursorPosition() + 1;
                int l = path.canonicalPath().length() + 1;
                lined->validateAndSet( path.canonicalPath() + "/" + nt, cp, cp, l + nt.length() );
                return TRUE;
            }
        }
    }

    return FALSE;
}

void HelpWindow::readHistory()
{
    if ( QFile::exists( QDir::currentDirPath() + "/.history" ) ) {
        QFile f( QDir::currentDirPath() + "/.history" );
        f.open( IO_ReadOnly );
        QDataStream s( &f );
        s >> history;
        f.close();
        while ( history.count() > 20 )
            history.remove( history.begin() );
    }
}

void HelpWindow::readBookmarks()
{
    if ( QFile::exists( QDir::currentDirPath() + "/.bookmarks" ) ) {
        QFile f( QDir::currentDirPath() + "/.bookmarks" );
        f.open( IO_ReadOnly );
        QDataStream s( &f );
        s >> bookmarks;
        f.close();
    }
}

void HelpWindow::histChosen( int i )
{
    if ( mHistory.contains( i ) )
        browser->setSource( mHistory[ i ] );
}

void HelpWindow::bookmChosen( int i )
{
    if ( mBookmarks.contains( i ) )
        browser->setSource( mBookmarks[ i ] );
}

void HelpWindow::addBookmark()
{
    mBookmarks[ bookm->insertItem( caption() ) ] = caption();
}

Main:
/****************************************************************************
** $Id: main.cpp,v 1.7.2.1 1999/07/13 19:17:57 reggie Exp $
**
** Copyright (C) 1992-1999 Troll Tech 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 <qwindowsstyle.h>
#include <qstylesheet.h>
#include "helpwindow.h"
#include <stdlib.h>

int main( int argc, char ** argv )
{
    QApplication::setColorSpec( QApplication::ManyColor );
    QApplication a(argc, argv);

    QStyleSheetItem* style;

    // Modify the application-wide default style sheet to handle
    // some extra HTML gracefully.
    //
    // Ignore any bodytext in <head>...</head>:
    style = new QStyleSheetItem( QStyleSheet::defaultSheet(), "head" );
    style->setDisplayMode(QStyleSheetItem::DisplayNone);
    //
    // Not in default style sheet, just fake it:
    style = new QStyleSheetItem( QStyleSheet::defaultSheet(), "dl" );
    style->setDisplayMode(QStyleSheetItem::DisplayBlock);
    style = new QStyleSheetItem( QStyleSheet::defaultSheet(), "dt" );
    style->setDisplayMode(QStyleSheetItem::DisplayBlock);
    style->setContexts("dl");
    //
    // Many HTML files omit the </p> or </li>, so we add this for efficiency:
    QStyleSheet::defaultSheet()->item("p")->setSelfNesting( FALSE );
    QStyleSheet::defaultSheet()->item("li")->setSelfNesting( FALSE );

    QString home;

    if (argc > 1)
        home = argv[1];
    else
        home = QString(getenv("QTDIR")) + "/doc/index.html";

    ( new HelpWindow(home, ".", 0, "qbrowser") )->show();

    QObject::connect( &a, SIGNAL(lastWindowClosed()),
                      &a, SLOT(quit()) );

    return a.exec();
}


Copyright 1999 Troll TechTrademarks
Qt version 2.0.2