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This example program looks like a complete modern application. It has a menu bar, it has a tool bar, it has a status bar and works like a simple text editor.
There is a walkthrough of this example.
Header file:
/****************************************************************************
** $Id: qt/application.h 3.3.6 edited Aug 31 2005 $
**
** Copyright (C) 1992-2005 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 APPLICATION_H
#define APPLICATION_H
#include <qmainwindow.h>
class QTextEdit;
class ApplicationWindow: public QMainWindow
{
Q_OBJECT
public:
ApplicationWindow();
~ApplicationWindow();
protected:
void closeEvent( QCloseEvent* );
private slots:
void newDoc();
void choose();
void load( const QString &fileName );
void save();
void saveAs();
void print();
void about();
void aboutQt();
private:
QPrinter *printer;
QTextEdit *e;
QString filename;
};
#endif
Implementation:
/****************************************************************************
** $Id: qt/application.cpp 3.3.6 edited Aug 31 2005 $
**
** Copyright (C) 1992-2005 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 "application.h"
#include <qimage.h>
#include <qpixmap.h>
#include <qtoolbar.h>
#include <qtoolbutton.h>
#include <qpopupmenu.h>
#include <qmenubar.h>
#include <qtextedit.h>
#include <qfile.h>
#include <qfiledialog.h>
#include <qstatusbar.h>
#include <qmessagebox.h>
#include <qprinter.h>
#include <qapplication.h>
#include <qaccel.h>
#include <qtextstream.h>
#include <qpainter.h>
#include <qpaintdevicemetrics.h>
#include <qwhatsthis.h>
#include <qsimplerichtext.h>
#include "filesave.xpm"
#include "fileopen.xpm"
#include "fileprint.xpm"
ApplicationWindow::ApplicationWindow()
: QMainWindow( 0, "example application main window", WDestructiveClose | WGroupLeader )
{
printer = new QPrinter( QPrinter::HighResolution );
QPixmap openIcon, saveIcon, printIcon;
QToolBar * fileTools = new QToolBar( this, "file operations" );
fileTools->setLabel( "File Operations" );
openIcon = QPixmap( fileopen );
QToolButton * fileOpen
= new QToolButton( openIcon, "Open File", QString::null,
this, SLOT(choose()), fileTools, "open file" );
saveIcon = QPixmap( filesave );
QToolButton * fileSave
= new QToolButton( saveIcon, "Save File", QString::null,
this, SLOT(save()), fileTools, "save file" );
printIcon = QPixmap( fileprint );
QToolButton * filePrint
= new QToolButton( printIcon, "Print File", QString::null,
this, SLOT(print()), fileTools, "print file" );
(void)QWhatsThis::whatsThisButton( fileTools );
const char * fileOpenText = "<p><img source=\"fileopen\"> "
"Click this button to open a <em>new file</em>.<br>"
"You can also select the <b>Open</b> command "
"from the <b>File</b> menu.</p>";
QWhatsThis::add( fileOpen, fileOpenText );
QMimeSourceFactory::defaultFactory()->setPixmap( "fileopen", openIcon );
const char * fileSaveText = "<p>Click this button to save the file you "
"are editing. You will be prompted for a file name.\n"
"You can also select the <b>Save</b> command "
"from the <b>File</b> menu.</p>";
QWhatsThis::add( fileSave, fileSaveText );
const char * filePrintText = "Click this button to print the file you "
"are editing.\n"
"You can also select the Print command "
"from the File menu.";
QWhatsThis::add( filePrint, filePrintText );
QPopupMenu * file = new QPopupMenu( this );
menuBar()->insertItem( "&File", file );
file->insertItem( "&New", this, SLOT(newDoc()), CTRL+Key_N );
int id;
id = file->insertItem( openIcon, "&Open...",
this, SLOT(choose()), CTRL+Key_O );
file->setWhatsThis( id, fileOpenText );
id = file->insertItem( saveIcon, "&Save",
this, SLOT(save()), CTRL+Key_S );
file->setWhatsThis( id, fileSaveText );
id = file->insertItem( "Save &As...", this, SLOT(saveAs()) );
file->setWhatsThis( id, fileSaveText );
file->insertSeparator();
id = file->insertItem( printIcon, "&Print...",
this, SLOT(print()), CTRL+Key_P );
file->setWhatsThis( id, filePrintText );
file->insertSeparator();
file->insertItem( "&Close", this, SLOT(close()), CTRL+Key_W );
file->insertItem( "&Quit", qApp, SLOT( closeAllWindows() ), CTRL+Key_Q );
menuBar()->insertSeparator();
QPopupMenu * help = new QPopupMenu( this );
menuBar()->insertItem( "&Help", help );
help->insertItem( "&About", this, SLOT(about()), Key_F1 );
help->insertItem( "About &Qt", this, SLOT(aboutQt()) );
help->insertSeparator();
help->insertItem( "What's &This", this, SLOT(whatsThis()), SHIFT+Key_F1 );
e = new QTextEdit( this, "editor" );
e->setFocus();
setCentralWidget( e );
statusBar()->message( "Ready", 2000 );
resize( 450, 600 );
}
ApplicationWindow::~ApplicationWindow()
{
delete printer;
}
void ApplicationWindow::newDoc()
{
ApplicationWindow *ed = new ApplicationWindow;
ed->setCaption("Qt Example - Application");
ed->show();
}
void ApplicationWindow::choose()
{
QString fn = QFileDialog::getOpenFileName( QString::null, QString::null,
this);
if ( !fn.isEmpty() )
load( fn );
else
statusBar()->message( "Loading aborted", 2000 );
}
void ApplicationWindow::load( const QString &fileName )
{
QFile f( fileName );
if ( !f.open( IO_ReadOnly ) )
return;
QTextStream ts( &f );
e->setText( ts.read() );
e->setModified( FALSE );
setCaption( fileName );
statusBar()->message( "Loaded document " + fileName, 2000 );
}
void ApplicationWindow::save()
{
if ( filename.isEmpty() ) {
saveAs();
return;
}
QString text = e->text();
QFile f( filename );
if ( !f.open( IO_WriteOnly ) ) {
statusBar()->message( QString("Could not write to %1").arg(filename),
2000 );
return;
}
QTextStream t( &f );
t << text;
f.close();
e->setModified( FALSE );
setCaption( filename );
statusBar()->message( QString( "File %1 saved" ).arg( filename ), 2000 );
}
void ApplicationWindow::saveAs()
{
QString fn = QFileDialog::getSaveFileName( QString::null, QString::null,
this );
if ( !fn.isEmpty() ) {
filename = fn;
save();
} else {
statusBar()->message( "Saving aborted", 2000 );
}
}
void ApplicationWindow::print()
{
printer->setFullPage( TRUE );
if ( printer->setup(this) ) { // printer dialog
statusBar()->message( "Printing..." );
QPainter p;
if( !p.begin( printer ) ) { // paint on printer
statusBar()->message( "Printing aborted", 2000 );
return;
}
QPaintDeviceMetrics metrics( p.device() );
int dpiy = metrics.logicalDpiY();
int margin = (int) ( (2/2.54)*dpiy ); // 2 cm margins
QRect view( margin, margin, metrics.width() - 2*margin, metrics.height() - 2*margin );
QSimpleRichText richText( QStyleSheet::convertFromPlainText(e->text()),
QFont(),
e->context(),
e->styleSheet(),
e->mimeSourceFactory(),
view.height() );
richText.setWidth( &p, view.width() );
int page = 1;
do {
richText.draw( &p, margin, margin, view, colorGroup() );
view.moveBy( 0, view.height() );
p.translate( 0 , -view.height() );
p.drawText( view.right() - p.fontMetrics().width( QString::number( page ) ),
view.bottom() + p.fontMetrics().ascent() + 5, QString::number( page ) );
if ( view.top() - margin >= richText.height() )
break;
printer->newPage();
page++;
} while (TRUE);
statusBar()->message( "Printing completed", 2000 );
} else {
statusBar()->message( "Printing aborted", 2000 );
}
}
void ApplicationWindow::closeEvent( QCloseEvent* ce )
{
if ( !e->isModified() ) {
ce->accept();
return;
}
switch( QMessageBox::information( this, "Qt Application Example",
"Do you want to save the changes"
" to the document?",
"Yes", "No", "Cancel",
0, 1 ) ) {
case 0:
save();
ce->accept();
break;
case 1:
ce->accept();
break;
case 2:
default: // just for sanity
ce->ignore();
break;
}
}
void ApplicationWindow::about()
{
QMessageBox::about( this, "Qt Application Example",
"This example demonstrates simple use of "
"QMainWindow,\nQMenuBar and QToolBar.");
}
void ApplicationWindow::aboutQt()
{
QMessageBox::aboutQt( this, "Qt Application Example" );
}
Main:
/****************************************************************************
** $Id: qt/main.cpp 3.3.6 edited Aug 31 2005 $
**
** Copyright (C) 1992-2005 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 "application.h"
int main( int argc, char ** argv ) {
QApplication a( argc, argv );
ApplicationWindow *mw = new ApplicationWindow();
mw->setCaption( "Qt Example - Application" );
mw->show();
a.connect( &a, SIGNAL(lastWindowClosed()), &a, SLOT(quit()) );
return a.exec();
}
See also Examples.
| Copyright © 2005 Trolltech | Trademarks | Qt 3.3.6
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