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A Complete Canvas Application
This is a complete example program with a main window, menus and toolbars. The main widget is a QCanvas, and this example demonstrates basic canvas usage.
Project file:
TEMPLATE = app
CONFIG += warn_on
HEADERS += element.h \
canvastext.h \
canvasview.h \
chartform.h \
optionsform.h \
setdataform.h
SOURCES += element.cpp \
canvasview.cpp \
chartform.cpp \
chartform_canvas.cpp \
chartform_files.cpp \
optionsform.cpp \
setdataform.cpp \
main.cpp
Header files:
#ifndef ELEMENT_H #define ELEMENT_H #include <qcolor.h> #include <qnamespace.h> #include <qstring.h> #include <qvaluevector.h> class Element; typedef QValueVector<Element> ElementVector; /* Elements are valid if they have a value which is > EPSILON. */ const double EPSILON = 0.0000001; // Must be > INVALID. class Element { public: enum { INVALID = -1 }; enum { NO_PROPORTION = -1 }; enum { MAX_PROPOINTS = 3 }; // One proportional point per chart type Element( double value = INVALID, QColor valueColor = Qt::gray, int valuePattern = Qt::SolidPattern, const QString& label = QString::null, QColor labelColor = Qt::black ) { init( value, valueColor, valuePattern, label, labelColor ); for ( int i = 0; i < MAX_PROPOINTS * 2; ++i ) m_propoints[i] = NO_PROPORTION; } ~Element() {} bool isValid() const { return m_value > EPSILON; } double value() const { return m_value; } QColor valueColor() const { return m_valueColor; } int valuePattern() const { return m_valuePattern; } QString label() const { return m_label; } QColor labelColor() const { return m_labelColor; } double proX( int index ) const; double proY( int index ) const; void set( double value = INVALID, QColor valueColor = Qt::gray, int valuePattern = Qt::SolidPattern, const QString& label = QString::null, QColor labelColor = Qt::black ) { init( value, valueColor, valuePattern, label, labelColor ); } void setValue( double value ) { m_value = value; } void setValueColor( QColor valueColor ) { m_valueColor = valueColor; } void setValuePattern( int valuePattern ); void setLabel( const QString& label ) { m_label = label; } void setLabelColor( QColor labelColor ) { m_labelColor = labelColor; } void setProX( int index, double value ); void setProY( int index, double value ); private: void init( double value, QColor valueColor, int valuePattern, const QString& label, QColor labelColor ); double m_value; QColor m_valueColor; int m_valuePattern; QString m_label; QColor m_labelColor; double m_propoints[2 * MAX_PROPOINTS]; }; Q_EXPORT QTextStream &operator<<( QTextStream&, const Element& ); Q_EXPORT QTextStream &operator>>( QTextStream&, Element& ); #endif
#ifndef CHARTFORM_H #define CHARTFORM_H #include "element.h" #include <qmainwindow.h> #include <qstringlist.h> class CanvasView; class QAction; class QCanvas; class QFont; class QPrinter; class QString; class ChartForm: public QMainWindow { Q_OBJECT public: enum { MAX_ELEMENTS = 100 }; enum { MAX_RECENTFILES = 9 }; // Must not exceed 9 enum ChartType { PIE, VERTICAL_BAR, HORIZONTAL_BAR }; enum AddValuesType { NO, YES, AS_PERCENTAGE }; ChartForm( const QString& filename ); ~ChartForm(); int chartType() { return m_chartType; } void setChanged( bool changed = true ) { m_changed = changed; } void drawElements(); QPopupMenu *optionsMenu; // Why public? See canvasview.cpp private slots: void fileNew(); void fileOpen(); void fileOpenRecent( int index ); void fileSave(); void fileSaveAs(); void fileSaveAsPixmap(); void filePrint(); void fileQuit(); void optionsSetData(); void updateChartType( QAction *action ); void optionsSetFont(); void optionsSetOptions(); void helpHelp(); void helpAbout(); void helpAboutQt(); void saveOptions(); private: void init(); void load( const QString& filename ); bool okToClear(); void drawPieChart( const double scales[], double total, int count ); void drawVerticalBarChart( const double scales[], double total, int count ); void drawHorizontalBarChart( const double scales[], double total, int count ); QString valueLabel( const QString& label, double value, double total ); void updateRecentFiles( const QString& filename ); void updateRecentFilesMenu(); void setChartType( ChartType chartType ); QPopupMenu *fileMenu; QAction *optionsPieChartAction; QAction *optionsHorizontalBarChartAction; QAction *optionsVerticalBarChartAction; QString m_filename; QStringList m_recentFiles; QCanvas *m_canvas; CanvasView *m_canvasView; bool m_changed; ElementVector m_elements; QPrinter *m_printer; ChartType m_chartType; AddValuesType m_addValues; int m_decimalPlaces; QFont m_font; }; #endif
Implementation:
#include "canvasview.h" #include "chartform.h" #include "optionsform.h" #include "setdataform.h" #include <qaction.h> #include <qapplication.h> #include <qcombobox.h> #include <qfile.h> #include <qfiledialog.h> #include <qfont.h> #include <qfontdialog.h> #include <qmenubar.h> #include <qmessagebox.h> #include <qpixmap.h> #include <qpopupmenu.h> #include <qprinter.h> #include <qradiobutton.h> #include <qsettings.h> #include <qspinbox.h> #include <qstatusbar.h> #include <qtoolbar.h> #include <qtoolbutton.h> #include "images/file_new.xpm" #include "images/file_open.xpm" #include "images/file_save.xpm" #include "images/file_print.xpm" #include "images/options_setdata.xpm" #include "images/options_setfont.xpm" #include "images/options_setoptions.xpm" #include "images/options_horizontalbarchart.xpm" #include "images/options_piechart.xpm" #include "images/options_verticalbarchart.xpm" const QString WINDOWS_REGISTRY = "/QtExamples"; const QString APP_KEY = "/Chart/"; ChartForm::ChartForm( const QString& filename ) : QMainWindow( 0, 0, WDestructiveClose ) { setIcon( QPixmap( options_piechart ) ); QAction *fileNewAction; QAction *fileOpenAction; QAction *fileSaveAction; QAction *fileSaveAsAction; QAction *fileSaveAsPixmapAction; QAction *filePrintAction; QAction *fileQuitAction; QAction *optionsSetDataAction; QAction *optionsSetFontAction; QAction *optionsSetOptionsAction; fileNewAction = new QAction( "New Chart", QPixmap( file_new ), "&New", CTRL+Key_N, this, "new" ); connect( fileNewAction, SIGNAL( activated() ), this, SLOT( fileNew() ) ); fileOpenAction = new QAction( "Open Chart", QPixmap( file_open ), "&Open...", CTRL+Key_O, this, "open" ); connect( fileOpenAction, SIGNAL( activated() ), this, SLOT( fileOpen() ) ); fileSaveAction = new QAction( "Save Chart", QPixmap( file_save ), "&Save", CTRL+Key_S, this, "save" ); connect( fileSaveAction, SIGNAL( activated() ), this, SLOT( fileSave() ) ); fileSaveAsAction = new QAction( "Save Chart As", QPixmap( file_save ), "Save &As...", 0, this, "save as" ); connect( fileSaveAsAction, SIGNAL( activated() ), this, SLOT( fileSaveAs() ) ); fileSaveAsPixmapAction = new QAction( "Save Chart As Bitmap", QPixmap( file_save ), "Save As &Bitmap...", CTRL+Key_B, this, "save as bitmap" ); connect( fileSaveAsPixmapAction, SIGNAL( activated() ), this, SLOT( fileSaveAsPixmap() ) ); filePrintAction = new QAction( "Print Chart", QPixmap( file_print ), "&Print Chart...", CTRL+Key_P, this, "print chart" ); connect( filePrintAction, SIGNAL( activated() ), this, SLOT( filePrint() ) ); optionsSetDataAction = new QAction( "Set Data", QPixmap( options_setdata ), "Set &Data...", CTRL+Key_D, this, "set data" ); connect( optionsSetDataAction, SIGNAL( activated() ), this, SLOT( optionsSetData() ) ); QActionGroup *chartGroup = new QActionGroup( this ); // Connected later chartGroup->setExclusive( true ); optionsPieChartAction = new QAction( "Pie Chart", QPixmap( options_piechart ), "&Pie Chart", CTRL+Key_I, chartGroup, "pie chart" ); optionsPieChartAction->setToggleAction( true ); optionsHorizontalBarChartAction = new QAction( "Horizontal Bar Chart", QPixmap( options_horizontalbarchart ), "&Horizontal Bar Chart", CTRL+Key_H, chartGroup, "horizontal bar chart" ); optionsHorizontalBarChartAction->setToggleAction( true ); optionsVerticalBarChartAction = new QAction( "Vertical Bar Chart", QPixmap( options_verticalbarchart ), "&Vertical Bar Chart", CTRL+Key_V, chartGroup, "Vertical bar chart" ); optionsVerticalBarChartAction->setToggleAction( true ); optionsSetFontAction = new QAction( "Set Font", QPixmap( options_setfont ), "Set &Font...", CTRL+Key_F, this, "set font" ); connect( optionsSetFontAction, SIGNAL( activated() ), this, SLOT( optionsSetFont() ) ); optionsSetOptionsAction = new QAction( "Set Options", QPixmap( options_setoptions ), "Set &Options...", 0, this, "set options" ); connect( optionsSetOptionsAction, SIGNAL( activated() ), this, SLOT( optionsSetOptions() ) ); fileQuitAction = new QAction( "Quit", "&Quit", CTRL+Key_Q, this, "quit" ); connect( fileQuitAction, SIGNAL( activated() ), this, SLOT( fileQuit() ) ); QToolBar* fileTools = new QToolBar( this, "file operations" ); fileTools->setLabel( "File Operations" ); fileNewAction->addTo( fileTools ); fileOpenAction->addTo( fileTools ); fileSaveAction->addTo( fileTools ); fileTools->addSeparator(); filePrintAction->addTo( fileTools ); QToolBar *optionsTools = new QToolBar( this, "options operations" ); optionsTools->setLabel( "Options Operations" ); optionsSetDataAction->addTo( optionsTools ); optionsTools->addSeparator(); optionsPieChartAction->addTo( optionsTools ); optionsHorizontalBarChartAction->addTo( optionsTools ); optionsVerticalBarChartAction->addTo( optionsTools ); optionsTools->addSeparator(); optionsSetFontAction->addTo( optionsTools ); optionsTools->addSeparator(); optionsSetOptionsAction->addTo( optionsTools ); fileMenu = new QPopupMenu( this ); menuBar()->insertItem( "&File", fileMenu ); fileNewAction->addTo( fileMenu ); fileOpenAction->addTo( fileMenu ); fileSaveAction->addTo( fileMenu ); fileSaveAsAction->addTo( fileMenu ); fileMenu->insertSeparator(); fileSaveAsPixmapAction->addTo( fileMenu ); fileMenu->insertSeparator(); filePrintAction->addTo( fileMenu ); fileMenu->insertSeparator(); fileQuitAction->addTo( fileMenu ); fileMenu->insertSeparator(); optionsMenu = new QPopupMenu( this ); menuBar()->insertItem( "&Options", optionsMenu ); optionsSetDataAction->addTo( optionsMenu ); optionsMenu->insertSeparator(); optionsPieChartAction->addTo( optionsMenu ); optionsHorizontalBarChartAction->addTo( optionsMenu ); optionsVerticalBarChartAction->addTo( optionsMenu ); optionsMenu->insertSeparator(); optionsSetFontAction->addTo( optionsMenu ); optionsMenu->insertSeparator(); optionsSetOptionsAction->addTo( optionsMenu ); menuBar()->insertSeparator(); QPopupMenu *helpMenu = new QPopupMenu( this ); menuBar()->insertItem( "&Help", helpMenu ); helpMenu->insertItem( "&Help", this, SLOT(helpHelp()), Key_F1 ); helpMenu->insertItem( "&About", this, SLOT(helpAbout()) ); helpMenu->insertItem( "About &Qt", this, SLOT(helpAboutQt()) ); m_printer = 0; m_elements.resize( MAX_ELEMENTS ); QSettings settings; settings.insertSearchPath( QSettings::Windows, WINDOWS_REGISTRY ); int windowWidth = settings.readNumEntry( APP_KEY + "WindowWidth", 460 ); int windowHeight = settings.readNumEntry( APP_KEY + "WindowHeight", 530 ); int windowX = settings.readNumEntry( APP_KEY + "WindowX", 0 ); int windowY = settings.readNumEntry( APP_KEY + "WindowY", 0 ); setChartType( ChartType( settings.readNumEntry( APP_KEY + "ChartType", int(PIE) ) ) ); m_addValues = AddValuesType( settings.readNumEntry( APP_KEY + "AddValues", int(NO) )); m_decimalPlaces = settings.readNumEntry( APP_KEY + "Decimals", 2 ); m_font = QFont( "Helvetica", 18, QFont::Bold ); m_font.fromString( settings.readEntry( APP_KEY + "Font", m_font.toString() ) ); for ( int i = 0; i < MAX_RECENTFILES; ++i ) { QString filename = settings.readEntry( APP_KEY + "File" + QString::number( i + 1 ) ); if ( !filename.isEmpty() ) m_recentFiles.push_back( filename ); } if ( m_recentFiles.count() ) updateRecentFilesMenu(); // Connect *after* we've set the chart type on so we don't call // drawElements() prematurely. connect( chartGroup, SIGNAL( selected(QAction*) ), this, SLOT( updateChartType(QAction*) ) ); resize( windowWidth, windowHeight ); move( windowX, windowY ); m_canvas = new QCanvas( this ); m_canvas->resize( width(), height() ); m_canvasView = new CanvasView( m_canvas, &m_elements, this ); setCentralWidget( m_canvasView ); m_canvasView->show(); if ( !filename.isEmpty() ) load( filename ); else { init(); m_elements[0].set( 20, red, 14, "Red" ); m_elements[1].set( 70, cyan, 2, "Cyan", darkGreen ); m_elements[2].set( 35, blue, 11, "Blue" ); m_elements[3].set( 55, yellow, 1, "Yellow", darkBlue ); m_elements[4].set( 80, magenta, 1, "Magenta" ); drawElements(); } statusBar()->message( "Ready", 2000 ); } ChartForm::~ChartForm() { delete m_printer; } void ChartForm::init() { setCaption( "Chart" ); m_filename = QString::null; m_changed = false; m_elements[0] = Element( Element::INVALID, red ); m_elements[1] = Element( Element::INVALID, cyan ); m_elements[2] = Element( Element::INVALID, blue ); m_elements[3] = Element( Element::INVALID, yellow ); m_elements[4] = Element( Element::INVALID, green ); m_elements[5] = Element( Element::INVALID, magenta ); m_elements[6] = Element( Element::INVALID, darkYellow ); m_elements[7] = Element( Element::INVALID, darkRed ); m_elements[8] = Element( Element::INVALID, darkCyan ); m_elements[9] = Element( Element::INVALID, darkGreen ); m_elements[10] = Element( Element::INVALID, darkMagenta ); m_elements[11] = Element( Element::INVALID, darkBlue ); for ( int i = 12; i < MAX_ELEMENTS; ++i ) { double x = (double(i) / MAX_ELEMENTS) * 360; int y = (int(x * 256) % 105) + 151; int z = ((i * 17) % 105) + 151; m_elements[i] = Element( Element::INVALID, QColor( int(x), y, z, QColor::Hsv ) ); } } void ChartForm::fileNew() { if ( okToClear() ) { init(); drawElements(); } } void ChartForm::fileOpen() { if ( !okToClear() ) return; QString filename = QFileDialog::getOpenFileName( QString::null, "Charts (*.cht)", this, "file open", "Chart -- File Open" ); if ( !filename.isEmpty() ) load( filename ); else statusBar()->message( "File Open abandoned", 2000 ); } void ChartForm::fileSaveAs() { QString filename = QFileDialog::getSaveFileName( QString::null, "Charts (*.cht)", this, "file save as", "Chart -- File Save As" ); if ( !filename.isEmpty() ) { int answer = 0; if ( QFile::exists( filename ) ) answer = QMessageBox::warning( this, "Chart -- Overwrite File", QString( "Overwrite\n\'%1\'?" ). arg( filename ), "&Yes", "&No", QString::null, 1, 1 ); if ( answer == 0 ) { m_filename = filename; updateRecentFiles( filename ); fileSave(); return; } } statusBar()->message( "Saving abandoned", 2000 ); } void ChartForm::fileOpenRecent( int index ) { if ( !okToClear() ) return; load( m_recentFiles[index] ); } void ChartForm::updateRecentFiles( const QString& filename ) { if ( m_recentFiles.find( filename ) != m_recentFiles.end() ) return; m_recentFiles.push_back( filename ); if ( m_recentFiles.count() > MAX_RECENTFILES ) m_recentFiles.pop_front(); updateRecentFilesMenu(); } void ChartForm::updateRecentFilesMenu() { for ( int i = 0; i < MAX_RECENTFILES; ++i ) { if ( fileMenu->findItem( i ) ) fileMenu->removeItem( i ); if ( i < int(m_recentFiles.count()) ) fileMenu->insertItem( QString( "&%1 %2" ). arg( i + 1 ).arg( m_recentFiles[i] ), this, SLOT( fileOpenRecent(int) ), 0, i ); } } void ChartForm::fileQuit() { if ( okToClear() ) { saveOptions(); qApp->exit( 0 ); } } bool ChartForm::okToClear() { if ( m_changed ) { QString msg; if ( m_filename.isEmpty() ) msg = "Unnamed chart "; else msg = QString( "Chart '%1'\n" ).arg( m_filename ); msg += "has been changed."; switch( QMessageBox::information( this, "Chart -- Unsaved Changes", msg, "&Save", "Cancel", "&Abandon", 0, 1 ) ) { case 0: fileSave(); break; case 1: default: return false; break; case 2: break; } } return true; } void ChartForm::saveOptions() { QSettings settings; settings.insertSearchPath( QSettings::Windows, WINDOWS_REGISTRY ); settings.writeEntry( APP_KEY + "WindowWidth", width() ); settings.writeEntry( APP_KEY + "WindowHeight", height() ); settings.writeEntry( APP_KEY + "WindowX", x() ); settings.writeEntry( APP_KEY + "WindowY", y() ); settings.writeEntry( APP_KEY + "ChartType", int(m_chartType) ); settings.writeEntry( APP_KEY + "AddValues", int(m_addValues) ); settings.writeEntry( APP_KEY + "Decimals", m_decimalPlaces ); settings.writeEntry( APP_KEY + "Font", m_font.toString() ); for ( int i = 0; i < int(m_recentFiles.count()); ++i ) settings.writeEntry( APP_KEY + "File" + QString::number( i + 1 ), m_recentFiles[i] ); } void ChartForm::optionsSetData() { SetDataForm *setDataForm = new SetDataForm( &m_elements, m_decimalPlaces, this ); if ( setDataForm->exec() ) { m_changed = true; drawElements(); } delete setDataForm; } void ChartForm::setChartType( ChartType chartType ) { m_chartType = chartType; switch ( m_chartType ) { case PIE: optionsPieChartAction->setOn( true ); break; case VERTICAL_BAR: optionsVerticalBarChartAction->setOn( true ); break; case HORIZONTAL_BAR: optionsHorizontalBarChartAction->setOn( true ); break; } } void ChartForm::updateChartType( QAction *action ) { if ( action == optionsPieChartAction ) { m_chartType = PIE; } else if ( action == optionsHorizontalBarChartAction ) { m_chartType = HORIZONTAL_BAR; } else if ( action == optionsVerticalBarChartAction ) { m_chartType = VERTICAL_BAR; } drawElements(); } void ChartForm::optionsSetFont() { bool ok; QFont font = QFontDialog::getFont( &ok, m_font, this ); if ( ok ) { m_font = font; drawElements(); } } void ChartForm::optionsSetOptions() { OptionsForm *optionsForm = new OptionsForm( this ); optionsForm->chartTypeComboBox->setCurrentItem( m_chartType ); optionsForm->setFont( m_font ); switch ( m_addValues ) { case NO: optionsForm->noRadioButton->setChecked( true ); break; case YES: optionsForm->yesRadioButton->setChecked( true ); break; case AS_PERCENTAGE: optionsForm->asPercentageRadioButton->setChecked( true ); break; } optionsForm->decimalPlacesSpinBox->setValue( m_decimalPlaces ); if ( optionsForm->exec() ) { setChartType( ChartType( optionsForm->chartTypeComboBox->currentItem()) ); m_font = optionsForm->font(); if ( optionsForm->noRadioButton->isChecked() ) m_addValues = NO; else if ( optionsForm->yesRadioButton->isChecked() ) m_addValues = YES; else if ( optionsForm->asPercentageRadioButton->isChecked() ) m_addValues = AS_PERCENTAGE; m_decimalPlaces = optionsForm->decimalPlacesSpinBox->value(); drawElements(); } delete optionsForm; } void ChartForm::helpHelp() { statusBar()->message( "Help is not implemented yet", 2000 ); } void ChartForm::helpAbout() { QMessageBox::about( this, "Chart -- About", "<center><h1><font color=blue>Chart<font></h1></center>" "<p>Chart your data with <i>chart</i>.</p>" ); } void ChartForm::helpAboutQt() { QMessageBox::aboutQt( this, "Chart -- About Qt" ); }
Main:
#include <qapplication.h> #include "chartform.h" int main( int argc, char *argv[] ) { QApplication app( argc, argv ); QString filename; if ( app.argc() > 1 ) { filename = app.argv()[1]; if ( !filename.endsWith( ".cht" ) ) filename = QString::null; } ChartForm *cf = new ChartForm( filename ); app.setMainWidget( cf ); cf->show(); app.connect( &app, SIGNAL(lastWindowClosed()), cf, SLOT(fileQuit()) ); return app.exec(); }
See also Step-by-step Examples.
| Copyright © 2002 Trolltech | Trademarks | Qt version 3.0.5
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