mainwindow.cpp Example File
^{tools/completer/mainwindow.cpp}

 /****************************************************************************
 **
 ** Copyright (C) 2006-2007 Trolltech ASA. All rights reserved.
 **
 ** This file is part of the example classes of the Qt Toolkit.
 **
 ** This file may be used under the terms of the GNU General Public
 ** License version 2.0 as published by the Free Software Foundation
 ** and appearing in the file LICENSE.GPL included in the packaging of
 ** this file.  Please review the following information to ensure GNU
 ** General Public Licensing requirements will be met:
 ** http://www.trolltech.com/products/qt/opensource.html
 **
 ** If you are unsure which license is appropriate for your use, please
 ** review the following information:
 ** http://www.trolltech.com/products/qt/licensing.html or contact the
 ** sales department at sales@trolltech.com.
 **
 ** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 ** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 **
 ****************************************************************************/

 #include <QtGui>
 #include "dirmodel.h"
 #include "mainwindow.h"

 MainWindow::MainWindow(QWidget *parent)
     : QMainWindow(parent), completer(0), comboBox(0), lineEdit(0)
 {
     createMenu();

     QWidget *centralWidget = new QWidget;

     QLabel *modelLabel = new QLabel;
     modelLabel->setText(tr("Model"));

     modelCombo = new QComboBox;
     modelCombo->addItem(tr("QDirModel"));
     modelCombo->addItem(tr("QDirModel that shows full path"));
     modelCombo->addItem(tr("Country list"));
     modelCombo->addItem(tr("Word list"));
     modelCombo->setCurrentIndex(0);

     QLabel *modeLabel = new QLabel;
     modeLabel->setText(tr("Completion Mode"));
     modeCombo = new QComboBox;
     modeCombo->addItem(tr("Inline"));
     modeCombo->addItem(tr("Filtered Popup"));
     modeCombo->addItem(tr("Unfiltered Popup"));
     modeCombo->setCurrentIndex(1);

     QLabel *caseLabel = new QLabel;
     caseLabel->setText(tr("Case Sensitivity"));
     caseCombo = new QComboBox;
     caseCombo->addItem(tr("Case Insensitive"));
     caseCombo->addItem(tr("Case Sensitive"));
 #ifdef Q_OS_WIN
     caseCombo->setCurrentIndex(0);
 #else
     caseCombo->setCurrentIndex(1);
 #endif

     contentsLabel = new QLabel;
     contentsLabel->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);

     connect(modelCombo, SIGNAL(activated(int)), this, SLOT(updateModel()));
     connect(modeCombo, SIGNAL(activated(int)), this, SLOT(changeMode(int)));
     connect(caseCombo, SIGNAL(activated(int)), this, SLOT(changeCase(int)));

     QGridLayout *layout = new QGridLayout;
     layout->addWidget(modelLabel, 0, 0); layout->addWidget(modelCombo, 0, 1);
     layout->addWidget(modeLabel, 1, 0);  layout->addWidget(modeCombo, 1, 1);
     layout->addWidget(caseLabel, 2, 0);  layout->addWidget(caseCombo, 2, 1);
     layout->addWidget(contentsLabel, 3, 0, 1, 2);
     centralWidget->setLayout(layout);
     setCentralWidget(centralWidget);

     useComboBox(false);
     updateModel();
     changeCase(caseCombo->currentIndex());
     changeMode(modeCombo->currentIndex());

     setWindowTitle(tr("Completer"));
 }

 void MainWindow::createMenu()
 {
     QAction *comboAction = new QAction(tr("Show QComboBox"), this);
     comboAction->setCheckable(true);
     QAction *exitAction = new QAction(tr("Exit"), this);
     QAction *aboutAct = new QAction(tr("About"), this);
     QAction *aboutQtAct = new QAction(tr("About Qt"), this);

     connect(comboAction, SIGNAL(toggled(bool)), this, SLOT(useComboBox(bool)));
     connect(exitAction, SIGNAL(triggered()), qApp, SLOT(quit()));
     connect(aboutAct, SIGNAL(triggered()), this, SLOT(about()));
     connect(aboutQtAct, SIGNAL(triggered()), qApp, SLOT(aboutQt()));

     QMenu* fileMenu = menuBar()->addMenu(tr("File"));
     fileMenu->addAction(comboAction);
     fileMenu->addSeparator();
     fileMenu->addAction(exitAction);

     QMenu* helpMenu = menuBar()->addMenu(tr("About"));
     helpMenu->addAction(aboutAct);
     helpMenu->addAction(aboutQtAct);
 }

 void MainWindow::changeMode(int index)
 {
     QCompleter::CompletionMode mode;
     if (index == 0)
         mode = QCompleter::InlineCompletion;
     else if (index == 1)
         mode = QCompleter::PopupCompletion;
     else
         mode = QCompleter::UnfilteredPopupCompletion;

     completer->setCompletionMode(mode);
 }

 QAbstractItemModel *MainWindow::modelFromFile(const QString& fileName)
 {
     QFile file(fileName);
     if (!file.open(QFile::ReadOnly))
         return new QStringListModel(completer);

     QApplication::setOverrideCursor(QCursor(Qt::WaitCursor));
     QStringList words;

     while (!file.atEnd()) {
         QByteArray line = file.readLine();
         if (!line.isEmpty())
             words << line.trimmed();
     }

     QApplication::restoreOverrideCursor();

     if (!fileName.contains(QLatin1String("countries.txt")))
         return new QStringListModel(words, completer);

     // The last two chars of the countries.txt file indicate the country
     // symbol. We put that in column 2 of a standard item model
     QStandardItemModel *m = new QStandardItemModel(words.count(), 2, completer);
     for (int i = 0; i < words.count(); ++i) {
         QModelIndex countryIdx = m->index(i, 0);
         QModelIndex symbolIdx = m->index(i, 1);
         QString country = words[i].mid(0, words[i].length() - 2).trimmed();
         QString symbol = words[i].right(2);
         m->setData(countryIdx, country);
         m->setData(symbolIdx, symbol);
     }

     return m;
 }

 void MainWindow::updateModel()
 {
     if (completer) {
         comboBox ? comboBox->setCompleter(0) : lineEdit->setCompleter(0);
         delete completer;
     }
     completer = new QCompleter(this);
     comboBox ? comboBox->setCompleter(completer) : lineEdit->setCompleter(completer);

     switch (modelCombo->currentIndex()) {
     default:
     case 0:
         { // Unsorted QDirModel
             QDirModel *dirModel = new QDirModel(completer);
             completer->setModel(dirModel);
             contentsLabel->setText(tr("Enter file path"));
         }
         break;
     case 1:
         { // DirModel that shows full paths
             DirModel *dirModel = new DirModel(completer);
             completer->setModel(dirModel);
             contentsLabel->setText(tr("Enter file path"));
         }
         break;
     case 2:
         { // Country List
             completer->setModel(modelFromFile(":/resources/countries.txt"));
             QTreeView *treeView = new QTreeView;
             completer->setPopup(treeView);
             treeView->setRootIsDecorated(false);
             treeView->header()->hide();
             treeView->header()->setStretchLastSection(false);
             treeView->header()->setResizeMode(0, QHeaderView::Stretch);
             treeView->header()->setResizeMode(1, QHeaderView::ResizeToContents);
             contentsLabel->setText(tr("Enter name of your country"));
         }
         break;
     case 3:
         { // Word list
             completer->setModel(modelFromFile(":/resources/wordlist.txt"));
             completer->setModelSorting(QCompleter::CaseInsensitivelySortedModel);
             contentsLabel->setText(tr("Enter a word"));
         }
         break;
     }

     changeCase(caseCombo->currentIndex());
     changeMode(modeCombo->currentIndex());
 }

 void MainWindow::useComboBox(bool combo)
 {
     if ((comboBox && combo) || (lineEdit && !combo))
         return;
     if (combo) {
         delete lineEdit;
         lineEdit = 0;
         comboBox = new QComboBox;
         comboBox->setEditable(true);
         comboBox->setCompleter(completer);
         (static_cast<QGridLayout *>(centralWidget()->layout()))->addWidget(comboBox, 4, 0, 1, 2);
         comboBox->setFocus();
     } else {
         delete comboBox;
         comboBox = 0;
         lineEdit = new QLineEdit;
         lineEdit->setCompleter(completer);
         (static_cast<QGridLayout *>(centralWidget()->layout()))->addWidget(lineEdit, 4, 0, 1, 2);
         lineEdit->setFocus();
     }
 }

 void MainWindow::about()
 {
     QMessageBox::about(this, tr("About"), tr("This example demonstrates the "
         "different features of the QCompleter class."));
 }

 void MainWindow::changeCase(int cs)
 {
     completer->setCaseSensitivity(cs ? Qt::CaseSensitive : Qt::CaseInsensitive);
 }