Qt 4.8: mainwindow.cpp Example File (tools/completer/mainwindow.cpp)

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# mainwindow.cpp Example File

tools/completer/mainwindow.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2015 The Qt Company Ltd.
     ** Contact: http://www.qt.io/licensing/
     **
     ** This file is part of the examples of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:BSD$
     ** You may use this file under the terms of the BSD license as follows:
     **
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     ** modification, are permitted provided that the following conditions are
     ** met:
     **   * Redistributions of source code must retain the above copyright
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     **     notice, this list of conditions and the following disclaimer in
     **     the documentation and/or other materials provided with the
     **     distribution.
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     **     contributors may be used to endorse or promote products derived
     **     from this software without specific prior written permission.
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     #include <QtGui>
     #include "fsmodel.h"
     #include "mainwindow.h"

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

         QWidget *centralWidget = new QWidget;

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

         modelCombo = new QComboBox;
         modelCombo->addItem(tr("QFileSytemModel"));
         modelCombo->addItem(tr("QFileSytemModel 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"));
         caseCombo->setCurrentIndex(0);

         QLabel *maxVisibleLabel = new QLabel;
         maxVisibleLabel->setText(tr("Max Visible Items"));
         maxVisibleSpinBox = new QSpinBox;
         maxVisibleSpinBox->setRange(3,25);
         maxVisibleSpinBox->setValue(10);

         wrapCheckBox = new QCheckBox;
         wrapCheckBox->setText(tr("Wrap around completions"));
         wrapCheckBox->setChecked(true);

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

         connect(modelCombo, SIGNAL(activated(int)), this, SLOT(changeModel()));
         connect(modeCombo, SIGNAL(activated(int)), this, SLOT(changeMode(int)));
         connect(caseCombo, SIGNAL(activated(int)), this, SLOT(changeCase(int)));
         connect(maxVisibleSpinBox, SIGNAL(valueChanged(int)), this, SLOT(changeMaxVisible(int)));

         lineEdit = new QLineEdit;

         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(maxVisibleLabel, 3, 0); layout->addWidget(maxVisibleSpinBox, 3, 1);
         layout->addWidget(wrapCheckBox, 4, 0);
         layout->addWidget(contentsLabel, 5, 0, 1, 2);
         layout->addWidget(lineEdit, 6, 0, 1, 2);
         centralWidget->setLayout(layout);
         setCentralWidget(centralWidget);

         changeModel();

         setWindowTitle(tr("Completer"));
         lineEdit->setFocus();
     }

     void MainWindow::createMenu()
     {
         QAction *exitAction = new QAction(tr("Exit"), this);
         QAction *aboutAct = new QAction(tr("About"), this);
         QAction *aboutQtAct = new QAction(tr("About Qt"), this);

         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(exitAction);

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

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

     #ifndef QT_NO_CURSOR
         QApplication::setOverrideCursor(QCursor(Qt::WaitCursor));
     #endif
         QStringList words;

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

     #ifndef QT_NO_CURSOR
         QApplication::restoreOverrideCursor();
     #endif

         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::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);
     }

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

     void MainWindow::changeModel()
     {
         delete completer;
         completer = new QCompleter(this);
         completer->setMaxVisibleItems(maxVisibleSpinBox->value());

         switch (modelCombo->currentIndex()) {
         default:
         case 0:
             { // Unsorted QFileSystemModel
                 QFileSystemModel *fsModel = new QFileSystemModel(completer);
                 fsModel->setRootPath("");
                 completer->setModel(fsModel);
                 contentsLabel->setText(tr("Enter file path"));
             }
             break;
         case 1:
             {   // FileSystemModel that shows full paths
                 FileSystemModel *fsModel = new FileSystemModel(completer);
                 completer->setModel(fsModel);
                 fsModel->setRootPath("");
                 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;
         }

         changeMode(modeCombo->currentIndex());
         changeCase(caseCombo->currentIndex());
         completer->setWrapAround(wrapCheckBox->isChecked());
         lineEdit->setCompleter(completer);
         connect(wrapCheckBox, SIGNAL(clicked(bool)), completer, SLOT(setWrapAround(bool)));
     }

     void MainWindow::changeMaxVisible(int max)
     {
         completer->setMaxVisibleItems(max);
     }

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