mainwindow.cpp Example File

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  #include <QtWidgets>
  #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()->setSectionResizeMode(0, QHeaderView::Stretch);
              treeView->header()->setSectionResizeMode(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."));
  }