mainwindow.cpp Example File | Qt Widgets 5.12.5

Qt 5.12 | Qt Widgets | Completer Example | mainwindow.cpp Example File

Qt 5.12.5 Reference Documentation

# mainwindow.cpp Example File

tools/completer/mainwindow.cpp

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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."));
      }