Custom Completer Example | Qt Widgets 5.13.0

Qt 5.13 | Qt Widgets | Custom Completer Example

Qt 5.13.0 Reference Documentation

# Custom Completer Example

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      #include <QtWidgets>
      #include "mainwindow.h"
      #include "textedit.h"

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

          completingTextEdit = new TextEdit;
          completer = new QCompleter(this);
          completer->setModel(modelFromFile(":/resources/wordlist.txt"));
          completer->setModelSorting(QCompleter::CaseInsensitivelySortedModel);
          completer->setCaseSensitivity(Qt::CaseInsensitive);
          completer->setWrapAround(false);
          completingTextEdit->setCompleter(completer);

          setCentralWidget(completingTextEdit);
          resize(500, 300);
          setWindowTitle(tr("Completer"));
      }

      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, &QAction::triggered, qApp, &QApplication::quit);
          connect(aboutAct, &QAction::triggered, this, &MainWindow::about);
          connect(aboutQtAct, &QAction::triggered, qApp, &QApplication::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
          QGuiApplication::setOverrideCursor(QCursor(Qt::WaitCursor));
      #endif
          QStringList words;

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

      #ifndef QT_NO_CURSOR
          QGuiApplication::restoreOverrideCursor();
      #endif
          return new QStringListModel(words, completer);
      }

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