mainwindow.cpp Example File

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

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

      completer = new TreeModelCompleter(this);
      completer->setModel(modelFromFile(":/resources/treemodel.txt"));
      completer->setSeparator(QLatin1String("."));
      QObject::connect(completer, SIGNAL(highlighted(QModelIndex)),
                       this, SLOT(highlight(QModelIndex)));

      QWidget *centralWidget = new QWidget;

      QLabel *modelLabel = new QLabel;
      modelLabel->setText(tr("Tree Model<br>(Double click items to edit)"));

      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 *separatorLabel = new QLabel;
      separatorLabel->setText(tr("Tree Separator"));

      QLineEdit *separatorLineEdit = new QLineEdit;
      separatorLineEdit->setText(completer->separator());
      connect(separatorLineEdit, SIGNAL(textChanged(QString)),
              completer, SLOT(setSeparator(QString)));

      QCheckBox *wrapCheckBox = new QCheckBox;
      wrapCheckBox->setText(tr("Wrap around completions"));
      wrapCheckBox->setChecked(completer->wrapAround());
      connect(wrapCheckBox, SIGNAL(clicked(bool)), completer, SLOT(setWrapAround(bool)));

      contentsLabel = new QLabel;
      contentsLabel->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
      connect(separatorLineEdit, SIGNAL(textChanged(QString)),
              this, SLOT(updateContentsLabel(QString)));

      treeView = new QTreeView;
      treeView->setModel(completer->model());
      treeView->header()->hide();
      treeView->expandAll();

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

      lineEdit = new QLineEdit;
      lineEdit->setCompleter(completer);

      QGridLayout *layout = new QGridLayout;
      layout->addWidget(modelLabel, 0, 0); layout->addWidget(treeView, 0, 1);
      layout->addWidget(modeLabel, 1, 0);  layout->addWidget(modeCombo, 1, 1);
      layout->addWidget(caseLabel, 2, 0);  layout->addWidget(caseCombo, 2, 1);
      layout->addWidget(separatorLabel, 3, 0); layout->addWidget(separatorLineEdit, 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);

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

      setWindowTitle(tr("Tree Model 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);
  }

  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);

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

      QStandardItemModel *model = new QStandardItemModel(completer);
      QVector<QStandardItem *> parents(10);
      parents[0] = model->invisibleRootItem();

      while (!file.atEnd()) {
          QString line = file.readLine();
          QString trimmedLine = line.trimmed();
          if (line.isEmpty() || trimmedLine.isEmpty())
              continue;

          QRegularExpression re("^\\s+");
          QRegularExpressionMatch match = re.match(line);
          int nonws = match.capturedStart();
          int level = 0;
          if (nonws == -1) {
              level = 0;
          } else {
              if (line.startsWith("\t")) {
                  level = match.capturedLength();
              } else {
                  level = match.capturedLength()/4;
              }
          }

          if (level+1 >= parents.size())
              parents.resize(parents.size()*2);

          QStandardItem *item = new QStandardItem;
          item->setText(trimmedLine);
          parents[level]->appendRow(item);
          parents[level+1] = item;
      }

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

      return model;
  }

  void MainWindow::highlight(const QModelIndex &index)
  {
      QAbstractItemModel *completionModel = completer->completionModel();
      QAbstractProxyModel *proxy = qobject_cast<QAbstractProxyModel *>(completionModel);
      if (!proxy)
          return;
      QModelIndex sourceIndex = proxy->mapToSource(index);
      treeView->selectionModel()->select(sourceIndex, QItemSelectionModel::ClearAndSelect | QItemSelectionModel::Rows);
      treeView->scrollTo(index);
  }

  void MainWindow::about()
  {
      QMessageBox::about(this, tr("About"), tr("This example demonstrates how "
          "to use a QCompleter with a custom tree model."));
  }

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

  void MainWindow::updateContentsLabel(const QString& sep)
  {
      contentsLabel->setText(tr("Type path from model above with items at each level separated by a '%1'").arg(sep));
  }