mainwindow.cpp Example File | Qt Widgets 5.12.10

- Qt 5.12
- Qt Widgets
- Tree Model Completer Example
- mainwindow.cpp Example File
- Qt 5.12.10 Reference Documentation

# mainwindow.cpp Example File

tools/treemodelcompleter/mainwindow.cpp

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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(sourceIndex);
     }

     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));
     }