Qt 5.8 | Qt UI Tools | Text Finder Example | textfinder.cpp Example File

Qt 5.8.0 Reference Documentation

# textfinder.cpp Example File

textfinder/textfinder.cpp

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      #include <QtUiTools>
      #include <QtWidgets>
      #include "textfinder.h"

      TextFinder::TextFinder(QWidget *parent)
          : QWidget(parent)
      {
          QWidget *formWidget = loadUiFile();

          ui_findButton = findChild<QPushButton*>("findButton");
          ui_textEdit = findChild<QTextEdit*>("textEdit");
          ui_lineEdit = findChild<QLineEdit*>("lineEdit");

          QMetaObject::connectSlotsByName(this);

          loadTextFile();

          QVBoxLayout *layout = new QVBoxLayout;
          layout->addWidget(formWidget);
          setLayout(layout);

          setWindowTitle(tr("Text Finder"));
          isFirstTime = true;
      }

      QWidget* TextFinder::loadUiFile()
      {
          QUiLoader loader;

          QFile file(":/forms/textfinder.ui");
          file.open(QFile::ReadOnly);

          QWidget *formWidget = loader.load(&file, this);
          file.close();

          return formWidget;
      }

      void TextFinder::loadTextFile()
      {
          QFile inputFile(":/forms/input.txt");
          inputFile.open(QIODevice::ReadOnly);
          QTextStream in(&inputFile);
          QString line = in.readAll();
          inputFile.close();

          ui_textEdit->append(line);
          ui_textEdit->setUndoRedoEnabled(false);
          ui_textEdit->setUndoRedoEnabled(true);
      }

      void TextFinder::on_findButton_clicked()
      {
          QString searchString = ui_lineEdit->text();
          QTextDocument *document = ui_textEdit->document();

          bool found = false;

          if (isFirstTime == false)
              document->undo();

          if (searchString.isEmpty()) {
              QMessageBox::information(this, tr("Empty Search Field"),
                      "The search field is empty. Please enter a word and click Find.");
          } else {

              QTextCursor highlightCursor(document);
              QTextCursor cursor(document);

              cursor.beginEditBlock();

              QTextCharFormat plainFormat(highlightCursor.charFormat());
              QTextCharFormat colorFormat = plainFormat;
              colorFormat.setForeground(Qt::red);

              while (!highlightCursor.isNull() && !highlightCursor.atEnd()) {
                  highlightCursor = document->find(searchString, highlightCursor, QTextDocument::FindWholeWords);

                  if (!highlightCursor.isNull()) {
                      found = true;
                      highlightCursor.movePosition(QTextCursor::WordRight,
                                             QTextCursor::KeepAnchor);
                      highlightCursor.mergeCharFormat(colorFormat);
                  }
              }

              cursor.endEditBlock();
              isFirstTime = false;

              if (found == false) {
                  QMessageBox::information(this, tr("Word Not Found"),
                      "Sorry, the word cannot be found.");
              }
          }
      }