Qt Reference Documentation

# textfinder.cpp Example File

uitools/textfinder/textfinder.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
     ** All rights reserved.
     ** Contact: Nokia Corporation (qt-info@nokia.com)
     **
     ** This file is part of the examples of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:BSD$
     ** You may use this file under the terms of the BSD license as follows:
     **
     ** "Redistribution and use in source and binary forms, with or without
     ** modification, are permitted provided that the following conditions are
     ** met:
     **   * Redistributions of source code must retain the above copyright
     **     notice, this list of conditions and the following disclaimer.
     **   * Redistributions in binary form must reproduce the above copyright
     **     notice, this list of conditions and the following disclaimer in
     **     the documentation and/or other materials provided with the
     **     distribution.
     **   * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
     **     the names of its contributors may be used to endorse or promote
     **     products derived from this software without specific prior written
     **     permission.
     **
     ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
     ** $QT_END_LICENSE$
     **
     ****************************************************************************/

     #include <QtUiTools>
     #include <QtGui>
     #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.");
             }
         }
     }