textfinder.cpp Example File

 /****************************************************************************
 **
 ** Copyright (C) 2011 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 = qFindChild<QPushButton*>(this, "findButton");
     ui_textEdit = qFindChild<QTextEdit*>(this, "textEdit");
     ui_lineEdit = qFindChild<QLineEdit*>(this, "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.");
         }
     }
 }