codeeditor.h Example File

 /****************************************************************************
 **
 ** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
 ** All rights reserved.
 ** Contact: Nokia Corporation ([email protected])
 **
 ** 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."
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #ifndef CODEEDITOR_H
 #define CODEEDITOR_H

 #include <QPlainTextEdit>
 #include <QObject>

 class QPaintEvent;
 class QResizeEvent;
 class QSize;
 class QWidget;

 class LineNumberArea;


 class CodeEditor : public QPlainTextEdit
 {
     Q_OBJECT

 public:
     CodeEditor(QWidget *parent = 0);

     void lineNumberAreaPaintEvent(QPaintEvent *event);
     int lineNumberAreaWidth();

 protected:
     void resizeEvent(QResizeEvent *event);

 private slots:
     void updateLineNumberAreaWidth(int newBlockCount);
     void highlightCurrentLine();
     void updateLineNumberArea(const QRect &, int);

 private:
     QWidget *lineNumberArea;
 };


 class LineNumberArea : public QWidget
 {
 public:
     LineNumberArea(CodeEditor *editor) : QWidget(editor) {
         codeEditor = editor;
     }

     QSize sizeHint() const {
         return QSize(codeEditor->lineNumberAreaWidth(), 0);
     }

 protected:
     void paintEvent(QPaintEvent *event) {
         codeEditor->lineNumberAreaPaintEvent(event);
     }

 private:
     CodeEditor *codeEditor;
 };


 #endif