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     7 ** This file is part of the examples of the Qt Toolkit.

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    16 ** GNU Lesser General Public License Usage

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    40 ****************************************************************************/

    41 

    42 #include <QtGui>

    43 

    44 #include "codeeditor.h"

    45 

    46 //![constructor]

    47 

    48 CodeEditor::CodeEditor(QWidget *parent) : QPlainTextEdit(parent)

    49 {

    50     lineNumberArea = new LineNumberArea(this);

    51 

    52     connect(this, SIGNAL(blockCountChanged(int)), this, SLOT(updateLineNumberAreaWidth(int)));

    53     connect(this, SIGNAL(updateRequest(const QRect &, int)), this, SLOT(updateLineNumberArea(const QRect &, int)));

    54     connect(this, SIGNAL(cursorPositionChanged()), this, SLOT(highlightCurrentLine()));

    55 

    56     updateLineNumberAreaWidth(0);

    57     highlightCurrentLine();

    58 }

    59 

    60 //![constructor]

    61 

    62 //![extraAreaWidth]

    63 

    64 int CodeEditor::lineNumberAreaWidth()

    65 {

    66     int digits = 1;

    67     int max = qMax(1, blockCount());

    68     while (max >= 10) {

    69         max /= 10;

    70         ++digits;

    71     }

    72 

    73     int space = 3 + fontMetrics().width(QLatin1Char('9')) * digits;

    74 

    75     return space;

    76 }

    77 

    78 //![extraAreaWidth]

    79 

    80 //![slotUpdateExtraAreaWidth]

    81 

    82 void CodeEditor::updateLineNumberAreaWidth(int /* newBlockCount */)

    83 { 

    84     setViewportMargins(lineNumberAreaWidth(), 0, 0, 0);

    85 }

    86 

    87 //![slotUpdateExtraAreaWidth]

    88 

    89 //![slotUpdateRequest]

    90 

    91 void CodeEditor::updateLineNumberArea(const QRect &rect, int dy)

    92 {

    93     if (dy)

    94         lineNumberArea->scroll(0, dy);

    95     else

    96         lineNumberArea->update(0, rect.y(), lineNumberArea->width(), rect.height());

    97 

    98     if (rect.contains(viewport()->rect()))

    99         updateLineNumberAreaWidth(0);

   100 }

   101 

   102 //![slotUpdateRequest]

   103 

   104 //![resizeEvent]

   105 

   106 void CodeEditor::resizeEvent(QResizeEvent *e)

   107 {

   108     QPlainTextEdit::resizeEvent(e);

   109 

   110     QRect cr = contentsRect();

   111     lineNumberArea->setGeometry(QRect(cr.left(), cr.top(), lineNumberAreaWidth(), cr.height()));

   112 }

   113 

   114 //![resizeEvent]

   115 

   116 //![cursorPositionChanged]

   117 

   118 void CodeEditor::highlightCurrentLine()

   119 {

   120     QList<QTextEdit::ExtraSelection> extraSelections;

   121 

   122     if (!isReadOnly()) {

   123         QTextEdit::ExtraSelection selection;

   124         

   125         QColor lineColor = QColor(Qt::yellow).lighter(160);

   126 

   127         selection.format.setBackground(lineColor);

   128         selection.format.setProperty(QTextFormat::FullWidthSelection, true);

   129         selection.cursor = textCursor();

   130         selection.cursor.clearSelection();

   131         extraSelections.append(selection);

   132     }

   133 

   134     setExtraSelections(extraSelections);

   135 }

   136 

   137 //![cursorPositionChanged]

   138 

   139 //![extraAreaPaintEvent_0]

   140 

   141 void CodeEditor::lineNumberAreaPaintEvent(QPaintEvent *event)

   142 {

   143     QPainter painter(lineNumberArea);

   144     painter.fillRect(event->rect(), Qt::lightGray);

   145 

   146 //![extraAreaPaintEvent_0]

   147 

   148 //![extraAreaPaintEvent_1]

   149     QTextBlock block = firstVisibleBlock();

   150     int blockNumber = block.blockNumber();

   151     int top = (int) blockBoundingGeometry(block).translated(contentOffset()).top();

   152     int bottom = top + (int) blockBoundingRect(block).height();

   153 //![extraAreaPaintEvent_1]

   154 

   155 //![extraAreaPaintEvent_2]

   156     while (block.isValid() && top <= event->rect().bottom()) {

   157         if (block.isVisible() && bottom >= event->rect().top()) {

   158             QString number = QString::number(blockNumber + 1);

   159             painter.setPen(Qt::black);

   160             painter.drawText(0, top, lineNumberArea->width(), fontMetrics().height(),

   161                              Qt::AlignRight, number);

   162         }

   163 

   164         block = block.next();

   165         top = bottom;

   166         bottom = top + (int) blockBoundingRect(block).height();

   167         ++blockNumber;

   168     }

   169 }

   170 //![extraAreaPaintEvent_2]

   171