src/codeeditor.cpp

   1 #include <QtWidgets>
   2
   3 #include "codeeditor.h"
   4
   5 extern bool usingDarkTheme;
   6
   7 CodeEditor::CodeEditor(QWidget *parent) : QPlainTextEdit(parent)
   8 {
   9     lineNumberArea = new LineNumberArea(this);
  10
  11     connect(this, SIGNAL(blockCountChanged(int)), this,
  12             SLOT(updateLineNumberAreaWidth(int)));
  13     connect(this, SIGNAL(updateRequest(QRect, int)), this,
  14             SLOT(updateLineNumberArea(QRect, int)));
  15     connect(this, SIGNAL(cursorPositionChanged()), this,
  16             SLOT(highlightCurrentLine()));
  17
  18     updateLineNumberAreaWidth(0);
  19     highlightCurrentLine();
  20 }
  21
  22 int CodeEditor::lineNumberAreaWidth()
  23 {
  24     int digits = 1;
  25     int max = qMax(1, blockCount());
  26     while (max >= 10) {
  27         max /= 10;
  28         ++digits;
  29     }
  30
  31     int space = 3 + fontMetrics().horizontalAdvance(QLatin1Char('9')) * digits;
  32
  33     return space;
  34 }
  35
  36 void CodeEditor::updateLineNumberAreaWidth(int /* newBlockCount */)
  37 {
  38     setViewportMargins(lineNumberAreaWidth(), 0, 0, 0);
  39 }
  40
  41 void CodeEditor::updateLineNumberArea(const QRect &rect, int dy)
  42 {
  43     if (dy)
  44         lineNumberArea->scroll(0, dy);
  45     else
  46         lineNumberArea->update(0, rect.y(), lineNumberArea->width(),
  47                                rect.height());
  48
  49     if (rect.contains(viewport()->rect()))
  50         updateLineNumberAreaWidth(0);
  51 }
  52
  53 void CodeEditor::resizeEvent(QResizeEvent *e)
  54 {
  55     QPlainTextEdit::resizeEvent(e);
  56
  57     QRect cr = contentsRect();
  58     lineNumberArea->setGeometry(
  59         QRect(cr.left(), cr.top(), lineNumberAreaWidth(), cr.height()));
  60 }
  61
  62 void CodeEditor::highlightCurrentLine()
  63 {
  64     QList<QTextEdit::ExtraSelection> extraSelections;
  65
  66     if (!isReadOnly()) {
  67         QTextEdit::ExtraSelection selection;
  68
  69         QColor lineColor;
  70         if (usingDarkTheme)
  71             lineColor = QColor(Qt::darkGray).darker(150);
  72         else
  73             lineColor = QColor(Qt::yellow).lighter(160);
  74
  75         selection.format.setBackground(lineColor);
  76         selection.format.setProperty(QTextFormat::FullWidthSelection, true);
  77         selection.cursor = textCursor();
  78         selection.cursor.clearSelection();
  79         extraSelections.append(selection);
  80     }
  81
  82     setExtraSelections(extraSelections);
  83 }
  84
  85 void CodeEditor::lineNumberAreaPaintEvent(QPaintEvent *event)
  86 {
  87     QPainter painter(lineNumberArea);
  88     if (usingDarkTheme)
  89         painter.fillRect(event->rect(), QColor(Qt::darkGray).darker(150));
  90     else
  91         painter.fillRect(event->rect(), Qt::lightGray);
  92
  93     QTextBlock block = firstVisibleBlock();
  94     int blockNumber = block.blockNumber();
  95     int top =
  96         (int)blockBoundingGeometry(block).translated(contentOffset()).top();
  97     int bottom = top + (int)blockBoundingRect(block).height();
  98
  99     QColor penColor;
 100     if (usingDarkTheme)
 101         penColor = Qt::lightGray;
 102     else
 103         penColor = Qt::black;
 104
 105     while (block.isValid() && top <= event->rect().bottom()) {
 106         if (block.isVisible() && bottom >= event->rect().top()) {
 107             QString number = QString::number(blockNumber + 1);
 108             painter.setPen(penColor);
 109             painter.drawText(0, top, lineNumberArea->width(),
 110                              fontMetrics().height(), Qt::AlignRight, number);
 111         }
 112
 113         block = block.next();
 114         top = bottom;
 115         bottom = top + (int)blockBoundingRect(block).height();
 116         ++blockNumber;
 117     }
 118 }