pgLab/pglab/CodeEditor.cpp
2018-12-16 15:38:32 +01:00

156 lines
4.3 KiB
C++

#include "CodeEditor.h"
#include "EditorGutter.h"
#include <QPainter>
#include <QTextBlock>
//
// Adapted from codeeditor example
// http://doc.qt.io/qt-5/qtwidgets-widgets-codeeditor-example.html
//
// Used term gutter as I want to expand it to do other things to like error
// position marking.
//
CodeEditor::CodeEditor(QWidget *parent)
: QPlainTextEdit(parent)
, gutterArea(new EditorGutter(this))
{
connect(this, SIGNAL(blockCountChanged(int)), this, SLOT(updateGutterAreaWidth(int)));
connect(this, SIGNAL(updateRequest(QRect,int)), this, SLOT(updateGutterArea(QRect,int)));
connect(this, SIGNAL(cursorPositionChanged()), this, SLOT(highlightCurrentLine()));
connect(this, SIGNAL(textChanged()), this, SLOT(onTextChanged()));
setWordWrapMode(QTextOption::NoWrap);
updateGutterAreaWidth(0);
highlightCurrentLine();
}
int CodeEditor::gutterAreaWidth()
{
int digits = 1;
int max = qMax(1, blockCount());
while (max >= 10) {
max /= 10;
++digits;
}
int space = 3 + fontMetrics().width(QLatin1Char('9')) * (digits + 2);
return space;
}
void CodeEditor::updateGutterAreaWidth(int /* newBlockCount */)
{
setViewportMargins(gutterAreaWidth(), 0, 0, 0);
}
void CodeEditor::updateGutterArea(const QRect &rect, int dy)
{
if (dy)
gutterArea->scroll(0, dy);
else
gutterArea->update(0, rect.y(), gutterArea->width(), rect.height());
if (rect.contains(viewport()->rect()))
updateGutterAreaWidth(0);
}
void CodeEditor::resizeEvent(QResizeEvent *e)
{
QPlainTextEdit::resizeEvent(e);
QRect cr = contentsRect();
gutterArea->setGeometry(QRect(cr.left(), cr.top(), gutterAreaWidth(), cr.height()));
}
void CodeEditor::highlightCurrentLine()
{
QTextEdit::ExtraSelection selection;
QColor lineColor = QColor(Qt::yellow).lighter(160);
selection.format.setBackground(lineColor);
selection.format.setProperty(QTextFormat::FullWidthSelection, true);
selection.cursor = textCursor();
selection.cursor.clearSelection();
currentLine = selection;
updateExtraSelections();
}
void CodeEditor::onTextChanged()
{
clearErrorMarkers();
}
void CodeEditor::addErrorMarker(int position, int length)
{
QTextEdit::ExtraSelection selection;
QColor lineColor = QColor(Qt::red).lighter(160);
selection.format.setBackground(lineColor);
selection.format.setFontItalic(true);
selection.cursor = textCursor();
selection.cursor.setPosition(position);
int lineno = selection.cursor.blockNumber();
errorLines.insert(lineno);
selection.cursor.movePosition(QTextCursor::Right, QTextCursor::KeepAnchor, length);
errorMarkers.append(selection);
update();
updateExtraSelections();
}
void CodeEditor::clearErrorMarkers()
{
errorMarkers.clear();
errorLines.clear();
update();
updateExtraSelections();
}
void CodeEditor::updateExtraSelections()
{
QList<QTextEdit::ExtraSelection> extraSelections;
extraSelections.append(currentLine);
for (auto&& e : errorMarkers)
extraSelections.append(e);
setExtraSelections(extraSelections);
}
void CodeEditor::gutterAreaPaintEvent(QPaintEvent *event)
{
QPainter painter(gutterArea);
painter.fillRect(event->rect(), Qt::lightGray);
QTextBlock block = firstVisibleBlock();
int blockNumber = block.blockNumber();
int top = (int) blockBoundingGeometry(block).translated(contentOffset()).top();
int bottom = top + (int) blockBoundingRect(block).height();
// We will now loop through all visible lines and paint the line numbers in the
// extra area for each line. Notice that in a plain text edit each line will
// consist of one QTextBlock; though, if line wrapping is enabled, a line may span
// several rows in the text edit's viewport.
//
// We get the top and bottom y-coordinate of the first text block, and adjust these
// values by the height of the current text block in each iteration in the loop.
while (block.isValid() && top <= event->rect().bottom()) {
if (block.isVisible() && bottom >= event->rect().top()) {
QString number = QString::number(blockNumber + 1);
painter.setPen(Qt::black);
painter.drawText(0, top, gutterArea->width(), fontMetrics().height(),
Qt::AlignRight, number);
if (errorLines.count(blockNumber) > 0) {
int s = fontMetrics().height() - 8;
painter.setBrush(QBrush(Qt::red));
painter.drawEllipse(4, top + 4, s, s);
}
}
block = block.next();
top = bottom;
bottom = top + (int) blockBoundingRect(block).height();
++blockNumber;
}
}