CodeEditor cell first commit

Algorithm-visualizer/GUI/codeeditor.cpp

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+#include "codeeditor.h"
+#include "linenumberarea.h"
+
+CodeEditor::CodeEditor(QWidget *parent)
+{
+    lineNumberArea = new LineNumberArea(this);
+
+    connect(this, &CodeEditor::blockCountChanged, this, &CodeEditor::updateLineNumberAreaWidth);
+    connect(this, &CodeEditor::updateRequest, this, &CodeEditor::updateLineNumberArea);
+    connect(this, &CodeEditor::cursorPositionChanged, this, &CodeEditor::highlightCurrentLine);
+
+    updateLineNumberAreaWidth(0);
+    highlightCurrentLine();
+
+}
+
+int CodeEditor::lineNumberAreaWidth()
+{
+    int digits = 1;
+    int max = qMax(1, blockCount());
+    while (max >= 10){
+        max /=10;
+        digits++;
+    }
+
+    int space = 3 + fontMetrics().horizontalAdvance(QLatin1Char('9')) * digits;
+
+    return space;
+}
+
+void CodeEditor::updateLineNumberAreaWidth(int /*newBlockCount*/)
+{
+    setViewportMargins(lineNumberAreaWidth(), 0, 0, 0);
+}
+
+void CodeEditor::updateLineNumberArea(const QRect &rect, int dy)
+{
+    //dy holds the number of pixels, if it is non-zero we call scrol method between 0 and dy.
+    //else,
+    if (dy) {
+        lineNumberArea->scroll(0, dy);
+    }
+    else {
+        lineNumberArea->update(0, rect.y(), lineNumberArea->width(), rect.height());
+    }
+
+    if (rect.contains(viewport()->rect())) {
+        updateLineNumberAreaWidth(0);
+    }
+}
+
+void CodeEditor::resizeEvent(QResizeEvent *event)
+{
+    QPlainTextEdit::resizeEvent(event);
+
+    QRect cr = contentsRect();
+    lineNumberArea->setGeometry(QRect(cr.left(), cr.top(), lineNumberAreaWidth(), cr.height()));
+}
+
+void CodeEditor::highlightCurrentLine()
+{
+    QList<QTextEdit::ExtraSelection> extraSelections;
+
+    if(!isReadOnly()) {
+        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();
+        extraSelections.append(selection);
+    }
+
+    setExtraSelections(extraSelections);
+}
+
+void CodeEditor::lineNumberAreaPaintEvent(QPaintEvent *event)
+{
+    //We start by creating the painter to paint the background of the widget.
+    QPainter painter(lineNumberArea);
+    painter.fillRect(event->rect(), Qt::lightGray);
+
+    //Getting information on the blocks (i.e. the text lines)
+    QTextBlock block = firstVisibleBlock();
+    int blockNumber = block.blockNumber();
+    int top = qRound(blockBoundingGeometry(block).translated(contentOffset()).top()); //Need doc on this line
+    int bottom = top + qRound(blockBoundingRect(block).height()); //Need doc on this line as well (qRound??)
+
+    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, lineNumberArea->width(), fontMetrics().height(), Qt::AlignRight, number);
+        }
+
+        //We go to the next block
+        block = block.next();
+        top = bottom;
+        bottom = top + qRound(blockBoundingRect(block).height());
+        blockNumber++;
+    }
+}

Algorithm-visualizer/GUI/codeeditor.h

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+#ifndef CODEEDITOR_H
+#define CODEEDITOR_H
+
+#include <QPlainTextEdit>
+#include <QWidget>
+#include <QPainter>
+#include <QTextBlock>
+
+class CodeEditor : public QPlainTextEdit
+{
+    Q_OBJECT
+public:
+    CodeEditor(QWidget *parent = nullptr);
+
+    //Methos to paint the line numbers and to have acess to it's width
+    void lineNumberAreaPaintEvent(QPaintEvent *event);
+    int lineNumberAreaWidth();
+
+protected:
+    //We need to be able to resize in case the viewer scrolls or the number of lines changes (adding a line at the bottom)
+    void resizeEvent(QResizeEvent *event) override;
+
+private slots:
+    //Methods to modify the elements of the line number are
+    void updateLineNumberAreaWidth(int newBlockCount);
+    void highlightCurrentLine();
+    void updateLineNumberArea(const QRect &rect, int dy);
+
+private:
+    QWidget *lineNumberArea;
+};
+
+#endif // CODEEDITOR_H

Algorithm-visualizer/GUI/linenumberarea.cpp

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+#include "linenumberarea.h"

Algorithm-visualizer/GUI/linenumberarea.h

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+#ifndef LINENUMBERAREA_H
+#define LINENUMBERAREA_H
+
+#include <QWidget>
+
+#include "codeeditor.h"
+
+class LineNumberArea : public QWidget
+{
+    //Q_OBJECT
+public:
+    //Constructor, we initialize the code editor attribute as a QWidget
+    LineNumberArea(CodeEditor *editor) : QWidget(editor), codeEditor(editor)
+    {}
+
+    QSize sizeHint() const override
+    {
+        return QSize(codeEditor->lineNumberAreaWidth(), 0);
+    }
+
+protected:
+    void paintEvent(QPaintEvent *event) override
+    {
+        codeEditor->lineNumberAreaPaintEvent(event);
+    }
+
+private:
+    CodeEditor *codeEditor;
+};
+
+#endif // LINENUMBERAREA_H