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50
51 #include "codeeditor.h"
52
53 #include <QPainter>
54 #include <QTextBlock>
55
56 //![constructor]
57
CodeEditor(QWidget * parent)58 CodeEditor::CodeEditor(QWidget *parent) : QPlainTextEdit(parent)
59 {
60 lineNumberArea = new LineNumberArea(this);
61
62 connect(this, &CodeEditor::blockCountChanged, this, &CodeEditor::updateLineNumberAreaWidth);
63 connect(this, &CodeEditor::updateRequest, this, &CodeEditor::updateLineNumberArea);
64 connect(this, &CodeEditor::cursorPositionChanged, this, &CodeEditor::highlightCurrentLine);
65
66 updateLineNumberAreaWidth(0);
67 highlightCurrentLine();
68 }
69
70 //![constructor]
71
72 //![extraAreaWidth]
73
lineNumberAreaWidth()74 int CodeEditor::lineNumberAreaWidth()
75 {
76 int digits = 1;
77 int max = qMax(1, blockCount());
78 while (max >= 10) {
79 max /= 10;
80 ++digits;
81 }
82
83 int space = 3 + fontMetrics().horizontalAdvance(QLatin1Char('9')) * digits;
84
85 return space;
86 }
87
88 //![extraAreaWidth]
89
90 //![slotUpdateExtraAreaWidth]
91
updateLineNumberAreaWidth(int)92 void CodeEditor::updateLineNumberAreaWidth(int /* newBlockCount */)
93 {
94 setViewportMargins(lineNumberAreaWidth(), 0, 0, 0);
95 }
96
97 //![slotUpdateExtraAreaWidth]
98
99 //![slotUpdateRequest]
100
updateLineNumberArea(const QRect & rect,int dy)101 void CodeEditor::updateLineNumberArea(const QRect &rect, int dy)
102 {
103 if (dy)
104 lineNumberArea->scroll(0, dy);
105 else
106 lineNumberArea->update(0, rect.y(), lineNumberArea->width(), rect.height());
107
108 if (rect.contains(viewport()->rect()))
109 updateLineNumberAreaWidth(0);
110 }
111
112 //![slotUpdateRequest]
113
114 //![resizeEvent]
115
resizeEvent(QResizeEvent * e)116 void CodeEditor::resizeEvent(QResizeEvent *e)
117 {
118 QPlainTextEdit::resizeEvent(e);
119
120 QRect cr = contentsRect();
121 lineNumberArea->setGeometry(QRect(cr.left(), cr.top(), lineNumberAreaWidth(), cr.height()));
122 }
123
124 //![resizeEvent]
125
126 //![cursorPositionChanged]
127
highlightCurrentLine()128 void CodeEditor::highlightCurrentLine()
129 {
130 QList<QTextEdit::ExtraSelection> extraSelections;
131
132 if (!isReadOnly()) {
133 QTextEdit::ExtraSelection selection;
134
135 QColor lineColor = QColor(Qt::yellow).lighter(160);
136
137 selection.format.setBackground(lineColor);
138 selection.format.setProperty(QTextFormat::FullWidthSelection, true);
139 selection.cursor = textCursor();
140 selection.cursor.clearSelection();
141 extraSelections.append(selection);
142 }
143
144 setExtraSelections(extraSelections);
145 }
146
147 //![cursorPositionChanged]
148
149 //![extraAreaPaintEvent_0]
150
lineNumberAreaPaintEvent(QPaintEvent * event)151 void CodeEditor::lineNumberAreaPaintEvent(QPaintEvent *event)
152 {
153 QPainter painter(lineNumberArea);
154 painter.fillRect(event->rect(), Qt::lightGray);
155
156 //![extraAreaPaintEvent_0]
157
158 //![extraAreaPaintEvent_1]
159 QTextBlock block = firstVisibleBlock();
160 int blockNumber = block.blockNumber();
161 int top = qRound(blockBoundingGeometry(block).translated(contentOffset()).top());
162 int bottom = top + qRound(blockBoundingRect(block).height());
163 //![extraAreaPaintEvent_1]
164
165 //![extraAreaPaintEvent_2]
166 while (block.isValid() && top <= event->rect().bottom()) {
167 if (block.isVisible() && bottom >= event->rect().top()) {
168 QString number = QString::number(blockNumber + 1);
169 painter.setPen(Qt::black);
170 painter.drawText(0, top, lineNumberArea->width(), fontMetrics().height(),
171 Qt::AlignRight, number);
172 }
173
174 block = block.next();
175 top = bottom;
176 bottom = top + qRound(blockBoundingRect(block).height());
177 ++blockNumber;
178 }
179 }
180 //![extraAreaPaintEvent_2]
181
182