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3 ** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
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7 ** This file is part of the examples of the Qt Toolkit.
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40
41 #include <QtGui>
42
43 #include "codeeditor.h"
44
45 //![constructor]
46
CodeEditor(QWidget * parent)47 CodeEditor::CodeEditor(QWidget *parent) : QPlainTextEdit(parent)
48 {
49 lineNumberArea = new LineNumberArea(this);
50
51 connect(this, SIGNAL(blockCountChanged(int)), this, SLOT(updateLineNumberAreaWidth(int)));
52 connect(this, SIGNAL(updateRequest(QRect,int)), this, SLOT(updateLineNumberArea(QRect,int)));
53 connect(this, SIGNAL(cursorPositionChanged()), this, SLOT(highlightCurrentLine()));
54
55 updateLineNumberAreaWidth(0);
56 highlightCurrentLine();
57 }
58
59 //![constructor]
60
61 //![extraAreaWidth]
62
lineNumberAreaWidth()63 int CodeEditor::lineNumberAreaWidth()
64 {
65 int digits = 1;
66 int max = qMax(1, blockCount());
67 while (max >= 10) {
68 max /= 10;
69 ++digits;
70 }
71
72 int space = 3 + fontMetrics().width(QChar('9')) * digits;
73
74 return space;
75 }
76
77 //![extraAreaWidth]
78
79 //![slotUpdateExtraAreaWidth]
80
updateLineNumberAreaWidth(int)81 void CodeEditor::updateLineNumberAreaWidth(int /* newBlockCount */)
82 {
83 setViewportMargins(lineNumberAreaWidth(), 0, 0, 0);
84 }
85
86 //![slotUpdateExtraAreaWidth]
87
88 //![slotUpdateRequest]
89
updateLineNumberArea(const QRect & rect,int dy)90 void CodeEditor::updateLineNumberArea(const QRect &rect, int dy)
91 {
92 if (dy)
93 lineNumberArea->scroll(0, dy);
94 else
95 lineNumberArea->update(0, rect.y(), lineNumberArea->width(), rect.height());
96
97 if (rect.contains(viewport()->rect()))
98 updateLineNumberAreaWidth(0);
99 }
100
101 //![slotUpdateRequest]
102
103 //![resizeEvent]
104
resizeEvent(QResizeEvent * e)105 void CodeEditor::resizeEvent(QResizeEvent *e)
106 {
107 QPlainTextEdit::resizeEvent(e);
108
109 QRect cr = contentsRect();
110 lineNumberArea->setGeometry(QRect(cr.left(), cr.top(), lineNumberAreaWidth(), cr.height()));
111 }
112
113 //![resizeEvent]
114
115 //![cursorPositionChanged]
116
highlightCurrentLine()117 void CodeEditor::highlightCurrentLine()
118 {
119 QList<QTextEdit::ExtraSelection> extraSelections;
120
121 if (!isReadOnly()) {
122 QTextEdit::ExtraSelection selection;
123
124 QColor lineColor = QColor(Qt::yellow).lighter(160);
125
126 selection.format.setBackground(lineColor);
127 selection.format.setProperty(QTextFormat::FullWidthSelection, true);
128 selection.cursor = textCursor();
129 selection.cursor.clearSelection();
130 extraSelections.append(selection);
131 }
132
133 setExtraSelections(extraSelections);
134 }
135
136 //![cursorPositionChanged]
137
138 //![extraAreaPaintEvent_0]
139
lineNumberAreaPaintEvent(QPaintEvent * event)140 void CodeEditor::lineNumberAreaPaintEvent(QPaintEvent *event)
141 {
142 QPainter painter(lineNumberArea);
143 painter.fillRect(event->rect(), Qt::lightGray);
144
145 //![extraAreaPaintEvent_0]
146
147 //![extraAreaPaintEvent_1]
148 QTextBlock block = firstVisibleBlock();
149 int blockNumber = block.blockNumber();
150 int top = (int) blockBoundingGeometry(block).translated(contentOffset()).top();
151 int bottom = top + (int) blockBoundingRect(block).height();
152 //![extraAreaPaintEvent_1]
153
154 //![extraAreaPaintEvent_2]
155 while (block.isValid() && top <= event->rect().bottom()) {
156 if (block.isVisible() && bottom >= event->rect().top()) {
157 QString number = QString::number(blockNumber + 1);
158 painter.setPen(Qt::black);
159 painter.drawText(0, top, lineNumberArea->width(), fontMetrics().height(),
160 Qt::AlignRight, number);
161 }
162
163 block = block.next();
164 top = bottom;
165 bottom = top + (int) blockBoundingRect(block).height();
166 ++blockNumber;
167 }
168 }
169 //![extraAreaPaintEvent_2]
170
171