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50
51#include "elidedlabel.h"
52
53#include <QPainter>
54#include <QSizePolicy>
55#include <QTextLayout>
56
57//! [0]
58ElidedLabel::ElidedLabel(const QString &text, QWidget *parent)
59 : QFrame(parent)
60 , elided(false)
61 , content(text)
62{
63 setSizePolicy(hor: QSizePolicy::Expanding, ver: QSizePolicy::Preferred);
64}
65//! [0]
66
67//! [1]
68void ElidedLabel::setText(const QString &newText)
69{
70 content = newText;
71 update();
72}
73//! [1]
74
75//! [2]
76void ElidedLabel::paintEvent(QPaintEvent *event)
77{
78 QFrame::paintEvent(event);
79
80 QPainter painter(this);
81 QFontMetrics fontMetrics = painter.fontMetrics();
82
83 bool didElide = false;
84 int lineSpacing = fontMetrics.lineSpacing();
85 int y = 0;
86
87 QTextLayout textLayout(content, painter.font());
88 textLayout.beginLayout();
89 forever {
90 QTextLine line = textLayout.createLine();
91
92 if (!line.isValid())
93 break;
94
95 line.setLineWidth(width());
96 int nextLineY = y + lineSpacing;
97
98 if (height() >= nextLineY + lineSpacing) {
99 line.draw(p: &painter, point: QPoint(0, y));
100 y = nextLineY;
101 //! [2]
102 //! [3]
103 } else {
104 QString lastLine = content.mid(position: line.textStart());
105 QString elidedLastLine = fontMetrics.elidedText(text: lastLine, mode: Qt::ElideRight, width: width());
106 painter.drawText(p: QPoint(0, y + fontMetrics.ascent()), s: elidedLastLine);
107 line = textLayout.createLine();
108 didElide = line.isValid();
109 break;
110 }
111 }
112 textLayout.endLayout();
113 //! [3]
114
115 //! [4]
116 if (didElide != elided) {
117 elided = didElide;
118 emit elisionChanged(elided: didElide);
119 }
120}
121//! [4]
122

source code of qtbase/examples/widgets/widgets/elidedlabel/elidedlabel.cpp