RetroShare/retroshare-gui/src/gui/common/ElidedLabel.cpp

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#include "ElidedLabel.h"

#include <QPainter>
#include <QTextLayout>
#include <QDebug>
#include <QStyleOption>

ElidedLabel::ElidedLabel(const QString &text, QWidget *parent)
  : QLabel(parent)
  , elided(false)
  , content(text)
{
	setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Preferred);
}

ElidedLabel::ElidedLabel(QWidget *parent)
  : QLabel(parent)
  , elided(false)
{
	setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Preferred);
	content="";
}

void ElidedLabel::setText(const QString &newText)
{
	content = newText;
	update();
}

void ElidedLabel::paintEvent(QPaintEvent *event)
{
	QLabel::paintEvent(event);
	
	QPainter painter(this);
	QFontMetrics fontMetrics = painter.fontMetrics();
	QRect cr = contentsRect();
	cr.adjust(margin(), margin(), -margin(), -margin());
	
	bool didElide = false;
	int lineSpacing = fontMetrics.lineSpacing();
	int x, y = x =cr.top()+(cr.height()-lineSpacing)/2;
	
	QTextLayout textLayout( content, painter.font());
	textLayout.beginLayout();
	forever {
		QTextLine line = textLayout.createLine();
		
		if (!line.isValid())
			break;
		
		line.setLineWidth(cr.width()+2*x);
		int nextLineY = y + lineSpacing;
		
		if (cr.height() >= nextLineY + lineSpacing) {
			line.draw(&painter, QPoint(x, y));
			y = nextLineY;
		} else {
			QString lastLine = content.mid(line.textStart());
			QString elidedLastLine = fontMetrics.elidedText(lastLine, Qt::ElideRight, cr.width());
			painter.drawText(QPoint(x, y + fontMetrics.ascent()), elidedLastLine);
			line = textLayout.createLine();
			didElide = line.isValid();
			break;
		}
	}
	textLayout.endLayout();
	
	if (didElide != elided) {
		elided = didElide;
		emit elisionChanged(didElide);
	}
}