svg icons not showing up

[ePharaoh]

I have this code, which shows a blank widget!

{
           QToolButton *toolButton = new QToolButton(0);
           QIcon *newTabIcon = new QIcon("newTab.svg");
           toolButton->setIcon (*newTabIcon);
           mainSplitter->addWidget(toolButton);
}

{
           QToolButton *toolButton = new QToolButton(0);
           QIcon *newTabIcon = new QIcon("newTab.svg");
           toolButton->setIcon (*newTabIcon);
           mainSplitter->addWidget(toolButton);
}

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Is this the right way to use SVGs in qt 4.1.1?

[jpn]

It's not the right way to use SVG files, see QtSvg Module documentation.

[ePharaoh]

It's not the right way to use SVG files, see QtSvg Module documentation.

Thanks; I did, but it was rather complex for a QT newbie like me. Besides, it uses custom widgets.

Isn't it possible to use svg with default widgets which support pixmaps?

[zlatko]

I think that svg format has some another task for using

[jpn]

Remember to add "QT += svg" to your .pro file..

#include <QSvgRenderer>
 
void SvgToolButton::paintEvent(QPaintEvent* e)
{
	// allow button to paint it's borders..
	QToolButton::paintEvent(e);
	// buffer is a member variable of type QPixmap
	if (buffer.isNull() || buffer.size() != size() - margin)
	{
		// margin is a member variable of type QSize
		buffer = QPixmap(size() - margin);
		QString fileName("button.svg");
		QSvgRenderer renderer(fileName);
		QPainter painter(&buffer);
		renderer.render(&painter);
	}
	// draw a pixmap on the button
	QPainter painter(this);
	painter.drawPixmap(margin.height()/2, margin.width()/2, buffer);
}

#include <QSvgRenderer>

void SvgToolButton::paintEvent(QPaintEvent* e)
{
	// allow button to paint it's borders..
	QToolButton::paintEvent(e);
	// buffer is a member variable of type QPixmap
	if (buffer.isNull() || buffer.size() != size() - margin)
	{
		// margin is a member variable of type QSize
		buffer = QPixmap(size() - margin);
		QString fileName("button.svg");
		QSvgRenderer renderer(fileName);
		QPainter painter(&buffer);
		renderer.render(&painter);
	}
	// draw a pixmap on the button
	QPainter painter(this);
	painter.drawPixmap(margin.height()/2, margin.width()/2, buffer);
}

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Edit: Btw, I did not test above code. Oh, and you might want to initialize the svg renderer somewhere else..

[jpn]

A bit more complex but definitely more elegant way would be to implement a QIconEnginePlugin.

From QIcon docs:
With QIconEnginePlugin it is possible to register different icon engines for different file suffixes, so you could provide a SVG icon engine or any other scalable format.

[ePharaoh]

A bit more complex but definitely more elegant way would be to implement a QIconEnginePlugin.

Thanks for the leads, jpn. This is what I finally implemented, and I think it is elegant enough (posting here for the benefit of future noobs).

{
        QToolButton *toolButton = new QToolButton(0);
 
        QPixmap pixmap(24, 24);
        QPainter painter(&pixmap);
        painter.setBackgroundMode(Qt::OpaqueMode);
        QSvgRenderer renderer (QString("newTab.svg"));
        renderer.render (&painter);
        QIcon newTabIcon(pixmap);
 
        toolButton->setIcon (newTabIcon);
        toolButton->setIconSize (QSize(24,24));
        tabs.setCornerWidget (toolButton, Qt::BottomLeftCorner);
    }

{
        QToolButton *toolButton = new QToolButton(0);

        QPixmap pixmap(24, 24);
        QPainter painter(&pixmap);
        painter.setBackgroundMode(Qt::OpaqueMode);
        QSvgRenderer renderer (QString("newTab.svg"));
        renderer.render (&painter);
        QIcon newTabIcon(pixmap);

        toolButton->setIcon (newTabIcon);
        toolButton->setIconSize (QSize(24,24));
        tabs.setCornerWidget (toolButton, Qt::BottomLeftCorner);
    }

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