Display of QML image ignoring pixel alpha

bradg

Hi. Fairly new to QT, but I've noticed that when I display an image where the source is a png file, the alpha for each pixel is ignored. Just where is displayed.

From c++, I'm using QQuickView to load the source and display.

Is there a setting somewhere to make this work?

	Image
	{
		source: "image.png"
	}

bradg

I've figured this out. The problem wasn't in fact due to image files pixel alpha. That works just fine. It had to do with the QQuickView not being transparent. What I am doing is displaying a QQuickView as a borderless window to be used as a popup dialog and I want to see through to the background, where there are no objects in the qml file. (Think of a pop up dialog with rounded corners).

Here's what I'm doing:

	QQuickView view;

	// don't display an icon in the task bar
	// no border on the window
    view.setFlags(Qt::SubWindow | Qt::FramelessWindowHint);
	
	// make the view transparent so that the edges of the window,
	// where there is no image, show through to the background
    QSurfaceFormat surfaceFormat;
    surfaceFormat.setAlphaBufferSize(8);

    view.setFormat(surfaceFormat);
    view.setClearBeforeRendering(true);
    view.setColor(QColor(Qt::transparent));

	// load qml file and display
	view.setSource(file.qml);
	view.show();