How to set transparency background?

[Luyao1271]

Now I need a transparency background,but the setting "rgba(255,255,255,0)" is not work.

[radkovo]

This actually should work. If you suspect a bug in CSSBox, please provide an example (a simple HTML/CSS code) that shows when it does not work. Another option is to use background-color: transparent.

[tbutter]

To get a transparent background of the Image returned from GraphicsEngine you need to set the Viewport Background and supply your own image:

GraphicsEngine contentCanvas = new GraphicsEngine(da.getRoot(), da, docSource.getURL());
            contentCanvas.setImage(new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB));
            contentCanvas.setAutoMediaUpdate(false); // we have a correct media specification, do not update
            contentCanvas.getConfig().setClipViewport(true);
            contentCanvas.getConfig().setLoadImages(true);
            contentCanvas.getConfig().setLoadBackgroundImages(true);

            contentCanvas.createLayout(windowSize, new Rectangle(windowSize), false);
            contentCanvas.getViewport().getConfig().setViewportBackgroundColor(new Color(0, 0, 0, 0));
            contentCanvas.redrawBoxes();
            bi = contentCanvas.getImage();

That only works for one render because the canvas is not cleared when you set a transparent background.