Does iText honors color transparency?

Question

I'm using iText 5.2.1 and I tried to use the BaseColor constructor with alpha channel, that is ``` public BaseColor(final int red, final int green, final int blue, final int alpha) ``` but when I actually draw text or shapes it seems that the alpha channel isn't taken into account. For example if I try this ``` Font f = ....; f.setColor(new BaseColor(130, 130, 130, 50); PdfContentByte cb = writer.getDirectContent(); ColumnText.showTextAligned(cb, Element.ALIGN_LEFT, new Phrase("my text", f), refPointX, refPointY, 0); ``` the text it's written with the color specified but without the alpha information, that is with the color with 100% opacity. The same thing happens if I try to draw some shape and I specify a fill color with transparency. In the book iText in Action second edition there's nothing about transparency in colors. Am I wrong?

Accepted Answer

I've found something in itext mailing list, I tried and... works! It's a undocumented feature. Anyway the following code does what I need:

```
PdfContentByte cb = writer.getDirectContent();
PdfGState gState = new PdfGState();
gState.setFillOpacity(0.1f);
cb.setGState(gState);
```

If a draw text or shapes, they have 10% opacity. With `gState.setStrokeOpacity` I can also set opacity on strokes.

Does iText honors color transparency?

Solution

Problem