Question

I’d like to create shadow effects around my JComponent and especially around my JTextField’s (JXTextField’s since i use SwingX api).

I already know about the DropShadowBorder class from SwingX but it’s not exactly what i want to achieve. I decided to do it myself by using rounded rectangle and gradients.

My idea is to create a rounded rectangle, apply a gradient to it and then draw the component on top of this rectangle with a given offset to create the shadow effect.

The problem is that i’m only aware of the GradientPaint class that allow me to specify start and end point of my gradient. Unless i’m wrong, i think i can’t achieve this effect which such a gradient, i think i would need a gradient that start at the center and then fade toward the edges. Is there a way to do such a gradient with the actual API or do i need to write it myself?

Thanks.

EDIT: The is to do a text field that looks like:

The shadow is more important on the bottom than on the right and left sides.

Answer 1

There is no easy way to achieve exactly what you want.

To create an exact effect of such shadow you will have to do several things:

1. Paint a black/gray (color of your shadow) rounded rectanle on a separate image sized to component plus some additional spacing at the sides
2. Blur that image to create a shadow from the flat rounded rectangle
3. Render that image under the field by either using your own UI or just replacing field’s paintComponent method

Let me explain each step a bit more:

1. You need a separate image so that the background/component won’t get blurred together with the shadow. Plus you cannot apply any filter directly to the Graphics – you need an Image.
2. You can read a good explanation of how-to-blur here: http://www.jhlabs.com/ip/blurring.html
3. You need to place (paint) the shadow image before the component itself and that is possible in two ways: paint it on the panel/container that contains the field or replace the field paintComponent method or UI itself.