setting gradient background color on button

[jun...@selma.hfmdk-frankfurt.de]

I'm trying to change the background color for a button. Since the default theme uses gradients I'd like to paint it with gradients, too. Unfortuately the following gives an error:

This works:

(do
  (def my-button (button))
    (config! my-button :background :red))

This doesn't work:

(do
  (def my-button (button))
    (config! my-button :background (linear-gradient :start [0 0] :end [0 1] :colors [:red :white])))


=> 1. Unhandled java.lang.ClassCastException
   java.awt.LinearGradientPaint cannot be cast to clojure.lang.Named

This neither:

(do
  (def my-button (button))
  (config! my-button :style (style :background (linear-gradient :start [0 0] :end [0 1] :colors [:red :white]))))


=> 1. Unhandled java.lang.IllegalArgumentException
        class seesaw.core.proxy$javax.swing.JButton$Tag$fd407141 does not
        support the :style option

How is this done?

[Dave Ray]

The :background property just passes through to setBackground [1] which only supports Color objects as arguments.

The only approach I know of is to override painting of the button. See the docstring for seesaw.core/canvas. For a button it would be something like:

(do

  (def my-button (button))

  (config! my-button :paint (fn [^java.awt.Graphics2D g] ... paint gradient ...)))

There's a java example of drawing a gradient here [2].

Dave

[1] http://docs.oracle.com/javase/7/docs/api/javax/swing/JComponent.html#setBackground%28java.awt.Color%29
[2] http://www.coderanch.com/t/459769/GUI/java/add-Gradient-colors-JComponents

--
You received this message because you are subscribed to the Google Groups "seesaw-clj" group.
To unsubscribe from this group and stop receiving emails from it, send an email to seesaw-clj+...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.