JavaFX: Language investigations

My previous blog, presenting the Life program, was quite long, still not really complete. I've continued the work, but soon found some interesting surprises. This new blog starts investigating an API bug, then trips into some surprising language behavior, and ends in a proposal for a small change in the JavaFX Script language. A Slider bug I was annoyed to see that the Slider control ignores my attempts to enforce granularity - I wanted that only multiples of 50ms could be selected. Setting the recommended properties, like snapToTicks and majorTickUnit, only works for clicks ("paging"), but not for dragging the thumb. The user can still use the thumb to set the slider's value to any number in the min..max range. I looked up the JIRA and found that this is an already-known bug: RT-5914: No change in behavior after changing the snapToTicks flag for Slider. Fortunately there is a workaround: def animSlider = Slider {    override var value on replace { value = round(value/50) * 50 }    snapToTicks: true majorTickUnit: 50 min: 0 max: 1000 value: 50 blockIncrement: 50 layoutInfo: LayoutInfo { width: 120 }} This demonstrates JavaFX Script's nice override var feature. The variable itself (class field) is not overriden, only the default value (including bind) and trigger. Overriding a trigger is similar to overriding a setter method in Java, except that you cannot remove existing triggers from th...

Date: May, 25 2010
Url: http://www.java.net/blog/opinali/archive/2010/05/25/javafx-language-investigations

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