The GXT Slider is beautiful and fun to use, it can even be passed to a SliderField and used as an input widget in forms (FormPanel), there is however one twist to its API that I think should be looked into in GXT3 and its the fact the you have very little control over the formatting of the tooltip message shown as you drag the slider's thumb back and forth.

I tested with GXT 2.2.3 and as of this release you can only configure the tip message thus :

Slider slider = new Slider();
....
slider.setMessage("{0} inches tall");

And with this setup you get the tooltip formatted like "1 inches tall", "2 inches tall", "3 inches tall" e.t.c Internally Slider usese Format.substitute(getMessage(), value) such that the value of the slider is substituted into what has been set with setMessage() method.

If we have a Slider configured to slide from 1 to 5 and need to use it to implement, say, a rating control such that the value 1 could mean "Poor" and the value 5 could mean "Excellent", the current API prevents us from doing that except with a subclass of Slider. Having to subclass Slider just to vary the "algorithm" for formatting its tooltip is not brilliant.

I