Set the size of a JSlider thumb

Question

How can the size of the thumb be configured for a JSlider?

With the defaults, and a range for the JSlider of 256, the thumb is only a few pixels wide, which makes it quite difficult to control with a mouse.

I am using the Windows 7 look and feel and the slider looks like this:

Enabling paintTicks with a major and minor tick spacing of 0 gives a better (although not preferred) display:

The desired display is shown in the following image - taken from a native Windows 7 application:

Lobby

How did you get it that skinny? – Buckshot

It's a horizontal JSlider with min and max of 0 and 255 respectively, nothing special. When I reduce the range to 0 to 16, the thumb is the same size. When I change the minor or major tick spacing, the thumb is the same size. So I don't know why it's so skinny. – Lobby

@Andrew Cecil, It would be cool if you included a screenshot. :D – Engender

@Andrew How much is a few pixels? Which UI are you using? – Wore

Enabling the paintTicks property (but with no ticks) gives the following: link. That will probably do. – Lobby

See also this answer. – Precision

@trashgod, You should make that an answer. :D – Engender

@mre: Thank you; but, as Thomas notes, replacing the UI delegate is a last resort. – Precision

"a better (although not preferred) display:" So what do you mean, wider still than the thumb in the 2nd screen-shot? Also I'm thinking maybe I should delete my 'answer', since your post now includes & explains the images better. Nice screenshots, BTW. :-) – Pernik

@Andrew Thompson - I've added explanation to the question of the desired look. Part of this is because enabling ticks (even with none displayed) adds space below the slider which makes a tight layout tricky. – Lobby

Answer 1

You could try customizing the JSlider Look and Feel as follows:

UIDefaults defaults = UIManager.getDefaults();
defaults.put("Slider.thumbHeight", HEIGHT_AS_INTEGER); // change height
defaults.put("Slider.thumbWidth", WIDTH_AS_INTEGER); // change width

Reference:

• Customizing a JSlider Look and Feel

It's important to note that these changes will apply to all JSlider instances, which may make this approach undesirable.

Engender

At what point does this need to be done? Before setting look and feel? Before creating JSlider components? So far I have been unable to get this to have any effect. – Lobby

@Andrew, Good question. I don't know yet. – Engender

Looks like these UIDefaults keys are only queried by Nimbus / Synth L&Fs (in Oracle Java at least) – Cadell

Answer 2

This depends on the SliderUI, which might have hard coded sizes. If not, using mre`s suggestion would be a way to go, if you want the same thumb size for all sliders.

Alternatively to setting the defaults for a UI that uses them, you could define a different UI for a special slider (e.g. myslider.setUI(new MyCustonSliderUI())), but be aware that that has its own drawbacks.

Wore