How do I speed up the scroll speed in a JScrollPane when using the mouse wheel?

Question

I see the method JScrollPane.setWheelScrollingEnabled(boolean) to enable or disable the mouse wheel scrolling. Is there any way to adjust the speed of the scro

Answer 1

My solution to speeding up the scroll:

1. Add scrollbar's parameter:

   scrollPane.getVerticalScrollBar().putClientProperty("JScrollBar.fastWheelScrolling", true);

2. Implement a wheel listener (on the component inside jViewport):

   public void mouseWheelMoved(MouseWheelEvent e) {
       boolean isCtrl = (e.getModifiersEx() & MouseWheelEvent.CTRL_DOWN_MASK) != 0;
       boolean isShift = (e.getModifiersEx() & MouseWheelEvent.SHIFT_DOWN_MASK) != 0;
   
       MouseWheelEvent eventToDispatch = e;
       if (isCtrl || isShift) {
           int amountMulti = 1;
           int rotMulti = 1;
           if (isCtrl) {
               amountMulti *= 10;
               if (isShift) {
                   amountMulti *= 5;
                   rotMulti *= 2;
               }
           }
           int mod = e.getModifiers() & ~InputEvent.CTRL_MASK & ~InputEvent.SHIFT_MASK;
           int modEx = e.getModifiersEx() & ~MouseWheelEvent.CTRL_DOWN_MASK & ~MouseWheelEvent.SHIFT_DOWN_MASK;
           eventToDispatch = new MouseWheelEvent(this, e.getID(), e.getWhen()
            , mod | modEx, e.getX(), e.getY()
            , e.getXOnScreen(), e.getYOnScreen(), e.getClickCount(), e.isPopupTrigger()
            , e.getScrollType(), e.getScrollAmount()*amountMulti, e.getWheelRotation()*rotMulti
            , e.getPreciseWheelRotation()*amountMulti*rotMulti);
       }
   
       getParent().dispatchEvent(eventToDispatch);
   }
   

   The increase of wheelRotation is necessary: otherwise the number of scrolled lines will be limited to the size of the screen.