public void scrollByUnit(int direction) {
float size;
if (orientation == VERTICAL) {
direction *= -1;
size = scrollSpace + slider.getThumbButton().getHeight() / slider.getHeight();
} else size = scrollSpace + slider.getThumbButton().getWidth() / slider.getWidth();
if (direction == DECREMENT) setValue(getValue() - size);
else setValue(getValue() + size);
}
/**
* Sets the appearance for this scroll bar. If <code>appearance</code> is not an instance of
* ScrollBarAppearance, an <code>IllegalArgumentException</code> is thrown.
*
* @param appearance the new appearance to set
*/
public void setAppearance(ComponentAppearance appearance) {
if (appearance == null)
throw new IllegalStateException("null appearance not allowed with ScrollBar");
if (!(appearance instanceof ScrollBarAppearance)) {
throw new IllegalArgumentException("appearance must be instance of ScrollBarAppearance");
}
super.setAppearance(appearance);
// de-init components
if (slider != null) {
remove(slider);
slider.removeMouseWheelListener(incDecListener);
slider.getThumbButton().removeMouseWheelListener(incDecListener);
// slider.getDelayTimer().removeActionListener(delayListener);
}
if (incButton != null) {
remove(incButton);
incButton.removeActionListener(incDecListener);
}
if (decButton != null) {
remove(decButton);
decButton.removeActionListener(incDecListener);
}
// re-init components
// gets the current appearance
ScrollBarAppearance a = (ScrollBarAppearance) this.getAppearance();
if (a == null) {
throw new IllegalStateException("no appearance set for this scroll bar");
}
// creates scroll & thumb buttons
// skins can choose how they should be created
incButton = a.createScrollButton(this, INCREMENT);
decButton = a.createScrollButton(this, DECREMENT);
slider = a.createSlider(this, orientation);
if (incButton == null || decButton == null || slider == null)
throw new NullPointerException("null components passed to scroll bar");
if (slider.getOrientation() != orientation)
throw new IllegalArgumentException("passed slider doesn't match orientation of scroll bar");
// add scroll listeners buttons
incButton.addActionListener(incDecListener);
decButton.addActionListener(incDecListener);
// slider.getDelayTimer().addActionListener(delayListener);
// add the new components to this bar
add(slider);
add(incButton);
add(decButton);
incButton.addMouseWheelListener(incDecListener);
decButton.addMouseWheelListener(incDecListener);
slider.addMouseWheelListener(incDecListener);
slider.getThumbButton().addMouseWheelListener(incDecListener);
addMouseWheelListener(incDecListener);
updateWidth();
updateHeight();
}