Java Utililty Methods JScrollBar

List of utility methods to do JScrollBar

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Description

The list of methods to do JScrollBar are organized into topic(s).

Method

booleanisPaintRequiredFor(javax.swing.JScrollBar jScrollBar)
is Paint Required For 
if (jScrollBar != null) {
    return (jScrollBar.getMinimum() != jScrollBar.getValue())
            || (jScrollBar.getMaximum() != jScrollBar.getVisibleAmount());
} else {
    return false;
voidscrollByBlock(JScrollBar scrollbar, int direction)
scroll By Block 
int oldValue = scrollbar.getValue();
int blockIncrement = scrollbar.getBlockIncrement(direction);
int delta = blockIncrement * ((direction > 0) ? +1 : -1);
int newValue = oldValue + delta;
if (delta > 0 && newValue < oldValue) {
    newValue = scrollbar.getMaximum();
} else if (delta < 0 && newValue > oldValue) {
    newValue = scrollbar.getMinimum();
...
voidscrollByUnits(JScrollBar scrollbar, int direction, int units, boolean limitToBlock)
scroll By Units 
int delta;
int limit = -1;
if (limitToBlock) {
    if (direction < 0) {
        limit = scrollbar.getValue() - scrollbar.getBlockIncrement(direction);
    } else {
        limit = scrollbar.getValue() + scrollbar.getBlockIncrement(direction);
for (int i = 0; i < units; i++) {
    if (direction > 0) {
        delta = scrollbar.getUnitIncrement(direction);
    } else {
        delta = -scrollbar.getUnitIncrement(direction);
    int oldValue = scrollbar.getValue();
    int newValue = oldValue + delta;
    if (delta > 0 && newValue < oldValue) {
        newValue = scrollbar.getMaximum();
    } else if (delta < 0 && newValue > oldValue) {
        newValue = scrollbar.getMinimum();
    if (oldValue == newValue) {
        break;
    if (limitToBlock && i > 0) {
        assert limit != -1;
        if ((direction < 0 && newValue < limit) || (direction > 0 && newValue > limit)) {
            break;
    scrollbar.setValue(newValue);