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package sun.lwawt;

import java.awt.Adjustable;
import java.awt.Scrollbar;
import java.awt.event.AdjustmentEvent;
import java.awt.event.AdjustmentListener;
import java.awt.peer.ScrollbarPeer;

import javax.swing.JScrollBar;

Lightweight implementation of ScrollbarPeer. Delegates most of the work to the JScrollBar.
/** * Lightweight implementation of {@link ScrollbarPeer}. Delegates most of the * work to the {@link JScrollBar}. */
final class LWScrollBarPeer extends LWComponentPeer<Scrollbar, JScrollBar> implements ScrollbarPeer, AdjustmentListener { // JScrollBar fires two changes with firePropertyChange (one for old value // and one for new one. // We save the last value and don't fire event if not changed. private int currentValue; LWScrollBarPeer(final Scrollbar target, final PlatformComponent platformComponent) { super(target, platformComponent); } @Override JScrollBar createDelegate() { return new JScrollBar(); } @Override void initializeImpl() { super.initializeImpl(); final Scrollbar target = getTarget(); setLineIncrement(target.getUnitIncrement()); setPageIncrement(target.getBlockIncrement()); setValues(target.getValue(), target.getVisibleAmount(), target.getMinimum(), target.getMaximum()); final int orientation = target.getOrientation(); final JScrollBar delegate = getDelegate(); synchronized (getDelegateLock()) { delegate.setOrientation(orientation == Scrollbar.HORIZONTAL ? Adjustable.HORIZONTAL : Adjustable.VERTICAL); delegate.addAdjustmentListener(this); } } @Override public void setValues(final int value, final int visible, final int minimum, final int maximum) { synchronized (getDelegateLock()) { currentValue = value; getDelegate().setValues(value, visible, minimum, maximum); } } @Override public void setLineIncrement(final int l) { synchronized (getDelegateLock()) { getDelegate().setUnitIncrement(l); } } @Override public void setPageIncrement(final int l) { synchronized (getDelegateLock()) { getDelegate().setBlockIncrement(l); } } // Peer also registered as a listener for ComponentDelegate component @Override public void adjustmentValueChanged(final AdjustmentEvent e) { final int value = e.getValue(); synchronized (getDelegateLock()) { if (currentValue == value) { return; } currentValue = value; } getTarget().setValueIsAdjusting(e.getValueIsAdjusting()); getTarget().setValue(value); postEvent(new AdjustmentEvent(getTarget(), e.getID(), e.getAdjustmentType(), value, e.getValueIsAdjusting())); } }