Patch for MetalScrollBarUI.java

[theUser BL]

Here a patch for a very old bug (which exists since the beginning of Swing), which I have also in the past mentioned.

In
javax/swing/plaf/metal/MetalScrollBarUI.java
in the method
protected void paintTrack( Graphics g, JComponent c, Rectangle trackBounds )

replace the part

--------------------------------
        else  // HORIZONTAL
        {
            if ( !isFreeStanding ) {
                trackBounds.height += 2;
            }

            if ( c.isEnabled() ) {
                g.setColor( darkShadowColor );
                g.drawLine( 0, 0, trackBounds.width - 1, 0 );  // top
                g.drawLine( 0, 2, 0, trackBounds.height - 2 ); // left
                g.drawLine( 0, trackBounds.height - 2, trackBounds.width - 1, trackBounds.height - 2 ); // bottom
                g.drawLine( trackBounds.width - 1, 2, trackBounds.width - 1, trackBounds.height - 1 ); // right

                g.setColor( shadowColor );
                //      g.setColor( Color.red);
                g.drawLine( 1, 1, trackBounds.width - 2, 1 );  // top
                g.drawLine( 1, 1, 1, trackBounds.height - 3 ); // left
                g.drawLine( 0, trackBounds.height - 1, trackBounds.width - 1, trackBounds.height - 1 ); // bottom
                if (scrollbar.getValue() != scrollbar.getMaximum()) {  // thumb shadow
                    int x = thumbRect.x + thumbRect.width - trackBounds.x;
                    g.drawLine( x, 1, x, trackBounds.height-1);
                }
            } else {
                MetalUtils.drawDisabledBorder(g, 0, 0, trackBounds.width, trackBounds.height );
            }
-----------------------------------------
with
------------------
        else  // HORIZONTAL
        {
            if ( !isFreeStanding ) {
                trackBounds.height += 2;
            }

            if ( c.isEnabled() ) {
                g.setColor( darkShadowColor );
                g.drawLine( 0, 0, trackBounds.width - 1, 0 );  // top
                g.drawLine( 0, 2, 0, trackBounds.height - 2 ); // left
                g.drawLine( 0, trackBounds.height - 2, trackBounds.width - 1, trackBounds.height - 2 ); // bottom
                g.drawLine( trackBounds.width - 1, 2, trackBounds.width - 1, trackBounds.height - 1 ); // right

                g.setColor( shadowColor );
                //      g.setColor( Color.red);
                g.drawLine( 1, 1, trackBounds.width - 2, 1 );  // top
                g.drawLine( 1, 1, 1, trackBounds.height - 3 ); // left
                g.setColor( highlightColor ); //+++ added
                g.drawLine( 0, trackBounds.height - 1, trackBounds.width - 1, trackBounds.height - 1 ); // bottom
                g.setColor( shadowColor ); //+++ added
                if (scrollbar.getValue() != scrollbar.getMaximum()) {  // thumb shadow
                    int x = thumbRect.x + thumbRect.width - trackBounds.x;
                    g.drawLine( x, 1, x, trackBounds.height-3);  //+++ changed -1 to -3
                }
            } else {
                MetalUtils.drawDisabledBorder(g, 0, 0, trackBounds.width, trackBounds.height );
            }
--------------------

The three comments with "//+++" you can remove. That are only for you, that you can easily see the changes I have done.


For see the changes, here a demo-program:
---------------------------------
import javax.swing.*;

public class ScrollBarDemo extends JFrame {

  public ScrollBarDemo (String title) {
    super(title);
    setLayout(null);
    JScrollBar h = new JScrollBar(JScrollBar.HORIZONTAL);
    JScrollBar v = new JScrollBar(JScrollBar.VERTICAL);
    h.setLocation(20,20);
    h.setSize(100, 20);
    v.setLocation(200,20);
    v.setSize(20, 200);
    add(h);
    add(v);
    
  }

  public static void main(String[] args) {
    ScrollBarDemo f = new ScrollBarDemo("ScrollBar-Demo");
    f.setSize(300, 300);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setVisible(true);
  }

}
---------------------------------

Have a look at the bottom of the horizontal scrollbar.

Please upload the fix.

Greatings
theuserbl