Code
Override WindowsScrollBarUI#paintTrack(...)
scrollbar.setUI(new WindowsScrollBarUI() {
@Override protected void paintTrack(
Graphics g, JComponent c, Rectangle trackBounds) {
super.paintTrack(g, c, trackBounds);
Rectangle rect = textArea.getBounds();
double sy = trackBounds.getHeight() / rect.getHeight();
AffineTransform at = AffineTransform.getScaleInstance(1.0, sy);
Highlighter highlighter = textArea.getHighlighter();
g.setColor(Color.YELLOW);
try {
for (Highlighter.Highlight hh : highlighter.getHighlights()) {
Rectangle r = textArea.modelToView(hh.getStartOffset());
Rectangle s = at.createTransformedShape(r).getBounds();
int h = 2; // Math.max(2, s.height - 2);
g.fillRect(trackBounds.x, trackBounds.y + s.y, trackBounds.width, h);
}
}catch (BadLocationException ex) {
ex.printStackTrace();
}
}
});
JLabel + Icon + RowHeader
Code
final JScrollPane scroll = new JScrollPane(textArea);
JLabel label = new JLabel(new Icon() {
private final Color THUMB_COLOR = new Color(0, 0, 255, 50);
private final Rectangle thumbRect = new Rectangle();
private final JTextComponent textArea;
private final JScrollBar scrollbar;
public HighlightIcon(JTextComponent textArea, JScrollBar scrollbar) {
this.textArea = textArea;
this.scrollbar = scrollbar;
}
@Override public void paintIcon(Component c, Graphics g, int x, int y) {
// Rectangle rect = textArea.getBounds();
// Dimension sbSize = scrollbar.getSize();
// Insets sbInsets = scrollbar.getInsets();
// double sy = (sbSize.height - sbInsets.top - sbInsets.bottom) / rect.getHeight();
int itop = scrollbar.getInsets().top;
BoundedRangeModel range = scrollbar.getModel();
double sy = range.getExtent() / (double) (range.getMaximum() - range.getMinimum());
AffineTransform at = AffineTransform.getScaleInstance(1.0, sy);
Highlighter highlighter = textArea.getHighlighter();
// paint Highlight
g.setColor(Color.RED);
try {
for (Highlighter.Highlight hh: highlighter.getHighlights()) {
Rectangle r = textArea.modelToView(hh.getStartOffset());
Rectangle s = at.createTransformedShape(r).getBounds();
int h = 2; // Math.max(2, s.height - 2);
g.fillRect(x, y + itop + s.y, getIconWidth(), h);
}
} catch (BadLocationException e) {
e.printStackTrace();
}
// paint Thumb
if (scrollbar.isVisible()) {
// JViewport vport = Objects.requireNonNull(
// (JViewport) SwingUtilities.getAncestorOfClass(JViewport.class, textArea));
// Rectangle thumbRect = vport.getBounds();
thumbRect.height = range.getExtent();
thumbRect.y = range.getValue(); // vport.getViewPosition().y;
g.setColor(THUMB_COLOR);
Rectangle s = at.createTransformedShape(thumbRect).getBounds();
g.fillRect(x, y + itop + s.y, getIconWidth(), s.height);
}
}
@Override public int getIconWidth() {
return 8;
}
@Override public int getIconHeight() {
JViewport vport = Objects.requireNonNull(
(JViewport) SwingUtilities.getAncestorOfClass(JViewport.class, textArea));
return vport.getHeight();
}
});
scroll.setVerticalScrollBar(scrollbar);
/*
// Fixed Versions: 7 (b134)
scroll.setRowHeaderView(label);
/*/
// 6826074 JScrollPane does not revalidate the component hierarchy after scrolling
// https://bugs.openjdk.org/browse/JDK-6826074
// Affected Versions: 6u12,6u16,7
JViewport vp = new JViewport() {
@Override public void setViewPosition(Point p) {
super.setViewPosition(p);
revalidate();
}
};
vp.setView(label);
scroll.setRowHeader(vp);
MatteBorder + Icon + RowHeader
Code
JScrollBar scrollBar = new JScrollBar(Adjustable.VERTICAL) {
@Override public Dimension getPreferredSize() {
Dimension d = super.getPreferredSize();
d.width += getInsets().left;
return d;
}
@Override public void updateUI() {
super.updateUI();
setBorder(BorderFactory.createMatteBorder(0, 4, 0, 0, new Icon() {
@Override public void paintIcon(Component c, Graphics g, int x, int y) {
// ...
}
@Override public int getIconWidth() {
return getInsets().left;
}
@Override public int getIconHeight() {
return getHeight();
}
}));
}
};
scroll.setVerticalScrollBar(scrollBar);
References
