protected void installDefaults() {
super.installDefaults();
scrollBarWidth = UIManager.getInt("ScrollBar.width");
incrGap = UIManager.getInt("ScrollBar.incrementButtonGap");
decrGap = UIManager.getInt("ScrollBar.decrementButtonGap");
// TODO this can be removed when incrGap/decrGap become protected
// handle scaling for sizeVarients for special case components. The
// key "JComponent.sizeVariant" scales for large/small/mini
// components are based on Apples LAF
String scaleKey = (String) scrollbar.getClientProperty("JComponent.sizeVariant");
if (scaleKey != null) {
if ("large".equals(scaleKey)) {
scrollBarWidth *= 1.15;
incrGap *= 1.15;
decrGap *= 1.15;
} else if ("small".equals(scaleKey)) {
scrollBarWidth *= 0.857;
incrGap *= 0.857;
decrGap *= 0.857;
} else if ("mini".equals(scaleKey)) {
scrollBarWidth *= 0.714;
incrGap *= 0.714;
decrGap *= 0.714;
}
}
}
/** Installs the defaults. */
protected void installDefaults() {
// need to initialise isFreeStanding before calling the super class,
// so that the value is set when createIncreaseButton() and
// createDecreaseButton() are called (unless there is somewhere earlier
// that we can do this).
Boolean prop = (Boolean) scrollbar.getClientProperty(FREE_STANDING_PROP);
isFreeStanding = prop == null ? true : prop.booleanValue();
scrollBarShadowColor = UIManager.getColor("ScrollBar.shadow");
super.installDefaults();
}
// 重绘滚动条的滑块
public void paintThumb(Graphics g, JComponent c, Rectangle thumbBounds) {
super.paintThumb(g, c, thumbBounds);
int tw = thumbBounds.width;
int th = thumbBounds.height;
// 重定图形上下文的原点，这句一定要写，不然会出现拖动滑块时滑块不动的现象
g.translate(thumbBounds.x, thumbBounds.y);
Graphics2D g2 = (Graphics2D) g;
GradientPaint gp = null;
if (this.scrollbar.getOrientation() == JScrollBar.VERTICAL) {
gp = new GradientPaint(0, 0, new Color(204, 204, 204), tw, 0, new Color(204, 204, 204));
}
if (this.scrollbar.getOrientation() == JScrollBar.HORIZONTAL) {
gp = new GradientPaint(0, 0, new Color(204, 204, 204), 0, th, new Color(204, 204, 204));
}
g2.setPaint(gp);
g2.fillRoundRect(0, 0, (tw - 1), (th - 1), 5, 5);
// 边框颜色
g2.setColor(thumbBorderColor);
g2.drawRoundRect(0, 0, (tw - 1), (th - 1), 5, 5);
}
protected void layoutHScrollbar(JScrollBar sb) {
if (AbstractLookAndFeel.getTheme().isLinuxStyleScrollBarOn()) {
Dimension sbSize = sb.getSize();
Insets sbInsets = sb.getInsets();
int sizeW = sbSize.width - sbInsets.left - sbInsets.right;
/*
* Height and top edge of the buttons and thumb.
*/
int itemY = sbInsets.top;
int itemH = sbSize.height - (sbInsets.top + sbInsets.bottom); // Math.min(itemW, sizeH / 2);
int itemW = Math.min(itemH, sizeW / 2); // sbSize.width - (sbInsets.left + sbInsets.right);
/* Nominal locations of the buttons, assuming their preferred
* size will fit.
*/
int decrButtonX = sbSize.width - sbInsets.right - itemW - itemW + 1;
int incrButtonX = sbSize.width - sbInsets.right - itemW;
/* Compute the width and origin of the thumb. The case
* where the thumb is at the right edge is handled specially
* to avoid numerical problems in computing thumbX. Enforce
* the thumbs min/max dimensions. If the thumb doesn't
* fit in the track (trackW) we'll hide it later.
*/
float trackW = sbSize.width - sbInsets.left - sbInsets.right - itemH - itemH + 1;
float min = sb.getMinimum();
float max = sb.getMaximum();
float extent = sb.getVisibleAmount();
float range = max - min;
float value = sb.getValue();
int maxThumbW = getMaximumThumbSize().width;
int minThumbW = getMinimumThumbSize().width;
int thumbW = (range <= 0) ? maxThumbW : (int) (trackW * (extent / range));
thumbW = Math.max(thumbW, minThumbW);
thumbW = Math.min(thumbW, maxThumbW);
int thumbX = decrButtonX - thumbW;
if (value < (max - extent)) {
float thumbRange = trackW - thumbW;
thumbX = (int) (0.5f + (thumbRange * ((value - min) / (range - extent))));
}
/* If the thumb isn't going to fit, zero it's bounds. Otherwise
* make sure it fits between the buttons. Note that setting the
* thumbs bounds will cause a repaint.
*/
if (thumbW > trackW) {
setThumbBounds(0, 0, 0, 0);
} else {
setThumbBounds(thumbX, itemY, thumbW, itemH);
}
decrButton.setBounds(decrButtonX, itemY, itemW, itemH);
incrButton.setBounds(incrButtonX, itemY, itemW, itemH);
/* Update the trackRect field.
*/
trackRect.setBounds(0, itemY, (int) trackW, itemH);
} else {
super.layoutHScrollbar(sb);
}
}
protected void layoutVScrollbar(JScrollBar sb) {
if (useAlternateLayout) alternateLayoutVScrollbar(sb);
else super.layoutVScrollbar(sb);
}
public void setThumbBounds(int x, int y, int w, int h) {
super.setThumbBounds(x, y, w, h);
}
// 设置滑块bounds
@Override
protected void setThumbBounds(int x, int y, int width, int height) {
super.setThumbBounds(x + width / 4, y, width / 2, height);
}
/*
* @see javax.swing.plaf.basic.BasicScrollBarUI#paint(java.awt.Graphics,
* javax.swing.JComponent)
*/
@Override
public void paint(Graphics g, JComponent c) {
super.paint(g, c);
}