public void doLayout() {
super.doLayout();
if (getScrollbarDisplayPolicy() == SCROLLBARS_NEVER) {
// Use this class's calculateChildSize() and re-do layout of child
Component c = getComponent(0);
Dimension cs = calculateChildSize();
Insets i = getInsets();
c.setBounds(i.left, i.top, cs.width, cs.height);
}
}
/**
* Determine the size to allocate the child component. Overrides calculateChildSize() in
* ScollPane. If the viewport area is bigger than the child's preferred size then the child is
* allocated enough to fill the viewport, otherwise the child is given its preferred size. Calls
* super.calculateChildSize(). If scrolling is disabled, the child is allocated enough to fill the
* viewport.
*/
Dimension calculateChildSize() {
// Calculate the view size, accounting for border but not scrollbars
// - don't use right/bottom insets since they vary depending
// on whether or not scrollbars were displayed on last resize.
Dimension size = getSize();
Insets insets = getInsets();
int viewWidth = size.width - insets.left * 2;
int viewHeight = size.height - insets.top * 2;
// Determine whether or not horz or vert scrollbars will be displayed.
boolean vbarOn;
boolean hbarOn;
Component child = getComponent(0);
Dimension childSize = new Dimension(child.getPreferredSize());
if (getScrollbarDisplayPolicy() == SCROLLBARS_AS_NEEDED) {
vbarOn = childSize.height > viewHeight;
hbarOn = childSize.width > viewWidth;
} else if (getScrollbarDisplayPolicy() == SCROLLBARS_ALWAYS) {
vbarOn = hbarOn = true;
} else { // SCROLLBARS_NEVER
vbarOn = hbarOn = false;
}
// Adjust predicted view size to account for scrollbars.
int vbarWidth = getVScrollbarWidth();
int hbarHeight = getHScrollbarHeight();
if (vbarOn) {
viewWidth -= vbarWidth;
}
if (hbarOn) {
viewHeight -= hbarHeight;
}
// If child is smaller than view, size it up.
if ((childSize.width < viewWidth) || (getScrollbarDisplayPolicy() == SCROLLBARS_NEVER)) {
childSize.width = viewWidth;
}
if ((childSize.height < viewHeight) || (getScrollbarDisplayPolicy() == SCROLLBARS_NEVER)) {
childSize.height = viewHeight;
}
return childSize;
}