JXLabel.java 文件源码

/**
 * Helper method for initializing multi line support.
 */
private void initLineWrapSupport() {
    addPropertyChangeListener(new MultiLineSupport());
    // FYI: no more listening for componentResized. Those events are delivered out
    // of order and without old values are meaningless and forcing us to react when
    // not necessary. Instead overriding reshape() ensures we have control over old AND new size.
    addHierarchyBoundsListener(new HierarchyBoundsAdapter() {
        @Override
        public void ancestorResized(HierarchyEvent e) {
            // if one of the parents is viewport, resized events will not be propagated down unless viewport is changing visibility of scrollbars.
            // To make sure Label is able to re-wrap text when viewport size changes, initiate re-wrapping here by changing size of view
            if (e.getChanged() instanceof JViewport) {
                Rectangle viewportBounds = e.getChanged().getBounds();
                if (viewportBounds.getWidth() < getWidth()) {
                    View view = getWrappingView();
                    if (view != null) {
                        view.setSize(viewportBounds.width, viewportBounds.height);
                    }
                }
            }
        }});
}