AltLabelTextProvider.java 文件源码

@Override
public String getText(Tree node) {
    if ( node instanceof PreviewInterpreterRuleContext) {
        PreviewInterpreterRuleContext inode = (PreviewInterpreterRuleContext)node;
        Rule r = g.getRule(inode.getRuleIndex());
        String[] altLabels = getAltLabels(r);
        String name = r.name;
        int outerAltNum = inode.getOuterAltNum();
        if ( altLabels!=null ) {
            if ( outerAltNum>=0 && outerAltNum<altLabels.length ) {
                return name+":"+altLabels[outerAltNum];
            }
            else {
                return name;
            }
        }
        else if ( r.getOriginalNumberOfAlts()>1 ) {
            return name + ":" +outerAltNum;
        }
        else {
            return name; // don't display an alternative number if there's only one
        }
    }
    return Trees.getNodeText(node, Arrays.asList(parser.getRuleNames()));
}