Eclipse RCP开发如何为PresentationReconciler添加多个RuleBasedScanner

方案1：单Scanner多规则（优先推荐，无需修改现有结构） #

如果只是要实现多规则高亮，不一定需要新增多个Scanner，同一个RuleBasedScanner支持传入多个IRule实现多规则匹配，这是更轻量化的方案，示例代码：

public class PropertiesReconciler extends PresentationReconciler {
    // 不同语法元素的样式定义
    private final TextAttribute keyAttribute = new TextAttribute(Display.getCurrent().getSystemColor(SWT.COLOR_DARK_GREEN));
    private final TextAttribute valueAttribute = new TextAttribute(Display.getCurrent().getSystemColor(SWT.COLOR_DARK_BLUE));
    private final TextAttribute commentAttribute = new TextAttribute(Display.getCurrent().getSystemColor(SWT.COLOR_GRAY));

    public PropertiesReconciler() {
        RuleBasedScanner scanner = new RuleBasedScanner();
        // 按优先级添加多个规则，匹配顺序从上到下
        IRule[] rules = new IRule[] {
            new PropertyCommentRule(new Token(commentAttribute)), // 注释规则
            new PropertyNameRule(new Token(keyAttribute)), // 属性名规则
            new PropertyValueRule(new Token(valueAttribute)) // 属性值规则
        };
        scanner.setRules(rules);
        DefaultDamagerRepairer dr = new DefaultDamagerRepairer(scanner);
        this.setDamager(dr, IDocument.DEFAULT_CONTENT_TYPE);
        this.setRepairer(dr, IDocument.DEFAULT_CONTENT_TYPE);
    }
}

该方案不需要修改plugin.xml配置。

方案2：多Scanner绑定不同文档分区 #

如果你的编辑器做了文档分区拆分（比如注释、属性名属于不同的内容分区），可以给每个分区绑定独立的Scanner，步骤如下：

1. 先实现自定义的文档分区常量，给不同内容定义专属的分区ID：

// 自定义分区常量定义
public interface IPropertiesPartitions {
    String PROPERTIES_COMMENT = "com.vogella.ide.editor.properties.comment";
    String PROPERTIES_KEY = "com.vogella.ide.editor.properties.key";
    String PROPERTIES_VALUE = "com.vogella.ide.editor.properties.value";
    String[] ALL_PARTITIONS = new String[] {PROPERTIES_COMMENT, PROPERTIES_KEY, PROPERTIES_VALUE};
}

2. 修改PropertiesReconciler，给每个分区创建独立的Scanner和DamagerRepairer：

public class PropertiesReconciler extends PresentationReconciler {
    private final TextAttribute keyAttribute = new TextAttribute(Display.getCurrent().getSystemColor(SWT.COLOR_DARK_GREEN));
    private final TextAttribute valueAttribute = new TextAttribute(Display.getCurrent().getSystemColor(SWT.COLOR_DARK_BLUE));
    private final TextAttribute commentAttribute = new TextAttribute(Display.getCurrent().getSystemColor(SWT.COLOR_GRAY));

    public PropertiesReconciler() {
        // 1. 注释分区对应的Scanner
        RuleBasedScanner commentScanner = new RuleBasedScanner();
        commentScanner.setRules(new IRule[] {new PropertyCommentRule(new Token(commentAttribute))});
        DefaultDamagerRepairer commentDr = new DefaultDamagerRepairer(commentScanner);
        this.setDamager(commentDr, IPropertiesPartitions.PROPERTIES_COMMENT);
        this.setRepairer(commentDr, IPropertiesPartitions.PROPERTIES_COMMENT);

        // 2. 属性名分区对应的Scanner
        RuleBasedScanner keyScanner = new RuleBasedScanner();
        keyScanner.setRules(new IRule[] {new PropertyNameRule(new Token(keyAttribute))});
        DefaultDamagerRepairer keyDr = new DefaultDamagerRepairer(keyScanner);
        this.setDamager(keyDr, IPropertiesPartitions.PROPERTIES_KEY);
        this.setRepairer(keyDr, IPropertiesPartitions.PROPERTIES_KEY);

        // 3. 属性值分区对应的Scanner
        RuleBasedScanner valueScanner = new RuleBasedScanner();
        valueScanner.setRules(new IRule[] {new PropertyValueRule(new Token(valueAttribute))});
        DefaultDamagerRepairer valueDr = new DefaultDamagerRepairer(valueScanner);
        this.setDamager(valueDr, IPropertiesPartitions.PROPERTIES_VALUE);
        this.setRepairer(valueDr, IPropertiesPartitions.PROPERTIES_VALUE);

        // 兜底默认分区配置
        DefaultDamagerRepairer defaultDr = new DefaultDamagerRepairer(new RuleBasedScanner());
        this.setDamager(defaultDr, IDocument.DEFAULT_CONTENT_TYPE);
        this.setRepairer(defaultDr, IDocument.DEFAULT_CONTENT_TYPE);
    }
}

该方案不需要修改原有plugin.xml的presentationReconcilers扩展配置，只需要确保你的编辑器文档正确绑定了自定义分区器即可。

内容的提问来源于stack exchange，提问作者steven