TDT4100-project/src/main/java/app/service/LanguageOperations.java

72 lines
2.1 KiB
Java

package app.service;
import java.util.Collection;
import java.util.Collections;
import java.util.regex.Matcher;
import org.fxmisc.richtext.model.StyleSpans;
import org.fxmisc.richtext.model.StyleSpansBuilder;
import app.model.ProgrammingLanguage;
/**
* Common static operations that can be executed on any class
* that implements {@link app.model.ProgrammingLanguage ProgrammingLanguage}
*/
public final class LanguageOperations {
private LanguageOperations() {}
/**
* Use a matcher to find the styleclass of the next match
* from several available styleclasses.
* @param m The matcher
* @param styleClasses Collection of styleclasses
* @return The styleclass of the next match
*/
private static String getMatch(Matcher m, Collection<String> styleClasses) {
return styleClasses
.stream()
.filter(keyword -> m.group(keyword) != null)
.findFirst()
.orElse(""); // This is not possible, but is needed to convert Optional<String> to String
}
/**
* Calculate syntax highlighting data for a code area
* @param text The text to highlight
* @param language The language object to use for highlighting
* @return The syntax highlighting data
* @see app.controllers.EditorController#setHighlighting(StyleSpans) EditorController.setHighlighting()
*/
public static StyleSpans<Collection<String>>
syntaxHighlight(String text, ProgrammingLanguage language) {
Matcher matcher = language.getPattern().matcher(text);
StyleSpansBuilder<Collection<String>> spansBuilder = new StyleSpansBuilder<>();
int lastKwEnd = 0;
while(matcher.find()) {
String styleClass = getMatch(matcher, language.getPatternMap().values());
spansBuilder.add(
Collections.emptyList(),
matcher.start() - lastKwEnd
);
spansBuilder.add(
Collections.singleton(styleClass),
matcher.end() - matcher.start()
);
lastKwEnd = matcher.end();
}
spansBuilder.add(
Collections.emptyList(),
text.length() - lastKwEnd
);
return spansBuilder.create();
}
}