package org.fxmisc.richtext.demo;
import java.time.Duration;
import java.util.Collection;
import java.util.Collections;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javafx.application.Application;
import javafx.concurrent.Task;
import javafx.scene.Scene;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
import org.fxmisc.richtext.CodeArea;
import org.fxmisc.richtext.LineNumberFactory;
import org.fxmisc.richtext.PlainTextChange;
import org.fxmisc.richtext.StyleSpans;
import org.fxmisc.richtext.StyleSpansBuilder;
import org.reactfx.EventStream;
public class JavaKeywordsAsync extends Application {
private static final String[] KEYWORDS = new String[] {
"abstract", "assert", "boolean", "break", "byte",
"case", "catch", "char", "class", "const",
"continue", "default", "do", "double", "else",
"enum", "extends", "final", "finally", "float",
"for", "goto", "if", "implements", "import",
"instanceof", "int", "interface", "long", "native",
"new", "package", "private", "protected", "public",
"return", "short", "static", "strictfp", "super",
"switch", "synchronized", "this", "throw", "throws",
"transient", "try", "void", "volatile", "while"
};
private static final String KEYWORD_PATTERN = "\\b(" + String.join("|", KEYWORDS) + ")\\b";
private static final String PAREN_PATTERN = "\\(|\\)";
private static final String BRACE_PATTERN = "\\{|\\}";
private static final String BRACKET_PATTERN = "\\[|\\]";
private static final String SEMICOLON_PATTERN = "\\;";
private static final String STRING_PATTERN = "\"([^\"]|\\\")*\"";
private static final Pattern PATTERN = Pattern.compile(
"(?<KEYWORD>" + KEYWORD_PATTERN + ")"
+ "|(?<PAREN>" + PAREN_PATTERN + ")"
+ "|(?<BRACE>" + BRACE_PATTERN + ")"
+ "|(?<BRACKET>" + BRACKET_PATTERN + ")"
+ "|(?<SEMICOLON>" + SEMICOLON_PATTERN + ")"
+ "|(?<STRING>" + STRING_PATTERN + ")"
);
private static final String sampleCode = String.join("\n", new String[] {
"package com.example;",
"",
"import java.util.*;",
"",
"public class Foo extends Bar implements Baz {",
"",
" public static void main(String[] args) {",
" for(String arg: args) {",
" if(arg.length() != 0)",
" System.out.println(arg);",
" else",
" System.err.println(\"Warning: empty string as argument\");",
" }",
" }",
"",
"}"
});
public static void main(String[] args) {
launch(args);
}
private CodeArea codeArea;
private ExecutorService executor;
@Override
public void start(Stage primaryStage) {
executor = Executors.newSingleThreadExecutor();
codeArea = new CodeArea();
codeArea.setParagraphGraphicFactory(LineNumberFactory.get(codeArea));
EventStream<PlainTextChange> textChanges = codeArea.plainTextChanges();
textChanges
.successionEnds(Duration.ofMillis(500))
.supplyTask(this::computeHighlightingAsync)
.awaitLatest(textChanges)
.subscribe(this::applyHighlighting);
codeArea.replaceText(0, 0, sampleCode);
Scene scene = new Scene(new StackPane(codeArea), 600, 400);
scene.getStylesheets().add(JavaKeywordsAsync.class.getResource("java-keywords.css").toExternalForm());
primaryStage.setScene(scene);
primaryStage.setTitle("Java Keywords Async Demo");
primaryStage.show();
}
@Override
public void stop() {
executor.shutdown();
}
private Task<StyleSpans<Collection<String>>> computeHighlightingAsync() {
String text = codeArea.getText();
Task<StyleSpans<Collection<String>>> task = new Task<StyleSpans<Collection<String>>>() {
@Override
protected StyleSpans<Collection<String>> call() throws Exception {
return computeHighlighting(text);
}
};
executor.execute(task);
return task;
}
private void applyHighlighting(StyleSpans<Collection<String>> highlighting) {
codeArea.setStyleSpans(0, highlighting);
}
private static StyleSpans<Collection<String>> computeHighlighting(String text) {
Matcher matcher = PATTERN.matcher(text);
int lastKwEnd = 0;
StyleSpansBuilder<Collection<String>> spansBuilder
= new StyleSpansBuilder<>();
while(matcher.find()) {
String styleClass =
matcher.group("KEYWORD") != null ? "keyword" :
matcher.group("PAREN") != null ? "paren" :
matcher.group("BRACE") != null ? "brace" :
matcher.group("BRACKET") != null ? "bracket" :
matcher.group("SEMICOLON") != null ? "semicolon" :
matcher.group("STRING") != null ? "string" :
null; /* never happens */ assert styleClass != null;
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();
}
}