UI/UX: Highlighting search keyword in alert log content

Author: Dokyeongyun

src/main/java/root/javafx/CustomView/AlertLogListViewCell.java

@@ -1,10 +1,22 @@
 package root.javafx.CustomView;
 
 import java.io.IOException;
-
+import java.util.Collection;
+import java.util.Collections;
+import java.util.function.Consumer;
+import java.util.function.Function;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import org.fxmisc.richtext.GenericStyledArea;
 import org.fxmisc.richtext.StyleClassedTextArea;
+import org.fxmisc.richtext.model.Paragraph;
+import org.fxmisc.richtext.model.StyleSpans;
+import org.fxmisc.richtext.model.StyleSpansBuilder;
+import org.reactfx.collection.ListModification;
 
 import de.jensd.fx.glyphs.fontawesome.FontAwesomeIconView;
+import javafx.application.Platform;
 import javafx.fxml.FXML;
 import javafx.fxml.FXMLLoader;
 import javafx.geometry.Insets;
@@ -24,6 +36,8 @@
 public class AlertLogListViewCell extends ListCell<Log> {
 	private FXMLLoader loader;
 
+	private Pattern KEYWORD_PATTERN;
+
 	@FXML
 	AnchorPane rootAP;
 	@FXML
@@ -36,6 +50,11 @@ public class AlertLogListViewCell extends ListCell<Log> {
 	HBox logContentHBox;
 
 	public AlertLogListViewCell(String... highlightKeywords) {
+		String join = String.join("|", highlightKeywords);
+		KEYWORD_PATTERN = Pattern.compile("(?<KEYWORD1>\\b(" + join + ")\\b)"
+				+ "|(?<KEYWORD2>\\b(" + join + ")\\B)"
+						+ "|(?<KEYWORD3>\\B(" + join + ")\\b)"
+								+ "|(?<KEYWORD4>\\B(" + join + ")\\B)");
 	}
 
 	@Override
@@ -80,6 +99,8 @@ protected void updateItem(Log logObj, boolean empty) {
 			codeArea.getStylesheets()
 					.add(getClass().getResource(baseDir + "/css/alertLogListViewCell.css").toExternalForm());
 			codeArea.getStyleClass().add("code-area");
+			codeArea.getVisibleParagraphs()
+					.addModificationObserver(new VisibleParagraphStyler<>(codeArea, this::computeHighlighting));
 
 			codeArea.replaceText(0, 0, logObj.getFullLogString());
 			if (isErrorLog) {
@@ -109,4 +130,51 @@ private boolean isErrorLog(String logContent) {
 		// TODO Remove hard-coding that identifying error log
 		return logContent.contains("ORA-");
 	}
+
+	private StyleSpans<Collection<String>> computeHighlighting(String text) {
+		Matcher matcher = KEYWORD_PATTERN.matcher(text);
+		int lastKeywordEnd = 0;
+		StyleSpansBuilder<Collection<String>> spansBuilder = new StyleSpansBuilder<>();
+		while (matcher.find()) {
+			String styleClass = matcher.group("KEYWORD1") != null ? "keyword"
+					: matcher.group("KEYWORD2") != null ? "keyword"
+							: matcher.group("KEYWORD3") != null ? "keyword"
+									: matcher.group("KEYWORD4") != null ? "keyword" : null;
+			spansBuilder.add(Collections.emptyList(), matcher.start() - lastKeywordEnd);
+			spansBuilder.add(Collections.singleton(styleClass), matcher.end() - matcher.start());
+			lastKeywordEnd = matcher.end();
+		}
+		spansBuilder.add(Collections.emptyList(), text.length() - lastKeywordEnd);
+
+		return spansBuilder.create();
+	}
+
+	private class VisibleParagraphStyler<PS, SEG, S>
+			implements Consumer<ListModification<? extends Paragraph<PS, SEG, S>>> {
+		private final GenericStyledArea<PS, SEG, S> area;
+		private final Function<String, StyleSpans<S>> computeStyles;
+		private int prevParagraph, prevTextLength;
+
+		public VisibleParagraphStyler(GenericStyledArea<PS, SEG, S> area,
+				Function<String, StyleSpans<S>> computeStyles) {
+			this.computeStyles = computeStyles;
+			this.area = area;
+		}
+
+		@Override
+		public void accept(ListModification<? extends Paragraph<PS, SEG, S>> lm) {
+			if (lm.getAddedSize() > 0) {
+				int paragraph = Math.min(area.firstVisibleParToAllParIndex() + lm.getFrom(),
+						area.getParagraphs().size() - 1);
+				String text = area.getText(paragraph, 0, paragraph, area.getParagraphLength(paragraph));
+
+				if (paragraph != prevParagraph || text.length() != prevTextLength) {
+					int startPos = area.getAbsolutePosition(paragraph, 0);
+					Platform.runLater(() -> area.setStyleSpans(startPos, computeStyles.apply(text)));
+					prevTextLength = text.length();
+					prevParagraph = paragraph;
+				}
+			}
+		}
+	}
 }