Dave Jarvis' Repositories
git clone https://repo.autonoma.ca/repo/keenwrite.git
MarkdownSyntaxHighlighter: use StyleSpansBuilder instead of invoking clearStyle() and setStyle() because: - clearStyle(0, textLength) has the problem that it always scrolls caret to the top of the view - probably more performat
| Author | Karl Tauber <email> |
|---|---|
| Date | 2015-07-26 13:57:56 GMT+0200 |
| Commit | b3ec4814c1d92db77943506e49e75dbed75e50c7 |
| Parent | 57e73bb |
| Delta | 25 lines added, 18 lines removed, 7-line increase |
src/main/java/org/markdownwriterfx/editor/MarkdownSyntaxHighlighter.java
| package org.markdownwriterfx.editor; | ||
| +import java.util.Collection; | ||
| import java.util.Collections; | ||
| import javafx.application.Platform; | ||
| import org.fxmisc.richtext.StyleClassedTextArea; | ||
| +import org.fxmisc.richtext.StyleSpans; | ||
| +import org.fxmisc.richtext.StyleSpansBuilder; | ||
| import org.pegdown.ast.*; | ||
 | ||
| implements Visitor | ||
| { | ||
| - private final StyleClassedTextArea textArea; | ||
| - private final int textLength; | ||
| + private int textLength; | ||
| + private StyleSpansBuilder<Collection<String>> spansBuilder; | ||
| + private int nextIndex; | ||
| static void highlight(StyleClassedTextArea textArea, RootNode astRoot) { | ||
| - new MarkdownSyntaxHighlighter(textArea).toStyles(astRoot); | ||
| + assert Platform.isFxApplicationThread(); | ||
| + | ||
| + textArea.setStyleSpans(0, new MarkdownSyntaxHighlighter() | ||
| + .computeHighlighting(astRoot, textArea.getLength())); | ||
| } | ||
| - private MarkdownSyntaxHighlighter(StyleClassedTextArea textArea) { | ||
| - this.textArea = textArea; | ||
| - this.textLength = textArea.getLength(); | ||
| + private MarkdownSyntaxHighlighter() { | ||
| } | ||
| - private void toStyles(RootNode astRoot) { | ||
| - assert Platform.isFxApplicationThread(); | ||
| + private StyleSpans<Collection<String>> computeHighlighting(RootNode astRoot, int textLength) { | ||
| + this.textLength = textLength; | ||
| - textArea.clearStyle(0, textLength); | ||
| + spansBuilder = new StyleSpansBuilder<>(); | ||
| + nextIndex = 0; | ||
| astRoot.accept(this); | ||
| + spansBuilder.add(Collections.emptyList(), textLength - nextIndex); | ||
| + return spansBuilder.create(); | ||
| } | ||
| ||
| private void setStyleClass(Node node, String styleClass) { | ||
| - try { | ||
| - // because PegDownProcessor.prepareSource() adds two trailing newlines | ||
| - // to the text before parsing, we need to limit the end index | ||
| - textArea.setStyle(node.getStartIndex(), | ||
| - Math.min(node.getEndIndex(), textLength), | ||
| - Collections.singleton(styleClass)); | ||
| - } catch(IllegalArgumentException ex) { | ||
| - ex.printStackTrace(); | ||
| - } | ||
| + // because PegDownProcessor.prepareSource() adds two trailing newlines | ||
| + // to the text before parsing, we need to limit the end index | ||
| + int startIndex = node.getStartIndex(); | ||
| + int endIndex = Math.min(node.getEndIndex(), textLength); | ||
| + | ||
| + spansBuilder.add(Collections.emptyList(), startIndex - nextIndex); | ||
| + spansBuilder.add(Collections.singleton(styleClass), endIndex - startIndex); | ||
| + nextIndex = endIndex; | ||
| } | ||
| } | ||