Dave Jarvis' Repositories
git clone https://repo.autonoma.ca/repo/keenwrite.git
MarkdownSyntaxHighlighter: support overlapping styles
| Author | Karl Tauber <email> |
|---|---|
| Date | 2015-07-26 17:24:44 GMT+0200 |
| Commit | 13171aa1f3e0829a20946013ef40ecac5ae5e453 |
| Parent | b3ec481 |
| Delta | 73 lines added, 15 lines removed, 58-line increase |
src/main/java/org/markdownwriterfx/editor/MarkdownSyntaxHighlighter.java
| package org.markdownwriterfx.editor; | ||
| +import java.util.ArrayList; | ||
| import java.util.Collection; | ||
| import java.util.Collections; | ||
 | ||
| implements Visitor | ||
| { | ||
| - private int textLength; | ||
| - private StyleSpansBuilder<Collection<String>> spansBuilder; | ||
| - private int nextIndex; | ||
| + private enum StyleClass { | ||
| + strong, | ||
| + em, | ||
| + | ||
| + // headers | ||
| + h1, | ||
| + h2, | ||
| + h3, | ||
| + h4, | ||
| + h5, | ||
| + h6, | ||
| + }; | ||
| + | ||
| + /** | ||
| + * style bits (1 << StyleClass.ordinal()) for each character | ||
| + * simplifies implementation of overlapping styles | ||
| + */ | ||
| + private int[] styleClassBits; | ||
| static void highlight(StyleClassedTextArea textArea, RootNode astRoot) { | ||
| + assert StyleClass.values().length <= 32; | ||
| assert Platform.isFxApplicationThread(); | ||
| ||
| private StyleSpans<Collection<String>> computeHighlighting(RootNode astRoot, int textLength) { | ||
| - this.textLength = textLength; | ||
| + styleClassBits = new int[textLength]; | ||
| - spansBuilder = new StyleSpansBuilder<>(); | ||
| - nextIndex = 0; | ||
| + // visit all nodes | ||
| astRoot.accept(this); | ||
| - spansBuilder.add(Collections.emptyList(), textLength - nextIndex); | ||
| + | ||
| + // build style spans | ||
| + StyleSpansBuilder<Collection<String>> spansBuilder = new StyleSpansBuilder<>(); | ||
| + if (styleClassBits.length > 0) { | ||
| + int spanStart = 0; | ||
| + int previousBits = styleClassBits[0]; | ||
| + | ||
| + for (int i = 1; i < styleClassBits.length; i++) { | ||
| + int bits = styleClassBits[i]; | ||
| + if (bits == previousBits) | ||
| + continue; | ||
| + | ||
| + spansBuilder.add(toStyleClasses(previousBits), i - spanStart); | ||
| + | ||
| + spanStart = i; | ||
| + previousBits = bits; | ||
| + } | ||
| + spansBuilder.add(toStyleClasses(previousBits), styleClassBits.length - spanStart); | ||
| + } else | ||
| + spansBuilder.add(Collections.emptyList(), 0); | ||
| return spansBuilder.create(); | ||
| + } | ||
| + | ||
| + private Collection<String> toStyleClasses(int bits) { | ||
| + if (bits == 0) | ||
| + return Collections.emptyList(); | ||
| + | ||
| + Collection<String> styleClasses = new ArrayList<>(1); | ||
| + for (StyleClass styleClass : StyleClass.values()) { | ||
| + if ((bits & (1 << styleClass.ordinal())) != 0) | ||
| + styleClasses.add(styleClass.name()); | ||
| + } | ||
| + return styleClasses; | ||
| } | ||
| ||
| @Override | ||
| public void visit(HeaderNode node) { | ||
| - setStyleClass(node, "h" + node.getLevel()); | ||
| + StyleClass styleClass; | ||
| + switch (node.getLevel()) { | ||
| + case 1: styleClass = StyleClass.h1; break; | ||
| + case 2: styleClass = StyleClass.h2; break; | ||
| + case 3: styleClass = StyleClass.h3; break; | ||
| + case 4: styleClass = StyleClass.h4; break; | ||
| + case 5: styleClass = StyleClass.h5; break; | ||
| + case 6: styleClass = StyleClass.h6; break; | ||
| + default: return; | ||
| + } | ||
| + setStyleClass(node, styleClass); | ||
| + visitChildren(node); | ||
| } | ||
| ||
| @Override | ||
| public void visit(StrongEmphSuperNode node) { | ||
| - setStyleClass(node, node.isStrong() ? "strong" : "em"); | ||
| + setStyleClass(node, node.isStrong() ? StyleClass.strong : StyleClass.em); | ||
| } | ||
| ||
| } | ||
| - private void setStyleClass(Node node, String styleClass) { | ||
| + private void setStyleClass(Node node, StyleClass styleClass) { | ||
| // 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); | ||
| + int start = node.getStartIndex(); | ||
| + int end = Math.min(node.getEndIndex(), styleClassBits.length); | ||
| + int styleBit = 1 << styleClass.ordinal(); | ||
| - spansBuilder.add(Collections.emptyList(), startIndex - nextIndex); | ||
| - spansBuilder.add(Collections.singleton(styleClass), endIndex - startIndex); | ||
| - nextIndex = endIndex; | ||
| + for (int i = start; i < end; i++) | ||
| + styleClassBits[i] |= styleBit; | ||
| } | ||
| } | ||