TextContentRenderer: Replace stripNewlines with lineBreakRendering

robinst · robinst · commit 42a025f24b4e · 2024-09-23T22:52:06.000+10:00
diff --git a/commonmark/src/main/java/org/commonmark/renderer/text/CoreTextContentNodeRenderer.java b/commonmark/src/main/java/org/commonmark/renderer/text/CoreTextContentNodeRenderer.java
@@ -65,25 +65,20 @@ public void visit(BlockQuote blockQuote) {
         // LEFT-POINTING DOUBLE ANGLE QUOTATION MARK
         textContent.write('\u00AB');
         visitChildren(blockQuote);
+        textContent.resetBlock();
         // RIGHT-POINTING DOUBLE ANGLE QUOTATION MARK
         textContent.write('\u00BB');
 
-        writeEndOfLineIfNeeded(blockQuote, null);
+        textContent.block();
     }
 
     @Override
     public void visit(BulletList bulletList) {
-        if (listHolder != null) {
-            writeEndOfLine();
-        }
+        // TODO: isTight()
         listHolder = new BulletListHolder(listHolder, bulletList);
         visitChildren(bulletList);
-        writeEndOfLineIfNeeded(bulletList, null);
-        if (listHolder.getParent() != null) {
-            listHolder = listHolder.getParent();
-        } else {
-            listHolder = null;
-        }
+        textContent.block();
+        listHolder = listHolder.getParent();
     }
 
     @Override
@@ -95,31 +90,40 @@ public void visit(Code code) {
 
     @Override
     public void visit(FencedCodeBlock fencedCodeBlock) {
-        if (context.stripNewlines()) {
-            textContent.writeStripped(fencedCodeBlock.getLiteral());
-            writeEndOfLineIfNeeded(fencedCodeBlock, null);
+        var literal = stripTrailingNewline(fencedCodeBlock.getLiteral());
+        if (stripNewlines()) {
+            textContent.writeStripped(literal);
         } else {
-            textContent.write(fencedCodeBlock.getLiteral());
+            textContent.write(literal);
         }
+        textContent.block();
     }
 
     @Override
     public void visit(HardLineBreak hardLineBreak) {
-        writeEndOfLineIfNeeded(hardLineBreak, null);
+        if (stripNewlines()) {
+            textContent.whitespace();
+        } else {
+            textContent.line();
+        }
     }
 
     @Override
     public void visit(Heading heading) {
         visitChildren(heading);
-        writeEndOfLineIfNeeded(heading, ':');
+        if (stripNewlines()) {
+            textContent.write(": ");
+        } else {
+            textContent.block();
+        }
     }
 
     @Override
     public void visit(ThematicBreak thematicBreak) {
-        if (!context.stripNewlines()) {
+        if (!stripNewlines()) {
             textContent.write("***");
         }
-        writeEndOfLineIfNeeded(thematicBreak, null);
+        textContent.block();
     }
 
     @Override
@@ -139,12 +143,13 @@ public void visit(Image image) {
 
     @Override
     public void visit(IndentedCodeBlock indentedCodeBlock) {
-        if (context.stripNewlines()) {
-            textContent.writeStripped(indentedCodeBlock.getLiteral());
-            writeEndOfLineIfNeeded(indentedCodeBlock, null);
+        var literal = stripTrailingNewline(indentedCodeBlock.getLiteral());
+        if (stripNewlines()) {
+            textContent.writeStripped(literal);
         } else {
-            textContent.write(indentedCodeBlock.getLiteral());
+            textContent.write(literal);
         }
+        textContent.block();
     }
 
     @Override
@@ -156,48 +161,43 @@ public void visit(Link link) {
     public void visit(ListItem listItem) {
         if (listHolder != null && listHolder instanceof OrderedListHolder) {
             OrderedListHolder orderedListHolder = (OrderedListHolder) listHolder;
-            String indent = context.stripNewlines() ? "" : orderedListHolder.getIndent();
+            String indent = stripNewlines() ? "" : orderedListHolder.getIndent();
             textContent.write(indent + orderedListHolder.getCounter() + orderedListHolder.getDelimiter() + " ");
             visitChildren(listItem);
-            writeEndOfLineIfNeeded(listItem, null);
+            textContent.block();
             orderedListHolder.increaseCounter();
         } else if (listHolder != null && listHolder instanceof BulletListHolder) {
             BulletListHolder bulletListHolder = (BulletListHolder) listHolder;
-            if (!context.stripNewlines()) {
+            if (!stripNewlines()) {
                 textContent.write(bulletListHolder.getIndent() + bulletListHolder.getMarker() + " ");
             }
             visitChildren(listItem);
-            writeEndOfLineIfNeeded(listItem, null);
+            textContent.block();
         }
     }
 
     @Override
     public void visit(OrderedList orderedList) {
-        if (listHolder != null) {
-            writeEndOfLine();
-        }
+        // TODO: isTight()
         listHolder = new OrderedListHolder(listHolder, orderedList);
         visitChildren(orderedList);
-        writeEndOfLineIfNeeded(orderedList, null);
-        if (listHolder.getParent() != null) {
-            listHolder = listHolder.getParent();
-        } else {
-            listHolder = null;
-        }
+        textContent.block();
+        listHolder = listHolder.getParent();
     }
 
     @Override
     public void visit(Paragraph paragraph) {
         visitChildren(paragraph);
-        // Add "end of line" only if its "root paragraph.
-        if (paragraph.getParent() == null || paragraph.getParent() instanceof Document) {
-            writeEndOfLineIfNeeded(paragraph, null);
-        }
+        textContent.block();
     }
 
     @Override
     public void visit(SoftLineBreak softLineBreak) {
-        writeEndOfLineIfNeeded(softLineBreak, null);
+        if (stripNewlines()) {
+            textContent.whitespace();
+        } else {
+            textContent.line();
+        }
     }
 
     @Override
@@ -216,7 +216,7 @@ protected void visitChildren(Node parent) {
     }
 
     private void writeText(String text) {
-        if (context.stripNewlines()) {
+        if (stripNewlines()) {
             textContent.writeStripped(text);
         } else {
             textContent.write(text);
@@ -255,26 +255,15 @@ private void writeLink(Node node, String title, String destination) {
         }
     }
 
-    private void writeEndOfLineIfNeeded(Node node, Character c) {
-        if (context.stripNewlines()) {
-            if (c != null) {
-                textContent.write(c);
-            }
-            if (node.getNext() != null) {
-                textContent.whitespace();
-            }
-        } else {
-            if (node.getNext() != null) {
-                textContent.line();
-            }
-        }
+    private boolean stripNewlines() {
+        return context.lineBreakRendering() == LineBreakRendering.STRIP;
     }
 
-    private void writeEndOfLine() {
-        if (context.stripNewlines()) {
-            textContent.whitespace();
+    private static String stripTrailingNewline(String s) {
+        if (s.endsWith("\n")) {
+            return s.substring(0, s.length() - 1);
         } else {
-            textContent.line();
+            return s;
         }
     }
 }
diff --git a/commonmark/src/main/java/org/commonmark/renderer/text/LineBreakRendering.java b/commonmark/src/main/java/org/commonmark/renderer/text/LineBreakRendering.java
@@ -0,0 +1,19 @@
+package org.commonmark.renderer.text;
+
+/**
+ * Control how line breaks are rendered.
+ */
+public enum LineBreakRendering {
+    /**
+     * Strip all line breaks within blocks and between blocks, resulting in all the text in a single line.
+     */
+    STRIP,
+    /**
+     * Use single line breaks between blocks, not a blank line (also render all lists as tight).
+     */
+    COMPACT,
+    /**
+     * Separate blocks by a blank line (and respect tight vs loose lists).
+     */
+    SEPARATE_BLOCKS,
+}
diff --git a/commonmark/src/main/java/org/commonmark/renderer/text/TextContentNodeRendererContext.java b/commonmark/src/main/java/org/commonmark/renderer/text/TextContentNodeRendererContext.java
@@ -4,10 +4,19 @@
 
 public interface TextContentNodeRendererContext {
 
+    /**
+     * TODO
+     *
+     * @return
+     */
+    LineBreakRendering lineBreakRendering();
+
     /**
      * @return true for stripping new lines and render text as "single line",
      * false for keeping all line breaks.
+     * @deprecated Use {@link #lineBreakRendering()} instead
      */
+    @Deprecated
     boolean stripNewlines();
 
     /**
diff --git a/commonmark/src/main/java/org/commonmark/renderer/text/TextContentRenderer.java b/commonmark/src/main/java/org/commonmark/renderer/text/TextContentRenderer.java
@@ -14,12 +14,12 @@
  */
 public class TextContentRenderer implements Renderer {
 
-    private final boolean stripNewlines;
+    private final LineBreakRendering lineBreakRendering;
 
     private final List<TextContentNodeRendererFactory> nodeRendererFactories;
 
     private TextContentRenderer(Builder builder) {
-        this.stripNewlines = builder.stripNewlines;
+        this.lineBreakRendering = builder.lineBreakRendering;
 
         this.nodeRendererFactories = new ArrayList<>(builder.nodeRendererFactories.size() + 1);
         this.nodeRendererFactories.addAll(builder.nodeRendererFactories);
@@ -43,7 +43,7 @@ public static Builder builder() {
 
     @Override
     public void render(Node node, Appendable output) {
-        RendererContext context = new RendererContext(new TextContentWriter(output));
+        RendererContext context = new RendererContext(new TextContentWriter(output, lineBreakRendering));
         context.render(node);
     }
 
@@ -59,8 +59,8 @@ public String render(Node node) {
      */
     public static class Builder {
 
-        private boolean stripNewlines = false;
         private List<TextContentNodeRendererFactory> nodeRendererFactories = new ArrayList<>();
+        private LineBreakRendering lineBreakRendering = LineBreakRendering.COMPACT;
 
         /**
          * @return the configured {@link TextContentRenderer}
@@ -69,15 +69,28 @@ public TextContentRenderer build() {
             return new TextContentRenderer(this);
         }
 
+        /**
+         * TODO
+         *
+         * @param lineBreakRendering
+         * @return
+         */
+        public Builder lineBreakRendering(LineBreakRendering lineBreakRendering) {
+            this.lineBreakRendering = lineBreakRendering;
+            return this;
+        }
+
         /**
          * Set the value of flag for stripping new lines.
          *
          * @param stripNewlines true for stripping new lines and render text as "single line",
          *                      false for keeping all line breaks
          * @return {@code this}
+         * @deprecated Use {@link #lineBreakRendering(LineBreakRendering)} with {@link LineBreakRendering#STRIP} instead
          */
+        @Deprecated
         public Builder stripNewlines(boolean stripNewlines) {
-            this.stripNewlines = stripNewlines;
+            this.lineBreakRendering = stripNewlines ? LineBreakRendering.STRIP : LineBreakRendering.COMPACT;
             return this;
         }
 
@@ -134,9 +147,14 @@ private RendererContext(TextContentWriter textContentWriter) {
             }
         }
 
+        @Override
+        public LineBreakRendering lineBreakRendering() {
+            return lineBreakRendering;
+        }
+
         @Override
         public boolean stripNewlines() {
-            return stripNewlines;
+            return lineBreakRendering == LineBreakRendering.STRIP;
         }
 
         @Override
diff --git a/commonmark/src/main/java/org/commonmark/renderer/text/TextContentWriter.java b/commonmark/src/main/java/org/commonmark/renderer/text/TextContentWriter.java
diff --git a/commonmark/src/test/java/org/commonmark/test/TextContentRendererTest.java b/commonmark/src/test/java/org/commonmark/test/TextContentRendererTest.java
