G2-1770 Support multi-line list items & nested lists during MD rendering

en-document/src/main/java/com/g2forge/enigma/document/convert/md/IMDRenderContext.java

@@ -2,13 +2,18 @@
 
 import com.g2forge.alexandria.java.close.ICloseable;
 import com.g2forge.enigma.backend.convert.textual.ITextualRenderContext;
+import com.g2forge.enigma.document.convert.md.linebreak.ILineBreakStrategy;
 
 public interface IMDRenderContext extends ITextualRenderContext<Object, IMDRenderContext> {
-	public LineBreakStrategy getLineBreakStrategy();
+	public ILineBreakStrategy getLineBreakStrategy();
 
 	public int getSectionLevel();
 
-	public ICloseable openLineBreakStrategy(LineBreakStrategy strategy);
+	public int getIndentLevel();
+
+	public ICloseable openLineBreakStrategy(ILineBreakStrategy strategy);
 
 	public ICloseable openSection();
+
+	public ICloseable openIndent();
 }

en-document/src/main/java/com/g2forge/enigma/document/convert/md/MDRenderer.java

@@ -4,15 +4,19 @@
 
 import com.g2forge.alexandria.java.close.ICloseable;
 import com.g2forge.alexandria.java.core.enums.EnumException;
+import com.g2forge.alexandria.java.function.IConsumer1;
 import com.g2forge.alexandria.java.function.IConsumer2;
 import com.g2forge.alexandria.java.function.IFunction1;
+import com.g2forge.alexandria.java.function.ISupplier;
 import com.g2forge.alexandria.java.type.function.TypeSwitch1;
 import com.g2forge.enigma.backend.ITextAppender;
 import com.g2forge.enigma.backend.convert.ARenderer;
 import com.g2forge.enigma.backend.convert.IExplicitRenderable;
 import com.g2forge.enigma.backend.convert.IRendering;
 import com.g2forge.enigma.backend.convert.textual.ATextualRenderer;
 import com.g2forge.enigma.backend.text.model.modifier.TextNestedModified;
+import com.g2forge.enigma.document.convert.md.linebreak.ILineBreakStrategy;
+import com.g2forge.enigma.document.convert.md.linebreak.LineBreakStrategy;
 import com.g2forge.enigma.document.model.Block;
 import com.g2forge.enigma.document.model.Definition;
 import com.g2forge.enigma.document.model.DocList;
@@ -34,52 +38,58 @@
 @RequiredArgsConstructor
 public class MDRenderer extends ATextualRenderer<Object, IMDRenderContext> {
 	protected class MDRenderContext extends ARenderContext implements IMDRenderContext {
-		protected final Stack<LineBreakStrategy> lineBreakStrategies = new Stack<>();
-
 		protected final Stack<ICloseable> stack = new Stack<>();
 
-		public MDRenderContext(TextNestedModified.TextNestedModifiedBuilder builder) {
-			super(builder);
-		}
+		@Getter
+		protected ILineBreakStrategy lineBreakStrategy = LineBreakStrategy.None;
 
-		@Override
-		public LineBreakStrategy getLineBreakStrategy() {
-			if (lineBreakStrategies.isEmpty()) return LineBreakStrategy.None;
-			return lineBreakStrategies.peek();
-		}
+		@Getter
+		protected int sectionLevel = 1;
 
-		@Override
-		public int getSectionLevel() {
-			return stack.size() + 1;
+		@Getter
+		protected int indentLevel;
+
+		public MDRenderContext(TextNestedModified.TextNestedModifiedBuilder builder) {
+			super(builder);
 		}
 
 		@Override
 		protected IMDRenderContext getThis() {
 			return this;
 		}
 
-		@Override
-		public ICloseable openLineBreakStrategy(LineBreakStrategy strategy) {
-			lineBreakStrategies.push(strategy);
-			final int size = lineBreakStrategies.size();
-			return () -> {
-				if (lineBreakStrategies.size() != size) throw new IllegalStateException();
-				lineBreakStrategies.pop();
-			};
-		}
-
-		@Override
-		public ICloseable openSection() {
+		protected <T> ICloseable open(ISupplier<T> start, IConsumer1<T> stop) {
+			final T value = start.get();
 			final ICloseable retVal = new ICloseable() {
 				@Override
 				public void close() {
 					if (stack.peek() != this) throw new IllegalArgumentException();
 					stack.pop();
+					stop.accept(value);
 				}
 			};
 			stack.push(retVal);
 			return retVal;
 		}
+
+		@Override
+		public ICloseable openLineBreakStrategy(ILineBreakStrategy strategy) {
+			return open(() -> {
+				final ILineBreakStrategy retVal = lineBreakStrategy;
+				lineBreakStrategy = strategy;
+				return retVal;
+			}, prev -> lineBreakStrategy = prev);
+		}
+
+		@Override
+		public ICloseable openSection() {
+			return open(() -> sectionLevel++, prev -> sectionLevel = prev);
+		}
+
+		@Override
+		public ICloseable openIndent() {
+			return open(() -> indentLevel++, prev -> indentLevel = prev);
+		}
 	}
 
 	protected static class MDRendering extends ARenderer.ARendering<Object, IMDRenderContext, IExplicitRenderable<? super IMDRenderContext>> {
@@ -127,18 +137,19 @@ protected void extend(TypeSwitch1.FunctionBuilder<Object, IExplicitRenderable<?
 			});
 
 			builder.add(Block.class, md -> c -> {
-				try (final ICloseable strategy = c.openLineBreakStrategy(LineBreakStrategy.fromBlockType(md.getType()))) {
+				try (final ICloseable strategy = c.openLineBreakStrategy(LineBreakStrategy.fromBlockType(c, md.getType()))) {
 					boolean first = true;
 					for (IBlock content : md.getContents()) {
 						if (first) first = false;
-						else c.getLineBreakStrategy().beforeItem(c, first);
+						else c.getLineBreakStrategy().beforeItem(c, first, content);
 						c.render(content, IBlock.class);
 					}
 				}
 			});
 			builder.add(DocList.class, md -> c -> {
 				final java.util.List<IDocListItem> items = md.getItems();
 				for (int i = 0; i < items.size(); i++) {
+					for (int j = 0; j < c.getIndentLevel(); j++) c.append("    ");
 					switch (md.getMarker()) {
 						case Ordered:
 							c.append("* ");
@@ -147,7 +158,9 @@ protected void extend(TypeSwitch1.FunctionBuilder<Object, IExplicitRenderable<?
 							c.append(String.format("%1$d. ", i + 1));
 							break;
 					}
-					c.render(items.get(i), IBlock.class);
+					try (ICloseable indent = c.openIndent()) {
+						c.render(items.get(i), IBlock.class);
+					}
 					if (i < (items.size() - 1)) c.newline();
 				}
 			});

en-document/src/main/java/com/g2forge/enigma/document/convert/md/linebreak/ILineBreakStrategy.java

@@ -0,0 +1,10 @@
+package com.g2forge.enigma.document.convert.md.linebreak;
+
+import com.g2forge.enigma.document.convert.md.IMDRenderContext;
+import com.g2forge.enigma.document.model.IDocListItem;
+
+public interface ILineBreakStrategy {
+	public void beforeItem(IMDRenderContext context, boolean first, IDocListItem item);
+
+	public void text(IMDRenderContext context, String text);
+}

en-document/src/main/java/com/g2forge/enigma/document/convert/md/LineBreakStrategy.java → en-document/src/main/java/com/g2forge/enigma/document/convert/md/linebreak/LineBreakStrategy.java

@@ -1,16 +1,18 @@
-package com.g2forge.enigma.document.convert.md;
+package com.g2forge.enigma.document.convert.md.linebreak;
 
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 import com.g2forge.alexandria.java.core.enums.EnumException;
+import com.g2forge.enigma.document.convert.md.IMDRenderContext;
 import com.g2forge.enigma.document.model.Block;
+import com.g2forge.enigma.document.model.IDocListItem;
 
-public enum LineBreakStrategy {
+public enum LineBreakStrategy implements ILineBreakStrategy {
 	None,
 	Item {
 		@Override
-		public void beforeItem(IMDRenderContext context, boolean first) {
+		public void beforeItem(IMDRenderContext context, boolean first, IDocListItem item) {
 			if (!first) context.newline().newline();
 		}
 	},
@@ -28,20 +30,25 @@ public void text(IMDRenderContext context, String text) {
 		}
 	};
 
-	public static LineBreakStrategy fromBlockType(Block.Type type) {
+	public static ILineBreakStrategy fromBlockType(IMDRenderContext context, Block.Type type) {
+		final LineBreakStrategy base;
 		switch (type) {
 			case Document:
 			case Block:
-				return Item;
+				base = Item;
+				break;
 			case Paragraph:
 			case ListItem:
-				return Period;
+				base = Period;
+				break;
 			default:
 				throw new EnumException(Block.Type.class, type);
 		}
+		if (context.getIndentLevel() > 0) return new ListLineBreakStrategy(base);
+		return base;
 	}
 
-	public void beforeItem(IMDRenderContext context, boolean first) {}
+	public void beforeItem(IMDRenderContext context, boolean first, IDocListItem item) {}
 
 	public void text(IMDRenderContext context, String text) {
 		context.append(text);

en-document/src/main/java/com/g2forge/enigma/document/convert/md/linebreak/ListLineBreakStrategy.java

@@ -0,0 +1,27 @@
+package com.g2forge.enigma.document.convert.md.linebreak;
+
+import com.g2forge.enigma.document.convert.md.IMDRenderContext;
+import com.g2forge.enigma.document.model.DocList;
+import com.g2forge.enigma.document.model.IDocListItem;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@Getter
+@RequiredArgsConstructor
+public class ListLineBreakStrategy implements ILineBreakStrategy {
+	protected final LineBreakStrategy base;
+
+	@Override
+	public void beforeItem(IMDRenderContext context, boolean first, IDocListItem item) {
+		if (!first) {
+			if (!(item instanceof DocList)) context.append("\\");
+			context.newline();
+		}
+	}
+
+	@Override
+	public void text(IMDRenderContext context, String text) {
+		context.append(text);
+	}
+}

en-document/src/test/java/com/g2forge/enigma/document/convert/md/TestMD.java

@@ -7,33 +7,48 @@
 import com.g2forge.enigma.document.model.Block;
 import com.g2forge.enigma.document.model.Definition;
 import com.g2forge.enigma.document.model.DocList;
+import com.g2forge.enigma.document.model.DocList.DocListBuilder;
 import com.g2forge.enigma.document.model.Emphasis;
 import com.g2forge.enigma.document.model.Text;
 import com.g2forge.enigma.document.model.Block.BlockBuilder;
 
 public class TestMD {
 	protected final MDRenderer renderer = new MDRenderer();
 
+	protected void assertEquals(final String filename, final Object actual) {
+		final String expected = HResource.read(getClass(), filename, true);
+		Assert.assertEquals(expected, renderer.render(actual));
+	}
+
 	@Test
 	public void help() {
 		final DocList.DocListBuilder builder = DocList.builder().marker(DocList.Marker.Ordered);
 		builder.item(Definition.builder().term(new Emphasis(Emphasis.Type.Code, new Text("-x"))).body(new Text("This is a sentence about the 'x' option!")).build());
 		builder.item(Definition.builder().term(new Emphasis(Emphasis.Type.Code, new Text("-y"))).body(new Text("Some description of another option")).build());
-		final DocList actual = builder.build();
-
-		final String expected = HResource.read(getClass(), "help.md", true);
-		Assert.assertEquals(expected, renderer.render(actual));
+		assertEquals("help.md", builder.build());
 	}
 
+	@Test
+	public void lists() {
+		final BlockBuilder builder = Block.builder().type(Block.Type.Block);
+		final DocListBuilder list0 = DocList.builder().marker(DocList.Marker.Ordered);
+		list0.item(Block.builder().type(Block.Type.Block).content(new Text("Item 1 Line 1")).content(new Text("Item 1 Line 2")).build());
+
+		final DocListBuilder list1 = DocList.builder().marker(DocList.Marker.Ordered);
+		list1.item(new Text("Item 2A"));
+		list1.item(new Text("Item 2B"));
+		list0.item(Block.builder().type(Block.Type.Block).content(new Text("Item 2")).content(list1.build()).build());
+
+		builder.content(list0.build());
+		assertEquals("lists.md", builder.build());
+	}
+
 	@Test
 	public void simple() {
 		final BlockBuilder builder = Block.builder().type(Block.Type.Block);
 		builder.content(DocList.builder().marker(DocList.Marker.Ordered).item(new Text("Item 1")).build());
 		builder.content(new Text("A paragraph goes here."));
 		builder.content(DocList.builder().marker(DocList.Marker.Numbered).item(new Text("Item 2")).item(new Text("Item 3")).build());
-		final Block actual = builder.build();
-
-		final String expected = HResource.read(getClass(), "simple.md", true);
-		Assert.assertEquals(expected, renderer.render(actual));
+		assertEquals("simple.md", builder.build());
 	}
 }

en-document/src/test/java/com/g2forge/enigma/document/convert/md/lists.md

@@ -0,0 +1,5 @@
+* Item 1 Line 1\
+Item 1 Line 2
+* Item 2
+    * Item 2A
+    * Item 2B