Pass symbolAddedInside state to split renderer of ListItemRenderer

DEVSIX-6662

Author: yulian-gaponenko

layout/src/main/java/com/itextpdf/layout/renderer/ListItemRenderer.java

@@ -250,6 +250,7 @@ protected AbstractRenderer createSplitRenderer(int layoutResult) {
         splitRenderer.parent = parent;
         splitRenderer.modelElement = modelElement;
         splitRenderer.occupiedArea = occupiedArea;
+        splitRenderer.symbolAddedInside = symbolAddedInside;
         splitRenderer.isLastRendererForModelElement = false;
         if (layoutResult == LayoutResult.PARTIAL) {
             splitRenderer.symbolRenderer = symbolRenderer;

layout/src/test/java/com/itextpdf/layout/renderer/ListRendererUnitTest.java

@@ -23,8 +23,16 @@ This file is part of the iText (R) project.
 package com.itextpdf.layout.renderer;
 
 import com.itextpdf.io.logs.IoLogMessageConstant;
+import com.itextpdf.kernel.pdf.PdfPage;
+import com.itextpdf.kernel.pdf.canvas.PdfCanvas;
+import com.itextpdf.layout.Document;
 import com.itextpdf.layout.element.List;
-import com.itextpdf.test.ExtendedITextTest;
+import com.itextpdf.layout.element.ListItem;
+import com.itextpdf.layout.element.Paragraph;
+import com.itextpdf.layout.element.Text;
+import com.itextpdf.layout.layout.LayoutResult;
+import com.itextpdf.layout.properties.ListSymbolPosition;
+import com.itextpdf.layout.properties.Property;
 import com.itextpdf.test.annotations.LogMessage;
 import com.itextpdf.test.annotations.LogMessages;
 import com.itextpdf.test.annotations.type.UnitTest;
@@ -34,7 +42,7 @@ This file is part of the iText (R) project.
 import org.junit.experimental.categories.Category;
 
 @Category(UnitTest.class)
-public class ListRendererUnitTest extends ExtendedITextTest {
+public class ListRendererUnitTest extends RendererUnitTest {
 
     @Test
     @LogMessages(messages = {
@@ -47,4 +55,81 @@ public void getNextRendererShouldBeOverriddenTest() {
 
         Assert.assertEquals(ListRenderer.class, listRenderer.getNextRenderer().getClass());
     }
+
+    @Test
+    public void symbolPositioningInsideDrawnOnceTest() {
+        InvocationsCounter invocationsCounter = new InvocationsCounter();
+
+        List modelElement = new List();
+        modelElement.setNextRenderer(new ListRendererCreatingNotifyingListSymbols(modelElement, invocationsCounter));
+        modelElement.add((ListItem) new ListItem().add(new Paragraph("ListItem1")).add(new Paragraph("ListItem2")));
+        modelElement.setProperty(Property.LIST_SYMBOL_POSITION, ListSymbolPosition.INSIDE);
+        modelElement.setFontSize(30);
+
+        // A hack for a test in order to layout the list at the very left border of the parent area.
+        // List symbols are not drawn outside the parent area, so we want to make sure that symbol renderer
+        // won't be drawn twice even if there's enough space around the list.
+        modelElement.setMarginLeft(500);
+        IRenderer listRenderer = modelElement.createRendererSubTree();
+
+        Document document = createDummyDocument();
+        listRenderer.setParent(document.getRenderer());
+        PdfPage pdfPage = document.getPdfDocument().addNewPage();
+
+        // should be enough to fit a single list-item, but not both
+        int height = 80;
+
+        // we don't want to impose any width restrictions
+        int width = 1000;
+        LayoutResult result = listRenderer.layout(createLayoutContext(width, height));
+        assert result.getStatus() == LayoutResult.PARTIAL;
+        result.getSplitRenderer().draw(new DrawContext(document.getPdfDocument(), new PdfCanvas(pdfPage)));
+
+        // only split part is drawn, list symbol is expected to be drawn only once.
+        Assert.assertEquals(1, invocationsCounter.getInvocationsCount());
+    }
+
+    private static class ListRendererCreatingNotifyingListSymbols extends ListRenderer {
+        private InvocationsCounter counter;
+
+        public ListRendererCreatingNotifyingListSymbols(List modelElement, InvocationsCounter counter) {
+            super(modelElement);
+            this.counter = counter;
+        }
+
+        @Override
+        protected IRenderer makeListSymbolRenderer(int index, IRenderer renderer) {
+            return new NotifyingListSymbolRenderer(new Text("-"), counter);
+        }
+
+        @Override
+        public IRenderer getNextRenderer() {
+            return new ListRendererCreatingNotifyingListSymbols((List) getModelElement(), counter);
+        }
+    }
+
+    private static class NotifyingListSymbolRenderer extends TextRenderer {
+        private InvocationsCounter counter;
+
+        public NotifyingListSymbolRenderer(Text textElement, InvocationsCounter counter) {
+            super(textElement);
+            this.counter = counter;
+        }
+
+        @Override
+        public void draw(DrawContext drawContext) {
+            counter.registerInvocation();
+            super.draw(drawContext);
+        }
+    }
+
+    private static class InvocationsCounter {
+        private int counter = 0;
+        void registerInvocation() {
+            ++counter;
+        }
+        int getInvocationsCount() {
+            return counter;
+        }
+    }
 }

layout/src/test/java/com/itextpdf/layout/renderer/RendererUnitTest.java

@@ -58,7 +58,12 @@ public abstract class RendererUnitTest extends ExtendedITextTest {
 
     // This also can be converted to a @Rule to have it all at hand in the future
     protected static Document createDummyDocument() {
-        return new Document(new PdfDocument(new PdfWriter(new ByteArrayOutputStream())));
+        Document document = new Document(new PdfDocument(new PdfWriter(new ByteArrayOutputStream())));
+
+        // setting margins to 0, because it's a dummy parent and this way it would less likely
+        // interfere with other calculations
+        document.setMargins(0, 0, 0, 0);
+        return document;
     }
 
     protected static TextRenderer createLayoutedTextRenderer(String text, Document document) {
@@ -78,4 +83,8 @@ protected static ImageRenderer createLayoutedImageRenderer(float width, float he
     protected static LayoutArea createLayoutArea(float width, float height) {
         return new LayoutArea(1, new Rectangle(width, height));
     }
+
+    protected static LayoutContext createLayoutContext(float width, float height) {
+        return new LayoutContext(createLayoutArea(width, height));
+    }
 }