Add a possibility to specify left or right alignment for list symbols explicitly. Default alignment is right

DEVSIX-433

Author: Snipx

layout/src/main/java/com/itextpdf/layout/Property.java

@@ -49,6 +49,7 @@ public enum Property {
     LINE_DRAWER,
     LIST_START,
     LIST_SYMBOL(true),
+    LIST_SYMBOL_ALIGNMENT,
     LIST_SYMBOL_INDENT,
     MARGIN_BOTTOM,
     MARGIN_LEFT,
@@ -148,6 +149,20 @@ public enum TextAlignment {
         JUSTIFIED_ALL
     }
 
+    /**
+     * A specialized enum containing alignment properties for list symbols.
+     * {@link ListSymbolAlignment#LEFT} means that the items will be aligned as follows:
+     * 9.  Item 9
+     * 10. Item 10
+     *
+     * Whereas {@link ListSymbolAlignment#RIGHT} means the items will be aligned as follows:
+     *  9. Item 9
+     * 10. Item 10
+     */
+    public enum ListSymbolAlignment {
+        RIGHT,
+        LEFT
+    }
 
     /**
      * A specialized class holding configurable properties related to an {@link

layout/src/main/java/com/itextpdf/layout/element/List.java

@@ -99,7 +99,7 @@ public List setListSymbol(Image image) {
     /**
      * Sets the list numbering type to be used. This will create an ordered list,
      * i.e. every {@link ListItem} will have a unique prefix.
-     * @param listNumberingType the {@link Property#ListNumberingType} that will generate appropriate prefixes for the {@link ListItem}s.
+     * @param listNumberingType the {@link Property.ListNumberingType} that will generate appropriate prefixes for the {@link ListItem}s.
      * @return this list.
      */
     public List setListSymbol(Property.ListNumberingType listNumberingType) {
@@ -111,6 +111,20 @@ public List setListSymbol(Property.ListNumberingType listNumberingType) {
         return setProperty(Property.LIST_SYMBOL, listNumberingType);
     }
 
+    /**
+     * A specialized enum containing alignment properties for list symbols.
+     * {@link Property.ListSymbolAlignment#LEFT} means that the items will be aligned as follows:
+     * 9.  Item 9
+     * 10. Item 10
+     *
+     * Whereas {@link Property.ListSymbolAlignment#RIGHT} means the items will be aligned as follows:
+     *  9. Item 9
+     * 10. Item 10
+     */
+    public List setListSymbolAlignment(Property.ListSymbolAlignment alignment) {
+        return setProperty(Property.LIST_SYMBOL_ALIGNMENT, alignment);
+    }
+
     /**
      * Gets the indent offset of the {@link ListItem} symbols.
      * 

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

@@ -73,7 +73,12 @@ public void draw(DrawContext drawContext) {
                         symbolRenderer.getOccupiedArea().getBBox().getHeight() - symbolRenderer.getOccupiedArea().getBBox().getY());
             }
 
-            symbolRenderer.move(x + symbolAreaWidth - symbolRenderer.getOccupiedArea().getBBox().getWidth() - symbolRenderer.getOccupiedArea().getBBox().getX(), 0);
+            Property.ListSymbolAlignment listSymbolAlignment = parent.getProperty(Property.LIST_SYMBOL_ALIGNMENT);
+            float xPosition = x - symbolRenderer.getOccupiedArea().getBBox().getX();
+            if (listSymbolAlignment == null || listSymbolAlignment == Property.ListSymbolAlignment.RIGHT) {
+                xPosition += symbolAreaWidth - symbolRenderer.getOccupiedArea().getBBox().getWidth();
+            }
+            symbolRenderer.move(xPosition, 0);
 
             if (isTagged) {
                 tagStructure.addTag(0, PdfName.Lbl);

layout/src/test/java/com/itextpdf/layout/ListTest.java

@@ -226,4 +226,25 @@ public void imageInListTest01() throws IOException, InterruptedException {
         Assert.assertNull(new CompareTool().compareByContent(outFileName, cmpFileName, destinationFolder, "diff"));
     }
 
+    @Test
+    public void listItemAlignmentTest01() throws IOException, InterruptedException {
+        String outFileName = destinationFolder + "listItemAlignmentTest01.pdf";
+        String cmpFileName = sourceFolder + "cmp_listItemAlignmentTest01.pdf";
+        PdfDocument pdfDocument = new PdfDocument(new PdfWriter(new FileOutputStream(outFileName)));
+
+        Document document = new Document(pdfDocument);
+
+        List list = new List(Property.ListNumberingType.DECIMAL).setListSymbolAlignment(Property.ListSymbolAlignment.LEFT);
+
+        for (int i = 1; i <= 30; i++) {
+            list.add("Item #" + i);
+        }
+
+        document.add(list);
+
+        document.close();
+
+        Assert.assertNull(new CompareTool().compareByContent(outFileName, cmpFileName, destinationFolder, "diff"));
+    }
+
 }