Fix a few bugs in libtiled-java (mapeditor#1840)

 * Make sure the properties of MapLayer is not null
 * Prevent MapObject's from being added twice (once manually, once with JXB)
 * Don't need to read properties again (already read with JXB)
 * Null-pointer issues with MapLayer.getBounds if x/y coordinate is null
 * Null-pointer issues when accessing objects list in ObjectGroup class
 * Add getProperty overload in Property class to allow a default value
 * Fix image loading issue in TMXMapReader when loading from an InputStream.
   Apparently this function was setting `xmlPath` to a url, not a path.
 * Add code to write object group attributes (previously it was completely
   omitted). A writeLayerAttributes method was added to write common attributes
   in both a tile-layer and object-group.
 * Fix writing of offsetx and offsety attributes.

util/java/libtiled-java/src/main/java/org/mapeditor/core/MapLayer.java

@@ -181,7 +181,7 @@ public void setOffset(int x, int y) {
      * @return the layer bounds in tiles
      */
     public Rectangle getBounds() {
-        return new Rectangle(x, y, width, height);
+        return new Rectangle(x == null ? 0 : x, y == null ? 0 : y, width, height);
     }
 
     /**
@@ -196,6 +196,15 @@ public void getBounds(Rectangle rect) {
         rect.height = this.height;
     }
 
+    /** {@inheritDoc} */
+    @Override
+    public Properties getProperties() {
+        if (properties == null) {
+            properties = new Properties();
+        }
+        return super.getProperties();
+    }
+
     /**
      * A convenience method to check if a point in tile-space is within the
      * layer boundaries.

util/java/libtiled-java/src/main/java/org/mapeditor/core/ObjectGroup.java

@@ -33,8 +33,10 @@
 import java.awt.Shape;
 import java.awt.geom.Ellipse2D;
 import java.awt.geom.Rectangle2D;
+import java.util.ArrayList;
 import java.util.LinkedList;
 import java.util.Iterator;
+import java.util.List;
 
 import javax.xml.bind.annotation.XmlAccessType;
 import javax.xml.bind.annotation.XmlAccessorType;
@@ -100,15 +102,15 @@ public ObjectGroup(Rectangle area) {
      * @return a boolean.
      */
     public boolean isEmpty() {
-        return objects.isEmpty();
+        return getObjects().isEmpty();
     }
 
     /** {@inheritDoc} */
     @Override
     public Object clone() throws CloneNotSupportedException {
         ObjectGroup clone = (ObjectGroup) super.clone();
         clone.objects = new LinkedList<>();
-        for (MapObject object : objects) {
+        for (MapObject object : getObjects()) {
             final MapObject objectClone = (MapObject) object.clone();
             clone.objects.add(objectClone);
             objectClone.setObjectGroup(clone);
@@ -122,7 +124,7 @@ public Object clone() throws CloneNotSupportedException {
      * @param o a {@link org.mapeditor.core.MapObject} object.
      */
     public void addObject(MapObject o) {
-        objects.add(o);
+        getObjects().add(o);
         o.setObjectGroup(this);
     }
 
@@ -132,14 +134,14 @@ public void addObject(MapObject o) {
      * @param o a {@link org.mapeditor.core.MapObject} object.
      */
     public void removeObject(MapObject o) {
-        objects.remove(o);
+        getObjects().remove(o);
         o.setObjectGroup(null);
     }
 
     /** {@inheritDoc} */
     @Override
     public Iterator<MapObject> iterator() {
-        return objects.iterator();
+        return getObjects().iterator();
     }
 
     /**
@@ -150,7 +152,7 @@ public Iterator<MapObject> iterator() {
      * @return a {@link org.mapeditor.core.MapObject} object.
      */
     public MapObject getObjectAt(double x, double y) {
-        for (MapObject obj : objects) {
+        for (MapObject obj : getObjects()) {
             // Attempt to get an object bordering the point that has no width
             if (obj.getWidth() == 0 && obj.getX() + this.x == x) {
                 return obj;
@@ -184,7 +186,7 @@ public MapObject getObjectNear(int x, int y, double zoom) {
         Rectangle2D mouse = new Rectangle2D.Double(x - zoom - 1, y - zoom - 1, 2 * zoom + 1, 2 * zoom + 1);
         Shape shape;
 
-        for (MapObject obj : objects) {
+        for (MapObject obj : getObjects()) {
             if (obj.getWidth() == 0 && obj.getHeight() == 0) {
                 shape = new Ellipse2D.Double(obj.getX() * zoom, obj.getY() * zoom, 10 * zoom, 10 * zoom);
             } else {

util/java/libtiled-java/src/main/java/org/mapeditor/core/Properties.java

@@ -72,12 +72,23 @@ public void setProperty(String name, String value) {
      * @return a {@link java.lang.String} object.
      */
     public String getProperty(String name) {
+        return getProperty(name, null);
+    }
+
+    /**
+     * Gets a property with a default value if this property is not found
+     *
+     * @param name a {@link java.lang.String} object.
+     * @param defaultValue the string value to return if property is not found
+     * @return a {@link java.lang.String} object.
+     */
+    public String getProperty(String name, String defaultValue) {
         for (Property property : properties) {
             if (name.equals(property.getName())) {
                 return property.getValue();
             }
         }
-        return null;
+        return defaultValue;
     }
 
     /**

util/java/libtiled-java/src/main/java/org/mapeditor/io/TMXMapReader.java

@@ -499,20 +499,17 @@ private ObjectGroup unmarshalObjectGroup(Node t) throws Exception {
         final int offsetY = getAttribute(t, "y", 0);
         og.setOffset(offsetX, offsetY);
 
-        // Add all objects from the objects group
-        NodeList children = t.getChildNodes();
+        // Manually parse the objects in object group
+        og.getObjects().clear();
 
+        NodeList children = t.getChildNodes();
         for (int i = 0; i < children.getLength(); i++) {
             Node child = children.item(i);
             if ("object".equalsIgnoreCase(child.getNodeName())) {
                 og.addObject(readMapObject(child));
             }
         }
 
-        Properties props = new Properties();
-        readProperties(children, props);
-        og.setProperties(props);
-
         return og;
     }
 
@@ -710,10 +707,9 @@ private void buildMap(Document doc) throws Exception {
             throw new Exception("Couldn't load map.");
         }
 
-        // Load properties
-        readProperties(mapNode.getChildNodes(), map.getProperties());
+        // Don't need to load properties again.
 
-        // Clear untl they are loaded correctly
+        // We need to load layers and tilesets manually so that they are loaded correctly
         map.getTileSets().clear();
         map.getLayers().clear();
 
@@ -805,7 +801,8 @@ public Map readMap(String filename) throws Exception {
      * @throws java.lang.Exception if any.
      */
     public Map readMap(InputStream in) throws Exception {
-        xmlPath = makeUrl(".");
+        //xmlPath = makeUrl(".");
+        xmlPath = System.getProperty("user.dir") + File.separatorChar;
 
         Map unmarshalledMap = unmarshal(in);
 

util/java/libtiled-java/src/main/java/org/mapeditor/io/TMXMapWriter.java

@@ -217,7 +217,7 @@ private void writeMap(Map map, XMLWriter w, String wp) throws IOException {
         w.endElement();
     }
 
-    private static void writeProperties(Properties props, XMLWriter w) throws
+    private void writeProperties(Properties props, XMLWriter w) throws
             IOException {
         if (props != null && !props.isEmpty()) {
             final Set<Object> propertyKeys = new TreeSet<>();
@@ -347,30 +347,43 @@ private void writeTileset(TileSet set, XMLWriter w, String wp)
         w.endElement();
     }
 
-    private static void writeObjectGroup(ObjectGroup o, XMLWriter w, String wp)
+    private void writeObjectGroup(ObjectGroup o, XMLWriter w, String wp)
             throws IOException {
+        w.startElement("objectgroup");
+
+        if (o.getColor() != null && o.getColor().isEmpty()) {
+            w.writeAttribute("color", o.getColor());
+        }
+        if (o.getDraworder() != null && !o.getDraworder().equalsIgnoreCase("topdown")) {
+            w.writeAttribute("draworder", o.getDraworder());
+        }
+        writeLayerAttributes(o, w);
+        writeProperties(o.getProperties(), w);
+
         Iterator<MapObject> itr = o.getObjects().iterator();
         while (itr.hasNext()) {
             writeMapObject(itr.next(), w, wp);
         }
+
+        w.endElement();
     }
 
     /**
-     * Writes this layer to an XMLWriter. This should be done <b>after</b> the
-     * first global ids for the tilesets are determined, in order for the right
-     * gids to be written to the layer data.
+     * Writes all the standard layer attributes to the XML writer.
+     * @param l the map layer to write attributes
+     * @param w the {@code XMLWriter} instance to write to.
+     * @throws IOException if an error occurs while writing.
      */
-    private void writeMapLayer(TileLayer l, XMLWriter w, String wp) throws IOException {
+    private void writeLayerAttributes(MapLayer l, XMLWriter w) throws IOException {
         Rectangle bounds = l.getBounds();
-
-        w.startElement("layer");
-
         w.writeAttribute("name", l.getName());
-        if (bounds.width != 0) {
-            w.writeAttribute("width", bounds.width);
-        }
-        if (bounds.height != 0) {
-            w.writeAttribute("height", bounds.height);
+        if (l instanceof TileLayer) {
+            if (bounds.width != 0) {
+                w.writeAttribute("width", bounds.width);
+            }
+            if (bounds.height != 0) {
+                w.writeAttribute("height", bounds.height);
+            }
         }
         if (bounds.x != 0) {
             w.writeAttribute("x", bounds.x);
@@ -388,6 +401,25 @@ private void writeMapLayer(TileLayer l, XMLWriter w, String wp) throws IOExcepti
             w.writeAttribute("opacity", opacity);
         }
 
+        if (l.getOffsetX() != null && l.getOffsetX() != 0) {
+            w.writeAttribute("offsetx", l.getOffsetX());
+        }
+        if (l.getOffsetY() != null && l.getOffsetY() != 0) {
+            w.writeAttribute("offsety", l.getOffsetY());
+        }
+    }
+
+    /**
+     * Writes this layer to an XMLWriter. This should be done <b>after</b> the
+     * first global ids for the tilesets are determined, in order for the right
+     * gids to be written to the layer data.
+     */
+    private void writeMapLayer(TileLayer l, XMLWriter w, String wp) throws IOException {
+        Rectangle bounds = l.getBounds();
+
+        w.startElement("layer");
+
+        writeLayerAttributes(l, w);
         writeProperties(l.getProperties(), w);
 
         final TileLayer tl = l;
@@ -535,7 +567,7 @@ private void writeAnimation(Sprite s, XMLWriter w) throws IOException {
         w.endElement();
     }
 
-    private static void writeMapObject(MapObject mapObject, XMLWriter w, String wp)
+    private void writeMapObject(MapObject mapObject, XMLWriter w, String wp)
             throws IOException {
         w.startElement("object");
         w.writeAttribute("name", mapObject.getName());
@@ -554,6 +586,13 @@ private static void writeMapObject(MapObject mapObject, XMLWriter w, String wp)
             w.writeAttribute("height", mapObject.getHeight());
         }
 
+        if (mapObject.getTile() != null) {
+            Tile t = mapObject.getTile();
+            w.writeAttribute("gid", firstGidPerTileset.get(t.getTileSet()) + t.getId());
+        } else if (mapObject.getGid() != null) {
+            w.writeAttribute("gid", mapObject.getGid());
+        }
+
         writeProperties(mapObject.getProperties(), w);
 
         if (mapObject.getImageSource().length() > 0) {

util/java/libtiled-java/src/main/resources/bindings.xjb

@@ -114,11 +114,11 @@
                     </jxb:javadoc>
                 </jxb:property>
             </jxb:bindings>
-            <jxb:bindings node="xs:attribute[@name='offsetx']">
-                <jxb:property name="offsetX"/>
-            </jxb:bindings>
-            <jxb:bindings node="xs:attribute[@name='offsety']">
-                <jxb:property name="offsetY"/>
+            <jxb:bindings node="xs:attribute[@name='offsetx']">		
+                <jxb:property name="offsetX"/>		
+            </jxb:bindings>		
+            <jxb:bindings node="xs:attribute[@name='offsety']">		
+                <jxb:property name="offsetY"/>		
             </jxb:bindings>
         </jxb:bindings>