Add layout feature (close algorithm-visualizer/algorithm-visualizer#235)

Author: 64json

build.gradle

@@ -4,7 +4,7 @@ plugins {
 }
 
 group = 'org.algorithm_visualizer'
-version = '2.2.0'
+version = '2.3.0'
 sourceCompatibility = 1.8
 
 repositories {

src/main/java/org/algorithm_visualizer/Commander.java

@@ -38,7 +38,7 @@ private static class Command {
     private static int objectCount = 0;
     private static ArrayList<Command> commands = new ArrayList<>();
 
-    private static void command(String key, String method, Object[] args) {
+    static void command(String key, String method, Object[] args) {
         commands.add(new Command(
                 key,
                 method,
@@ -50,18 +50,6 @@ private static void command(String key, String method, Object[] args) {
             throw new Error("Too Many Objects");
     }
 
-    public static void setRoot(Commander child) {
-        command(null, "setRoot", new Object[]{child});
-    }
-
-    public static void delay(int lineNumber) {
-        command(null, "delay", new Object[]{lineNumber});
-    }
-
-    public static void delay() {
-        command(null, "delay", new Object[]{});
-    }
-
     private final String key;
 
     Commander(Object[] args) {
@@ -81,9 +69,9 @@ void command(String method, Object[] args) {
     }
 
     static {
-        GsonBuilder gsonBuilder = new GsonBuilder();
+        GsonBuilder gsonBuilder = new GsonBuilder().serializeNulls();
         JsonSerializer<Commander> serializer = (src, typeOfSrc, context) -> new JsonPrimitive(src.key);
-        gsonBuilder.registerTypeAdapter(Commander.class, serializer);
+        gsonBuilder.registerTypeHierarchyAdapter(Commander.class, serializer);
         gson = gsonBuilder.create();
 
         Runtime.getRuntime().addShutdownHook(new Thread(() -> {

src/main/java/org/algorithm_visualizer/HorizontalLayout.java

@@ -0,0 +1,7 @@
+package org.algorithm_visualizer;
+
+public class HorizontalLayout extends Layout {
+    public HorizontalLayout(Commander[] children) {
+        super(children);
+    }
+}

src/main/java/org/algorithm_visualizer/Layout.java

@@ -0,0 +1,27 @@
+package org.algorithm_visualizer;
+
+public abstract class Layout extends Commander {
+    public static void setRoot(Commander child) {
+        command(null, "setRoot", new Object[]{child});
+    }
+
+    public Layout(Commander[] children) {
+        super(new Object[]{children});
+    }
+
+    public void add(Commander child, int index) {
+        command("add", new Object[]{child, index});
+    }
+
+    public void add(Commander child) {
+        command("add", new Object[]{child});
+    }
+
+    public void remove(Commander child) {
+        command("remove", new Object[]{child});
+    }
+
+    public void removeAll() {
+        command("removeAll", new Object[]{});
+    }
+}

src/main/java/org/algorithm_visualizer/Tracer.java

@@ -1,6 +1,14 @@
 package org.algorithm_visualizer;
 
 public abstract class Tracer extends Commander {
+    public static void delay(int lineNumber) {
+        command(null, "delay", new Object[]{lineNumber});
+    }
+
+    public static void delay() {
+        command(null, "delay", new Object[]{});
+    }
+
     public Tracer(String title) {
         super(new Object[]{title});
     }

src/main/java/org/algorithm_visualizer/VerticalLayout.java

@@ -0,0 +1,7 @@
+package org.algorithm_visualizer;
+
+public class VerticalLayout extends Layout {
+    public VerticalLayout(Commander[] children) {
+        super(children);
+    }
+}

src/test/java/org/algorithm_visualizer/Test.java

@@ -2,7 +2,8 @@
 
 class Test {
     public static void main(String[] args) {
-        ChartTracer chartTracer = new ChartTracer<>();
-        chartTracer.set(new Object[]{}).myMethod();
+        ChartTracer chartTracer = new ChartTracer();
+        chartTracer.set(new Object[]{});
+        Layout.setRoot(new VerticalLayout(new Commander[]{chartTracer}));
     }
 }