Create working scaffolding of Component Inflater

engine/build.gradle

@@ -86,6 +86,9 @@ dependencies {
     compileOnly 'org.projectlombok:lombok'
     annotationProcessor 'org.projectlombok:lombok'
 
+    implementation "org.codehaus.janino:janino:${janinoVersion}"
+    implementation "org.codehaus.janino:commons-compiler:${janinoVersion}"
+
     // This dependency is used by the application.
     implementation "org.joml:joml:${jomlVersion}"
 }

engine/src/main/java/com/bartlomiejpluta/base/engine/gui/widget/ScreenWidget.java

@@ -58,32 +58,32 @@ public class ScreenWidget implements Widget {
    }
 
    @Override
-   public void setX(float x) {
+   public void setX(Float x) {
       throw new UnsupportedOperationException();
    }
 
    @Override
-   public void setY(float y) {
+   public void setY(Float y) {
       throw new UnsupportedOperationException();
    }
 
    @Override
-   public void setPosition(float x, float y) {
+   public void setPosition(Float x, Float y) {
       throw new UnsupportedOperationException();
    }
 
    @Override
-   public void setWidth(float width) {
+   public void setWidth(Float width) {
       throw new UnsupportedOperationException();
    }
 
    @Override
-   public void setHeight(float height) {
+   public void setHeight(Float height) {
       throw new UnsupportedOperationException();
    }
 
    @Override
-   public void setSize(float width, float height) {
+   public void setSize(Float width, Float height) {
       throw new UnsupportedOperationException();
    }
 
@@ -113,42 +113,42 @@ public class ScreenWidget implements Widget {
    }
 
    @Override
-   public void setMargin(float top, float right, float bottom, float left) {
+   public void setMargin(Float top, Float right, Float bottom, Float left) {
       throw new UnsupportedOperationException();
    }
 
    @Override
-   public void setMargin(float top, float rightLeft, float bottom) {
+   public void setMargin(Float top, Float rightLeft, Float bottom) {
       throw new UnsupportedOperationException();
    }
 
    @Override
-   public void setMargin(float topBottom, float rightLeft) {
+   public void setMargin(Float topBottom, Float rightLeft) {
       throw new UnsupportedOperationException();
    }
 
    @Override
-   public void setMargin(float all) {
+   public void setMargin(Float all) {
       throw new UnsupportedOperationException();
    }
 
    @Override
-   public void setMarginTop(float margin) {
+   public void setMarginTop(Float margin) {
       throw new UnsupportedOperationException();
    }
 
    @Override
-   public void setMarginRight(float margin) {
+   public void setMarginRight(Float margin) {
       throw new UnsupportedOperationException();
    }
 
    @Override
-   public void setMarginBottom(float margin) {
+   public void setMarginBottom(Float margin) {
       throw new UnsupportedOperationException();
    }
 
    @Override
-   public void setMarginLeft(float margin) {
+   public void setMarginLeft(Float margin) {
       throw new UnsupportedOperationException();
    }
 
@@ -173,42 +173,42 @@ public class ScreenWidget implements Widget {
    }
 
    @Override
-   public void setPadding(float top, float right, float bottom, float left) {
+   public void setPadding(Float top, Float right, Float bottom, Float left) {
       throw new UnsupportedOperationException();
    }
 
    @Override
-   public void setPadding(float top, float rightLeft, float bottom) {
+   public void setPadding(Float top, Float rightLeft, Float bottom) {
       throw new UnsupportedOperationException();
    }
 
    @Override
-   public void setPadding(float topBottom, float rightLeft) {
+   public void setPadding(Float topBottom, Float rightLeft) {
       throw new UnsupportedOperationException();
    }
 
    @Override
-   public void setPadding(float all) {
+   public void setPadding(Float all) {
       throw new UnsupportedOperationException();
    }
 
    @Override
-   public void setPaddingTop(float padding) {
+   public void setPaddingTop(Float padding) {
       throw new UnsupportedOperationException();
    }
 
    @Override
-   public void setPaddingRight(float padding) {
+   public void setPaddingRight(Float padding) {
       throw new UnsupportedOperationException();
    }
 
    @Override
-   public void setPaddingBottom(float padding) {
+   public void setPaddingBottom(Float padding) {
       throw new UnsupportedOperationException();
    }
 
    @Override
-   public void setPaddingLeft(float padding) {
+   public void setPaddingLeft(Float padding) {
       throw new UnsupportedOperationException();
    }
 

engine/src/main/java/com/bartlomiejpluta/base/engine/gui/xml/inflater/ComponentInflater.java

@@ -0,0 +1,126 @@
+package com.bartlomiejpluta.base.engine.gui.xml.inflater;
+
+import com.bartlomiejpluta.base.api.game.gui.base.GUI;
+import com.bartlomiejpluta.base.api.game.gui.base.SizeMode;
+import com.bartlomiejpluta.base.api.game.gui.component.Component;
+import com.bartlomiejpluta.base.engine.util.reflection.ClassLoader;
+import lombok.SneakyThrows;
+import org.codehaus.janino.ExpressionEvaluator;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.w3c.dom.NamedNodeMap;
+import org.w3c.dom.Node;
+
+import javax.xml.parsers.DocumentBuilder;
+import javax.xml.parsers.DocumentBuilderFactory;
+import java.io.File;
+import java.io.InputStream;
+import java.util.stream.Stream;
+
+@org.springframework.stereotype.Component
+public class ComponentInflater {
+   private static final String[] IMPORTS = Stream.of(GUI.class, SizeMode.class).map(Class::getCanonicalName).toArray(String[]::new);
+   private final DocumentBuilder builder;
+   private final ClassLoader loader;
+
+   @Autowired
+   @SneakyThrows
+   public ComponentInflater(ClassLoader loader) {
+      this.loader = loader;
+
+      var factory = DocumentBuilderFactory.newInstance();
+      factory.setNamespaceAware(true);
+      this.builder = factory.newDocumentBuilder();
+   }
+
+   @SneakyThrows
+   public Component inflate(String xml) {
+      var document = builder.parse(xml);
+      return parseNode(document.getDocumentElement());
+   }
+
+   @SneakyThrows
+   public Component inflate(File file) {
+      var document = builder.parse(file);
+      return parseNode(document.getDocumentElement());
+   }
+
+   @SneakyThrows
+   public Component inflate(InputStream is) {
+      var document = builder.parse(is);
+      return parseNode(document.getDocumentElement());
+   }
+
+   @SneakyThrows
+   private Component parseNode(Node node) {
+      var uri = node.getNamespaceURI();
+      var name = node.getLocalName();
+
+      if (uri != null) {
+         name = uri + "." + name;
+      }
+
+      var canonicalName = name.replaceAll("\\*", "").replaceAll("\\.+", ".");
+
+      var componentClass = loader.loadClass(canonicalName);
+      var component = createComponent(componentClass, node.getAttributes());
+
+      var children = node.getChildNodes();
+
+      // The component is text-like node (e.g. <Label>Some text</Label>)
+      if (children.getLength() == 1) {
+         var child = children.item(0);
+         if (child.getNodeType() == Node.TEXT_NODE) {
+            var textSetter = componentClass.getMethod("setText", String.class);
+            textSetter.invoke(component, child.getNodeValue());
+            return component;
+         }
+      }
+
+      // The component has non-text children (e.g. <HLayout><Label>Some text</Label></HLayout>)
+      for (int i = 0; i < children.getLength(); ++i) {
+         var childNode = children.item(i);
+
+         if (childNode.getNodeType() != Node.ELEMENT_NODE) {
+            continue;
+         }
+
+         component.add(parseNode(childNode));
+      }
+
+      return component;
+   }
+
+   @SneakyThrows
+   private Component createComponent(Class<?> componentClass, NamedNodeMap attributes) {
+      var component = (Component) componentClass.getConstructor().newInstance();
+
+      // Set attributes via setter methods
+      for (int i = 0; i < attributes.getLength(); ++i) {
+         var attribute = attributes.item(i);
+
+         // Ignore namespaces definitions
+         if ("xmlns".equals(attribute.getPrefix())) {
+            continue;
+         }
+
+         var setterName = createSetterMethodName(attribute.getLocalName());
+         var value = parseValue(attribute.getNodeValue());
+         var setter = componentClass.getMethod(setterName, value.getClass());
+         setter.invoke(component, value);
+      }
+
+      return component;
+   }
+
+   private static String createSetterMethodName(String name) {
+      return "set" + name.substring(0, 1).toUpperCase() + name.substring(1);
+   }
+
+   @SneakyThrows
+   private Object parseValue(String value) {
+      var evaluator = new ExpressionEvaluator();
+      evaluator.setDefaultImports(IMPORTS);
+      evaluator.cook(value);
+      return evaluator.evaluate();
+   }
+}